Insects & Pests

Arthropods of Canadian Grasslands - Volume 1: Ecology and Interactions in Grassland Habitats

Volume 1: Ecology and Interactions in Grassland Habitats

This authoritative book is the first of a planned three volume series on Canada’s grassland arthropods.

Targeting a broad audience, chapters review the biotic and abiotic attributes of different types of grasslands in Canada, and select grassland habitats and their associated arthropods.

Publication of the series is intended to increase awareness of Canada’s vanishing grasslands, the rich diversity of arthropods that they support, and to provide a baseline reference for future studies in these fascinating environments.

To order please see The volume can be downloaded at no charge as a series of pdf files using the links below. Adobe Acrobat reader is needed to view the files. This software can be downlaoded for free from

Arthropods of Canadian Grasslands - Volume 2: Inhabitants of a Changing Landscape

This is the second of a planned three-volume series that will provide an overview of Canada's grasslands and its associated insects, mites, and their close relatives. Volume 1 reviews the formation and extent of native grasslands and subsets of their associated arthropods. Volume 2 expands this focus with chapters on arthropods in agro-ecosystems.

Grasslands were once a dominant feature of Canada's landscape, extending across most of southern Alberta, Saskatchewan and Manitoba, with smaller expanses in the Yukon, the interior of British Columbia, and in eastern Ontario. Now, virtually all of these grasslands have been extensively modified for agricultural production with only scattered patches left undisturbed.

Our current knowledge of grassland arthropods largely is limited to species of economic importance; usually exotic species or native species that have become agricultural pests. There exists relatively little information on the arthropods of native grasslands, such that we know little about their biodiversity, their role in ecosystems, and their ability to respond to habitat change.

With the publication of Arthropods of Canadian Grasslands, the Biological Survey of Canada hopes to increase awareness of the plight of Canada's grasslands, to draw attention to its associated arthropods, and to provide a baseline reference to support future studies of arthropods in these environments. To order please see The volume can be downloaded at no charge as a series of pdf files using the links below. Adobe Acrobat reader is needed to view the files. This software can be downloaded for free from

Bees - EU says pesticides linked to bee decline should be restricted (2013)

By Matt McGrath, Environment correspondent, BBC News

The European Commission has proposed that member states restrict the use of certain classes of pesticide that are believed to be harmful to bees.

Sprays that use neonicotinoid chemicals should only be used on crops that are not attractive to the insects they said.  The sale of seeds treated with these chemicals should also be prohibited.

Bayer, one of the companies who make the pesticides, says they are convinced they can be used without harm to bees.

Earlier this month, the European Food Safety Authority (Efsa) issued guidance on the use of neonicotinoids, in which they recognised "high acute risks" to bees who encountered residue from these sprays in pollen and nectar in crops like oilseed rape and sunflowers.

They also said there were risks to bees from dust in crops like maize that had been sprayed with these pesticides.

However they stopped short of recommending a complete ban.

Now the European Commissioner for health and consumer policy Tonio Borg has adopted the same line saying it was time for "swift and decisive action."

Significant step

He has tabled a discussion paper that asks EU member states to restrict the use of neonicotinoids to crops not attractive to bees and to prohibit the sale and use of seeds treated with products that contain the active substances.

Three pesticides would be affected -clothianidin, imidacloprid and thiametoxam. Farmers would be banned from using them with sunflowers, oilseed rape, cotton and maize.

Commission spokesman Frederic Vincent told BBC News the measure was based on the latest scientific advice.

"We have requested a proper scientific assessment of neonicotinoids from Efsa. They came up with some concerns, some kind of worrying assessment. So now we are saying to members we have some scientific evidence that there are some concerns from those pesticides and the effects they might have on bees," he said.

The Commission wants restrictions in place by July and the measures will be reviewed after two years. There are already bans in place in France, Germany and Slovenia.

Campaigners were delighted with the EU stance - Friends of the Earth's Andrew Pendleton said it was a timely move.

"This hugely significant EU proposal promises a first, important step on the road to turning around the decline on our bees. The UK Government must throw its weight behind it," he said.

"The evidence linking neonicotinoid chemicals to declining bee populations is growing. We can't afford to ignore the threat they pose to these crucial pollinators.

Museum agriculture

But Bayer CropSciences which manufactures some of the chemicals that face restrictions says it remains convinced that neonicotinoids can be used safely and effectively in sustainable agriculture.

