Aphids in field crops

Aphid populations can quickly increase at this point in the season and particularly when growing conditions are warm and dry. Access the Provincial Insect Pest Report for Wk12 to remain alert to areas and crops suffering from aphid pest pressure.

Figure 1. Pea aphid adults (each 3-4 mm long) and nymph. Photo: M. Dolinski.

Biological and monitoring information (including tips for scouting and economic thresholds) related to aphids in field crops is posted by:
• Manitoba Agriculture (aphids on cereals, aphids on flax, soybean aphid, aphids on peas)
• Saskatchewan Pulse Growers (aphids in pulse crops or access the PDF copy)
• Saskatchewan Flax Development Commission
• Manitoba Pulse and Soybean Growers (soybean aphids: identification, scouting and management or access the PDF copy)
• The Canola Council of Canada’s “Canola Encyclopedia” section on aphids
• or check your provincial commodity group’s insect pest webpages for more detailed information.

Alternatively, several aphid pest species are described in the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide” (2018) and is accessible as a free downloadable PDF in either English or French on our Field Guides page. PDF copies of the individual pages have been linked below to access quickly:
Corn leaf aphid or Rhopalosiphum maidis (Fitch)
English grain aphid or Sitobion (Macrosiphum) avenae (Fabricius)
Oat-birdcherry aphid or Rhopalosiphum padi (Linnaeus)
Pea aphid or Acyrthosiphon pisum (Harris)
Potato aphid or Macrosiphum euphorbiae (Thomas)
Soybean aphid or Aphis glycines (Matsumura)
Turnip aphid or Lipaphis erysimi (Kaltenbach)
Sugar beet root aphid or Pemphigus betae Doane
Russian wheat aphid or Diuraphis noxia (Mordvilko)

Over the years, both the Weekly Updates and Insect of the Week have included aphid-related information but also important natural enemy details to support in-field scouting. Review the list below so pest and beneficial insects can be distinguished readily when scouting fields:
Aphidius wasp (Insect of the Week; 2015 Wk15)
Aphids in canola (Insect of the Week; 2016 Wk13)
Aphids in cereals (Insect of the Week; 2017 Wk09)
Cereal aphid manager APP (Weekly Update; 2021 Wk07) that presently is available only for iOS
Ladybird larva vs. lacewing larva (Insect of the Week; 2019 Wk18)
Ladybird beetles and mummies (Weekly Update; 2020 Wk15)
Lygus bug nymphs vs. aphids (Insect of the Week; 2019 Wk16)
Hoverflies vs. bees vs. yellow jacket wasps (Insect of the Week; 2019 Wk19)
Pea aphids: a persistent problem for legume growers (Insect of the Week; 2021 Wk12)
Soybean aphids and aphid annihilating allies (Insect of the Week; 2022 Wk07)
Syrphid flies (Insect of the Week; 2015 Wk16)

Aphids in field crops

Aphid populations can quickly increase at this point in the season and particularly when growing conditions are warm and dry. Over the years, both the Weekly Updates and Insect of the Week included aphid-related information so here’s a list of these items to access when scouting fields:

Aphidius wasp (Insect of the Week; 2015 Wk15)
Aphids in canola (Insect of the Week; 2016 Wk13)
Aphids in cereals (Insect of the Week; 2017 Wk09)
Cereal aphid manager APP (Weekly Update; 2021 Wk07) that presently is available only for iOS
Ladybird larva vs. lacewing larva (Insect of the Week; 2019 Wk18)
Ladybird beetles and mummies (Weekly Update; 2020 Wk15)
Lygus bug nymphs vs. aphids (Insect of the Week; 2019 Wk16)
Hoverflies vs. bees vs. yellow jacket wasps (Insect of the Week; 2019 Wk19)
Pea aphids: a persistent problem for legume growers (Insect of the Week; 2021 Wk12)
Soybean aphids and aphid annihilating allies (Insect of the Week; 2022 Wk07)
Syrphid flies (Insect of the Week; 2015 Wk16)

Field heroes

The Field Heroes campaign continues to raise awareness of the role of beneficial insects in western Canadian crops.

