Tag: Cutworm

Cutworms

Cutworm scouting spans April to late June across the Canadian prairies! Scout 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 either very early or late in the day when some cutworm species (or climbing cutworms) move above-ground to feed. Start to dig below the soil surface (1-5 cm deep) near the base of symptomatic plants and also any healthy plants immediately adjacent to missing rows or wilting or clipped plants. Some cutworms feed by remaining just below the soil surface, clipping then pulling the plant below as they munch away! If the plant is well-established (e.g., perennial grass or legume), check within the crown plus in the adjacent soil. The culprits could be cutworms, wireworms, or more!

Important: Several species of cutworms (Lepidoptera: Noctuidae) can be present in fields. They range in colour from shiny opaque, to tan, to brownish-red with chevron patterning. A field guide is available to help growers scout and manage the various species of cutworms that can appear in field crops grown on the Canadian prairies. Cutworm Pest of Crops is available free in either English or French! Download a searchable PDF copy to access helpful diagnostic photos plus a table showing which larvae are active at different points in the growing season!

Other vital resources to scout and manage cutworms include:

● For anyone on the Canadian prairies, Manitoba Agriculture’s Cutworms in Field Crops fact sheet includes action and economic thresholds for cutworms in several crops, important biological information, and great cutworm photos to support in-field scouting.

● For Albertans….. If you find cutworms, please consider using the Alberta Insect Pest Monitoring Network’s “2024 Cutworm Reporting Tool” then view the live 2024 cutworm map updated daily. Review the live map to see where cutworms are appearing then prioritize in-field scouting accordingly.

● Cutworms were featured as 2024’s first Insect of the Week.

Week 1: Cutworms

Insect of the Week 2024

Welcome back to the Prairie Pest Monitoring Network Insect of the Week! In 2024, the Insect of the Week theme is “What is eating my crop?” All of the Insect of the Week posts will focus on the damage that insects pests cause to their host plants. In many cases, insect feeding damage is characteristic of certain pest species and can help to identify the insect pest or narrow down the list of suspects.

Cutworm Damage

Numerous species of cutworms can cause economic damage to crops in western Canada, including pale western cutworm (Agriotis orthogonia) and redbacked cutworm (Euxoa orchrogaster). Because there are so many species of cutworms, cutworms are an important pest complex, with quite diverse life histories, preferred host plants, and damage symptoms.

All cutworm species undergo complete metamorphosis during their lifetime, progressing through four stages: egg, larva, pupa, and adult. The larval stage is responsible for damage to crops and forage plants. Several cutworm species overwinter as larvae in western Canada, including army cutworm (Euxoa auxiliaris), dusky cutworm (Agrotis venerabilis), and glassy cutworm (Apamea devastator). Therefore, there might already be larval feeding activity happening where these species are present.

**A cereal field with patchy crop establishment due to cutworm infestation (picture courtesy of AAFC)**

There are three primary types of feeding behaviour used by larval cutworms:

1) Subterranean larval feeding, where larvae cut the main stem and consume the foliage by pulling it underground. These larvae are almost never seen out of the soil. The glassy cutworm is an example of a subterranean cutworm. Bare patches in crops, as pictured above, can be indicative of larval feeding by subterranean cutworms.

2) Defoliation by above-ground and surface-feeding larvae that feed on foliage at night but spend the day hiding under leaf litter or under the soil. The army cutworm is a typical above-ground feeding cutworm; late-instar larvae will eat entire leaves, while young larvae feed along the leaf margins. Damage typical of the black cutworm (Agrotis ipsilon) includes irregularly shaped holes in the leaves and stem cutting.

3) Defoliation by climbing cutworms, where the main stem is not usually damaged but is used by larvae to reach the leaves. Damage to the foliage is similar to that caused by above-ground or surface-feeding cutworms.

For more information about cutworms and the damage that they do, please check out Cutworm Pests of Crops on the Canadian Prairies, available in English and in French. You can also read about cutworms in Field Crop and Forage Pests and Their Natural Enemies in Western Canada (in English or in French).

