Insect of the Week – Redbacked cutworm

Jennifer Otani
Week 2

For many, seed isn’t even in the ground yet, but the cutworms are ready for it when it is. So the time to start scouting for cutworms is now! Even if it is too wet to seed, consider checking volunteer plants for cutworms or feeding damage. General cutworm monitoring protocols can be found on the Monitoring Protocols page. Species-specific protocols can be found in the new Cutworm Pests of Crops on the Canadian Prairies (see below for download details).

There are over 20 cutworm species that may cause economic damage to your crop, each with different feeding behaviour, preferred hosts and lifecycle. This is why species identification is so important: it helps growers understand what they are up against: determining how and when to scout, knowing whether the cutworm species is found above-ground (climbing) or below-ground, recognizing damage, choosing control options. Species also impacts the most appropriate time of day for monitoring and applying controls.

Action and economic thresholds do exist for many of the cutworm species – please use them. This will help control costs by eliminating unnecessary/un-economic sprays and reduce your impact on non-target insects – insects that include cutworm natural enemies that work in the background to control cutworm populations.

This week’s Insect of the Week is the redbacked cutworm. This is an above ground species. Young larvae feed on newly-emerging shoots and furled leaves, creating small holes. Older larvae cut off leaves and sever plants just below the soil surface. Occasionally, the larvae pull the plants underground to feed on them.

For more information about Redbacked Cutworms, go to the Insect of Week page.

Redbacked cutworms – John Gavloski, Manitoba Agriculture

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

Weekly Update – Weather Synopsis

Ross Weiss, David Giffen, Owen Olfert and prairiepest_admin
Week 2

Weather synopsis – Many locations across southern Saskatchewan and Alberta experienced temperatures above 25°C this week. Average temperatures were warmest across southeastern Saskatchewan from May 1-8, 2017. 

The map below reflects the Accumulated Precipitation for the Growing Season so far for the prairie provinces (i.e., April 1-May 10, 2017):

Whereas the seven-day precipitation accumulations were greatest across Saskatchewan:

The map below shows the Lowest Temperatures the Past 7 Days (May 4-10, 2017) across the prairies:

Whereas the map below shows the Highest Temperatures the Past 7 Days (May 4-10, 2017):

The updated growing degree day map (GDD) (Base 5ºC, March 1 – May 7, 2017) is below:

While the growing degree day map (GDD) (Base 10ºC, March 1 – May 7, 2017) is below:

The maps above are all produced by Agriculture and Agri-Food Canada.  Growers may wish to bookmark the AAFC Drought Watch Maps for the growing season.

2017 Wind Trajectories

Ross Weiss, Serge Trudel, Owen Olfert and prairiepest_admin
Week 2

THE WEEK OF MAY 1, 2017:  Wind trajectory data processing by AAFC-Saskatoon Staff began in April.  Reverse Trajectories track arriving air masses back to their point of origin while Forward Trajectories predict favourable winds expected to arrive across the Canadian Prairies for the week of May 9, 2017:

Reverse trajectories (RT)

Wind trajectories have been monitored since April 1 this year.  This week there was an increase in the number of RT winds that crossed the prairies from the Pacific Northwest (PNW) of USA.  In Alberta, Grande Prairie and Beiseker had a significant increase in the number of RT winds over this past week (Fig. 1 and 2). In addition to the PNW, there were three prairie locations (Selkirk MB, Unity SK and Olds AB) that had winds originating from California and Texas. 

Figure 1. Weekly cumulative counts of Reverse Trajectories (RT) from the Pacific Northwest (PNW) from May 3-9, 2017 (2017 Olfert et al.).

Figure 2. Total number of RT winds from the Pacific Northwest from April 1-May 9, 2017.

Forward trajectories (FT)
Similar to Reverse Trajectories, most of the model output of Forward Trajectories (FT) have originated from the Pacific Northwest (PNW).  However, a few winds have been forecasted to cross the prairies from the southern USA since April 1, 2017 (Fig. 3).

Figure 3. Source destinations and number of FT winds originating from the USA between April 1-May 9, 2017.

Diamondback moth

Jennifer Otani
Week 2

Diamondback moth (Plutellidae: Plutella xylostella) – Pheromone traps attracting male Diamondback moths are being deployed across the prairies.  High altitude air masses are tracked by AAFC-Saskatoon Staff (forward and backward trajectories).  These wind events have the potential to aid the movement of diamondback moth and aster leafhoppers northward on to the Canadian prairies from Mexico, southern and central USA as well as the Pacific Northwest.  Diamondback moth pheromone traps deployed across the prairies confirm their arrival – many thanks to the people who deploy and do the weekly monitoring!

Alberta Agriculture and Forestry has a live 2017 map reporting Diamondback moth pheromone trap interceptions.  Watch for updates from Manitoba and Saskatchewan as growing season progresses.