Speaking to the House of Commons environmental audit committee yesterday, the company's Dr Julian Little said that Europe was in danger of "enshrining some sort of museum agriculture".

"I personally absolutely support very strict regulation, but not to the point where we believe you are taking out major advances in chemistry and major advances in agriculture with no discernible improvement in bee health. And other countries will continue to use these products," he said.

In the UK the Department for Environment, Food and Rural Affairs (Defra) rejected a ban late last year saying the scientific evidence wasn't clear. They have commissioned new studies that will look at the impacts of neonicotinoids on bumble bees in field conditions and to understand what levels of pesticide residues and disease in honey bees are normal. These are due to be completed shortly.

But if the EU agrees to limit the use of these pesticides, it will apply to the UK as well, according to spokesman Frederic Vincent.

"If what we have tabled today is approved by members states in the short run, it will mean there will be a new regulation and the measures would apply from the first of July to everybody," he said.

In recent days a number of UK retailers have removed from sale neonicotinoid chemicals linked to bee decline.


Bees - Honey Bee Health and Pesticides (2013)


Pollinators in Canada, such as honey bees and wild bees, pollinate many fruits, vegetables, field crops such as canola, and flower gardens. They are an essential part of a robust agricultural system. 

Honey bee health can be affected by a number of different factors, including parasites (such as the Varroa mite), disease, and other stress factors (such as habitat loss, poor nutrition, climate change, and chemical exposure). The agriculture industry has a vested interest in protecting pollinators and is committed to thoroughly researching and protecting bee health. 

What is causing elevated overwintering honey bee losses in Canada? Over the past four or five years, overwintering honey bee losses have been higher than normal (in the range of 20 to 40 per cent nationally, compared to the more typical 15 per cent). Losses of bee colonies have been variable among the provinces and researchers haven’t identified a single cause of these losses, although recent scientific research points toward a combination of parasitic mites (specifically the Varroa mite) and pathogens (such as Nosema and viral diseases) as main factors. Other possible factors include a lack of genetic diversity, climate change, pesticides, and stressinducers such as colony transport, poor nutrition, weather, and starvation. 

Nonetheless, early Canadian figures from 2011/2012 indicate a significant improvement in overwintering losses, likely due to the mild winter and better disease control. 

What is Colony Collapse Disorder (CCD)? Numerous beekeeping experts believe that Colony Collapse Disorder (CCD) symptoms have not been reported in Canada. CCD is a term used to describe a very specific set of symptoms, characterized by the sudden disappearance of worker bees from a colony, leaving behind an apparently healthy queen and brood. 

Researchers haven’t been able to identify a single cause of CCD but most experts agree that pollinator health decline in recent years is the result of a combination of factors, including parasitic mites and diseases. Many researchers suspect that invasive parasitic mites have weakened bees’ defenses, making them more susceptible to diseases or other environmental factors. 

CCD is a separate issue from overwintering losses and acute poisonings. While some overwintering loss is normal, the levels experienced by some professional beekeepers in various parts of the world over the past seven years have raised concerns. 

How are pesticides regulated to ensure they do not harm bees? All pesticides go through a rigorous testing process to ensure they can be used without causing harm to humans or the environment. This process includes more than 200 separate studies that test a range of health and environmental impacts, including effects on bees. The results of these studies help determine the instructions for use that appear on the product label. As scientific information evolves, products are continuously re-evaluated to ensure they meet the latest safety standards. See:

Is there any connection between neonicotinoid insecticides and long-term honey bee losses in Canada? There is no evidence to suggest a link between neonicotinoids and long-term honey bee losses in Canada. There is no geographical correlation between long-term bee losses and insecticide use. Although some neonicotinoids are toxic to bees upon direct contact (as are many insecticides), they are used in a way that minimizes any direct exposure to bees. Under normal field use, the exposure to bees is at very low levels, far too low to cause harmful effects. Independent, long-term, controlled field tests have repeatedly shown no effects on bee mortality, weight gain, worker longevity, brood development, honey yield, and overwinter survival relative to bees in areas where treated seed was not used. Many of these studies have been published in peer-reviewed journals and presented at international conferences. For example, a recent Canadian study by G. Christopher Cutler and Cynthia D. ScottDupree was published in the Journal of Economic Entomology, 100(3): pages 765-772 (2007). What about recent studies that claim neonicotinoids are a principle cause of pollinator decline? The weight of the scientific evidence clearly shows that these products do not affect long-term colony health. A few recent studies have claimed some impact on bees, but a careful evaluation of the research shows significant errors were made in the experimental design, or incorrect conclusions were drawn from the data. Unfortunately, these studies have received wide media attention. 