Field Heroes resources include:

  1. Real Agriculture went live in 2024 with Season 5 of the Pest and Predators podcast series!
    NEW Episode 30Farmer feedback: Insect pest management practices  Haley Catton and Emma Stephens (Agriculture and Agri-Food Canada-Lethbridge) and Shaun Haney (RealAg). Published online May 29, 2024.
    Episode 29The ecology of fear  Maya Evenden (University of Alberta) and Shaun Haney (RealAg). Published online May 14, 2024.
    Episode 28Research roundup: Lesser clover leaf weevil  Jeremy Irvine (University of Saskatchewan) and Shaun Haney (RealAg). Published online May 1, 2024.
    Episode 27Armoured tanks: Beetles in battle  Tyler Wist (Agriculture and Agri-Food Canada-Saskatoon) and Shaun Haney (RealAg). Published online April 17, 2024.
    Episode 26Invasive species awareness: Knowing what to look for and how to report it  Meghan Vankosky (Agriculture and Agri-Food Canada-Saskatoon), James Tansey (Saskatchewan Ministry of Agriculture), John Gavloski (Manitoba Agriculture), and Shaun Haney (RealAg). Published online April 2, 2024.
    Episode 25 20 years of canola surveying and counting!  Jennifer Otani (Agriculture and Agri-Food Canada-Beaverlodge) and Shaun Haney (RealAg). Published online March 19, 2024.
    • Review SEASON 4 of the Pest and Predators podcasts (2023)
    • Review SEASON 3 of the Pest and Predators podcasts (2022)
    • Review SEASON 2 of the Pest and Predators podcasts (2021)
    • Review SEASON 1 of the Pest and Predators podcasts (2020)
  2. The Pests and Predators Field Guide (2021) is filled with helpful images for quick insect identification and plenty of tips to manage the pests AND natural enemies in your fields.
  3. Crop Scouting Guides (2021) specific to cereals, oilseeds, or pulses.
  4. Scouting Guides (2022) for aphids, cutworms, diamondback moth larvae, or bertha armyworms.

Follow @FieldHeroes!

Field heroes

The Field Heroes campaign continues to raise awareness of the role of beneficial insects in western Canadian crops.

Two NEW Field Heroes resources for 2021 include:

  1. Real Agriculture went live in 2021 with Season 2 of the Pest and Predators podcast series!
    NEW – Episode 11 – Free farm labour (June 15, 2021)
    • Episode 10 – Good bugs relocate for work (June 1, 2021)
    • Episode 9 – Secret agents in the stubble (May 18, 2021)
    • Episode 8 – Good vs pea leaf weEVIL (May 4, 2021)
    • Episode 7 – Powerful parasitoids: Better than fiction (April 20, 2021)
    • Recap of SEASON 1: Episode 1 – Do you know your field heroes? Episode 2 – An inside look at the Prairie Pest Monitoring Network. Episode 3 – How much can one wasp save you? Episode 4 – Eat and be eaten — grasshoppers as pests and food Episode 5 – Killer wasp has only one target — wheat stem sawfly Episode 6 – Plentiful parasitoids
  2. The NEW Pests and Predators Field Guide is filled with helpful images for quick insect identification and plenty of tips to manage the pests AND natural enemies in your fields. Claim your free copy at http://fieldheroes.ca/fieldguide/ or download for free to arm your in-field scouting efforts!

Access ALL the Field Heroes links here and be sure to follow @FieldHeroes!

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)

Field heroes

The Field Heroes campaign continues to raise awareness of the role of beneficial insects in western Canadian crops. Check the recently updated Field Heroes website for scouting guides, downloadable posters, and videos. Learn about these important organisms at work in your fields!  

Two important NEW resources for 2021 include:

  1. The NEW Pests and Predators Field Guide is filled with helpful images for quick insect indentification and plenty of tips to manage the pests AND natural enemies in your fields. Claim your free copy at http://fieldheroes.ca/fieldguide/ or download for free to arm your in-field scouting efforts!

