Cereal leaf beetle

The cereal leaf beetle (Chrysomelidae: Oulema melanopus) has a broad host range. Wheat is the preferred host, but adults and larvae also feed on leaf tissue of oats, barley, corn, rye, triticale, reed canarygrass, ryegrass, fescue, wild oats, millet and other grasses. Yield quality and quantity is decreased, if the flag leaf is stripped. Fun fact: Cereal leaf beetle larvae carry their own fecal waste above their body to help protect themselves from predators.

Fortunately, the parasitoid wasp, Tetrastichus julis Walker (Hymenoptera: Eulophidae), is an important natural enemy of cereal leaf beetle larvae. Learn more about this beneficial insect species featured in Week 9 of 2023’s Insect of the Week!

Cereal Leaf Beetle Lifecycle and Damage:

Adult: Adult cereal leaf beetles (CLB) have shiny bluish-black wing covers (Fig. 1). The thorax and legs are light orange-brown. Females (4.9 to 5.5 mm) are slightly larger than males (4.4 to 5 mm). Adult beetles overwinter in and along the margins of grain fields in protected places such as in straw stubble, under crop and leaf litter, and in the crevices of tree bark. They favour sites adjacent to shelterbelts, deciduous and conifer forests. They emerge in the spring once temperatures reach 10-15 ºC and the adults are active for about 6 weeks. They usually begin feeding on grasses, then move into winter cereals and later into spring cereals.  

Figure 1. Adult Oulema melanopus measure 4.4-5.5 mm long (Photo: M. Dolinski).

Egg: Eggs are laid approximately 14 days following the emergence of the adults. Eggs are laid singly or in pairs along the midvein on the upper side of the leaf and are cylindrical, measuring 0.9 mm by 0.4 mm, and yellowish in colour. Eggs darken to black just before hatching.  

Larva: The larvae hatch in about 5 days and feed for about 3 weeks, passing through 4 growth stages (instars). The head and legs are brownish-black; the body is yellowish. Larvae are usually covered with a secretion of mucus and fecal material, giving them a shiny black, wet appearance (Fig. 2).  When the larva completes its growth, it drops to the ground and pupates in the soil. 

Figure 2.  Larval stage of Oulema melanopus with characteristic feeding damage visible on leaf (Photo: M. Dolinski).

Pupa: Pupal colour varies from a bright yellow when it is first formed, to the colour of the adult just before emergence. The pupal stage lasts 2 – 3 weeks. Adult beetles emerge and feed for a couple of weeks before seeking overwintering sites. There is one generation per year.

Access scouting tips for cereal leaf beetle or find more detailed information by accessing the Oulema melanopus page from the “Field crop and forage pests and their natural enemies in western Canada – Identification and management field guide” (2018; accessible as a free downloadable PDF in either English or French on our new Field Guides page.

True armyworm

Similar to diamondback moth, the true armyworm, or just armyworm (Mythimna unipuncta or Pseudaletia unipunctata) is a migratory pest in Canada. After arriving from the United States, true armyworm can have two generations of larvae before cool temperatures in the fall stop their development. True armyworm caterpillars feed along leaf margins of their hosts, leaving damage that could be misdiagnosed as grasshopper or bertha armyworm damage. Preferred hosts include native grasses, wheat, rye, corn, oats, and barley. Other hosts can include crucifer vegetables (e.g., cabbage) and alfalfa.

Phermone traps have been deployed by the Saskatchewan Ministry of Agriculture and Manitoba Agriculture and by their collaborators and volunteers in both provinces to detect the arrival of immigrating true armyworm. In Saskatchewan, true armyworm have been caught by pheromone traps in the northeast and central parts of the province. In Manitoba, true armyworm have been caught in the central, eastern, and Interlake regions.

The economic threshold for true armyworm larvae in cereals is 10 larvae/m2. If scouting in the evening or at night, beat plants in a 1 m2 area and count the dislodged larvae. True armyworm larvae are more likely to be on the ground during the day, so look under leaf litter and other debris around the plants in a 1 m2 area and count the larvae. For more information and tips for scouting, refer to the armyworm pages of the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” (2018) accessible as a free downloadable PDF in either English or French on our new Field Guides page OR access Manitoba Agriculture’s scouting guide.

Cereal leaf beetle

The cereal leaf beetle (Chrysomelidae: Oulema melanopus) has a broad host range. Wheat is the preferred host, but adults and larvae also feed on leaf tissue of oats, barley, corn, rye, triticale, reed canarygrass, ryegrass, fescue, wild oats, millet and other grasses. Yield quality and quantity is decreased, if the flag leaf is stripped. Fun fact: Cereal leaf beetle larvae carry their own fecal waste above their body to help protect themselves from predators.

Fortunately, the parasitoid wasp, Tetrastichus julis Walker (Hymenoptera: Eulophidae), is an important natural enemy of cereal leaf beetle larvae. Learn more about this beneficial insect species featured in Week 9 of 2023’s Insect of the Week!

Cereal Leaf Beetle Lifecycle and Damage:

Adult: Adult cereal leaf beetles (CLB) have shiny bluish-black wing covers (Fig. 3). The thorax and legs are light orange-brown. Females (4.9 to 5.5 mm) are slightly larger than males (4.4 to 5 mm). Adult beetles overwinter in and along the margins of grain fields in protected places such as in straw stubble, under crop and leaf litter, and in the crevices of tree bark. They favour sites adjacent to shelterbelts, deciduous and conifer forests. They emerge in the spring once temperatures reach 10-15 ºC and the adults are active for about 6 weeks. They usually begin feeding on grasses, then move into winter cereals and later into spring cereals.  

Figure 3. Adult Oulema melanopus measure 4.4-5.5 mm long (Photo: M. Dolinski).

Egg: Eggs are laid approximately 14 days following the emergence of the adults. Eggs are laid singly or in pairs along the midvein on the upper side of the leaf and are cylindrical, measuring 0.9 mm by 0.4 mm, and yellowish in colour. Eggs darken to black just before hatching.  

Larva: The larvae hatch in about 5 days and feed for about 3 weeks, passing through 4 growth stages (instars). The head and legs are brownish-black; the body is yellowish. Larvae are usually covered with a secretion of mucus and fecal material, giving them a shiny black, wet appearance (Fig. 4).  When the larva completes its growth, it drops to the ground and pupates in the soil. 

Figure 4.  Larval stage of Oulema melanopus with characteristic feeding damage visible on leaf (Photo: M. Dolinski).

Pupa: Pupal colour varies from a bright yellow when it is first formed, to the colour of the adult just before emergence. The pupal stage lasts 2 – 3 weeks. Adult beetles emerge and feed for a couple of weeks before seeking overwintering sites. There is one generation per year.

Access scouting tips for cereal leaf beetle or find more detailed information by accessing the Oulema melanopus page from the “Field crop and forage pests and their natural enemies in western Canada – Identification and management field guide” (2018; accessible as a free downloadable PDF in either English or French on our new Field Guides page.

Thrips in small grains cereal crops

Thrips (used for both singular and plural) are members of the Order Thysanoptera. Even more confusing, there is also a genus of thrips named Thrips. That is, all Thrips are thrips but not all thrips are Thrips!

Thrips are characterized by small size (the largest species is only 2 mm as adults; the smallest is 0.6 mm), long slender bodies, and fringed wings (winged and wingless adults exist in some species). Males are smaller than females.

Figure 1: Adult thrips on barley leaf showing off fringed wings neatly folded over its abdomen. Photo: Sheila Elder, Saskatchewan, Canada

Adult thrips are generally relatively weak flyers and employ a‘clap and fling’ technique. The animal claps the leading edges of its wings together at the end of the upstroke then rotates the wings around the trailing edges, flinging them apart. Many small insects use this technique to promote air circulation and generate lift quickly. Pigeons also use this technique for their noisy flight initiations. For small insects, the viscosity of the air has a much greater effect than on larger animals. Fringed wings reduce drag associated with this effect.  

There are about 6,000 species of thrips worldwide with 147 described species in two suborders in Canada, including 28 non-natives. Recent molecular work indicates that there may be as many as 255 additional as-yet-undescribed species in Canada. The most common and broadly distributed family is the Thripidae, followed by the Phlaeothripidae and Aeolothripidae. Other families are far less represented.

Although some species are important for pollination and a few are predators of other small insects, some are pests in crops. They have unique, asymmetrical mouthparts characterized by a greatly reduced right mandible. Their feeding is described as ‘rasping-sucking’: they scrape the surface of plant tissue and ingest fluid flowing from the wound. When feeding on actively growing plant tissue, growth reductions and distorted growth may be observed and yield loss can occur. When they feed on more mature tissue, silver leaf scars can occur that reduce the quality and marketability of some crops. Thrips are also important vectors of topsoviruses.

One suborder of thrips lays very small eggs (0.08 mm to 0.2 mm) singly in slits in plant tissue; the other lays eggs on plant surfaces. Eggs hatch into nymphs: juveniles resemble adults but are not sexually mature and have no wings. There are two juvenile feeding stages, followed by two non-feeding stages: pre-pupa and pupa.   

The barley thrips, Limothrips denticornis, was first reported in North America in 1923 in New York. In its native Europe and Asia, it can be found on a wide variety of grass species but is a minor pest and only on rye. In North America, it is generally more important on barley, though it can be found on winter wheat, durum, winter rye, corn, and triticale. Adults are small (1.1 mm to 1.8 mm), elongate, and dark brown to black. These thrips lay eggs on upper leaf sheaths and each female can produce 100 eggs. Juveniles are smaller and lighter coloured. Barley thrips overwinter as adults and move to winter grasses in the spring. They are somewhat stronger flyers than many thrips species, but are still limited by their size. In Northern Europe, cereal thrips, including L. denticornis, have been reported to appearin large numbers ahead of thunderstorms. This may be associated with the warm conditions that precede these events, but it has also been suggested that they are sensitive to the electrical fields associated with storms.    

Another cereal thrips, Limothrips cerealium, has also been reported in Canadian small grains cereals and was reported in 1928 to be responsible for 10 per cent losses in oats in Canada.

Thrips feeding on cereals can result in tissues appearing bleached. When numbers are high and feeding is intense, kernels can be shriveled. Severe flag leaf feeding can result in kernels filling improperly and reduced kernel weight.

Figure 2: Thrips nestled at the base of leaf. Photo: Sheila Elder, Saskatchewan, Canada

Scouting for barley thrips should be done from first sign of flag leaf until the head is completely emerged from the boot. Barley thrips can be found on stems but are more commonly under the top two leaf sheaths. Because thrips are relatively weak flyers, there may be greater concentrations in protected field edges. Greatest damage has been reported in dryland cropping areas after prolonged drought.

Economic thresholds:

Threshold (thrips/stem) = (Cost of control per acre / expected $ value per bushel) / 0.4

.Sample at least 50 stems from different parts of the field. One adult thrips per stem can cause a loss of 0.4 bushels per acre. This usually translates to an action threshold for barley and oats of 7 – 8 thrips/stem prior to head emergence but greater precision can be achieved by using the formula. The action threshold is the number of insects detected that can cause enough damage to justify the expense and effort of applying control. Numbers lower than this do not warrant control. Only apply control prior to the completion of heading.

Thresholds for cereal thrips have been determined for barley and oats but effects on other cereals crops in North America are less well understood. Work in Europe indicated comparable damage per thrips in rye, triticale, and winter barley. Recent reports of barley thrips in durum also suggest a risk of damaging effects, but these are not as well understood. A report from Germany indicated that, despite some relatively high thrips numbers, there was no correlation between barley thrips and damage. However, there is also evidence from Europe of the importance of long crop rotation to thrips damage control in wheat.

Predicted grasshopper development

The grasshopper (Acrididae: Melanoplus sanguinipes) model predicts development using biological parameters known for the pest species and environmental data observed across the Canadian prairies on a daily basis. Model outputs provided below as geospatial maps are a tool to help time in-field scouting on a regional scale but local development can vary and is only accurately assessed through in-field scouting.

SCOUT NOW – Some areas of the Canadian prairies are presently experiencing high densities of nymphs and economically important species are present. Review lifecycle and damage information for this pest to support in-field scouting.

Warm, dry conditions across central and southern regions of Saskatchewan have resulted in rapid grasshopper development. Model simulations were used to estimate grasshopper development as of June 26, 2022. The grasshopper hatch is nearly complete for the southern prairies (Fig. 1). Hatch is still progressing across the Parkland and Peace River regions. Based on estimates of average nymphal development, first to fifth instar nymphs should be occurring across southern and central regions of all three prairie provinces (Fig. 2).

Figure 1. Predicted migratory grasshopper (Melanoplus sanguinipes) hatch (%) across the Canadian prairies as of June 26, 2022.
Figure 2. Predicted migratory grasshopper (Melanoplus sanguinipes) development, presented as average instar, across the Canadian prairies as of June 26, 2022.

Grasshopper Scouting Tips:
Review grasshopper diversity and photos of nymphs, adults, and non-grasshopper species to aid in-field scouting from egg hatch and onwards.
● Access the PPMN’s Grasshopper Monitoring Protocol as a guide to help implement in-field monitoring.
● Review grasshopper lifecycle, damage and scouting and economic thresholds to support sound management decisions enabling the preservation of beneficial arthropods and mitigation of economic losses.

Biological and monitoring information (including tips for scouting and economic thresholds) related to grasshoppers in field crops is posted by Manitoba Agriculture and Resource DevelopmentSaskatchewan AgricultureAlberta Agriculture and Forestry, the BC Ministry of Agriculture, and the Prairie Pest Monitoring Network.  Also, refer to the grasshopper pages within the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” (2018) accessible as a free downloadable PDF in either English or French on our new Field Guides page. Review the historical grasshopper maps based on late-summer in-field counts of adults performed across the prairies.