Can agriculture and bees really co-exist? Bees and pesticides are very much complementary – both are essential to the success of agriculture. More than one-third of the world’s food production comes from crops that depend on pollination. Modern crop protection products are critical tools that farmers use to protect their crops from potentially devastating pests. In fact, without pesticides, the world would lose at least 40 per cent of its food supply. Our industry is committed to the developing products that allow Canadian farmers to grow food in an environmentally sustainable manner. For example, seed treatment insecticides evolved as a way to protect seeds and crops while also minimizing potential exposures of non-target insects such as bees. Indeed, these modern seed-applied insecticides have been used for a decade with almost no incidences of negative impacts on bees. Only small quantities of the insecticide are needed to coat the seed, which reduces the need to spray insecticides to control insects. In fact, in contrast to a traditional spray treatment, where 100 per cent of a field is treated, less than 1 per cent of the field is treated when a modern seed treatment is used. This helps to reduce the exposure of pollinators and other beneficial insects (as well as human and environmental exposures) throughout the growing season. Furthermore, in Canada the climate is such that most years treated seed is planted during a period when bees are not actively foraging. 

What role do farmers play in ensuring bees are protected from insecticides? Farmers understand the tremendous importance of pollinators to the success of modern agriculture. To ensure farmers are well equipped to use our products safely, our industry provides them with technical advice on best practices to ensure they plant treated seeds in a way that protects nontarget organisms such as bees. For example, during planting, farmers can limit dust when pouring seed into the planter; properly dispose of empty seeds bags; and follow manufacturer recommendations. Growers plant only during proper weather conditions, they take precautions when planting near flowering crops and they control flowering weeds in their fields prior to planting. More extensive information on the Best Management Practices for the handling of seed-applied insecticides is available at 


Bees - Ontario Bee Incidents Update (2012)

This spring, beginning in April 2012, incidents of bee mortality were reported by beekeepers across southern Ontario. Timing and location of these incidents appears to have generally coincided with corn planting. Health Canada’s Pest Management Regulatory Agency (PMRA) has been working with the Ontario Ministry of the Environment (MOE) and the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA) to evaluate the role pesticides may have played in these bee losses. Initial analyses of the circumstances surrounding the bee losses indicate that there was no pesticide misuse.

Samples of affected bees were taken at many incident locations and are being analyzed for specific pesticide residues by the PMRA laboratory services. To date, residue analysis has been completed for 104 bee samples, as well as some samples of pollen and vegetation. Analysis is currently underway for an additional set of bee samples. Preliminary residue results show that insecticides used to treat corn seed were detected in approximately 70% of the dead bee samples analyzed.

Based on the preliminary information evaluated to date, there is an indication that pesticides used on treated corn seeds may have contributed to at least some of the 2012 spring bee losses that occurred in Ontario, however, there is still additional information being collected for consideration and final conclusions have not been made. We are looking closely at the specific circumstances that may have contributed to the unusual number of bee mortalities this spring.

The PMRA (assisted by MOE) is continuing to gather information for the purpose of determining the role pesticides may have played in the bee losses, how exposure occurred, and to determine what steps can be taken to prevent future bee losses. Information is being collected from affected bee yard owners/operators to help in the evaluation. Furthermore, the PMRA and MOE staff are contacting owners/operators of agricultural land in the vicinity of certain affected bee yards to collect details on agricultural activities including: crops grown, seeding dates, seed treatments, planting equipment, planting practices used, pesticide applications, weather conditions at the time of planting and other factors that may have played a role in the bee losses.

Once all current samples have been analyzed and available details gathered from the affected bee yards and adjacent agricultural land owners, a final analysis of the results will be conducted. A report will be made available, which will include information on the findings of the evaluation as well as the PMRA’s final conclusions.

In the interim, the PMRA will take additional steps to further protect pollinators from potential pesticide exposure, and is working with the United States Environmental Protection Agency (US EPA) and other Canadian and international regulatory partners towards this goal. Work is ongoing to ensure that additional safety measures and best management practices to reduce pollinator exposure to treated seed dust are developed and communicated to beekeepers, agricultural producers and other stakeholders prior to the next planting season.