CUTWORM KILLERS: ICHNEUMONIDS and TACHINIDS

While you’re out scouting for cutworms, tachinids flies and ichneumonid wasps are scouting for them too! We have two Insects of the Week this week and both are parasitoids of cutworm pests. Parasitoids complete part of their lifecycle inside another organism, in this case cutworms, eventually killing them.

Adult tachinid flies are pale or dark brown in colour with long, bristly hairs covering their bodies. Females typically lay one to several eggs on a host. Upon hatching the larvae burrow into the host, develop inside, and then exit to pupate in the soil. Adult flies feed on flower nectar, honeydew from aphids, scale insects, and mealybugs. The tachinid, Athrycia cinerea (Coq.), is a parasitoid of the Bertha armyworm.

**An adult tachinid fly (*Tachinia algens*) reared from glassy cutworm. Photo credit: Shelby Dufton, AAFC-Beaverlodge Research Farm.**

Ichneumonidae adults vary in size and colouration but all have a narrow waist, a long abdomen, and long antennae. Females have long ovipositors that they use to inject eggs into their hosts, including cutworm larvae. Adults eat nectar and aphid honeydew. Ichneumonid larvae (including Banchus flavescens) are parasitoids of Lepidoptera, Coleoptera, Diptera, Hymenoptera, and some spiders.

**An adult Ichneumonid parasitoid of the genus *Banchus*, reared from a dingy cutworm. Photo credit: Shelby Dufton, AAFC-Beaverlodge Research Farm.**

For more information about these parasitoids, the other pests they control and other important crop and forage insects, see the Field Crop and Forage Pests and their Natural Enemies in Western Canada guide. The guide has helpful information about the life cycle of these and other parasitoids. The guide also has tips for conserving parasitoids and pictures to help with identification.

PALE WESTERN CUTWORM

Growers are out seeding, and the cutworms are ready for it – the time to start scouting for cutworms is now! Scouting occurs by manually examining plant foliage and digging in the soil near damaged or missing plants – focus on transition zones between damaged and healthy plants. Even if you have not started seeding a field yet, 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 Cutworm Pests of Crops on the Canadian Prairies.

There are over 20 cutworm species that can cause economic damage to your crop, each with different feeding behaviour, preferred hosts, and lifecycle. Cutworms will feed on prairie-grown commodities including canola, mustard, wheat, barley, triticale, peas, alfalfa, clover, fescue, and timothy. Species identification is especially important! It helps growers determine how and when to scout, whether the cutworm species is found above-ground (climbing) or below-ground, recognize damage, and choose appropriate control options. The species of cutworm will also determine the time of day for monitoring and applying controls.

Action and economic thresholds exist for many of the cutworm species – please use them. Thresholds help control costs by eliminating unnecessary and non-economic spraying and reduce your impact on non-target insects. These non-target insects include the natural enemies that work in the background to control cutworm populations!

Pale western cutworm, Phil Sloderbeck, Kansas State University, Bugwood.org (cc-by-nc 3.0)

This week’s Insect of the Week is the Pale Western Cutworm. This cutworm feeds below ground, with larvae hatching in late April through early May. Young larvae tunnel through the soil, producing holes on newly emerged shoots and furled leaves. Older larvae will sever plants just below the soil surface and may pull and eat the severed shoots underground. Mature larvae are a pale greenish gray, with a yellow, black striped head.

Weekly Update

Week 4 and scouting continues despite the rain, some frost, and all those other crazy springtime things that affect agriculture! Be sure to catch the Insect of the Week – it’s pea leaf weevil! Click to review scouting information for cutworms, wireworms, pea leaf weevil, ladybird beetles, canola and flax scouting charts, Field Heroes, and the 2021 crop protection guides, plus there’s more updated information coming your way this week!

Stay safe and good scouting to you!

Questions or problems accessing the contents of this Weekly Update? Please contact us so we can connect you to our information. Past “Weekly Updates” can be accessed on our Weekly Update page .

The cutworms are coming …

For many, seed isn’t in the ground yet, but cutworms may be in the soil ready for when it does. 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.