Predicted cereal leaf beetle development

The cereal leaf beetle (CLB) (Chysomelidae: Oulema melanopus) model predicts larval development using biological parameters known for the pest species and environmental data observed across the Canadian prairies on a daily basis. Review lifecycle and damage information for this pest.

Warmer conditions in southern Alberta and western Saskatchewan are predicted to result in more rapid development of cereal leaf beetle (CLB) populations in those regions than in southern Manitoba. CLB model output predicts that hatch should be nearly complete for southern Alberta and western Saskatchewan. First to third instar larvae are predicted to be present in these areas (Fig. 1). As a result of cooler conditions, the model predicts that egg development has been delayed in southern Manitoba; first instar and second instar larvae may be appearing this week (Fig. 2).

Figure 1. Predicted status of cereal leaf beetle (Oulema melanopus) populations near Lethbridge AB as of June 12, 2022.
Figure 2. Predicted status of cereal leaf beetle (Oulema melanopus) populations near Winnipeg MB as of June 512 2022.

Access scouting tips for cereal leaf beetle or find more detailed information by accessing the Oulema melanopus page from the “Field crop and forage pests and their natural enemies in western Canada – Identification and management field guide” (2018; accessible as a free downloadable PDF in either English or French on our new Field Guides page.

Cereal Aphid Manager APP

Aphids can cause significant damage to fields and increase crop losses but low densities in a grain field sometimes have little economic impact on production. This is especially true if the aphid’s natural enemies (beneficial insects) are present in the field because they can keep the aphids under control.

The Cereal Aphid Manager is an easy-to-use mobile app that helps farmers and crop advisors control aphid populations in wheat, barley, oat or rye. It is based on Dr. Tyler Wist’s (AAFC-Saskatoon) Dynamic Action Threshold model. The model treats the grain field as an ecosystem and takes into account many complex biological interactions including:

  • the number of aphids observed and how quickly they reproduce
  • the number of different natural enemies of aphids in the field and how many aphids they eat or parasitize per day
  • the lifecycles of aphids and their enemies taking into account developmental stages, egg laying behaviour, population growth rate, lifespan, etc.

Frequent in-field scouting, supported by the app’s dynamic threshold, allows growers to weigh the above factors and the app predicts what the aphid population will be in seven days and the best time to apply insecticide based on economic thresholds.

To learn more and to download the app (Android or iOS), go to AAFC’s CAM webpage

Cereal leaf beetle development

The cereal leaf beetle (CLB) model output predicts that egg hatch may be starting across the prairies. The graphs provide a comparison of development at Saskatoon (Fig. 1) and at Lethbridge (Fig. 2). The simulation indicates that second instar larvae may occur during the last week of May near Saskatoon and Lethbridge.

Figure 1. Predicted status of cereal leaf beetle (Oulema melanopus) populations near Saskatoon, SK
as of May 23, 2021 (projected to June 7, 2021).
Figure 2. Predicted status of cereal leaf beetle (Oulema melanopus) populations near Lethbridge, AB
as of May 23, 2021 (projected to June 7, 2021).

Lifecycle and Damage:

Adult: Adult cereal leaf beetles (CLB) have shiny bluish-black wing covers (Fig. 3). The thorax and legs are light orange-brown. Females (4.9 to 5.5 mm) are slightly larger than males (4.4 to 5 mm). Adult beetles overwinter in and along the margins of grain fields in protected places such as in straw stubble, under crop and leaf litter, and in the crevices of tree bark. They favour sites adjacent to shelterbelts, deciduous and conifer forests. They emerge in the spring once temperatures reach 10-15 ºC and the adults are active for about 6 weeks. They usually begin feeding on grasses, then move into winter cereals and later into spring cereals.  

Figure 3. Adult Oulema melanopus measure 4.4-5.5 mm long (Photo: M. Dolinski).

Egg: Eggs are laid approximately 14 days following the emergence of the adults. Eggs are laid singly or in pairs along the midvein on the upper side of the leaf and are cylindrical, measuring 0.9 mm by 0.4 mm, and yellowish in colour. Eggs darken to black just before hatching.  

Larva: The larvae hatch in about 5 days and feed for about 3 weeks, passing through 4 growth stages (instars). The head and legs are brownish-black; the body is yellowish. Larvae are usually covered with a secretion of mucus and fecal material, giving them a shiny black, wet appearance (Fig. 4).  When the larva completes its growth, it drops to the ground and pupates in the soil. 

Figure 4.  Larval stage of Oulema melanopus with characteristic feeding damage visible on leaf (Photo: M. Dolinski).

Pupa: Pupal colour varies from a bright yellow when it is first formed, to the colour of the adult just before emergence. The pupal stage lasts 2 – 3 weeks. Adult beetles emerge and feed for a couple of weeks before seeking overwintering sites. There is one generation per year.

Fact sheets for CLB are published by the province of Alberta and available from the Prairie Pest Monitoring Network. Also access the Oulema melanopus page from the “Field crop and forage pests and their natural enemies in western Canada – Identification and management field guide” (2018; accessible in either English-enhanced or French-enhanced versions).

Ladybird beetles

Early in the growing season many of the native and introduced species of ladybird beetles become active and are easily observed (Fig. 1). These adults give rise to a whole new legion of voracious larvae and adults so preserve and protect them in fields – it could pay off!

Figure 1. Ladybird beetle (Coleoptera: Coccinellidae) hunting on wheat head (photo: AAFC-Otani).

Coccinellids are recognized as general predators with a real taste for aphids. Many species exist in North America but introduced species (either released or adventively establishing on this continent) have displaced many native species. With such a fantastic array of colours, sizes, shapes, and spots, we’re providing a few resources to help you recognize the amazing diversity in fields:
● Access “Bug Guide” and their entries falling within the Family Coccinellidae.
● “Key to the lady beetles of Saskatchewan“, released by D.J. Larson in 2013 – a technical key that includes colour photos of ladybird beetle adults. Species included in this key will most closely resemble what’s present across the Canadian prairies.
● “Ladybugs of South Dakota” is a PDF visual example of several species of coccinellids, some of which will also occur on the Canadian prairies. The poster was produced in conjunction with the “Lost Ladybug Project” and other supporting institutions.
● Consider participating in citizen-science – the Lost Ladybug Project has been in place for many years but the group welcomes reports of coccinellids from anywhere in North America and helps identify from submitted photos. The goal is to keep track of native species in comparison to the helpful but fairly competitive introduced species like Coccinella semptempunctata or Harmonia axyridis (Pallas).
● The Canadian portal of iNaturalist.ca was launched in 2015 and is connected to iNaturalist.org but the premise is the same: By signing up and submitting photos with relevant brief observations (e.g., date, location, e-contact info), users can communicate online with creditable and knowledgeable resources that help identify flora and fauna. Watch their YouTube video to learn more. Download the App (Android Google Play OR iOS App Store).

FYI…. CABI’s Invasive Species Compendium entries contain more information about our most common introduced species of ladybird beetles in North America:
Coccinella septempunctata (seven-spot ladybird)
Harmonia axyridis (asian or harlequin ladybird)

Wireworms

Newly seeded fields should be scouted throughout the germination and emergence periods for a variety of insect pests – one of the most difficult to detect can be wireworms! Wireworms are the juvenile stages of a complex comprised of several species of Elateridae, commonly referred to as ‘Click beetles’. On the Canadian prairies, wireworm collections from field crops indicate that three economically important species of wireworms or click beetles can be present; Selatosomus destructor, Limonius californicus, and Hypnoides bicolor. According to van Herk and Vernon (2014), a wide variety of Elateridae have been described from across the Canadian prairies; Alberta 144 species described in Alberta, 108 species described from Saskatchewan, and 109 species described from Manitoba.

Review these two wireworm posts to learn more and supplement in-field scouting:

Wireworms – Insect of the Week (2018)

Wireworm distribution map – Weekly Update (2018)

Biological and monitoring information related to wireworms in field crops is posted by Manitoba Agriculture and Resource Development, and Alberta Agriculture and Forestry. Also, refer to the wireworm pages within the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” (2018; accessible in either English-enhanced or French-enhanced versions).

Preparing and protecting grains for market

A few helpful tools to keep at your finger tips:

A number of important resources are available at Keep It Clean to help prepare and protect grains for market.  Learn more about preparing canola, cereals and pulses! They also have tools to manage pre-harvest intervals including a spray to swath calculator and describe the importance of avoiding malathion in bins storing canola.

Download searchable PDFs of 2020 Crop Production Guides for Alberta, Saskatchewan and Manitoba.

The Canadian Grain Commission has information to help you manage stored grain.  Read tips to prepare your bins to prevent insect infestations.  If there are insects in your grain, use their online diagnostic tools to help identify the problem species.  If pest species are confirmed, there are control options – read more to make the right choice for your grain storage system and your specific grain.

Ladybird beetles and mummies

Ladybird beetle larvae (Fig. 1), pupae (Fig. 2), and adults (Fig. 3) can all be found in fields at this time of year.  Take a look at the various stages and the many patterns of native and introduced species to recognize these as Field Heroes!  Ladybird beetles are categorized as general predators and will feed on several species of arthropods but are partial to aphids.  

Figure 1. Ladybird beetle larva (photo credit: AAFC-Beaverlodge)
Figure 2. Ladybird beetle pupa (photo credit: AAFC-Beaverlodge).
Figure 3. Ladybird beetle (Coccinella septempunctata) (photo credit: AAFC-Beaverlodge)

Another “beneficial” found in fields at this point in the season are mummified aphids (Fig. 4). The “mummy” contains a maturing parasitoid wasp which will emerge from the host and seek other aphids to parasitize. Read more about the amazing Aphidiinae wasps by accessing the pages from the  “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and Field Guide“.  The guide is available as a free downloadable document in both an English-enhanced or French-enhanced version.

Figure 4. An aphid “mummy” adhered to a wheat awn.  A “mummy” is the aphid host transformed to enclose a soon-to-emerge parasitoid wasp (photo credit: AAFC-Beaverlodge).

Cereal Aphid Manager

Aphids can cause significant damage to fields and increase crop losses but low densities in a grain field sometimes have little economic impact on production. This is especially true if the aphid’s natural enemies (beneficial insects) are present in the field because they can keep the aphids under control.

The Cereal Aphid Manager is an easy-to-use mobile app that helps farmers and crop advisors control aphid populations in wheat, barley, oat or rye. It is based on Dr. Tyler Wist’s (AAFC-Saskatoon) Dynamic Action Threshold model. The model treats the grain field as an ecosystem and takes into account many complex biological interactions including:

  • the number of aphids observed and how quickly they reproduce
  • the number of different natural enemies of aphids in the field and how many aphids they eat or parasitize per day
  • the lifecycles of aphids and their enemies taking into account developmental stages, egg laying behaviour, population growth rate, lifespan, etc.

Frequent in-field scouting, supported by the app’s dynamic threshold, allows growers to weigh the above factors and the app predicts what the aphid population will be in seven days and the best time to apply insecticide based on economic thresholds.

To learn more and to download, go to AAFC’s CAM webpage

Doppelgangers: Cereal leaf beetle vs. Collops beetles

The case of the innocuous versus the evil twin: When making pest management decisions, be sure that the suspect is actually a pest. This can be challenge since insects often mimic each other or look very similar. An insect that looks, moves and acts like a pest may in fact be a look-alike or doppelganger.

Doppelgangers may be related (e.g. same genus) or may not be related, as in the case of monarch butterflies (Danaus plexippus) and viceroys (Limenitis achrippus).  Doppelgangers are  usually relatively harmless but sometimes the doppelganger is a pest yet their behaviour, lifecycle or hosts may be different.

Correctly identifying a pest enables selection of the most accurate scouting or monitoring protocol. Identification and monitoring enables the application of economic thresholds. It also enables a producer to select and apply the most effective control option(s) including method and timing of application.  For the rest of the growing season, the Insect of the Week will feature insect crop pests and their doppelgangers.

The case of the cereal leaf beetle versus Collops beetles: 

Cereal leaf beetle, Boris Loboda

Cereal leaf beetles (Oulema melanopus), both adults and larva, feed on leaves (oat, barley, wheat, corn, etc), but it is the larval damage that can reduce yield and quality, especially if the flag leaf is stripped. Adults are 6-8 millimeters (.25-.31 inches) long with reddish legs and thorax (middle section between head and abdomen) and metallic bluish-black head and elytra (wing coverings).

Collops beetle, cc-by-nd-nc 1.0 Ashley Bradford

They may be confused with beneficial beetles belonging to the Collops genus (adults feed on aphids, stink bug eggs, moth eggs, small caterpillars, spider mites, whiteflies). Roughly the same size, they may have a red or orange thorax with/without red markings on their elytra, depending on the species. One consistent feature that will help distinguish between the two species is that the cereal leaf beetle elytra are smooth and shiny whereas the Collops’ elytra are covered in hairs.

Specific information on the cereal leaf beetle can be found in the updated Field Crop and Forage Pests and their Natural enemies in Western Canada field guide.

Review previously featured insects by visiting the Insect of the Week page.

Cereal Aphid Manager (CAM)

Reminder  and Congratulations!  The Cereal Aphid Management (CAM) Mobile Application Team was recognized with an Agriculture and Agri-Food Canada Gold Harvest Award this month!  Team members included Ashraf Eid, Paul Faure, John Gavloski, François Jodoin, Elham Karimi, Eric Li, Jackson Macdonald, Nancy MacDonald, Owen Olfert, Chrystel Y. Olivier, Daniel Shen, Erl Svendsen, Gabriel Tobian, Tyler J. Wist.  