Source:  Health Canada

Bees – Support the Bees and They Will Support You (2014)

By Margaret Holm
Orchard & Vine Magazine, Summer 2014

We’ve all heard that honey bees and native bees are in trouble in North America. There seem to be a number of factors leading to the decline of native pollinator populations of honey bee colonies. Minute quantities of neonicotinoid pesticides have been implicated in bee population decline and have been banned in many European countries. The second factor severely affecting honey bees is the Varroa mite. A third factor may related to poor nutritional opportunities for bees feeding on monocultures of some commodity crops. Recent drastic declines in some native bumblebee populations have lead researchers to hypothesize that diseases were spread from non-native bumblebees used in greenhouses.

Both wild and domestic bees provide millions of dollars of pollination services to fruit and ground crops. Although they are not needed for grape pollination they do pollinate cover crops and plants that support beneficial insects. Maintaining a healthy population of insect pollinators is vital to agricultural production and the environment.

Use of pesticides is part of most farm operations, however good management practices can ensure that bees have little or no direct contact with toxic sprays. Consider the following before applying pesticides:

  • Are you practicing Integrated Pest Management by correctly identifying the pest problem and applying treatment at the lowest effective label rate?
  • Have you checked pesticide options available and the toxicity of the product to bees? Check the label, the Pest Management Regulatory Agency (PMRA) website, or get advice from field services staff and your local pesticide supplier.
  • Do you know the location of beehives owned or being used for pollination by neighbouring agricultural properties? If they are nearby, contact the bee-keeper about your spraying plans.
  • Have you planned your spraying to avoid the time when bees are most active? Remember that native bees are active at lower temperatures than honey bees.
  • Avoid flower bloom times – for crops, cover crops, and flowering weeds – when bees are attracted to your property. One option is to remove flowers before pesticide application by mowing.
  • Are you using techniques to reduce pesticide spray drift? Air-blast sprayers can produce finer droplets with greater drift potential. Consider redirecting or turning off nozzles, or use technologies that reduce your drift. Have you tested or calibrated your nozzles this year?
  • Are you carefully considering wind and temperature conditions before spraying to reduce spray drift?


Go to the Health Canada site and search for “Protecting Pollinators during Pesticide Spraying” for more tips on best management practices. Be aware that pollinators collect pollen and water as well as flower nectar and can be harmed by pesticide residue from these sources. Ground-nesting bumble bees are also very susceptible to pesticides used in turf management.

You can support bees by providing areas of native habitat or buffer crops of clover and other flowering plants that are not sprayed. Minimize tillage in natural areas and leave gullies and hedgerows which are ideal nesting and foraging habitat. Weathered wood such as fence posts, sheds and trees offer homes to many native pollinators such as mason bees. Native bumble bee and mason bee species are more efficient pollinators then honeybees and are active longer when the weather is cold and wet. They need very little in return for their services – a small hole to nest in and native habitat to support them after the commercial crop has blossomed.

Report suspected pollinator pesticide poisonings to Health Canada’s Pest Management Regulatory Agency at 1-800-267-6315.

Margaret Holm works for the Okanagan Similkameen Conservation Alliance. Contact her at

Beetles Help Degrade Dung on Canadian Pastures (2012)

Click here for PDF of entire article.

It can take hours, days or weeks for dung-breeding beetles to scatter or bury cow pies deposited on pastures. Much depends on the number and species of beetles at hand – and they have a lot of work to do. A cow can deposit up to 22 kg of fresh dung each day throughout the grazing season, and Canada has a national herd of about 14 million animals. The tireless efforts of these beetles in degrading cattle dung provide huge returns to Canada’s ranchers.

Dr. Kevin Floate, a scientist and dung beetle specialist with Agriculture and Agri-Food Canada (AAFC) in Lethbridge, Alberta, leads a research team to increase awareness of these beetles and introduce more efficient dung-degrading species onto Canadian pastures.

Benefits of Dung Degradation

Undegraded dung reduces the amount of pasture available for grazing, provides breeding sites for pests of cattle, and removes nitrogen and minerals from pasture soils. Through their feeding and tunneling activities, dung-breeding insects hasten the return of organic matter from the pat back into the soil to increase forage yields, increase soil aeration and water retention, remove breeding sites for livestock pests, and generally improve the aesthetic value of the countryside. 