While they may be related and share many similarities, cutworms are not all the same, nor cause the same kind of damage. For example, the armyworm (Mythimna unipuncta) is a climbing cutworm and feeds on leaves. In contrast, young pale western cutworms (Agrotis orthogonia) feed on the surface of newly-emerging shoots and furled leaves of young plants causing small holes and older larvae sever plants just below the soil surface and occasionally pull and eat severed plants underground. In addition, there is likely more than one cutworm species present in your field.

A few of the important cutworms we’ve highlighted in the past include army, darksided, dingy, glassy, pale western and redbacked cutworms. There is a lot more information about cutworm lifecycle, the damage they cause, and management options in the recent Cutworm Pests of Crops on the Canadian Prairies. For even more information on cutworms (and many other pests) including information about their natural enemies, check out Field Crop and Forage Pests and their Natural Enemies in Western Canada.

Pale western cutworm, Frank Peairs (cc-by-nc 3.0)

Cutworms

Manitoba continues to experience cutworm issues this spring! Thanks to John Gavloski (Manitoba Agriculture) who was able to provide a quick summary:

There has been a lot of insecticide applications and some reseeding of crops in Manitoba because of cutworms. Damage is to a variety of crops. Redbacked and dingy cutworms have been the two dominant species, although some other species of cutworms are being found. They are starting to turn to pupae, however stages are quite variable in some fields and scouting and insecticide applications continue.

Please refer back to our earlier Cutworm post (Wk05) for help with scouting and identification tips. Also access the free downloadable Cutworm Field Guide.

Cutworms

Cutworms (Noctuidae) – Still important this week to scout for cutworms!! Access Wk05 for help!

Cutworms

Cutworms (Noctuidae) – A field guide is available to help growers scout and manage Cutworms. Cutworm Pest of Crops is available for free in either English or French and is posted on the Cutworm Field Guide page!

Several species of cutworms can be present in fields (Refer to downloadable PDF below). 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 Manitoba Agriculture cutworm fact sheet which includes action and economic thresholds for cutworms in several crops.

In 2018, the Insect of the Week featured two economically important species of cutworms and some of the important natural enemies that help regulate these pests:

Wk01 (May 07, 2018) – Glassy cutworm
Wk02 (May 14, 2018) – Darksided cutworm
Wk03 (21 May, 2018) – Ground beetles: cutworm natural enemies

Scout 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.

CutwormSeasonalChart_Floate

For Albertans….. If you find cutworms, please consider using the Alberta Pest Surveillance Network’s “2019 Cutworm Reporting Tool” then view the live 2019 cutworm map which is updated daily.

Cutworms

The following is a list of 2018 Posts – click to review:

Abundant parasitoids in canola – Week 10
Alfalfa weevil – Week 6

Cabbage seedpod weevil – Week 12
Cabbage root maggot – Week 11
Cereal aphid manager (CAM) – Week 2
Cereal leaf beetle larvae request – Week 8
Crop protection guides – Week 2
Cutworms – Week 4

Diamondback moth – Week 7
Download the field guide – Week 10

Field heroes – Week 8
Flea beetles – Week 4

Monarch migration – Week 8

PMRA Pesticide Label Mobile App – Week 4

Scouting charts (canola and flax) – Week 3

Ticks and Lyme Disease – Week 4

Weather radar – Week 3
Wheat midge – Week 12

White grubs in fields – Week 8

Wind trajectories – Week 6
Wireworm distribution maps – Week 6

The following is a list of 2018 Posts – click to review:

Abundant parasitoids in canola – Week 10
Alfalfa weevil – Week 6

Cabbage seedpod weevil – Week 8
Cabbage root maggot – Week 11
Cereal aphid manager (CAM) – Week 2
Cereal leaf beetle – Week 5
Cereal leaf beetle larvae request – Week 8
Crop protection guides – Week 2
Crop reports – Week 8
Cutworms – Week 4

Diamondback moth – Week 7
Download the field guide – Week 10

Field heroes – Week 8
Flea beetles – Week 4

Monarch migration – Week 8

Pea leaf weevil – Week 8
PMRA Pesticide Label Mobile App – Week 4

Scouting charts (canola and flax) – Week 3

Ticks and Lyme Disease – Week 4

Weather radar – Week 3
White grubs in fields – Week 8
Wind trajectories – Week 6
Wireworm distribution maps – Week 6