“The app is a culmination of innovative thinking, extensive research, and most importantly collaboration in order to design a tool that met the needs of the farming community. The team’s ability to work together and build this application will result in economic savings, a greener environment, and increased crop quality in the food production industry.”

The Cereal Aphid Manager is an easy-to-use mobile app that helps farmers and crop advisors control aphid populations in wheat, barley, oat or rye. It is based on Dr. Tyler Wist’s (AAFC-Saskatoon) innovative Dynamic Action Threshold model. The model treats the grain field as an ecosystem and takes into account many complex biological interactions including:

  • the number of aphids observed and how quickly they reproduce
  • the number of different natural enemies of aphids in the field and how many aphids they eat or parasitize per day
  • the lifecycles of aphids and their enemies taking into account developmental stages, egg laying behaviour, population growth rate, lifespan, etc.

By taking into consideration factors like these, the app predicts what the aphid population will be in seven days and the best time to apply insecticide based on economic thresholds.

Available in iOS and Android.

To learn more and to download, go to AAFC’s CAM webpage.

Note: Cereal aphids can blow up from the South at any time which cannot be predicted by the app. Therefore, farmers and crop advisors should regularly check fields during the growing season regardless of what Cereal Aphid Manager Mobile may recommend.

CAM Homepage
CAM monitoring report and recommendation
CAM icon

Cereal leaf beetle

Cereal leaf beetle (Oulema melanopus) – The cereal leaf beetle model indicates hatch has begun (Fig. 1).  Models were projected to June 21, 2019 and run for Lethbridge AB (Fig. 2), Grande Prairie AB (Fig. 3), and Brandon MB (Fig. 4). 

Figure 1.  Percent of populations of cereal leaf beetle (Oulema melanopus) in the larval stage as of June 3, 2019, across the Canadian prairies. 
Figure 2. Predicted status of cereal leaf beetle populations near Lethbridge AB projected to June 21, 2019, generated using long term average temperatures.
Figure 3. Predicted status of cereal leaf beetle populations near Grande Prairie AB projected to June 21, 2019, generated using long term average temperatures.
Figure 4. Predicted status of cereal leaf beetle populations near Brandon MB projected to June 21, 2019, generated using long term average temperatures.

Lifecycle and Damage:

Adult: Adult cereal leaf beetles (CLB) have shiny bluish-black wing-covers (Fig. 5). The thorax and legs are light orange-brown. Females (4.9 to 5.5 mm) are slightly larger than the males (4.4 to 5 mm). Adult beetles overwinter in and along the margins of grain fields in protected places such as in straw stubble, under crop and leaf litter, and in the crevices of tree bark. They favour sites adjacent to shelter belts, deciduous and conifer forests. They emerge in the spring once temperature reaches 10-15 ºC and are active for about 6 weeks. They usually begin feeding on grasses, then move into winter cereals and later into spring cereals.  

Figure 5. Adult Oulema melanopus measure 4.4-5.5 mm long (Photo: M. Dolinski).

Egg: Eggs are laid approximately 14 days following the emergence of the adults. Eggs are laid singly or in pairs along the mid vein on the upper side of the leaf and are cylindrical, measuring 0.9 mm by 0.4 mm, and yellowish in colour. Eggs darken to black just before hatching.  

Larva: The larvae hatch in about 5 days and feed for about 3 weeks, passing through 4 growth stages (instars). The head and legs are brownish-black; the body is yellowish. Larvae are usually covered with a secretion of mucus and fecal material, giving them a shiny black, wet appearance (Fig. 6).  When the larva completes its growth, it drops to the ground and pupates in the soil. 

Figure 6.  Larval stage of Oulema melanopus with characteristic feeding damage visible on leaf (Photo: M. Dolinski).

Pupa: Pupal colour varies from a bright yellow when it is first formed, to the colour of the adult just before emergence. The pupal stage lasts 2 – 3 weeks. Adult beetles emerge and feed for a couple of weeks before seeking overwintering sites. There is one generation per year.

Fact sheets for CLB are published by the province of Alberta and available from the Prairie Pest Monitoring Network. Also access the Oulema melanopus page from the new “Field crop and forage pests and their natural enemies in western Canada – Identification and management field guide”.

Cereal Aphid Manager (CAM)

Congratulations!  The Cereal Aphid Management (CAM) Mobile Application Team was recognized with an Agriculture and Agri-Food Canada Gold Harvest Award this month!  Team members included Ashraf Eid, Paul Faure, John Gavloski, François Jodoin, Elham Karimi, Eric Li, Jackson Macdonald, Nancy MacDonald, Owen Olfert, Chrystel Y. Olivier, 

Daniel Shen, Erl Svendsen, Gabriel Tobian, Tyler J. Wist.

“The app is a culmination of innovative thinking, extensive research, and most importantly collaboration in order to design a tool that met the needs of the farming community. The team’s ability to work together and build this application will result in economic savings, a greener environment, and increased crop quality in the food production industry.”

The Cereal Aphid Manager is an easy-to-use mobile app that helps farmers and crop advisors control aphid populations in wheat, barley, oat or rye. It is based on Dr. Tyler Wist’s (AAFC-Saskatoon) innovative Dynamic Action Threshold model. The model treats the grain field as an ecosystem and takes into account many complex biological interactions including:

  • the number of aphids observed and how quickly they reproduce
  • the number of different natural enemies of aphids in the field and how many aphids they eat or parasitize per day
  • the lifecycles of aphids and their enemies taking into account developmental stages, egg laying behaviour, population growth rate, lifespan, etc.

By taking into consideration factors like these, the app predicts what the aphid population will be in seven days and the best time to apply insecticide based on economic thresholds.

Available in iOS and Android.

To learn more and to download, go to AAFC’s CAM webpage.

Note: Cereal aphids can blow up from the South at any time which cannot be predicted by the app. Therefore, farmers and crop advisors should regularly check fields during the growing season regardless of what Cereal Aphid Manager Mobile may recommend.

CAM Homepage
CAM monitoring report and recommendation
CAM icon

Cereal leaf beetle

Cereal leaf beetle (Oulema melanopus) – The CLB model was run for Brandon MB (Fig. 1), Lethbridge AB (Fig. 2), Grande Prairie AB (Fig. 3) and projected to June 15, 2019.  The cereal leaf beetle model indicates that eggs may begin to hatch later next week in Brandon (Fig. 1) and Lethbridge (Fig. 3). Hatch is predicted to be 4-7 days later in the Peace River region (Fig. 3).

Figure 1. Projected predicted status of cereal leaf beetle populations near Lethbridge AB to June 15, 2019,generated using long term average temperatures.
Figure 2. Projected predicted status of cereal leaf beetle populations near Brandon MB to June 15, 2019,generated using long term average temperatures.
Figure 3. Projected predicted status of cereal leaf beetle populations near Grande Prairie AB to June 15, 2019, generated using long term average temperatures.
 

Lifecycle and Damage:

Adult: Adult cereal leaf beetles (CLB) have shiny bluish-black wing-covers (Fig. 2). The thorax and legs are light orange-brown. Females (4.9 to 5.5 mm) are slightly larger than the males (4.4 to 5 mm). Adult beetles overwinter in and along the margins of grain fields in protected places such as in straw stubble, under crop and leaf litter, and in the crevices of tree bark. They favour sites adjacent to shelter belts, deciduous and conifer forests. They emerge in the spring once temperature reaches 10-15 ºC and are active for about 6 weeks. They usually begin feeding on grasses, then move into winter cereals and later into spring cereals.  

Figure 2. Adult Oulema melanopus measure 4.4-5.5 mm long (Photo: M. Dolinski).

Egg: Eggs are laid approximately 14 days following the emergence of the adults. Eggs are laid singly or in pairs along the mid vein on the upper side of the leaf and are cylindrical, measuring 0.9 mm by 0.4 mm, and yellowish in colour. Eggs darken to black just before hatching.  

Larva: The larvae hatch in about 5 days and feed for about 3 weeks, passing through 4 growth stages (instars). The head and legs are brownish-black; the body is yellowish. Larvae are usually covered with a secretion of mucus and fecal material, giving them a shiny black, wet appearance (Fig. 3).  When the larva completes its growth, it drops to the ground and pupates in the soil. 

Figure 3.  Larval stage of Oulema melanopus with characteristic feeding damage visible on leaf (Photo: M. Dolinski).

Pupa: Pupal colour varies from a bright yellow when it is first formed, to the colour of the adult just before emergence. The pupal stage lasts 2 – 3 weeks. Adult beetles emerge and feed for a couple of weeks before seeking overwintering sites. There is one generation per year.

Fact sheets for CLB are published by the province of Alberta and available from the Prairie Pest Monitoring Network. Also access the Oulema melanopus page from the new “Field crop and forage pests and their natural enemies in western Canada – Identification and management field guide”.

Cereal leaf beetle

Cereal leaf beetle (Oulema melanopus) – The CLB model was run for Lethbridge AB (Fig. 1), Brandon MB (Fig. 2), and Grande Prairie AB (Fig. 3) and projected to June 15, 2019.  The cereal leaf beetle model indicates that eggs may begin to hatch later next week in Lethbridge (Fig. 1) and Brandon (Fig. 2). Hatch is predicted to be 4-7 days later in the Peace River region (Fig. 3).

Figure 1. Projected predicted status of cereal leaf beetle populations near Lethbridge AB to June 15, 2019, generated using long term average temperatures.
Figure 2. Projected predicted status of cereal leaf beetle populations near Brandon MB to June 15, 2019, generated using long term average temperatures.
Figure 3. Projected predicted status of cereal leaf beetle populations near Grande Prairie AB to June 15, 2019, generated using long term average temperatures.

Lifecycle and Damage:

Adult: Adult cereal leaf beetles (CLB) have shiny bluish-black wing-covers (Fig. 2). The thorax and legs are light orange-brown. Females (4.9 to 5.5 mm) are slightly larger than the males (4.4 to 5 mm). Adult beetles overwinter in and along the margins of grain fields in protected places such as in straw stubble, under crop and leaf litter, and in the crevices of tree bark. They favour sites adjacent to shelter belts, deciduous and conifer forests. They emerge in the spring once temperature reaches 10-15 ºC and are active for about 6 weeks. They usually begin feeding on grasses, then move into winter cereals and later into spring cereals.  

Figure 2. Adult Oulema melanopus measure 4.4-5.5 mm long (Photo: M. Dolinski).

Egg: Eggs are laid approximately 14 days following the emergence of the adults. Eggs are laid singly or in pairs along the mid vein on the upper side of the leaf and are cylindrical, measuring 0.9 mm by 0.4 mm, and yellowish in colour. Eggs darken to black just before hatching.  

Larva: The larvae hatch in about 5 days and feed for about 3 weeks, passing through 4 growth stages (instars). The head and legs are brownish-black; the body is yellowish. Larvae are usually covered with a secretion of mucus and fecal material, giving them a shiny black, wet appearance (Fig. 3).  When the larva completes its growth, it drops to the ground and pupates in the soil. 

Figure 3.  Larval stage of Oulema melanopus with characteristic feeding damage visible on leaf (Photo: M. Dolinski).

Pupa: Pupal colour varies from a bright yellow when it is first formed, to the colour of the adult just before emergence. The pupal stage lasts 2 – 3 weeks. Adult beetles emerge and feed for a couple of weeks before seeking overwintering sites. There is one generation per year.

Fact sheets for CLB are published by the province of Alberta and available from the Prairie Pest Monitoring Network. Also access the Oulema melanopus page from the new “Field crop and forage pests and their natural enemies in western Canada – Identification and management field guide”.

Cereal leaf beetle

Cereal leaf beetle (Oulema melanopus) – The CLB model was run for Lethbridge AB and projected to June 15, 2019 (Fig. 1).  The cereal leaf beetle model indicates that eggs may begin to hatch later next week Lethbridge.

Figure 1.  Projected predicted status of cereal leaf beetle populations near Lethbridge AB to June 15, 2019 generated using long term average temperatures.

Lifecycle and Damage:

Adult: Adult cereal leaf beetles (CLB) have shiny bluish-black wing-covers (Fig. 2). The thorax and legs are light orange-brown. Females (4.9 to 5.5 mm) are slightly larger than the males (4.4 to 5 mm). Adult beetles overwinter in and along the margins of grain fields in protected places such as in straw stubble, under crop and leaf litter, and in the crevices of tree bark. They favour sites adjacent to shelter belts, deciduous and conifer forests. They emerge in the spring once temperature reaches 10-15 ºC and are active for about 6 weeks. They usually begin feeding on grasses, then move into winter cereals and later into spring cereals.  

Figure 2. Adult Oulema melanopus measure 4.4-5.5 mm long (Photo: M. Dolinski).

Egg: Eggs are laid approximately 14 days following the emergence of the adults. Eggs are laid singly or in pairs along the mid vein on the upper side of the leaf and are cylindrical, measuring 0.9 mm by 0.4 mm, and yellowish in colour. Eggs darken to black just before hatching.  

Larva: The larvae hatch in about 5 days and feed for about 3 weeks, passing through 4 growth stages (instars). The head and legs are brownish-black; the body is yellowish. Larvae are usually covered with a secretion of mucus and fecal material, giving them a shiny black, wet appearance (Fig. 3).  When the larva completes its growth, it drops to the ground and pupates in the soil. 

Figure 3.  Larval stage of Oulema melanopus with characteristic feeding damage visible on leaf (Photo: M. Dolinski).

Pupa: Pupal colour varies from a bright yellow when it is first formed, to the colour of the adult just before emergence. The pupal stage lasts 2 – 3 weeks. Adult beetles emerge and feed for a couple of weeks before seeking overwintering sites. There is one generation per year.