It is difficult to capture the economic benefits of these services, although some have tried. One study calculated a potential annual benefit of $2 billion associated with accelerated dung pat degradation in the United States1. A second study estimated that the dung deposited by a group of 455 cattle on pastures in northern California equated to a loss of about $4800 from time of deposition to complete degradation (3 years)2.

Dung-Breeding Insects

Literally within minutes, fresh cow pats deposited on pastures during the grazing season are colonized by a mix of dung beetles, flies, parasitic wasps, and predatory beetles. More than 450 species of insects occur in cattle dung in North America with more than 80 such species in western Canada3. Face fly, horn fly and stable fly are pests, but represent a small fraction of the total. The vast majority of dung-dwelling insects are beneficial as they are natural enemies of pest species or, through their feeding and tunneling activities, accelerate the degradation of the pat.

Insect activity is highest in the spring, declines during the hot, dry months of July and August, and then increases again in autumn before the onset of winter. From October through April, the insects remain inactive in soil or dung. In spring, they emerge to colonize moist, fresh dung, passing by older pats that are dry and no longer attractive. This pattern of activity helps explain why pats deposited in February can remain intact for years.

Dung beetles, often the largest and most abundant insects in cattle dung, are the main contributors to pat degradation. Although there are many species, dung beetles are commonly grouped as ‘tunnelers’, ‘rollers’ or ‘dwellers’. Tunnelers and rollers are most desired. They can scatter and bury a fresh pat in less than a week. Adults arrive at the pat to remove small pieces of manure. Tunnelers will bury this manure in chambers that may be 15-20 cm below the pat. Rollers will carry the manure away from the pat and then bury it. The manure provides food for beetle grubs that hatch from eggs laid in the chambers. Burying the manure not only increases soil fertility, but also increases soil aeration and its permeability to water. Dwellers are least desired. 

They degrade dung pats over a period of weeks and do not tunnel in the soil. Instead, adults lay eggs in chambers they form in the pat. Feeding by the grubs that hatch from these eggs slowly degrades the pat to the consistency of sawdust. Dwellers are most common on Canadian pastures. 

New Beetles for Canada? 

In 2007, funding from the Canada/Alberta Livestock Research Trust provided the opportunity to assess the likelihood of establishing two new species of tunnelers in Canada. Digitonthophagus gazella and Onthophagus taurus are European species that were introduced into the southeastern United States in the early 1970s.

AAFC researchers developed computer models, performed temperature studies, and made field-cage releases to determine whether these two new species could survive in Canada.

The computer models, developed by Dr. Owen Olfert (AAFC, Saskatoon Research Centre, Saskatoon, SK), use temperature and moisture data from sites where the two species occur elsewhere in the world to predict establishment based on corresponding data for Canada. Results ruled out D. gazella for Canada, but predicted survival and establishment for O. taurus across most of southern Canada with greatest potential in southern Ontario and Quebec.

Temperature studies support these predictions. Lab colonies of D. gazella and O. taurus were established at Lethbridge using insects provided by Dr. Wes Watson (North Carolina State University, Raleigh, NC). Eggs from these colonies were then held at constant temperatures ranging from 10 to 32°C in 2°C increments. A minimum temperature of 22°C was required for egg-to-adult development for D. gazella, but of only 16°C for O. taurus. Both species develop in manure buried in the soil at depths of about 10-15 cm. Cool soil temperatures at these depths in southern Canada prohibit development of D. gazella, but not necessarily of O. taurus.

Field releases confirmed results of the computer models and lab experiments. Plastic tubs of soil were placed in the ground during the summers of 2009 and 2010. Adult D. gazella and O. taurus were released into the tubs, which were provisioned weekly with fresh dung until October and kept covered with wire mesh to prevent the escape of beetles. In spring of 2010 and 2011, the soil and spent manure in each tub was carefully examined. Live O. taurus recovered in the tubs in each year were determined to be the adult progeny of the beetles placed in the tubs. Thus, O. taurus can both overwinter and complete egg-to-adult development in southern Alberta. No live D. gazella were recovered.