The following is a list of 2018 Posts – click to review:

Abundant parasitoids in canola – Week 10

Alfalfa weevil – Week 6

Cabbage seedpod weevil – Week 8
Cereal aphid manager (CAM) – Week 2
Cereal leaf beetle – Week 5
Cereal leaf beetle larvae request – Week 8
Crop protection guides – Week 2
Crop reports – Week 8
Cutworms – Week 4

Diamondback moth – Week 7
Download the field guide – Week 10

Field heroes – Week 8
Flea beetles – Week 4

Monarch migration – Week 8

Pea leaf weevil – Week 8
PMRA Pesticide Label Mobile App – Week 4

Scouting charts (canola and flax) – Week 3

Ticks and Lyme Disease – Week 4

Weather radar – Week 3
Wind trajectories – Week 6
Wireworm distribution maps – Week 6
White grubs in fields – Week 8

Abundant parastioids in canola!

The cabbage seedpod weevil is a chronic pest of canola in southern Alberta and south western Saskatchewan; it has recently reached Manitoba as well. The pest is managed with insecticides, which are sprayed at early flower. This year, in some canola fields around Lethbridge AB, an abundant parasitoid wasp was noticed at the time when fields may be sprayed. The wasp was identified as Diolcogaster claritibia (Fig. 1; thanks to Vincent Hervet and Jose Fernandez for confirming identification).

The wasp is a parasitoid that attacks diamondback moth larvae and recently abundant in some fields in 2017. In some of the fields sampled, as many parasitoids as cabbage seedpod weevil (i.e., nearly one per sweep) were observed. In the fields sampled (i.e., around 10), cabbage seedpod weevils were below thresholds on average, though some spots may have been close to the threshold of 2-3 weevils per sweep.

The above observation emphasizes the value of beneficial arthropods like Diolcogaster claritibia. It is important to recognize that foliar applications of insecticides kill beneficial insects like this small wasp (about 2 mm) which attacks and helps regulate pest populations of diamondback moth or other Lepidoptera, including cutworms and cabbage worms. Thus, think beneficials before you spray!

Figure 1. *Diolcagaster claritibia* adult measuring ~2mm in length (Photo credit J. Fernandez, AAFC-Ottawa).

Learn more about beneficials by accessing Field Heroes and all the Blog’s Parasitoid posts.

The following is a list of 2018 Posts – click to review:

Alfalfa weevil – Week 6

Diamondback moth – Week 7

Field heroes – Week 8
Flea beetles – Week 4

Monarch migration – Week 8

Pea leaf weevil – Week 8
PMRA Pesticide Label Mobile App – Week 4

Scouting charts (canola and flax) – Week 3

Ticks and Lyme Disease – Week 4

Weather radar – Week 3
West nile virus – Week 8
Wind trajectories – Week 6
Wireworm distribution maps – Week 6
White grubs in fields – Week 8

Cutworms

Cutworms (Noctuidae) – A field guide is available to help growers scout and manage Cutworms! Cutworm Pest of Crops is available for free in either English or French and is posted on the Cutworm Field Guide page! Also be sure to check the Insect of the Week through May – it highlights cutworms.

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 Manitoba Agriculture cutworm fact sheet which includes action and economic thresholds for cutworms in several crops.

Scout 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.

The following page extracted from the new “Cutworm Pests of Crops on the Canadian Prairies” (Floate 2017; Page 5) shows the seasonal occurrence of lifecycle stages for different species of cutworms. To aid scouting, the seasonal chart outlines what time of year larvae of different pest species are present (i.e., when to scout) but it also describes larval feeding habit (i.e., where to look for them relative to the plant host).

For Albertans….. If you find cutworms, please consider using the Alberta Pest Surveillance Network’s “2018 Cutworm Reporting Tool”. Once data entry occurs, growers can view the live 2018 cutworm map which is updated daily (see below for screenshot of map retrieved June 5, 2018).

Cutworms

Cutworms (Noctuidae) – A field guide is now available to help growers scout and manage Cutworms! Cutworm Pest of Crops is available for free in either English or French and is posted on the Cutworm Field Guide page! Also be sure to check the Insect of the Week through May – it highlights cutworms.