Fact sheets for CLB are published by the province of Alberta and available from the Prairie Pest Monitoring Network. Also access the Oulema melanopus page from the new “Field crop and forage pests and their natural enemies in western Canada – Identification and management field guide”.

Cereal leaf beetle

Cereal leaf beetle (Oulema melanopus) – The cereal leaf beetle model indicates that oviposition is well underway in Lethbridge AB as of May 7, 2019 (Fig. 1).

Figure 1.  Predicted status of cereal leaf beetle populations near Lethbridge AB as of April 30, 2019

Lifecycle and Damage:

Adult: Adult cereal leaf beetles (CLB) have shiny bluish-black wing-covers (Fig. 2). The thorax and legs are light orange-brown. Females (4.9 to 5.5 mm) are slightly larger than the males (4.4 to 5 mm). Adult beetles overwinter in and along the margins of grain fields in protected places such as in straw stubble, under crop and leaf litter, and in the crevices of tree bark. They favour sites adjacent to shelter belts, deciduous and conifer forests. They emerge in the spring once temperature reaches 10-15 ºC and are active for about 6 weeks. They usually begin feeding on grasses, then move into winter cereals and later into spring cereals.  

Figure 2. Adult Oulema melanopus measure 4.4-5.5 mm long (Photo: M. Dolinski).

Egg: Eggs are laid approximately 14 days following the emergence of the adults. Eggs are laid singly or in pairs along the mid vein on the upper side of the leaf and are cylindrical, measuring 0.9 mm by 0.4 mm, and yellowish in colour. Eggs darken to black just before hatching.  

Larva: The larvae hatch in about 5 days and feed for about 3 weeks, passing through 4 growth stages (instars). The head and legs are brownish-black; the body is yellowish. Larvae are usually covered with a secretion of mucus and fecal material, giving them a shiny black, wet appearance (Fig. 3).  When the larva completes its growth, it drops to the ground and pupates in the soil. 

Figure 3.  Larval stage of Oulema melanopus with characteristic feeding 
damage visible on leaf (Photo: M. Dolinski).

Pupa: Pupal colour varies from a bright yellow when it is first formed, to the colour of the adult just before emergence. The pupal stage lasts 2 – 3 weeks. Adult beetles emerge and feed for a couple of weeks before seeking overwintering sites. There is one generation per year.

Fact sheets for CLB are published by the province of Alberta and available from the Prairie Pest Monitoring Network. Also access the Oulema melanopus page from the new “Field crop and forage pests and their natural enemies in western Canada – Identification and management field guide”.

Cereal leaf beetle

Cereal leaf beetle (Oulema melanopus) – Model output indicates that CLB adults have begun to oviposit eggs near Lethbridge AB (Fig. 1). 

Figure 1.  Predicted CLB adults near Lethbridge AB as of April 30, 2019.

Lifecycle and Damage:

Adult: Adult cereal leaf beetles (CLB) have shiny bluish-black wing-covers (Fig. 2). The thorax and legs are light orange-brown. Females (4.9 to 5.5 mm) are slightly larger than the males (4.4 to 5 mm). Adult beetles overwinter in and along the margins of grain fields in protected places such as in straw stubble, under crop and leaf litter, and in the crevices of tree bark. They favour sites adjacent to shelter belts, deciduous and conifer forests. They emerge in the spring once temperature reaches 10-15 ºC and are active for about 6 weeks. They usually begin feeding on grasses, then move into winter cereals and later into spring cereals.  

Figure 2. Adult Oulema melanopus measure 4.4-5.5 mm long (Photo: M. Dolinski).

Egg: Eggs are laid approximately 14 days following the emergence of the adults. Eggs are laid singly or in pairs along the mid vein on the upper side of the leaf and are cylindrical, measuring 0.9 mm by 0.4 mm, and yellowish in colour. Eggs darken to black just before hatching.  

Larva: The larvae hatch in about 5 days and feed for about 3 weeks, passing through 4 growth stages (instars). The head and legs are brownish-black; the body is yellowish. Larvae are usually covered with a secretion of mucus and fecal material, giving them a shiny black, wet appearance (Fig. 3).  When the larva completes its growth, it drops to the ground and pupates in the soil. 

Figure 3.  Larval stage of Oulema melanopus with characteristic feeding damage visible on leaf (Photo: M. Dolinski).

Pupa: Pupal colour varies from a bright yellow when it is first formed, to the colour of the adult just before emergence. The pupal stage lasts 2 – 3 weeks. Adult beetles emerge and feed for a couple of weeks before seeking overwintering sites. There is one generation per year.

Fact sheets for CLB are published by the province of Alberta and available from the Prairie Pest Monitoring Network. Also access the Oulema melanopus page from the new “Field crop and forage pests and their natural enemies in western Canada – Identification and management field guide”.

Ladybird beetles

Reminder – While scouting, you may encounter these fascinating organisms…..

Figure 1. Ladybird beetle larva (photo credit: AAFC-Beaverlodge)
Figure 2. Ladybird beetle pupa (Left) and larva (Right) (photo credit: AAFC-Beaverlodge)
Figure 3. Ladybird beetle pupa (photo credit: AAFC-Beaverlodge)
Figure 4. Ladybird beetle (Coccinella septempunctata) (photo credit: AAFC-Beaverlodge)
Figure 5. Aphids nestled on wheat head (photo credit: AAFC-Beaverlodge)
Figure 6. An aphid “mummy” adhered to a wheat awn.  Mummy is the aphid host converted to enclose a soon-to-emerge parasitoid wasp (photo credit: AAFC-Beaverlodge)

Ladybird beetle larvae (Fig. 1-2), pupae (Fig. 2-3), and adults (Fig. 4) can all be found in fields at this time of year.  Take a look at the various stages and the many patterns of native and introduced species to recognize these as Field Heroes!  Ladybird beetles are categorized as general predators and will feed on several species of arthropods but are partial to aphids (Fig. 5).  

Ladybird beetles

While scouting, you may encounter these fascinating organisms…..

Figure 1. Ladybird beetle larva (photo credit: AAFC-Beaverlodge)
Figure 2. Ladybird beetle pupa (Left) and larva (Right) (photo credit: AAFC-Beaverlodge)
Figure 3. Ladybird beetle pupa (photo credit: AAFC-Beaverlodge)
Figure 4. Ladybird beetle (Coccinella septempunctata) (photo credit: AAFC-Beaverlodge)
Figure 5. Aphids nestled on wheat head (photo credit: AAFC-Beaverlodge)
Figure 6. An aphid “mummy” adhered to a wheat awn.  Mummy is the aphid host converted to enclose a soon-to-emerge parasitoid wasp (photo credit: AAFC-Beaverlodge)

Ladybird beetle larvae (Fig. 1-2), pupae (Fig. 2-3), and adults (Fig. 4) can all be found in fields at this time of year.  Take a look at the various stages and the many patterns of native and introduced species to recognize these as Field Heroes!  Ladybird beetles are categorized as general predators and will feed on several species of arthropods but are partial to aphids (Fig. 5).  

Cereal leaf beetle

Cereal leaf beetle (Oulema melanopus) – By this point in the season, pupae and newly emerged adults will be present in fields.  

Pupa: Pupal colour varies from a bright yellow when it is first formed, to the colour of the adult just before emergence. The pupal stage lasts 2 – 3 weeks. Adult beetles emerge and feed for a couple of weeks before seeking overwintering sites. There is one generation per year.

Adult: Adult cereal leaf beetles (CLB) have shiny bluish-black wing-covers (Fig. 1). The thorax and legs are light orange-brown. Females (4.9 to 5.5 mm) are slightly larger than the males (4.4 to 5 mm). Adult beetles overwinter in and along the margins of grain fields in protected places such as in straw stubble, under crop and leaf litter, and in the crevices of tree bark. They favour sites adjacent to shelter belts, deciduous and conifer forests. They will emerge in the spring once temperature reaches 10-15 ºC.

Figure 1. Adult Oulema melanopus measure 4.4-5.5 mm long (Photo: M. Dolinski).

Fact sheets for CLB are published by the province of Alberta and available from the Prairie Pest Monitoring Network. Also access the Oulema melanopus page from the new “Field crop and forage pests and their natural enemies in western Canada – Identification and management field guide”.

Cereal Aphid Manager (CAM)

Reminder – Aphids can cause significant damage to fields and increase crop losses, but just because aphids are present in a grain field doesn’t mean they will have a negative economic impact on production. This is especially true if there are aphid’s natural enemies (beneficial insects) in the field to keep them under control.

The Cereal Aphid Manager is an easy-to-use mobile app that helps farmers and crop advisors control aphid populations in wheat, barley, oat or rye. It is based on Dr. Tyler Wist’s (AAFC-Saskatoon) innovative Dynamic Action Threshold model. The model treats the grain field as an ecosystem and takes into account many complex biological interactions including:

  • the number of aphids observed and how quickly they reproduce
  • the number of different natural enemies of aphids in the field and how many aphids they eat or parasitize per day
  • the lifecycles of aphids and their enemies taking into account developmental stages, egg laying behaviour, population growth rate, lifespan, etc.

By taking into consideration factors like these, the app predicts what the aphid population will be in seven days and the best time to apply insecticide based on economic thresholds.

Available in iOS and Android.

To learn more and to download, go to AAFC’s CAM webpage.

Note: Cereal aphids can blow up from the South at any time which cannot be predicted by the app. Therefore, farmers and crop advisors should regularly check fields during the growing season regardless of what Cereal Aphid Manager Mobile may recommend.

CAM Homepage
CAM monitoring report and recommendation
CAM icon

Insect of the Week – Bruner grasshopper (Orthoptera: Acrididae)

The insect of the week is the Bruner grasshopper (Melanoplus bruneri).  Observed since the 1920s in Canada, this species is a relatively recent addition to the list of grasshopper pest species occurring in crop production areas. Previously, it was not considered a crop pest.

It is a medium-sized grasshopper (males 18-22 mm; females 22-27 mm) with dark and often reddish colour tones. It is similar in appearance and size to the migratory grasshopper (Melanoplus sanguinipes) but is distinguished by differences in the male genitalia. The Bruner grasshopper has recently become the predominant grasshopper species in many northern crop production areas of Alberta and parts of Saskatchewan. It occupies a wide geographic range and is found throughout much of Canada and the United States.

The Bruner grasshopper feeds mainly on broadleaf host plants but the species can feed upon several species of grasses. It has been observed in high numbers feeding in pulse crops, canola, and cereals.

Researchers are investigating if this species follows a two-year life cycle (i.e. do eggs require exposure to two winters before hatching?) in the Peace River region and parts of central Alberta.

For more information, see our Insect of the Week page!

Bruner grasshopper (Melanoplus bruneri) adult.
Photo credit: S. Barkley, Alberta Agriculture and Forestry.

Access these websites for more information related to the Bruner Grasshopper:

Access more information related to grasshoppers here.

Request for Cereal Leaf Beetle Larvae

Reminder – Researchers need your help – They are looking for LIVE cereal leaf beetle larvae from any field across the Canadian prairies in order to assess Tetrastichus julis parasitism rates.

If larvae are encountered in 2018, please carefully collect 20-30 of them and put them with some cereal leaves and a moist paper towel in a hard container (e.g. plastic yogurt container) with holes poked in the lid for air. Pack the parcel with ice packs, label with your name, date, crop type, and location, and send them to us.  Email or phone us for information on how to ship for free.

What’s in it for you? Learn if cereal leaf beetle is being controlled by natural enemies in your field. If you need T. julis, we may be able provide you with some.

Contact:
Dr. Haley Catton, Agriculture and Agri-Food Canada
5403 – 1 Ave S, Lethbridge, Alberta T1J 4B1
403-317-3404, haley.catton@agr.gc.ca

Request for Cereal Leaf Beetle Larvae

Researchers need your help – They are looking for LIVE cereal leaf beetle larvae from any field across the Canadian prairies in order to assess Tetrastichus julis parasitism rates.

If larvae are encountered in 2018, please carefully collect 20-30 of them and put them with some cereal leaves and a moist paper towel in a hard container (e.g. plastic yogurt container) with holes poked in the lid for air. Pack the parcel with ice packs, label with your name, date, crop type, and location, and send them to us.  Email or phone us for information on how to ship for free.

What’s in it for you? Learn if cereal leaf beetle is being controlled by natural enemies in your field. If you need T. julis, we may be able provide you with some.

Contact:
Dr. Haley Catton, Agriculture and Agri-Food Canada
5403 – 1 Ave S, Lethbridge, Alberta T1J 4B1
403-317-3404, haley.catton@agr.gc.ca

Wireworm distribution map

Reminder – Last week turned out to be our wireworm blitz!  This complicated group of insect species was featured in the Insect of the Week AND we include the survey results again this week!

The following maps summarize the main results of a survey of pest species of wireworms of the Canadian Prairie Provinces.  Samples (both larvae and beetles) were submitted to Dr. Bob Vernon’s lab in Agassiz, BC, from 2004 to 2017, and identified by Dr. Wim van Herk (Fig. 1).  Species identifications were confirmed with barcoding.

Figure 1.  Sampling locations for click beetles and wireworm larvae (Coleoptera: Elateridae) submitted for wireworm surveying from 2004-2017.

Approximately 600 samples were submitted, with the number of larvae per sample typically less than five (Fig. 1).  More samples are welcome, particularly from areas currently not well represented on the maps.  Please provide either the legal land description or latitude and longitude coordinates with a sample.  Any information on the cropping history or whether fields were irrigated is helpful.