Biological and monitoring information for DBM is posted by Manitoba Agriculture, Food and Rural DevelopmentSaskatchewan AgricultureAlberta Agriculture and Forestry, and the Prairie Pest Monitoring Network.  

More information about Diamondback moths can be found by accessing the pages from the new “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and Field Guide”.  View ONLY the Diamondback moth page but remember the guide is available as a free downloadable document as both an English-enhanced or French-enhanced version.

Weekly Update – Flea beetles

Jennifer Otani
Week 2

Flea Beetles (Chrysomelidae: Phyllotreta species) – Be on the lookout for flea beetle damage resulting from feeding on canola cotyledons but also on the stem.

Remember, the Action Threshold for flea beetles on canola is 25% of cotyledon leaf area consumed.  Shot-hole feeding is the traditional damage in seedling canola but watch the growing point and stems of seedlings.

Refer to the flea beetle page from the new “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” as an English-enhanced or French-enhanced version.

Weekly Update – Cutworms

Jennifer Otani
Week 2

Cutworms (Noctuidae) – NEW – Just in time for spring scouting!  A new field guide is now available to help growers scout and manage Cutworms!  Cutworm Pest of Crops is now available for free in either English or French and is featured at our new Cutworm Field Guide!  Also be sure to check the Insect of the Week throughout May – it highlights cutworms!  Be sure to read more about Redbacked cutworms.

Figure 1. Redbacked cutworms retrieved from a Manitoban field (Photo: J. Gavloski)

Several species of cutworms  can be present in fields.  They range in colour from shiny opaque, to tan, to brownish-red with chevron patterning.  Cutworm biology, species information, plus monitoring recommendations are available in the Prairie Pest Monitoring Network’s Cutworm Monitoring Protocol.  Also refer to the Manitoba Agriculture cutworm fact sheet which includes action and economic thresholds for cutworms in several crops. 

Keep an eye on fields that are “slow” to emerge, are missing rows, include wilting or yellowing plants, have bare patches, or appear highly attractive to birds – these are areas warranting a closer look.  Plan to follow-up by walking these areas later in the day when some cutworm species move above-ground to feed.  Start to dig below the soil surface (1-5 cm deep) near the base of a symptomatic plant or the adjacent healthy plant.  If the plant is well-established, check within the crown in addition to the adjacent soil.  The culprits could be wireworms or cutworms.  

For Albertans….. If you find cutworms, please consider using the Alberta Pest Surveillance Network’s “2017 Cutworm Reporting Tool”.  Once data entry occurs, growers can view the live 2017 cutworm map which is updated daily.

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

Weekly Update – Cereal leaf beetle

Ross Weiss, Owen Olfert and prairiepest_admin
Week 2

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 – Alfalfa weevil

David Giffen and prairiepest_admin
Week 2

Alfalfa Weevil (Hypera postica) – The larval stage of this weevil feeds on alfalfa leaves in a manner that characterizes the pest as a “skeletonizer”.  The green larva featuring a dorsal, white line down the length of its body has a dark brown head capsule and will grow to 9mm long.  Alfalfa growers are encouraged to check the Alfalfa Weevil Fact Sheet prepared by Dr. Julie Soroka (AAFC-Saskatoon).

Degree-day maps of base 9°C are now being produced by Soroka, Olfert, and Giffen (2016) using the Harcourt/North Dakota models.  The aim or the modelling is to predict the development of Alfalfa weevil (Hypera postica) across the prairies and to help growers time their in-field scouting as second-instar larvae are predicted to occur.  Compare the following predicted development stages and degree-day values copied below (Soroka 2015) to the map below.

This week, alfalfa growers in southern Alberta and southern Saskatchewan (areas of the map highlighted tan) are on the verge of predicted egg hatch of the alfalfa weevil.

Use the figure below as a visual reference to identify alfalfa weevil larvae.  Note the white dorsal line, the tapered shape and the dark head capsule.

Weekly Update – Pea leaf weevil

Ross Weiss, Owen Olfert and Meghan Vankosky
Week 2

Pea Leaf Weevil (Sitona lineatus– This species was one of the “big” insects of 2016’s field crop growing season.  The distribution of pea leaf weevil increased dramatically based on both damage assessments AND collection of adults in 2016 (Fig. 1) compared to previous years (Fig. 2).

Figure 1. Distribution of pea leaf weevil (Sitona lineatus) based on surveying conducted in 2016 (Olfert et al. 2017).

Figure 2.  Distributions of pea leaf weevil based on surveying conducted between 2012-2015 (Olfert et al. 2017).

Pea leaf weevils emerge in the spring primarily by flying (at temperatures above 17ºC) or they may walk short distances. Pea leaf weevil movement into peas and faba beans is achieved primarily through flight.  Adults are slender, greyish-brown measuring approximately 5 mm in length (Fig. 3, Left).  