Releases of O. taurus were made on native pastures near Lethbridge in 2009 and 2010. Small numbers of O. taurus were recovered in dung-baited pitfall traps in 2010, but none were recovered in 2011. AAFC researchers continue to monitor the release sites to assess establishment success.

Ideally, populations of O. taurus will establish and gradually spread to increase the degradation of cattle dung and promote the productivity of pastures in southern Alberta.


1 Fincher, G.T. 1981. The potential value of dung beetles in pasture ecosystems. Journal of the Georgia Entomological Society 16(2): 316-333. 

2 Anderson, J.R., Merritt, R.W. and Loomis, E.C. 1984. The insect-free cattle dropping and its relationship to increased dung fouling of rangeland pastures. Journal of Economic Entomology 77(1): 133-141. 

3 Floate, K.D. 2011. Arthropods in cattle dung on Canada’s grasslands. pp. 71-88. In: Arthropods of Canadian Grasslands (Volume 2): Inhabitants of a Changing Landscape. Floate, K.D. (ed.), Biological Survey of Canada, Ottawa, ON. Biological Survey of Canada, Ottawa, ON. 


For more information, please contact:
Dr. Kevin Floate Research Scientist, Insect Biocontrol
Lethbridge Research Centre 5403 – 1st Avenue South Lethbridge, AB T1J 4B1 Tel 403-317-2242 

Brown Marmorated Stink Bug - Samurai Wasps (2018)

BC Recruiting Samurai Wasps for Stink Bug Battle (2018)
By Gary Symons

The BC Ministry of Agriculture is looking for a special type of warrior to help them deal with an invasion that threatens orchards and berry farms in the province.

Susanna Acheampong says Ministry officials are on the lookout for the deadly Samurai wasp, which can lay waste to populations of the invasive brown marmorated stink bug.

“We are working on a biological control, which is generally the best way to manage this pest,” says Susanna Acheampong, a Kelowna-based entomologist with the Ministry of Agriculture. “Unfortunately, we haven’t found the Samurai wasp in Canada yet, but perhaps in time we can bring them in to control the stink bugs.”

BC farmers and the Ministry of Agriculture are gearing up for the first phase of an intense battle with the invasive brown marmorated stink bug this year. Acheampong says new funding will be dedicated to putting up new traps in farms, to get an idea of just how far the stink bugs have spread into farmland.

The pesky and sometimes smelly pests are a major concern for farmers throughout the US and Canada. A 2010 study found the insect caused $37 million in damage to the US apple industry alone, and since then the stink bugs have moved into southern Ontario, Prince Edward Island and now British Columbia.

The stink bug also attacks and damages various tree fruits, berries, grapes, vegetables, corn and a variety of ornamental plants.

The first sighting of the destructive Brown Marmorated species was in Penticton in 2016, but as of November last year most of the sightings of the insect have been in or around the City of Kelowna.

“Brown marmorated stink bugs will start in backyards; that is their behaviour,” says Acheampong. “The numbers build up and then they move into our commercial crops.”

For that reason the stink bugs haven’t caused much damage to crops yet; they are still primarily being seen in urban back yards, although one stink bug was found in an orchard in Vernon.

Acheampong’s colleague Tracy Hueppelsheuser says the same thing is happening in the Fraser Valley. The BMSB varmints have been spotted in urban areas including Vancouver, Burnaby, Langley, Coquitlam, Maple Ridge, Mission, Abbotsford, and particularly in Chilliwack.

“It’s been all urban, and mainly it’s people spotting these big, weird bugs in their yards and reporting them to the Ministry,” Hueppelsheuser says.

Neither she nor Acheampong expect that reprieve to last long.

“Our orchards are very close to our downtown areas,” Acheampong points out. “We might not have a lot of time before they move into our commercial fruit.”

The Ministry is setting up additional traps in agricultural areas in the Okanagan and the Fraser Valley to track the movement and expansion of the stink bug invasion. More than 1,000 of the invasive insects were found in Kelowna’s downtown core alone between May and October of last year, when the Ministry set up more than 150 traps from Salmon Arm to Osoyoos.

Data coming in from the new traps over the spring and summer months in 2018 will give farmers and ministry officials a better idea of the size and scale of the coming threat to BC’s tree fruit and berry crops.

“For our region we don’t really know what this year is going to look like until we can complete this monitoring,” Acheampong said.

The Ministry is also asking residents and farmers to keep an eye out for the large, brown insect, to report sightings to the Ministry, and ideally to kill them on sight.