Review the complete survey summary posted in Week 05 (for Jun 7, 2018).

Disclaimer: 
Please do not distribute or use the contents of this post, including any maps, without obtaining prior permission.

Obtain further information or arrange shipment of wireworm or click beetle samples by contacting:
Dr. Wim van Herk
Agriculture and Agri-Food Canada
Agassiz Research and Development Centre
6947 Highway 7, Agassiz, BC, V0M 1A0
wim.vanherk@agr.gc.ca

Insect of the Week – Wireworms

This week’s Insect of the Week is a frustrating pest of many crops: wireworm. Wireworms are the soil-dwelling larval stage of the click beetles (Elateridae). There are hundreds of click beetle species in the prairies, but the term wireworm refers to those that are pests, which in Canada is approximately 20 species. With the loss of effective insecticides (e.g. lindane), wireworms have re-emerged in recent years as primary pests of potato, cereals, and vegetables. On the prairies, we have 3 predominant pest species (Selatosomus destructor, Limonius californicus, and Hypnoidus bicolor; see photo), and their larvae vary (among other things) in life history (2-7 years), color (white to orange), cuticle thickness, distribution, behaviour, and susceptibility to insecticides.

Wireworms are patchy in distribution, difficult to monitor, and difficult to kill. We have a lot to learn about these resilient pests. Since the mid-1990’s AAFC has had a national research team (Bob Vernon et al.) screening for effective insecticides and developing trapping and monitoring methods, cultural controls (e.g., crop rotation), and biocontrols to manage the adult and larval forms of these pests.

For more information about wireworms, check out our Insect of the Week page!

The three most troublesome wireworm species on the prairies in their adult and larval stages. Note the different sizes and colours. From left to right, S. destructor, L. californicus, H. bicolor.
Photo by David Shack, AAFC-Lethbridge.

For more information, please contact Dr. Haley Catton (AAFC-Lethbridge) or Dr. Wim van Herk (AAFC-Agassiz)

Also link here to access a summary of Wireworm surveying (2004-2017) conducted across the Canadian prairies by van Herk and Vernon (AAFC-Agassiz).

Wireworm distribution map

The following maps summarize the main results of a survey of pest species of wireworms of the Canadian Prairie Provinces.  Samples (both larvae and beetles) were submitted to Dr. Bob Vernon’s lab in Agassiz, BC, from 2004 to 2017, and identified by Dr. Wim van Herk (Fig. 1).  Species identifications were confirmed with barcoding.

Figure 1.  Sampling locations for click beetles and wireworm larvae (Coleoptera: Elateridae) submitted for wireworm surveying from 2004-2017.

Approximately 600 samples were submitted, with the number of larvae per sample typically less than five (Fig. 1).  More samples are welcome, particularly from areas currently not well represented on the maps.  Please provide either the legal land description or latitude and longitude coordinates with a sample.  Any information on the cropping history or whether fields were irrigated is helpful.

The main findings of this survey are that:
1. Wireworms are re-emerging as primary pests of cereals and other crops, particularly in southern Alberta and Saskatchewan.  This can be attributed to several factors, including changes in seeding and cultivation resulting in higher soil moisture and increased food availability, and therefore greater wireworm survival; the elimination of effective insecticides such as lindane and the decline of organochlorine residues in the soil; and the present lack of insecticides that actually kill wireworms.

2. Limonius californicus is generally the predominant pest species in fields reporting heavy wireworm damage, occasionally building up to very high populations and resulting in complete crop wrecks (Fig. 2).  This was not the case when Glen et al. (1943) or Doane (1977) conducted their surveys; L. californicus was considered a minor species at those times.  Selatosomus destructor (Fig. 3) and Hypnoidus bicolor (Fig. 4) are still the most common species.  The pest status of another commonly found species, the predaceous Aeolus mellillus (Fig. 5), is unclear.  The following species listed by Glen et al. (1943) as pests of agriculture in the Prairie Provinces were found also, but infrequently: Agriotes mancusA. criddleiA. stabilisHemicrepidius memnoniusL. pectoralis, and various Dalopius sp.

Figure 2.  Distribution of Limonius californicus (Coleoptera: Elateridae) submitted for wireworm surveying from 2004-2017.
Figure 3.  Distribution of Selatosomus destructor (Coleoptera: Elateridae) submitted for wireworm surveying from 2004-2017.
Figure 4.  Distribution of Hypniodes bicolor (Coleoptera: Elateridae) submitted for wireworm surveying from 2004-2017.
Figure 5. Distribution of Aeolus mellillus (Coleoptera: Elateridae) submitted for wireworm surveying from 2004-2017.

3. Multiple pest species are frequently found in the same fields where damage is reported (i.e. about 25% of the time, despite the small number of larvae per sample).  This is particularly important as pest species can vary considerably in the type of damage they cause (e.g. it remains unclear if H. bicolor is damaging to potato), their life history (e.g. duration of the larval stage), and susceptibility to insecticides.

Details related to the biology and management of these species are reviewed in van Herk and Vernon (2014) and Vernon and van Herk (2013).

Acknowledgements:
These maps are only possible thanks to the collections done by a large team of local entomologists and agrologists.  We are extremely grateful to them; thank you to everyone who participated!  A special thank you to Ted Labun and colleagues at Syngenta Crop Protection (Canada), and to Bayer CropScience, for providing the bulk of the samples. 

Disclaimer: 
Please do not distribute or use the contents of this post, including any maps, without obtaining prior permission.

Obtain further information or arrange shipment of wireworm or click beetle samples by contacting:
Dr. Wim van Herk
Agriculture and Agri-Food Canada
Agassiz Research and Development Centre
6947 Highway 7, Agassiz, BC, V0M 1A0
wim.vanherk@agr.gc.ca

Further wireworm reading:
Burrage RH (1964) Trends in damage by wireworms (Coleoptera: Elateridae) in grain crops in Saskatchewan, 1954–1961. Canadian Journal of Plant Science, 44: 515–519.  https://doi.org/10.4141/cjps64-102 

Doane JF (1977) Spatial pattern and density of Ctenicera destructor and Hypolithus bicolor (Coleoptera: Elateridae) in soil in spring wheat. The Canadian Entomologist 109: 807–822. https://doi.org/10.4039/Ent109807-6

Doane JF (1977) The flat wireworm, Aeolus mellillus: studies on seasonal occurrence of adults and incidence of the larvae in the wireworm complex attacking wheat in Saskatchewan. Environmental Entomology 6: 818–822. https://doi.org/10.1093/ee/6.6.818 

Glen R, King KM, Arnason AP (1943) The identification of wireworms of economic importance in Canada. Canadian Journal of Research 21: 358-387. https://doi.org/10.1139/cjr43d-030

van Herk WG, Vernon RS (2014) Click beetles and wireworms (Coleoptera: Elateridae) of Alberta, Saskatchewan, and Manitoba.  In: Arthropods of Canadian Grasslands (Volume 4): Biodiversity and Systematics Part 2. (Edited by D.J. Giberson and H.A. Carcamo).  Biological Survey of Canada, pp. 87-117. https://biologicalsurvey.ca/monographs/read/17

Vernon RS, van Herk WG (2013) Wireworms as pests of potato. In: Insect pests of potato: Global perspectives on biology and management.  (Edited by P. Giordanengo, C. Vincent, A. Alyokhin).  Academic Press, Elsevier, Amsterdam, pp 103–164.  https://www.elsevier.com/books/insect-pests-of-potato/alyokhin/978-0-12-386895-4 

Zacharuk RY (1962) Distribution, habits, and development of Ctenicera destructor (Brown) in western Canada, with notes on the related species C. aeripennis (Kby.) (Coleoptera: Elateridae). Canadian Journal of Zoology 40: 539–552.  https://doi.org/10.1139/z62-046

Cereal leaf beetle

Cereal leaf beetle (Oulema melanopus) – Model output indicates that CLB are primarily in the larval stage (Fig. 1). 

Figure 1.  Percent of cereal leaf beetle population that is in the larval stage, based on model simulations, for April 1-June 4, 2018.

Lifecycle and Damage:

Adult: Adult cereal leaf beetles (CLB) have shiny bluish-black wing-covers (Fig. 2). The thorax and legs are light orange-brown. Females (4.9 to 5.5 mm) are slightly larger than the males (4.4 to 5 mm). Adult beetles overwinter in and along the margins of grain fields in protected places such as in straw stubble, under crop and leaf litter, and in the crevices of tree bark. They favour sites adjacent to shelter belts, deciduous and conifer forests. They emerge in the spring once temperature reaches 10-15 ºC and are active for about 6 weeks. They usually begin feeding on grasses, then move into winter cereals and later into spring cereals.  

Figure 2. Adult Oulema melanopus measure 4.4-5.5 mm long (Photo: M. Dolinski).

Egg: Eggs are laid approximately 14 days following the emergence of the adults. Eggs are laid singly or in pairs along the mid vein on the upper side of the leaf and are cylindrical, measuring 0.9 mm by 0.4 mm, and yellowish in colour. Eggs darken to black just before hatching.  

Larva: The larvae hatch in about 5 days and feed for about 3 weeks, passing through 4 growth stages (instars). The head and legs are brownish-black; the body is yellowish. Larvae are usually covered with a secretion of mucus and fecal material, giving them a shiny black, wet appearance (Fig. 3).  When the larva completes its growth, it drops to the ground and pupates in the soil. 

Figure 3.  Larval stage of Oulema melanopus with characteristic feeding  damage visible on leaf (Photo: M. Dolinski).

Pupa: Pupal colour varies from a bright yellow when it is first formed, to the colour of the adult just before emergence. The pupal stage lasts 2 – 3 weeks. Adult beetles emerge and feed for a couple of weeks before seeking overwintering sites. There is one generation per year.

Fact sheets for CLB are published by the province of Alberta and available from the Prairie Pest Monitoring Network. Also access the Oulema melanopus page from the new “Field crop and forage pests and their natural enemies in western Canada – Identification and management field guide”.

Cereal leaf beetle

Cereal leaf beetle (Oulema melanopus) – Model output indicates that CLB are primarily in the larval stage (example Lethbridge – Fig. 1). 
Figure 1. Predicted cereal leaf beetle phenology at Lethbridge AB. 
Values are based on model simulations (April 1-May 28, 2018 and projected to June 21, 2018).

Lifecycle and Damage:

Adult: Adult cereal leaf beetles (CLB) have shiny bluish-black wing-covers (Fig. 2). The thorax and legs are light orange-brown. Females (4.9 to 5.5 mm) are slightly larger than the males (4.4 to 5 mm). Adult beetles overwinter in and along the margins of grain fields in protected places such as in straw stubble, under crop and leaf litter, and in the crevices of tree bark. They favour sites adjacent to shelter belts, deciduous and conifer forests. They emerge in the spring once temperature reaches 10-15 ºC and are active for about 6 weeks. They usually begin feeding on grasses, then move into winter cereals and later into spring cereals.  

Figure 2. Adult Oulema melanopus measure 4.4-5.5 mm long (Photo: M. Dolinski).


Egg: Eggs are laid approximately 14 days following the emergence of the adults. Eggs are laid singly or in pairs along the mid vein on the upper side of the leaf and are cylindrical, measuring 0.9 mm by 0.4 mm, and yellowish in colour. Eggs darken to black just before hatching.  


Larva: The larvae hatch in about 5 days and feed for about 3 weeks, passing through 4 growth stages (instars). The head and legs are brownish-black; the body is yellowish. Larvae are usually covered with a secretion of mucus and fecal material, giving them a shiny black, wet appearance (Fig. 3).  When the larva completes its growth, it drops to the ground and pupates in the soil. 


Figure 3.  Larval stage of Oulema melanopus with characteristic feeding 
damage visible on leaf (Photo: M. Dolinski).

Pupa: Pupal colour varies from a bright yellow when it is first formed, to the colour of the adult just before emergence. The pupal stage lasts 2 – 3 weeks. Adult beetles emerge and feed for a couple of weeks before seeking overwintering sites. There is one generation per year.

Fact sheets for CLB are published by the province of Alberta and available from the Prairie Pest Monitoring Network. Also access the Oulema melanopus page from the new “Field crop and forage pests and their natural enemies in western Canada – Identification and management field guide”.

Cereal leaf beetle

Cereal leaf beetle (Oulema melanopus) – Model output predicts that CLB larvae should be appearing at many locations across the southern prairies. An example of CLB predicted phenology for Lethbridge AB is presented in Figure 1. 

Figure 1. Predicted CLB phenology at Lethbridge. Values are based on model
simulations, for April 1 – May 21, 2018 (projected to June 21, 2018).
Lifecycle and Damage:

Adult: Adult cereal leaf beetles (CLB) have shiny bluish-black wing-covers (Fig. 2). The thorax and legs are light orange-brown. Females (4.9 to 5.5 mm) are slightly larger than the males (4.4 to 5 mm). Adult beetles overwinter in and along the margins of grain fields in protected places such as in straw stubble, under crop and leaf litter, and in the crevices of tree bark. They favour sites adjacent to shelter belts, deciduous and conifer forests. They emerge in the spring once temperature reaches 10-15 ºC and are active for about 6 weeks. They usually begin feeding on grasses, then move into winter cereals and later into spring cereals.  

Figure 2. Adult Oulema melanopus measure 4.4-5.5 mm long (Photo: M. Dolinski).


Egg: Eggs are laid approximately 14 days following the emergence of the adults. Eggs are laid singly or in pairs along the mid vein on the upper side of the leaf and are cylindrical, measuring 0.9 mm by 0.4 mm, and yellowish in colour. Eggs darken to black just before hatching.  