2. Real Agriculture went live in 2021 with Season 2 of the Pest and Predators podcast series!

• Access Episode 6 – Powerful parasitoids: Better than fiction (April 20, 2021)

• Access Episode 7 – Good vs pea leaf weEVIL (May 4, 2021)

• Recap of SEASON 1: Episode 1 – Do you know your field heroes? Episode 2 – An inside look at the Prairie Pest Monitoring Network. 3 – How much can one wasp save you? Episode 4 – Eat and be eaten — grasshoppers as pests and food Episode 5 – Killer wasp has only one target — wheat stem sawfly Episode 6Plentiful parasitoids

Access ALL the Field Heroes links here and be sure to follow @FieldHeroes!

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).

Field heroes

The Field Heroes campaign continues to raise awareness of the role of beneficial insects in western Canadian crops. Check the recently updated Field Heroes website for scouting guides, downloadable posters, and videos. Learn about these important organisms at work in your fields!  

Real Agriculture went live in 2020 with a Pest and Predators podcast series!

• Access Episode 1 – Do you know your field heroes? Jennifer Otani (Agriculture and Agri-Food Canada-Beaverlodge) and Shaun Haney (RealAg). Published online May 12, 2020.

• Access Episode 2 – An inside look at the Prairie Pest Monitoring Network. Meghan Vankosky (Agriculture and Agri-Food Canada-Saskatoon) and Shaun Haney (RealAg). Published online May 26, 2020.

• Access Episode 3 – How much can one wasp save you? Haley Catton (Agriculture and Agri-Food Canada-Lethbridge) and Shaun Haney (RealAg). Published online June 9, 2020.

• Access Episode 4 – Eat and be eaten — grasshoppers as pests and food John Gavloski (Manitoba Agriculture and Resource Development) and Shaun Haney (RealAg). Published online June 23, 2020.

• Access Episode 5 – Killer wasp has only one target — wheat stem sawfly Scott Meers (Mayland Consulting) and Shaun Haney (RealAg). Published online July 7, 2020.

• Access Episode 6Plentiful parasitoids Tyler Wist ( Agriculture and Agri-Food Canada-Saskatoon) and Shaun Haney (RealAg). Published online July 21, 2020.

Access ALL the Field Heroes links here and be sure to follow @FieldHeroes!

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).  

Insect of the Week – Pterostichus melanarius

This week’s insect is the ground beetlePterostichus melanarius (Coleoptera: Carabidae).  This large (12-19 mm), shiny black beetle originates from Europe and probably arrived to North America in the 1920s in ships’ ballasts. It has become a widespread insect throughout North America, particularly in habitats used by humans: urban areas, forests, and agricultural land.

Flight has been the main method of colonization and dispersal for this species. In newly arrived populations of P. melanarius, individuals generally have longer hind wings which allow for more efficient dispersal. After a population has become established in an area, short-winged morphs of the species become dominant.

This species is an excellent example of a generalist predator. Generalist predators include many species of ground beetles, some rove beetles, ants, centipedes and spiders. These arthropods are not picky when it comes to choosing a meal. For example, P. melanarius will eat nearly anything including many different arthropods, earthworms, slugs and even some small vertebrates. Generalist predators are effective in keeping some insects from reaching high numbers that can damage agricultural crops.

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

Pterostichus melanarius
Photo credit: Henri Goulet (retired), Agriculture and Agri-Food Canada
Photograph of Pterostichus melanarius catching a fourth-instar P. xylostella in a plastic container (LRC, Photo credit: A. Mauduit)

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**

 

Insect of the Week – Rove beetle

This week’s Insect of the Week is the Rove Beetle (Delia spp.). This beetle feeds on aphids, mites, eggs and larvae of many other insects present under plant debris, rocks, stones, carrion, dung, and other materials. It is also an important natural enemy of the pea leaf weevil. One species of the rove beetle, Aleochara bilineata, is an important natural enemy of cabbage, seedcorn, onion and turnip maggots.