The pea leaf weevil resembles the sweet clover weevil (Sitona cylindricollis) but the former is distinguished by three light-coloured stripes extending length-wise down thorax and sometimes the abdomen.  All species of Sitona, including the pea leaf weevil, have a short snout.  

Figure 3.  Comparison images and descriptions of four Sitona species adults including pea leaf weevil (Left).

Adults will feed upon the leaf margins and growing points of legume seedlings (alfalfa, clover, dry beans, faba beans, peas) and produce a characteristic, scalloped (notched) edge.  Females lay 1000 to 1500 eggs in the soil either near or on developing pea or faba bean plants from May to June.

Biological and monitoring information related to pea leaf weevil in field crops is posted by the province of Alberta.  Also refer to the pea leaf weevil page within the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” – both English-enhanced or French-enhanced versions are available.  A review of this insect was published in 2011 in Prairie Soils and Crops by Carcamo and Vankosky.

Weekly Update – Predicted Grasshopper Development

Ross Weiss, Owen Olfert, David Giffen and prairiepest_admin
Week 2

Grasshopper Simulation Model Output – The grasshopper simulation model will be used to monitor grasshopper development across the prairies. Weekly temperature data collected across the prairies is incorporated into the simulation model which calculates estimates of grasshopper development stages based on biological parameters for Melanoplus sanguinipes (Migratory grasshopper).  

As of May 8, 2017, predicted mean embryological development was 62% (56% last week); the greatest development was predicted to be across southern Saskatchewan. Embryological development was very similar to long term averages (60%) though well behind 2016 (74%). Hatch was not predicted for any locations. 

Reminder – The Prairie Pest Monitoring Network’s 2017 Grasshopper Forecast Map (Figure 1) was released in January.  While spring temperatures, soil moisture conditions, and precipitation can all have an impact on overwintered grasshopper eggs, growers in areas highlighted orange or red in the map below should be vigilant as nymphs begin to hatch this season.

Figure 1. Prairie Pest Monitoring Network’s 2017 Grasshopper Forecast Map.

Biological and monitoring information related to grasshoppers in field crops is posted by Manitoba Agriculture, Food and Rural DevelopmentSaskatchewan AgricultureAlberta Agriculture and Forestry, the BC Ministry of Agriculture and the Prairie Pest Monitoring Network.  Also refer to the grasshopper pages within the new “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” as an English-enhanced or French-enhanced version.

Weekly Update – Scouting Charts (Canola and Flax)

Jennifer Otani
Week 2

Field scouting is critical – it enables the identification of potential risks to crops.  Field crop production systems across the Canadian prairies will suffer insect pest outbreaks.  However, the identification of these insect pests PLUS the application of established monitoring methods will enable growers to make informed pest management decisions.

For 2017, we offer TWO generalized insect pest scouting charts to aid in-field scouting on the Canadian prairies:



These charts feature hyperlinks directing growers to downloadable PDF pages within the “Field crop and forage pests and their natural enemies in western Canada: Identification and management field guide“.

Growers can access biological information about the pest and its natural enemies, the type of damage it causes, how to monitor, and what pest management strategies might apply to help protect yield and quality (Fig. 1).

Whenever possible, monitor and compare pest densities to established economic or action thresholds to protect and preserve pollinators and beneficial arthropods. Economic thresholds, by definition, help growers avoid crop losses related to outbreaking insect pest species.

Good luck with your scouting!

Figure 1. Example of Bertha armyworm pages from the above field guide:

Provincial Insect Pest Reports

John Gavloski, Scott Meers and Scott Hartley
Week 2

Provincial entomologists provide insect pest updates throughout the growing season so we have attempted to link to their most recent information: 

Manitoba’s Insect and Disease Update for 2017 will be posted soon. Watch for updates prepared by John Gavloski and Pratisara Bajracharya).

Saskatchewan’s Crop Production News for 2017 will be posted soon. Watch for updates prepared by Scott Hartley and Danielle Stephens.  

Watch for Alberta Agriculture and Forestry’s Call of the Land for updates from Scott Meers who recently provided an update (posted on May 11, 2017). Cutworms, flea beetles and alfalfa weevil were noted as being insects to watch at this point in Alberta.

Crop reports

Jennifer Otani
Week 2

Crop reports are produced by:
• Manitoba Agriculture, Rural Development (May 8, 2017)
• Saskatchewan Agriculture Crop Report (May 2-8, 2017)
• Alberta Agriculture and Forestry Crop Report (May 2, 2017)

International reports are produced by:
• The United States Department of Agriculture’s Crop Progress Report (May 8, 2017)
• The European Commission’s Agriculture Balance Sheets and Production Details by Member States (Excel file retrieved May 11, 2017).

Weekly Update – Monarch migration

Jennifer Otani
Week 2

We again track the migration of the Monarch butterflies and they move north by checking the 2017 Monarch Migration Map!  A screen shot of the map has been placed below as an example (retrieved 11May2017) but follow the hyperlink to check the interactive map!  They’re getting closer to Canada!