Larva: The larvae hatch in about 5 days and feed for about 3 weeks, passing through 4 growth stages (instars). The head and legs are brownish-black; the body is yellowish. Larvae are usually covered with a secretion of mucus and fecal material, giving them a shiny black, wet appearance (Fig. 3).  When the larva completes its growth, it drops to the ground and pupates in the soil. 


Figure 3.  Larval stage of Oulema melanopus with characteristic feeding 
damage visible on leaf (Photo: M. Dolinski).

Pupa: Pupal colour varies from a bright yellow when it is first formed, to the colour of the adult just before emergence. The pupal stage lasts 2 – 3 weeks. Adult beetles emerge and feed for a couple of weeks before seeking overwintering sites. There is one generation per year.


Fact sheets for CLB are published by the province of Alberta and available from the Prairie Pest Monitoring Network. Also access the Oulema melanopus page from the new “Field crop and forage pests and their natural enemies in western Canada – Identification and management field guide”.

Cereal leaf beetle

Cereal leaf beetle (Oulema melanopus) – Model output indicates that CLB oviposition has begun in many locations, and that larvae may begin to appear in the next 7-10 days.  As of May 13th, CLB model runs indicated that oviposition was similar Lethbridge, Swift Current, Saskatoon and Brandon (Fig. 1). 

Figure 1.  Predicted cereal leaf beetle (O. melanupus) oviposition at four prairie locations. Values represent
predicted values based on 2018 weather and for model predictions based on long term average
weather (model simulations for April 1-May 13, 2018).

Lifecycle and Damage:

Adult: Adult cereal leaf beetles (CLB) have shiny bluish-black wing-covers (Fig. 2). The thorax and legs are light orange-brown. Females (4.9 to 5.5 mm) are slightly larger than the males (4.4 to 5 mm). Adult beetles overwinter in and along the margins of grain fields in protected places such as in straw stubble, under crop and leaf litter, and in the crevices of tree bark. They favour sites adjacent to shelter belts, deciduous and conifer forests. They emerge in the spring once temperature reaches 10-15 ºC and are active for about 6 weeks. They usually begin feeding on grasses, then move into winter cereals and later into spring cereals.  

Figure 2. Adult Oulema melanopus measure 4.4-5.5 mm long (Photo: M. Dolinski).


Egg: Eggs are laid approximately 14 days following the emergence of the adults. Eggs are laid singly or in pairs along the mid vein on the upper side of the leaf and are cylindrical, measuring 0.9 mm by 0.4 mm, and yellowish in colour. Eggs darken to black just before hatching.  


Larva: The larvae hatch in about 5 days and feed for about 3 weeks, passing through 4 growth stages (instars). The head and legs are brownish-black; the body is yellowish. Larvae are usually covered with a secretion of mucus and fecal material, giving them a shiny black, wet appearance (Fig. 3).  When the larva completes its growth, it drops to the ground and pupates in the soil. 


Figure 3.  Larval stage of Oulema melanopus with characteristic feeding 
damage visible on leaf (Photo: M. Dolinski).

Pupa: Pupal colour varies from a bright yellow when it is first formed, to the colour of the adult just before emergence. The pupal stage lasts 2 – 3 weeks. Adult beetles emerge and feed for a couple of weeks before seeking overwintering sites. There is one generation per year.


Fact sheets for CLB are published by the province of Alberta and available from the Prairie Pest Monitoring Network. Also access the Oulema melanopus page from the new “Field crop and forage pests and their natural enemies in western Canada – Identification and management field guide”.

Cereal leaf beetle

Cereal leaf beetle (Oulema melanopus) – Model output indicates that CLB oviposition has begun in many locations.  As of May 6th, CLB model runs indicated that cool temperatures have delayed oviposition (compared to long term average) in Lethbridge, but more advanced in Swift Current, Brandon and Saskatoon (Fig. 1). 
 
Figure 1.  Predicted CLB oviposition at four prairie locations. Values are based on 
model simulations, for April 1 – May 6, 2018.
Lifecycle and Damage:

Adult: Adult cereal leaf beetles (CLB) have shiny bluish-black wing-covers (Fig. 1). The thorax and legs are light orange-brown. Females (4.9 to 5.5 mm) are slightly larger than the males (4.4 to 5 mm). Adult beetles overwinter in and along the margins of grain fields in protected places such as in straw stubble, under crop and leaf litter, and in the crevices of tree bark. They favour sites adjacent to shelter belts, deciduous and conifer forests. They emerge in the spring once temperature reaches 10-15 ºC and are active for about 6 weeks. They usually begin feeding on grasses, then move into winter cereals and later into spring cereals.  

Figure 1. Adult Oulema melanopus measure 4.4-5.5 mm long (Photo: M. Dolinski).


Egg: Eggs are laid approximately 14 days following the emergence of the adults. Eggs are laid singly or in pairs along the mid vein on the upper side of the leaf and are cylindrical, measuring 0.9 mm by 0.4 mm, and yellowish in colour. Eggs darken to black just before hatching.  


Larva: The larvae hatch in about 5 days and feed for about 3 weeks, passing through 4 growth stages (instars). The head and legs are brownish-black; the body is yellowish. Larvae are usually covered with a secretion of mucus and fecal material, giving them a shiny black, wet appearance (Fig. 2).  When the larva completes its growth, it drops to the ground and pupates in the soil. 



Figure 2.  Larval stage of Oulema melanopus with characteristic feeding 
damage visible on leaf (Photo: M. Dolinski).

Pupa: Pupal colour varies from a bright yellow when it is first formed, to the colour of the adult just before emergence. The pupal stage lasts 2 – 3 weeks. Adult beetles emerge and feed for a couple of weeks before seeking overwintering sites. There is one generation per year.

 

Fact sheets for CLB are published by the province of Alberta and available from the Prairie Pest Monitoring Network. Also access the Oulema melanopus page from the new “Field crop and forage pests and their natural enemies in western Canada – Identification and management field guide”.

Are cereal aphids damaging your crops? There’s now an app for that: Cereal Aphid Manager (CAM)

Aphids can cause significant damage to fields and increase crop losses, but just because aphids are present in a grain field doesn’t mean they will have a negative economic impact on production. This is especially true if there are aphid’s natural enemies (beneficial insects) in the field to keep them under control.
The Cereal Aphid Manager is an easy-to-use mobile app that helps farmers and crop advisors control aphid populations in wheat, barley, oat or rye. It is based on Dr. Tyler Wist’s (Agriculture and Agri-Food Canada Field Crop Entomologist) innovative Dynamic Action Threshold model. The model treats the grain field as an ecosystem and takes into account many complex biological interactions including:
  • the number of aphids observed and how quickly they reproduce
  • the number of different natural enemies of aphids in the field and how many aphids they eat or parasitize per day
  • the lifecycles of aphids and their enemies taking into account developmental stages, egg laying behaviour, population growth rate, lifespan, etc.
By taking into consideration factors like these, the app predicts what the aphid population will be in seven days and the best time to apply insecticide based on economic thresholds.
Available in iOS and Android.
To learn more and to download, go to AAFC’s CAM webpage.
Note: Cereal aphids can blow up from the South at any time which cannot be predicted by the app. Therefore, farmers and crop advisors should regularly check fields during the growing season regardless of what Cereal Aphid Manager Mobile may recommend.



CAM Homepage

CAM monitoring report and recommendation

CAM icon

Insect of the Week – Brown marmorated stink bug

This week’s Insect of the Week is the brown marmorated stink bug (Halyomorpha halys). Stink bugs get their name from the foul odour they release when threatened. Nymphs and adults prefer field corn and soybean, but infestations have been reported on rape, pea, sunflower and cereals in the USA. They have also been known to attack tree fruits, berries, vegetables and many ornamental trees and shrubs. They are not known to be established in the Prairies, but have been found in the BC Southern Interior, Ontario and Quebec. Feeding causes damage to seeds and seed pods, reducing yield.

Brown marmorated stink bug – adult (CC-BY 2.0 Katja Schulz)

Additional information and fact sheets for this insect have been posted by Ontario Ministry of Agriculture, Food, and Rural Development, and BC Ministry of Agriculture and Seafood.

Remember the NEW Cutworm Field Guide is free and downloadable in 2017!

BONUS Insect of the Week – Wheat stem maggot

The Wheat Stem Maggot, Meromyza americana (Diptera) is minor pest that causes eye-catching damage in wheat, rye, barley, oat, millet, timothy, brome, crested wheatgrass and bluegrass. This is a timely insect of the week, because the larval damage (dead white heads in an otherwise green field) started to appear in the last few weeks and is now highly visible in many fields.

Your eyes are naturally drawn to these white heads and can cause you to overestimate the actual amount of damage to your fields. However, the damage is usually limited to 1-5% of the crop. To identify if the wheat stem maggot is the culprit, gently pull on the white head to see if it easily separates from the flag leaf sheath and shows evidence of feeding damage at the base of the culm.

By the time you see damage, the greenish-white larva has exited and is off to begin a second generation that will overwinter in volunteer cereals. There are no registered chemicals or resistant varieties so your best management practices are rotate to non-cereals/non-grassses, destroy infested stubble, and control volunteer hosts and grassy weeds. Delayed seeding, where/when possible may also limit damage.

For more information on the Wheat Stem Maggot, see our Insect of the Week page.

Wheat stem maggot damage (Tyler Wist – AAFC)


Remember the NEW Cutworm Field Guide is free and downloadable in 2017!

Insect of the Week – Cereal leaf beetle

This week’s Insect of the Week is the cereal leaf beetle. Wheat is their preferred host, but they also feed on oats, barley, corn, rye, triticale, reed canarygrass, ryegrass, fescue, wild oats, millet and other grasses. Adults and larvae feed on the leaf tissue of host plants. Yield quality and quantity is decreased if the flag leaf is stripped. It is also interesting to note that larvae carry all of their own fecal waste with them as protection from predators.


For more information on the cereal leaf beetle, see our Insect of the Week page.



Cereal leaf beetle larva (cc-by 2.0 Christophe Quintin)




Cereal leaf beetle damage (cc-by-nc-sa 2.0 CIMMYT)



Remember the NEW Cutworm Field Guide is free and downloadable in 2017!

Insect of the Week – Cereal aphids

This week’s Insect of the Week is the group of aphids known
as cereal aphids. These aphids include the corn leaf aphid, the English grain
aphid, the oat-birdcherry aphid and the Russian wheat aphid. They feed on
cereal crops and are vectors of viruses, causing lower crop quality and yield. There are several natural enemies of cereal aphids, including various species of wasps and beetles. 

For more information on cereal aphids, see our Insect of the Week page. 

English grain aphid – adult, nymph (Tyler Wist, AAFC)



Remember the NEW Cutworm Field Guide is free and downloadable in 2017!

Weekly Update – Cereal leaf beetle

Cereal leaf beetle (Oulema melanopus) – As of June 5, 2017, model output indicates that oviposition should be nearly complete and larval populations should peak across the southern prairies

Lifecycle and Damage:
Adult: Adult cereal leaf beetles (CLB) have shiny bluish-black wing-covers (Fig. 2). The thorax and legs are light orange-brown. Females (4.9 to 5.5 mm) are slightly larger than the males (4.4 to 5 mm). Adult beetles overwinter in and along the margins of grain fields in protected places such as in straw stubble, under crop and leaf litter, and in the crevices of tree bark. They favour sites adjacent to shelter belts, deciduous and conifer forests. They emerge in the spring once temperature reaches 10-15 ºC and are active for about 6 weeks. They usually begin feeding on grasses, then move into winter cereals and later into spring cereals.  

Figure 2. Adult Oulema melanopus (~4.4-5.5 mm long).


Egg: Eggs are laid approximately 14 days following the emergence of the adults. Eggs are laid singly or in pairs along the mid vein on the upper side of the leaf and are cylindrical, measuring 0.9 mm by 0.4 mm, and yellowish in colour. Eggs darken to black just before hatching.  

Larva: The larvae hatch in about 5 days and feed for about 3 weeks, passing through 4 growth stages (instars). The head and legs are brownish-black; the body is yellowish. Larvae are usually covered with a secretion of mucus and fecal material, giving them a shiny black, wet appearance (Fig. 3).  When the larva completes its growth, it drops to the ground and pupates in the soil. 

Figure 3.  Larval stage of Oulema melanopus with characteristic feeding damage visible on leaf.


Pupa: Pupal colour varies from a bright yellow when it is first formed, to the colour of the adult just before emergence. The pupal stage lasts 2 – 3 weeks. Adult beetles emerge and feed for a couple of weeks before seeking overwintering sites. There is one generation per year.

Fact sheets for CLB are published by the province of Alberta and available from the Prairie Pest Monitoring Network. Also access the Oulema melanopus page from the new “Field crop and forage pests and their natural enemies in western Canada – Identification and management field guide”.

Weekly Update – Cereal leaf beetle

Cereal leaf beetle (Oulema melanopus) – As of May 29, 2017, the CLB model indicates that larvae should be present across the southern prairies (Fig. 1). Compared to Lethbridge AB, populations near Brandon MB are predicted to be delayed by approximately five days. At Lethbridge, the hatch should be almost complete, while hatch should be approximately 50% complete near Brandon.

Figure 1. Predicted percent of Cereal leaf beetle (Oulema melanopus) in larval stage
across the Canadian prairies as of May 29, 2017.

Lifecycle and Damage:
Adult: Adult cereal leaf beetles (CLB) have shiny bluish-black wing-covers (Fig. 2). The thorax and legs are light orange-brown. Females (4.9 to 5.5 mm) are slightly larger than the males (4.4 to 5 mm). Adult beetles overwinter in and along the margins of grain fields in protected places such as in straw stubble, under crop and leaf litter, and in the crevices of tree bark. They favour sites adjacent to shelter belts, deciduous and conifer forests. They emerge in the spring once temperature reaches 10-15 ºC and are active for about 6 weeks. They usually begin feeding on grasses, then move into winter cereals and later into spring cereals.  