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 Manitoba Agriculture cutworm fact sheet which includes action and economic thresholds for cutworms in several crops.

Scout 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.

The following page extracted from the new “Cutworm Pests of Crops on the Canadian Prairies” (Floate 2017; Page 5) shows the seasonal occurrence of lifecycle stages for different species of cutworms. To aid scouting, the seasonal chart outlines what time of year larvae of different pest species are present (i.e., when to scout) but it also describes larval feeding habit (i.e., where to look for them relative to the plant host).

For Albertans….. If you find cutworms, please consider using the Alberta Pest Surveillance Network’s “2018 Cutworm Reporting Tool”. Once data entry occurs, growers can view the live 2018 cutworm map which is updated daily (see below for the map retrieved May 24, 2018).

Insect of the Week – Ground beetles: cutworm natural enemies

This week’s Insect of the Week is a large group of insects called ground beetles, also known as carabid beetles. Many species feed on cutworms as well as other pests.

Almost 400 different species of ground beetles occur on the Prairies, ranging in size from just a few millimetres to more than 2 centimetres. A field may contain 50 or more species, with densities ranging up to 10 beetles per square meter.

Ground beetles are characterized with long threadlike antennae, have a body that is flattened top-to-bottom, and have strong legs designed for running, large eyes, and obvious jaws (mandibles). Smaller ground beetle species can be important predators of cutworm eggs. Larger species attack and kill fully-grown cutworm larvae.

With all the work they do protecting your crop, ground beetles are real @FieldHeroes.

Find out more about ground beetles at the Insect of the Week page!

Adult Carabus nemoralis attacking a bertha armyworm caterpillar.

Photocredit – Vincent Hervet, Agriculture and Agri-Food Canada

Species of ground beetles common in agricultural fields on the Prairies.

From left to right: Bembidion quadrimaculatum, Agonum cupreum,

Pterostichus melanarius, Calosoma calidum.

Photocredit – Henri Goulet (retired), Agriculture and Agri-Food Canada

For a detailed review of ground beetle research, biology, distribution, habitat, diet, etc., see Chapter 1: Ground Beetles (Coleoptera: Carabidae) of the Prairie Grasslands of Canada.

**NEW – Don’t forget there’s a new cutworm identification manual you can download from the Cutworm Field Guide page – NEW**

Cutworms

Cutworms (Noctuidae) – A field guide is now available to help growers scout and manage Cutworms! Cutworm Pest of Crops is available for free in either English or French and is posted on the Cutworm Field Guide page! Also be sure to check the Insect of the Week through May – it highlights cutworms.

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 Manitoba Agriculture cutworm fact sheet which includes action and economic thresholds for cutworms in several crops.

Scout 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 “2018 Cutworm Reporting Tool”. Once data entry occurs, growers can view the live 2018 cutworm map which is updated daily (see below for the map retrieved May 15, 2018).

Insect of the Week – Darksided cutworm

It’s spring, so it’s cutworm season. This week’s insect is the darksided cutworm. Mature larvae are hairless, greyish with a prominent white stripe on either side just above their legs. It is a climbing cutworm with feeding occurring at night. They have a broad host range including cereals, canola, corn, flax, sunflower, vegetables berry and tree fruits.

Find out more about the darksided cutworm at the Insect of the Week page. Other important species include dingy, army, redbacked and pale western cutworms (See Insect of the Week: 2017 – May 1, 8, 15 and 29).

Darksided cutworm
Photocredit John Gavloski, Manitoba Ministry of Agriculture

In addition, Cutworm Pests of Crops on the Canadian Prairies – Identification and Management Field Guide was recently published (2017). This new handy manual has chapters on general biology, history of outbreaks, scouting techniques, natural enemies and general control options. The meat of the manual is descriptions of 24 cutworm species, their lifecycle, hosts, damage, monitoring and economic thresholds. To download a copy, go to the Cutworm Field Guide page.