Follow @FieldHeroes to learn more about the Natural Enemies that are working for you for FREE to protect your crops!

For more information on the Rove Beetle, see our Insect of the Week page.

Rove beetle – adult (Tyler Wist, AAFC)
Remember the NEW Cutworm Field Guide is free and downloadable in 2017!

Insect of the Week – Predatory mites

Predatory mites

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 feature natural enemies are predatory mites. These are not insects but instead belong to the Arachnid or spider class of arthropods. My known encounters with mites have been of the pest type (e.g. two-spotted spider mite), spinning their webs and literally sucking the life out of their host plants and transmitting viruses. But this group, the predatory mites get their meal instead from insect eggs, all stages of pest mites, thrips, young aphids and leafhoppers. They may be small, but they are ‘mity’.
For more information about these natural enemies, other pests they control 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).

Adult whirligig mite,
Aleksander Balodis (AfroBrazillian), Wikimedia Commons
Adult red velvet mite,
Jorg Hempel, Wikimedia Commons

Insect of the Week – Assassin bug

Assassin
bug
Last
year, the focus of the Beneficial 
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 feature beneficial insect is the Assassin Bug. I love it when a common
name is so apt. Assassins (at least in the movies) are guns for hire and
they’ll take out whoever is on their list. They’re usually the bad guys but on
occasion can be a force for good (e.g.
Jason Bourne). Similarly
in the insect world, assassin bugs are indiscriminate in who they attack,
preying on immature and adult forms of beneficials and pests alike by patiently
lying in wait for their target to come within stabbing distance.
For
more information about these natural enemies, other pests they control 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).

Assassin bug (Reduvius personatus), Keith Roragen, Flickr

Insect of the Week – Natural Predators

The importance of non-crop areas as habitat for beneficial insects



Last year, the focus of the
Beneficial 
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] 
Natural enemies don’t just appear from nowhere – they rely on nearby
non-crop and (semi-)natural sites for shelter, food, overwintering sites and
alternate hosts for when crop pests are either not present or in low numbers.
How you manage these sites can have a huge impact on natural enemies’ capacity
to supress pests when you need them to. These same sites are also essential
habitats for pollinators, important for maximizing yield of non-cereal seed
crops (e.g. oil seed crop). A recent publication, ‘Agricultural practices that
promote crop pest suppression by natural predators’, describes the role of
non-crop areas and management practices to nurture natural enemy populations.
Go to the Insect of the Week page for download links for
this publication. There you will also find more information about natural
enemies, the pests they control and details about important crop and forage
pest insects by downloading the new Field Crop and Forage Pests and their
Natural Enemies in Western Canada – Identification and Management Field Guide.



Insect of the Week – Natural predators

Last year, the focus of the
Beneficial 
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] 
Natural enemies don’t just appear from nowhere – they rely on nearby
non-crop and (semi-)natural sites for shelter, food, overwintering sites and
alternate hosts for when crop pests are either not present or in low numbers.
How you manage these sites can have a huge impact on natural enemies’ capacity
to supress pests when you need them to. These same sites are also essential
habitats for pollinators, important for maximizing yield of non-cereal seed
crops (e.g. oil seed crop). A recent publication, ‘Agricultural practices that
promote crop pest suppression by natural predators’, describes the role of
non-crop areas and management practices to nurture natural enemy populations.
Go to the Insect of the Week page for download links for
this publication. There you will also find more information about natural
enemies, the pests they control and details about important crop and forage
pest insects by downloading the new Field Crop and Forage Pests and their
Natural Enemies in Western Canada – Identification and Management Field Guide.



Insect of the Week – Ladybird beetle larva

Last year, the focus of the Beneficial 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] 

You can’t tell by looks whether an insect is a good bug (beneficial) or a bad bug (pest). And while you might recognize the adult, the immature form might appear quite alien. This is definitely the case with the ladybird beetle (aka lady beetle). This cute, orange, nearly round beetle with varying number of spots depending on species appears harmless but is a voracious eater, consuming up to 100 aphids a day (and other soft bodied insects). The larvae (slate blue, elongated body with varying black and yellow patterns) can be just as hungry.