Figure 2. Adult Oulema melanopus (~4.4-5.5 mm long).


Egg: Eggs are laid approximately 14 days following the emergence of the adults. Eggs are laid singly or in pairs along the mid vein on the upper side of the leaf and are cylindrical, measuring 0.9 mm by 0.4 mm, and yellowish in colour. Eggs darken to black just before hatching.  

Larva: The larvae hatch in about 5 days and feed for about 3 weeks, passing through 4 growth stages (instars). The head and legs are brownish-black; the body is yellowish. Larvae are usually covered with a secretion of mucus and fecal material, giving them a shiny black, wet appearance (Fig. 3).  When the larva completes its growth, it drops to the ground and pupates in the soil. 

Figure 3.  Larval stage of Oulema melanopus with characteristic feeding damage visible on leaf.


Pupa: Pupal colour varies from a bright yellow when it is first formed, to the colour of the adult just before emergence. The pupal stage lasts 2 – 3 weeks. Adult beetles emerge and feed for a couple of weeks before seeking overwintering sites. There is one generation per year.

Fact sheets for CLB are published by the province of Alberta and available from the Prairie Pest Monitoring Network. Also access the Oulema melanopus page from the new “Field crop and forage pests and their natural enemies in western Canada – Identification and management field guide”.

Weekly Update – Cereal leaf beetle

Cereal leaf beetle (Oulema melanopus) – As of May 22, 2017, the CLB model indicates that oviposition is well underway across the southern prairies. Compared to southern Alberta and Saskatchewan, populations in southern Manitoba are predicted to be delayed by approximately five days (Fig. 1). Compared to 2016, development in 2017 is approximately 1 week later. Hatch is predicted to occur in isolated areas. 

Lifecycle and Damage:
Adult: Adult cereal leaf beetles (CLB) have shiny bluish-black wing-covers (Fig. 2). The thorax and legs are light orange-brown. Females (4.9 to 5.5 mm) are slightly larger than the males (4.4 to 5 mm). Adult beetles overwinter in and along the margins of grain fields in protected places such as in straw stubble, under crop and leaf litter, and in the crevices of tree bark. They favour sites adjacent to shelter belts, deciduous and conifer forests. They emerge in the spring once temperature reaches 10-15 ºC and are active for about 6 weeks. They usually begin feeding on grasses, then move into winter cereals and later into spring cereals.  

Figure 2. Adult Oulema melanopus (~4.4-5.5 mm long).


Egg: Eggs are laid approximately 14 days following the emergence of the adults. Eggs are laid singly or in pairs along the mid vein on the upper side of the leaf and are cylindrical, measuring 0.9 mm by 0.4 mm, and yellowish in colour. Eggs darken to black just before hatching.  

Larva: The larvae hatch in about 5 days and feed for about 3 weeks, passing through 4 growth stages (instars). The head and legs are brownish-black; the body is yellowish. Larvae are usually covered with a secretion of mucus and fecal material, giving them a shiny black, wet appearance (Fig. 3).  When the larva completes its growth, it drops to the ground and pupates in the soil. 

Figure 3.  Larval stage of Oulema melanopus with characteristic feeding damage visible on leaf.


Pupa: Pupal colour varies from a bright yellow when it is first formed, to the colour of the adult just before emergence. The pupal stage lasts 2 – 3 weeks. Adult beetles emerge and feed for a couple of weeks before seeking overwintering sites. There is one generation per year.

Fact sheets for CLB are published by the province of Alberta and available from the Prairie Pest Monitoring Network. Also access the Oulema melanopus page from the new “Field crop and forage pests and their natural enemies in western Canada – Identification and management field guide”.

Weekly Update – Cereal leaf beetle

Cereal leaf beetle (Oulema melanopus) – As of May 15, 2017, the CLB model predicts that oviposition should be underway in the Lethbridge, Swift Current and Brandon areas. Compared to southern Alberta and Saskatchewan, populations in southern Manitoba are predicted to be delayed by approximately a week.

Lifecycle and Damage:
Adult: Adult cereal leaf beetles (CLB) have shiny bluish-black wing-covers (Fig. 1). The thorax and legs are light orange-brown. Females (4.9 to 5.5 mm) are slightly larger than the males (4.4 to 5 mm). Adult beetles overwinter in and along the margins of grain fields in protected places such as in straw stubble, under crop and leaf litter, and in the crevices of tree bark. They favour sites adjacent to shelter belts, deciduous and conifer forests. They emerge in the spring once temperature reaches 10-15 ºC and are active for about 6 weeks. They usually begin feeding on grasses, then move into winter cereals and later into spring cereals.  

Figure 1. Adult Oulema melanopus (~4.4-5.5 mm long).


Egg: Eggs are laid approximately 14 days following the emergence of the adults. Eggs are laid singly or in pairs along the mid vein on the upper side of the leaf and are cylindrical, measuring 0.9 mm by 0.4 mm, and yellowish in colour. Eggs darken to black just before hatching.  

Larva: The larvae hatch in about 5 days and feed for about 3 weeks, passing through 4 growth stages (instars). The head and legs are brownish-black; the body is yellowish. Larvae are usually covered with a secretion of mucus and fecal material, giving them a shiny black, wet appearance (Fig. 2).  When the larva completes its growth, it drops to the ground and pupates in the soil. 

Figure 2.  Larval stage of Oulema melanopus with characteristic feeding damage visible on leaf.



Pupa: Pupal colour varies from a bright yellow when it is first formed, to the colour of the adult just before emergence. The pupal stage lasts 2 – 3 weeks. Adult beetles emerge and feed for a couple of weeks before seeking overwintering sites. There is one generation per year.

Fact sheets for CLB are published by the province of Alberta and available from the Prairie Pest Monitoring Network. Also access the Oulema melanopus page from the new “Field crop and forage pests and their natural enemies in western Canada – Identification and management field guide”.

Weekly Update – Cereal leaf beetle

Cereal leaf beetle (Oulema melanopus) – As
of May 8, 2017, CLB model output predicted that oviposition is underway in populations
that may be present in the Lethbridge, Swift Current and Brandon areas. Compared
to 2016, phenological development in 2017 is approximately 1 week later.

Lifecycle and Damage:
Adult: Adult cereal leaf beetles (CLB) have shiny bluish-black wing-covers (Fig. 1). The thorax and legs are light orange-brown. Females (4.9 to 5.5 mm) are slightly larger than the males (4.4 to 5 mm). Adult beetles overwinter in and along the margins of grain fields in protected places such as in straw stubble, under crop and leaf litter, and in the crevices of tree bark. They favour sites adjacent to shelter belts, deciduous and conifer forests. They emerge in the spring once temperature reaches 10-15 ºC and are active for about 6 weeks. They usually begin feeding on grasses, then move into winter cereals and later into spring cereals.  

Figure 1. Adult Oulema melanopus (~4.4-5.5 mm long).


Egg: Eggs are laid approximately 14 days following the emergence of the adults. Eggs are laid singly or in pairs along the mid vein on the upper side of the leaf and are cylindrical, measuring 0.9 mm by 0.4 mm, and yellowish in colour. Eggs darken to black just before hatching.  

Larva: The larvae hatch in about 5 days and feed for about 3 weeks, passing through 4 growth stages (instars). The head and legs are brownish-black; the body is yellowish. Larvae are usually covered with a secretion of mucus and fecal material, giving them a shiny black, wet appearance (Fig. 2).  When the larva completes its growth, it drops to the ground and pupates in the soil. 

Figure 2.  Larval stage of Oulema melanopus with characteristic feeding damage visible on leaf.



Pupa: Pupal colour varies from a bright yellow when it is first formed, to the colour of the adult just before emergence. The pupal stage lasts 2 – 3 weeks. Adult beetles emerge and feed for a couple of weeks before seeking overwintering sites. There is one generation per year.

Fact sheets for CLB are published by the province of Alberta and available from the Prairie Pest Monitoring Network. Also access the Oulema melanopus page from the new “Field crop and forage pests and their natural enemies in western Canada – Identification and management field guide”.

Weekly Update – Cereal leaf beetle

Cereal leaf beetle (Oulema melanopus) – As of May 1, 2017, the CLB model indicates that oviposition has begun in the Lethbridge and Swift Current areas.

Lifecycle and Damage:
Adult: Adult cereal leaf beetles (CLB) have shiny bluish-black wing-covers (Fig. 1). The thorax and legs are light orange-brown. Females (4.9 to 5.5 mm) are slightly larger than the males (4.4 to 5 mm). Adult beetles overwinter in and along the margins of grain fields in protected places such as in straw stubble, under crop and leaf litter, and in the crevices of tree bark. They favour sites adjacent to shelter belts, deciduous and conifer forests. They emerge in the spring once temperature reaches 10-15 ºC and are active for about 6 weeks. They usually begin feeding on grasses, then move into winter cereals and later into spring cereals.  

Figure 1. Adult Oulema melanopus (~4.4-5.5 mm long).


Egg: Eggs are laid approximately 14 days following the emergence of the adults. Eggs are laid singly or in pairs along the mid vein on the upper side of the leaf and are cylindrical, measuring 0.9 mm by 0.4 mm, and yellowish in colour. Eggs darken to black just before hatching.  

Larva: The larvae hatch in about 5 days and feed for about 3 weeks, passing through 4 growth stages (instars). The head and legs are brownish-black; the body is yellowish. Larvae are usually covered with a secretion of mucus and fecal material, giving them a shiny black, wet appearance (Fig. 2).  When the larva completes its growth, it drops to the ground and pupates in the soil. 

Figure 2.  Larval stage of Oulema melanopus with characteristic feeding damage visible on leaf.




Pupa: Pupal colour varies from a bright yellow when it is first formed, to the colour of the adult just before emergence. The pupal stage lasts 2 – 3 weeks. Adult beetles emerge and feed for a couple of weeks before seeking overwintering sites. There is one generation per year.


Fact sheets for CLB are published by the province of Alberta and available from the Prairie Pest Monitoring Network. Also access the Oulema melanopus page from the new “Field crop and forage pests and their natural enemies in western Canada – Identification and management field guide”.

Weekly Update – Cereal leaf beetle

Cereal leaf beetle (Oulema melanopus) – Reminder – Cereal leaf beetle larvae hatch from eggs in about 5 days and feed for about 3 weeks, passing through 4 growth stages (instars). The head and legs are brownish-black; the body is yellowish. Larvae are usually covered with a secretion of mucus and fecal material, giving them a shiny black, wet appearance (Fig. 1).  When the larva completes its growth, it drops to the ground and pupates in the soil.  The pupal stage lasts 2 – 3 weeks. Adult beetles emerge and feed for a couple of weeks before seeking overwintering sites. There is one generation per year.


Figure 1.  Larval stage of Oulema melanopus with characteristic feeding damage visible on leaf.

Monitoring:
Give priority to following factors when selecting monitoring sites:
   □ Choose fields and sections of the fields with past or present damage symptoms.
   □ Choose fields that are well irrigated (leaves are dark green in color), including young, lush crops. Areas of a field that are under stress and not as lush (yellow) are less likely to support CLB. 
   □ Monitor fields located along riparian corridors, roads and railroads. 
   □ Survey field areas that are close to brush cover or weeds, easy to access, or are nearby sheltered areas such as hedge rows, forest edges, fence lines, etc.

Focus your site selection on the following host plant priorities:
   □ First – winter wheat. If no winter wheat is present then;
   □ Second – other cereal crops (barley, wheat, oats, and rye). If no cereal crops are present then;
   □ Third – hay crops. If no hay crops or cereal crops are present then;
   □ Fourth – ditches and water corridors


Sweep-net Sampling for Adults and Larvae:
 ● A sweep is defined as a one pass (from left to right, executing a full 180 degrees) through the upper foliage of the crop using a 37.5 cm diameter sweep-net. 
 ● A sample is defined as 100 sweeps taken at a moderate walking pace collected 4-5 meters inside the border of a field.  
 ● At each site, four samples should be collected, totaling 400 sweeps per site.  The contents of each sample should be visually inspected for life stages of CLB and all suspect specimens should be retained for identification.  
 ● Because the CLB larvae are covered in a sticky secretion, they are often covered in debris and are very difficult to see within a sweep-net sample. 
 ● To help determine the presence of CLB, place the contents of the sweep net into a large plastic bag for observation.


Visual Inspection:
Both the adults and larvae severely damage plants by chewing out long strips of tissue between the veins of leaves (Fig. 1), leaving only a thin membrane. When damage is extensive, leaves turn whitish. 

Fact sheets for CLB are published by the province of Alberta and available from the Prairie Pest Monitoring Network. Also access the Oulema melanopus page from the new “Field crop and forage pests and their natural enemies in western Canada – Identification and management field guide”.

Weekly Update – Cereal leaf beetle

Cereal leaf beetle (Oulema melanopus) – Reminder – Cereal leaf beetle larvae hatch from eggs in about 5 days and feed for about 3 weeks, passing through 4 growth stages (instars). The head and legs are brownish-black; the body is yellowish. Larvae are usually covered with a secretion of mucus and fecal material, giving them a shiny black, wet appearance (Fig. 1).  When the larva completes its growth, it drops to the ground and pupates in the soil.  The pupal stage lasts 2 – 3 weeks. Adult beetles emerge and feed for a couple of weeks before seeking overwintering sites. There is one generation per year.