Cutworms

Cutworms (Noctuidae) – A field guide is now available to help growers scout and manage Cutworms! Cutworm Pest of Crops is available for free in either English or French and is posted on the Cutworm Field Guide page! Also be sure to check the Insect of the Week through May – it highlights cutworms.

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 Manitoba Agriculture cutworm fact sheet which includes action and economic thresholds for cutworms in several crops.

Scout 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 “2018 Cutworm Reporting Tool”. Once data entry occurs, growers can view the live 2018 cutworm map which is updated daily.

Insect of the Week – Glassy cutworm

This week’s insect is the glassy cutworm. The larva is greyish-white, semi-translucent and shiny (i.e. glass-like) with a orange-brown head. Since it overwinters as a larva, it is active as soon as the ground thaws. It feeds underground and rarely come to the surface. Their main host crop are grasses but will also attack wheat and corn. Corn planted following wheat may be particularly at risk.

Find out more about the glassy cutworm at the Insect of the Week page.

Glassy cutworm
cc-by Joseph Berger, bugwood.org

Other important species include dingy, army, redbacked and pale western cutworms (See Insect of the Week: 2017 – May 1, 8, 15 and 29).

In addition, Cutworm Pests of Crops on the Canadian Prairies – Identification and Management Field Guide was just published (2017). This new handy field guide has chapters on general biology, history of outbreaks, scouting techniques, natural enemies and general control options. The guide includes descriptions of 24 cutworm species, their lifecycle, hosts, damage, monitoring and economic thresholds. To download a copy, go to the Cutworm Field Guide page.

Winter Update – True armyworm

Earlier this summer (Week 14), the true armyworm (Lepidoptera: Noctuidae: Mythimna unipuncta) was reported on the lower west coast and a summary was provided by Tracy Hueppelsheuser (BC Ministry of Agriculture).

Tracy kindly provided an update to the situation…. The initial true armyworm damage reported earlier did not relent and a second generation of voracious larvae continued to cause damage in late August through to late September in southwestern British Columbia. In addition to Vancouver Island (hit a second time), true armyworm larvae showed up south of Abbotsford, Sumas, Matsqui, Dereoche, as well as east through Chilliwack (Greendale, Rosedale), and west all the way to Delta and Westham Island. The outbreak resulted in damage to grass fields and even corn was defoliated and cobs damaged!

True armyworm pupae were observed mid-September and moths are expected over the next while in lower BC. A third generation is anticipated but is not expected to cause as much damage owing to the cooler nights (~8°C) which should slow insect development and feeding. Parasitism was noted which is good news in terms of natural enemies responding to the outbreak. Also, lots of bird feeding activity has been observed although the birds’ seeking and feeding activities have also damaged grass fields!

The outbreak of true armyworm in lower BC appears to be part of a larger outbreak that has similarly afflicted western Oregon and Washington this year.

Find more information on true armyworms in the NEW Cutworm Field Guide, free and downloadable in 2017!

Screenshots of true armyworm from the Cutworm Field guide are also shown below:

Weekly Update – Cutworms

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.

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.

For Albertans….. If you find cutworms, please consider using the Alberta Pest Surveillance Network’s “2017 Cutworm Reporting Tool”. The map now has reports of pale western and redbacked cutworms in central and southern Alberta so view the live 2017 cutworm map.

Check the Insect of the Week – the month of May highlighted cutworms! Be sure to read more about Pale western cutworms, Redbacked cutworms, Army cutworms, Dingy cutworms.

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

Insect of the Week – Dingy cutworm

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 dingy cutworm. This is an above ground climbing species. Crops are at greatest risk in the spring when partially mature larvae emerge to feed primarily on leaves. The name ‘dingy cutworm’ is generally applied to three closely related species with similar appearance and life cycles.

For more information about dingy cutworms, go to the Insect of Week page.

Dingy cutworm larva (cc John Gavioski, Manitoba Agriculture)

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

Weekly Update – Cutworms

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 Dingy cutworms.

Dingy cutworm larva (cc John Gavloski, Manitoba Agriculture)

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”. The map now has reports of pale western and redbacked cutworms in central and southern Alberta so view the live 2017 cutworm map.