One of the exciting projects at Agriculture Canada is looking at how natural enemies like ladybird beetles control cereal aphids in wheat, oat, barley and rye, preventing them from causing economic damage without you having to lift a finger (or hook up a sprayer). Of course, there are times when there aren’t enough free helpers/natural enemies and we’re developing an app that will help growers figure out if and when they need to control cereal aphids. (Refining and making accessible to growers a validated dynamic action threshold for cereal aphid control in cereal crops).

For more information about these natural enemies, other pests they control 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).


Ladybird beetle larva eating aphids
Mike Dolinski, MikeDolinski@hotmail.com

Insect of the Week – Crab spiders

Crab spiders


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 Insects of the Week are crab spiders. These are generalist predators, capturing any insects (small flies, ants, bees, wasps, beetles, small moths, thrips) visiting flowers, including canola which is in full flower right now. They are called crab spiders because they walk sideways like a crab.

For more information about these spiders, the other pests they control 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).

‘Will you walk into my parlor?’ said the [yellow crab] spider to the fly
– (c) AAFC, Tyler Wist


Insect of the Week – Rove beetle

Rove Beetle (predator and 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 the rove beetle (Delia spp.), is a generalist predator. The adult feeds on aphids, mites and larvae of many species under plant debris, rocks, dead animals, dung and other materials. The rove beetle larvae have similar hosts as the adult; the larvae of Aleochara spp parasitize various fly species including cabbage root maggot.

For more information about rove beetle, 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).

Adult rove beetle. (c) AAFC-Tyler Wist


Insect of the Week – Blister beetle

Blister Beetles (predator)

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 the blister beetle (Lytta nuttalli and Epicauta spp.). This is a good news/bad news story. The good news is that the Epicauta spp. larvae feed on grasshopper eggs. But the bad news is that the Nuttall blister beetle larvae feed on ground-dwelling leaf-cutter and bumble bees. The bad news continues: adult blister beetles contain a toxin, cantharidin. When beetles get baled in with alfalfa hay, the toxin can cause severe distress in livestock, especially horses.


See more information in 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).

Adult blister beetles. Photo credit: Whitney Cranshaw, Colorado State University, Bugwood.org

Insect of the Week – Ground beetles

Ground beetles (predator)


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 the ground beetle. There are nearly 400 known ground beetle species on the prairies. Some of these provide important pest control service: eating redbacked cutworm eggs, grasshopper eggs, pea leaf weevil eggs, cabbage maggots and diamondback moth larvae. See more information in 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).



The ground beetle Pterostichus melanarius can help prevent pest outbreaks of diamondback moth (Plutella xylostella). © Canadian Biodiversity Information Facility (www.cbif.gc.ca)
For those that just can’t get enough about the fascinating world of insects, Ground Beetles (Coleoptera: Carabidae) of the Prairie Grasslands of Canada is a recent literature review on the topic.

Insect of the week – Syrphid flies

This week’s Insect of the week is an important aphid predator, the syrphid fly. Syrphid flies are more commonly known as hoverflies. There are many species in the Syrphidae family and the adults of several species mimic wasps.   


Wasps are characterized by having two pairs of wings, a tightly tapered ‘waist’, long antennae, and a yellow and black body. In contrast, hoverflies or syrphid flies have one pair of wings, a less distinct ‘waist’, have short antennae, and an abdomen striped yellow and black or a black and brown body. Syrphid flies also have relatively large compound eyes  characteristic to all Diptera spp. Mimicking the appearance of a wasp helps protect syrphid flies from predation.  

Find out more about hoverflies and more at the Insect of the Week page!

Two syrphid flies on a hawkweed flower.
(c) 2015 John Gavloski, Manitoba Agriculture, Food and Rural Development