Figure 1.  Larval stage of Oulema melanopus with characteristic feeding damage visible on leaf.

Monitoring:
Give priority to following factors when selecting monitoring sites:
   □ Choose fields and sections of the fields with past or present damage symptoms.
   □ Choose fields that are well irrigated (leaves are dark green in color), including young, lush crops. Areas of a field that are under stress and not as lush (yellow) are less likely to support CLB. 
   □ Monitor fields located along riparian corridors, roads and railroads. 
   □ Survey field areas that are close to brush cover or weeds, easy to access, or are nearby sheltered areas such as hedge rows, forest edges, fence lines, etc.

Focus your site selection on the following host plant priorities:
   □ First – winter wheat. If no winter wheat is present then;
   □ Second – other cereal crops (barley, wheat, oats, and rye). If no cereal crops are present then;
   □ Third – hay crops. If no hay crops or cereal crops are present then;
   □ Fourth – ditches and water corridors


Sweep-net Sampling for Adults and Larvae:
 ● A sweep is defined as a one pass (from left to right, executing a full 180 degrees) through the upper foliage of the crop using a 37.5 cm diameter sweep-net. 
 ● A sample is defined as 100 sweeps taken at a moderate walking pace collected 4-5 meters inside the border of a field.  
 ● At each site, four samples should be collected, totaling 400 sweeps per site.  The contents of each sample should be visually inspected for life stages of CLB and all suspect specimens should be retained for identification.  
 ● Because the CLB larvae are covered in a sticky secretion, they are often covered in debris and are very difficult to see within a sweep-net sample. 
 ● To help determine the presence of CLB, place the contents of the sweep net into a large plastic bag for observation.


Visual Inspection:
Both the adults and larvae severely damage plants by chewing out long strips of tissue between the veins of leaves (Fig. 1), leaving only a thin membrane. When damage is extensive, leaves turn whitish. 

Fact sheets for CLB are published by the province of Alberta and available from the Prairie Pest Monitoring Network. Also access the Oulema melanopus page from the new “Field crop and forage pests and their natural enemies in western Canada – Identification and management field guide”.

Weekly Update – Cereal leaf beetle

Cereal leaf beetle (Oulema melanopus) – Reminder – Please refer to earlier posts for information
related to the biology, damage and monitoring of the Cereal leaf beetle.



Cereal leaf beetle larvae hatch from eggs in about 5 days and feed for about 3 weeks, passing through 4 growth stages (instars). The head and legs are brownish-black; the body is yellowish. Larvae are usually covered with a secretion of mucus and fecal material, giving them a shiny black, wet appearance (Fig. 1).  When the larva completes its growth, it drops to the ground and pupates in the soil.  The pupal stage lasts 2 – 3 weeks. Adult beetles emerge and feed for a couple of weeks before seeking overwintering sites. There is one generation per year.

Figure 1.  Larval stage of Oulema melanopus with characteristic feeding damage visible on leaf.


Monitoring:
Give priority to following factors when selecting monitoring sites:
   □ Choose fields and sections of the fields with past or present damage symptoms.
   □ Choose fields that are well irrigated (leaves are dark green in color), including young, lush crops. Areas of a field that are under stress and not as lush (yellow) are less likely to support CLB. 
   □ Monitor fields located along riparian corridors, roads and railroads. 
   □ Survey field areas that are close to brush cover or weeds, easy to access, or are nearby sheltered areas such as hedge rows, forest edges, fence lines, etc.

Focus your site selection on the following host plant priorities:
   □ First – winter wheat. If no winter wheat is present then;
   □ Second – other cereal crops (barley, wheat, oats, and rye). If no cereal crops are present then;
   □ Third – hay crops. If no hay crops or cereal crops are present then;
   □ Fourth – ditches and water corridors
Sweep-net Sampling for Adults and Larvae:
 ● A sweep is defined as a one pass (from left to right, executing a full 180 degrees) through the upper foliage of the crop using a 37.5 cm diameter sweep-net. 
 ● A sample is defined as 100 sweeps taken at a moderate walking pace collected 4-5 meters inside the border of a field.  
 ● At each site, four samples should be collected, totaling 400 sweeps per site.  The contents of each sample should be visually inspected for life stages of CLB and all suspect specimens should be retained for identification.  
 ● Because the CLB larvae are covered in a sticky secretion, they are often covered in debris and are very difficult to see within a sweep-net sample. 
 ● To help determine the presence of CLB, place the contents of the sweep net into a large plastic bag for observation.

Visual Inspection:
Both the adults and larvae severely damage plants by chewing out long strips of tissue between the veins of leaves (Fig. 1), leaving only a thin membrane. When damage is extensive, leaves turn whitish. 

Fact sheets for CLB are published by the province of Alberta and available from the Prairie Pest Monitoring Network. Also access the Oulema melanopus page from the new “Field crop and forage pests and their natural enemies in western Canada – Identification and management field guide”.

Weekly Update – Cereal leaf beetle

Cereal leaf beetle (Oulema melanopus) – Reminder – Back in May, the cereal leaf beetle (CLB) bioclimatic model was utilized to help predict when eggs and larvae might appear in fields along with its parasitoid, Tetrastichus julis

Recall the following (posted May 25, 2016) – Predicted dates of peak emergence of CLB eggs and larvae:




Cereal leaf beetle larvae hatch from eggs in about 5 days and feed for about 3 weeks, passing through 4 growth stages (instars). The head and legs are brownish-black; the body is yellowish. Larvae are usually covered with a secretion of mucus and fecal material, giving them a shiny black, wet appearance (Fig. 1).  When the larva completes its growth, it drops to the ground and pupates in the soil.  The pupal stage lasts 2 – 3 weeks. Adult beetles emerge and feed for a couple of weeks before seeking overwintering sites. There is one generation per year.

Figure 1.  Larval stage of Oulema melanopus with characteristic feeding damage visible on leaf.

Monitoring:
Give priority to following factors when selecting monitoring sites:
   □ Choose fields and sections of the fields with past or present damage symptoms.
   □ Choose fields that are well irrigated (leaves are dark green in color), including young, lush crops. Areas of a field that are under stress and not as lush (yellow) are less likely to support CLB. 
   □ Monitor fields located along riparian corridors, roads and railroads. 
   □ Survey field areas that are close to brush cover or weeds, easy to access, or are nearby sheltered areas such as hedge rows, forest edges, fence lines, etc.

Focus your site selection on the following host plant priorities:
   □ First – winter wheat. If no winter wheat is present then;
   □ Second – other cereal crops (barley, wheat, oats, and rye). If no cereal crops are present then;
   □ Third – hay crops. If no hay crops or cereal crops are present then;
   □ Fourth – ditches and water corridors


Sweep-net Sampling for Adults and Larvae:
 ● A sweep is defined as a one pass (from left to right, executing a full 180 degrees) through the upper foliage of the crop using a 37.5 cm diameter sweep-net. 
 ● A sample is defined as 100 sweeps taken at a moderate walking pace collected 4-5 meters inside the border of a field.  
 ● At each site, four samples should be collected, totaling 400 sweeps per site.  The contents of each sample should be visually inspected for life stages of CLB and all suspect specimens should be retained for identification.  
 ● Because the CLB larvae are covered in a sticky secretion, they are often covered in debris and are very difficult to see within a sweep-net sample. 
 ● To help determine the presence of CLB, place the contents of the sweep net into a large plastic bag for observation.



Visual Inspection:
Both the adults and larvae severely damage plants by chewing out long strips of tissue between the veins of leaves (Fig. 1), leaving only a thin membrane. When damage is extensive, leaves turn whitish. 

Fact sheets for CLB are published by the province of Alberta and available from the Prairie Pest Monitoring Network. Also access the Oulema melanopus page from the new “Field crop and forage pests and their natural enemies in western Canada – Identification and management field guide”.

Weekly Update – Cereal leaf beetle

Cereal leaf beetle (Oulema melanopus) – Back in May, the cereal leaf beetle (CLB) bioclimatic model was utilized to help predict when eggs and larvae might appear in fields along with its parasitoid, Tetrastichus julis

Recall the following (posted May 25, 2016) – Predicted dates of peak emergence of CLB eggs and larvae:





Lifecycle and Damage:
Adult: Adult cereal leaf beetles (CLB) have shiny bluish-black wing-covers (Fig. 1). The thorax and legs are light orange-brown. Females (4.9 to 5.5 mm) are slightly larger than the males (4.4 to 5 mm). Adult beetles overwinter in and along the margins of grain fields in protected places such as in straw stubble, under crop and leaf litter, and in the crevices of tree bark. They favour sites adjacent to shelter belts, deciduous and conifer forests. They emerge in the spring once temperature reaches 10-15 ºC and are active for about 6 weeks. They usually begin feeding on grasses, then move into winter cereals and later into spring cereals.  

Figure 1. Adult Oulema melanopus (~4.4-5.5 mm long).



Egg: Eggs are laid approximately 14 days following the emergence of the adults. Eggs are laid singly or in pairs along the mid vein on the upper side of the leaf and are cylindrical, measuring 0.9 mm by 0.4 mm, and yellowish in colour. Eggs darken to black just before hatching.  


Larva: The larvae hatch in about 5 days and feed for about 3 weeks, passing through 4 growth stages (instars). The head and legs are brownish-black; the body is yellowish. Larvae are usually covered with a secretion of mucus and fecal material, giving them a shiny black, wet appearance (Fig. 2).  When the larva completes its growth, it drops to the ground and pupates in the soil. 

Figure 2.  Larval stage of Oulema melanopus with characteristic feeding damage visible on leaf.






Pupa: Pupal colour varies from a bright yellow when it is first formed, to the colour of the adult just before emergence. The pupal stage lasts 2 – 3 weeks. Adult beetles emerge and feed for a couple of weeks before seeking overwintering sites. There is one generation per year.



Monitoring:
Give priority to following factors when selecting monitoring sites:
   □ Choose fields and sections of the fields with past or present damage symptoms.
   □ Choose fields that are well irrigated (leaves are dark green in color), including young, lush crops. Areas of a field that are under stress and not as lush (yellow) are less likely to support CLB. 
   □ Monitor fields located along riparian corridors, roads and railroads. 
   □ Survey field areas that are close to brush cover or weeds, easy to access, or are nearby sheltered areas such as hedge rows, forest edges, fence lines, etc.

Focus your site selection on the following host plant priorities:
   □ First – winter wheat. If no winter wheat is present then;
   □ Second – other cereal crops (barley, wheat, oats, and rye). If no cereal crops are present then;
   □ Third – hay crops. If no hay crops or cereal crops are present then;
   □ Fourth – ditches and water corridors


Sweep-net Sampling for Adults and Larvae:
 ● A sweep is defined as a one pass (from left to right, executing a full 180 degrees) through the upper foliage of the crop using a 37.5 cm diameter sweep-net. 
 ● A sample is defined as 100 sweeps taken at a moderate walking pace collected 4-5 meters inside the border of a field.  
 ● At each site, four samples should be collected, totaling 400 sweeps per site.  The contents of each sample should be visually inspected for life stages of CLB and all suspect specimens should be retained for identification.  
 ● Because the CLB larvae are covered in a sticky secretion, they are often covered in debris and are very difficult to see within a sweep-net sample. 
 ● To help determine the presence of CLB, place the contents of the sweep net into a large plastic bag for observation.

Visual Inspection:
Both the adults and larvae severely damage plants by chewing out long strips of tissue between the veins of leaves (Fig. 2), leaving only a thin membrane. When damage is extensive, leaves turn whitish. 

Fact sheets for CLB are published by the province of Alberta and available from the Prairie Pest Monitoring Network. Also access the Oulema melanopus page from the new “Field crop and forage pests and their natural enemies in western Canada – Identification and management field guide”.

Insect of the Week – Tetrastichus julis

Tetrastichus julis (parasitoid)

Last year, the focus of the Insect of the Week was crop pests. This year, we’re changing things up and highlighting the many natural enemies that help you out, silently and efficiently killing off crop pests. [note: featured Insects of the Week in 2015 are available on the Insect of the Week page] 

This week’s Insect of the Week is Tetrastichus julis (sorry, no common name), an important cereal leaf beetle parasitoid. Where T. julis has become established, it can reduce cereal leaf beetle populations by 40 – 90%, preventing yield loss without using pesticides. See also the factsheet, Biological Control at its Best, Using the T. julis Wasp to Control the Cereal Leaf Beetle (French version).


For information about the cereal leaf beetle (p. 24) and other pests and their natural enemies, see the new Field Crop and Forage Pests and their Natural Enemies in Western Canada – Identification and Management Field Guide for identification, life cycle and conservation options (download links for field guide available on the Insect of the Week page).

T. julis adult parasitizing a cereal leaf beetle larva 
– Swaroop Kher, University of Alberta/AAFC


Weekly Update – Cereal leaf beetle predictions

Cereal leaf beetle (Oulema melanopus) – The following are results from the bioclimate model which predicts cereal leaf beetle (CLB) populations.




As of May 23, 2016, the CLB model indicated that oviposition is well underway: 

  • In Alberta and western Saskatchewan, development was similar to the previous week.
  • Warmer conditions in eastern Saskatchewan and Manitoba resulted in faster development. 
  • Larval populations are predicted to peak in mid-June across most locations in the southern prairies.

Predicted dates of peak emergence of CLB eggs and larvae:



The following model outputs have been updated this week and reflect the predicted stages of CLB present in fields in relation to its parasitoid, Tetrastichus julis














Fact sheets for CLB are published by the province of Alberta and available from the Prairie Pest Monitoring Network. Also access the Oulema melanopus page from the new “Field crop and forage pests and their natural enemies in western Canada – Identification and management field guide”.