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

Insect of the Week – Army cutworm

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 army cutworm. This is an above ground species. Young larvae chew holes in leaves and notch leaf margins. Older larvae will consume entire leaves. They get their name from the fact that when food is scarce, larvae move as a large group in the same direction to locate more host plants.

For more information about army cutworms, go to the Insect of Week page.

Army cutworm larva (cc-by 3.0 Whitney Cranshaw, bugwood.org)

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

Weekly Update – Cutworms

Army cutworm larva (cc-by 3.0 Whitney Cranshaw, bugwood.org)

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!

Insect of the Week – Redbacked cutworm

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 – 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!

Insect of the Week – Pale western cutworm

This week’s Insect of the Week is the Pale Western Cutworm. This is a below-ground feeder. Larvae hatch in late April/early May. As they feed on/tunnel through shoots as they pass through the soil, young larvae produce holes on newly-emerged shoots and furled leaves . Older larvae will sever plants just below the soil surface and may pull and eat the severed shoots underground.

For more information about Pale Western Cutworm, go to the Insect of Week page.

Pale western cutwom. cc-by-nc 3.0 Frank Peairs,
Colorado State University, bugwood.org

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

Weekly Update – Cutworms

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 Manitoba Agriculture and Rural Initiatives 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!

NEW Cutworm Identification and Management Field Guide

Cutworms are part of Canadian agriculture on the Prairies. Most of the time they are of little concern but outbreaks do occur from time to time, causing significant economic damage if not controlled. Cutworm outbreaks can range from small patches of clipped or missing plants in individual fields to widespread areas with entire quarter
sections needing re-seeding.

Cutworm management starts with identification – knowing what species is at work in your fields helps unlock information
that improves cutworm scouting and management. Knowledge of cutworm biology, behaviour, preferred habitat, impacts of weather and interaction with its natural enemies will all improve scouting
techniques and pest management decisions for growers.

Just released, the Cutworm Pests of Crop on the Canadian Prairies – Identification and Management Field Guide describes the economically important cutworm pests in detail and provides the information needed to manage them. [Funding for preparation of this publication was provided by the Canola Council of Canada]

For more information and a download link, go to our Cutworm Field Guide.

Weekly Update – Cutworms

Cutworms (Noctuidae) – Please refer to earlier cutworm posts describing scouting tips, monitoring protocols and fact sheets (including cutworm images plus action and economic thresholds).

For Manitobans….The earlier Insect Update included great photos of dingy and redbacked cutworms plus monitoring tips including how to discern these two species from one another. Reports of cutworm continued in the current Insect Update.

For Saskatchewanians…. Cutworms were reported in the recent Saskatchewan Insect Report (Issue 3).

For Albertans….. Additional reports of cutworms have occurred throughout the province the past week! If you find cutworms, please consider using the Alberta Pest Surveillance Network’s “2016 Cutworm Reporting Tool”. Once data entry occurs, your growers can view the live 2016 cutworm map.

A screen shot of the live map has been retrieved (22Jun2016) below for your reference.

Insect of the Week – Cotesia margeniventris

Cotesia margeniventris (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 Cotesia marginiventris (sorry, no common name), a braconidid wasp parasitoid. Female C. marginiventris lay their eggs in the larvae of cabbage looper, black cutworm, corn earworm, variegated cutworm, armyworm and fall armyworm.

For more information about C. marginiventris, the pests it controls and other important crop and forage insects, 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).

Cotesia marginiventris parasitoidizing beet armyworm larva.
Photo cc-by-nc Debbie Waters, University of Georgia, Bugwood.org

Weekly Update – Cutworms

Cutworms (Noctuidae) – Please refer to earlier cutworm posts describing scouting tips, monitoring protocols and fact sheets (including cutworm images plus action and economic thresholds).

For Manitobans….The earlier Insect Update included great photos of dingy and redbacked cutworms plus monitoring tips including how to discern these two species from one another. Reports of cutworm continued in the current Insect Update.

For Saskatchewanians…. Cutworms were again reported in the recent Saskatchewan Insect Report.

For Albertans….. Additional reports of cutworms have occurred throughout the province the past week! If you find cutworms, please consider using the Alberta Pest Surveillance Network’s “2016 Cutworm Reporting Tool”. Once data entry occurs, your growers can view the live 2016 cutworm map.

A screen shot of the live map has been retrieved (15Jun2016) below for your reference.

Weekly Update – Cutworms

Cutworms (Noctuidae) – The past week, cutworms were reported across Manitoba, Saskatchewan and Alberta.

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.

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 Manitoba Agriculture and Rural Initiatives cutworm fact sheet which includes action and economic thresholds for cutworms in several crops.

More information about cutworms 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 an excerpt of ONLY the Cutworm pages from the new “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide”. The guide is available as a free downloadable document as both an English-enhanced or French-enhanced version.

For Manitobans….The earlier Insect Update included great photos of dingy and redbacked cutworms plus monitoring tips including how to discern these two species from one another. Reports of cutworm continued in the most recent Insect Update.

For Saskatchewanians…. Cutworms were reported in the recent Saskatchewan Insect Report.

For Albertans….. Additional reports of cutworms have occurred throughout the province the past week! If you find cutworms, please consider using the Alberta Pest Surveillance Network’s “2016 Cutworm Reporting Tool”. Once data entry occurs, your growers can view the live 2016 cutworm map.

A screen shot of the live map has been retrieved (06Jun2016) below for your reference.

Weekly Update – Cutworms

Cutworms (Noctuidae) – Reminder – 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.

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 Manitoba Agriculture and Rural Initiatives cutworm fact sheet which includes action and economic thresholds for cutworms in several crops.

For Manitobans….Last week’s Insect Update includes great photos of dingy and redbacked cutworms plus monitoring tips which include how to discern these two species from one another.

For Saskatchewanians….Cutworms have been reported in several areas of the Province this spring. Affected crops include pea, lentil, barley and canola. If damage is significant and re-seeding is an option, seed first then spray an insecticide registered for cutworms in the applicable crop. Recommended economic thresholds for cutworms are:
– 25 to 30 per cent stand reduction (canola)
– 3 to 6 cutworms / square metre (wheat, barley, oats)
– 2 to 3 cutworms / sq. metre (pea, lentil)
– 4 to 5 / sq. metre (flax)

For Albertans….. Cutworms have been reported throughout the province the past week! If you find cutworms, please consider using the Alberta Pest Surveillance Network’s “2016 Cutworm Reporting Tool”. Once data entry occurs, your growers can view the live 2016 cutworm map. A screen shot of the live map has been retrieved (01Jun2016) below for your reference and this week it includes additional reporting sites!

Weekly Update – Cutworms

Reminder – Cutworms (Noctuidae) – 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.

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 Manitoba Agriculture and Rural Initiatives cutworm fact sheet which includes action and economic thresholds for cutworms in several crops.

For Manitobans….The most recent Insect Update includes great photos of dingy and redbacked cutworms plus monitoring tips which include how to discern these two species from one another.

For Albertans….. Cutworms have been reported throughout the province the past week! If you find cutworms, please consider using the Alberta Pest Surveillance Network’s “2016 Cutworm Reporting Tool”. Once data entry occurs, your growers can view the live 2016 cutworm map.

A screen shot of the live map has been retrieved (25May2016) below for your reference.

Weekly Update – Cutworms

For ALBERTANS….. If cutworms are spotted in Albertan fields, please consider using the Alberta Pest Surveillance Network’s “2016 Cutworm Reporting Tool”. Once data entry occurs, your growers can view the live 2016 cutworm map.

A screen shot of the live map has been retrieved (18May2016) below for your reference.

Weekly Update – Cutworms

Cutworms (Noctuidae) – 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.

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 Manitoba Agriculture and Rural Initiatives cutworm fact sheet which includes action and economic thresholds for cutworms in several crops.

More information about cutworms 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”. An excerpt of ONLY Cutworm pages 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.

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

2016 Cutworm Monitoring

Today Alberta Agriculture & Forestry posted the link to their online 2016 Cutworm reporting tool which is located at: http://www1.agric.gov.ab.ca/$Department/deptdocs.nsf/all/prm13779

Cutworm reports are mapped in real-time to help keep the agricultural industry informed.