The brown marmorated stink bugs are distinguished from the native species of stink bug by distinctive white bands along their legs and their very large antennae. The regular stink bugs are not really harmful for local growers and should be left alone, but if you see one of the Brown marmorated variety, assassination is the preferred option.

The only caution is that the bugs will emit a foul stench if they are stepped on.

Acheampong says if you see one, you can vacuum or sweep it up and then kill it by immersing the bug in soapy water. Or, if you’re just good and mad and don’t mind the smell, squishing is definitely a valid option!

Stink bugs are generally dormant in a Canadian winter, revive in the spring and have two generations of stink bugs per year. They become their peskiest from September through October when the peak populations occur. The eggs can usually be found on the underside of leaves in clumps of 20 to 30 eggs per leaf, and the nymphs grow throughout the summer, becoming adults in the fall when the cycle repeats.

The bugs have a narrow, needle-like mouth, and pierce fruit to suck out the juices, a bit like a kid with a straw in a juice box. The piercing causes widespread discoloration of the fruit.

Unfortunately, the best ‘assassins’ are Samurai wasps that don’t currently exist in Canada.

“We’ve tried to find them, but they are not native to BC,” says Hueppelsheuser. “We have people looking for these wasps in insect egg masses, because that’s what they eat, but no luck so far.

“Stink bugs in general are vulnerable to egg parasites, but the brown marmorated variety doesn’t seem to be as affected by the parasitic insects we have here in BC.”

Hueppelsheuser and Acheampong say the Samurai wasps do exist in large numbers in Oregon and southern Washington State, and there is a real chance they could follow their prey into British Columbia.

“The hope is that they will find their way here naturally,” says Hueppelsheuser.

In the meantime, anyone who does spot either the BM stink bugs or one of the tiny but effective Samurai wasps is asked to contact the Ministry of Agriculture at this toll-free number: 1-888-332-3352.


Brown Marmorated Stink Bug Photo - Adult

corn rootworm adult

Brown Marmorated Stink Bugs - Help protect B.C. fruit farms (2016)

B.C. residents, particularly those in the Lower Mainland, Fraser Valley and Penticton area are being asked to support the Ministry of Agriculture’s surveillance efforts by being on the lookout for any brown marmorated stink bugs, (Halyomorpah halys) that may be seeking winter refuge inside homes and buildings.

The bug does not pose a risk to people, but can be devastating to tree fruits, berries, grapes, vegetables and ornamental plants, and a nuisance to homeowners as the adults aggregate on and in buildings while seeking warm overwintering sites.

Both adults and nymphs feed by inserting their mouthparts into the flesh of fruit or vegetables. Feeding punctures result in small dead areas on fruit, vegetables and leaves.

Brown marmorated stink bugs can be a contamination issue for grapes because the presence of a few adults at crush can taint wine.

The ministry has conducted outreach to growers and the general public for brown marmorated stink bugs since 2010, and is increasing 2017 efforts through a multi-agency surveillance and monitoring plan, after the bugs were found in B.C. for the first time in 2016. A few were identified in Penticton in the spring and summer, and several more in the Kitsilano area of Vancouver and Chilliwack. The bugs are excellent hitchhikers and can be moved in shipping containers, wood, wood-packing material, cargo and vehicles

The brown marmorated stink bug, a native pest of Asia, was first identified in North America in Pennsylvania in 2001. It has since spread throughout the mid-Atlantic states and is present in California, Oregon and Washington. The adults are brown, about 13 to 17 mm long, and can be distinguished from other brown stink bugs by the presence of distinctive white bands on the antennae and their tendency to cluster together in groups.

Pictures, I.D. tips, and additional information is at:

And at:

The bug is a very serious pest that feeds on more than 100 different plant species and causes tens-of-millions of dollars of fruit losses annually in the United States. B.C. growers and homeowners are asked to report any suspect brown marmorated stink bug to the B.C. Ministry of Agriculture contacts below:

In the Southern Interior: Susanna Acheampong Ministry of Agriculture Email:

In the Lower Mainland: Tracy Hueppelsheuser Ministry of Agriculture Email:

Corn Producers Can Take Steps towards Reducing Risk to Pollinators (2012)

Tracey Baute ‐ Field Crop Entomologist, Ontario
Greg Stewart ‐ Corn Specialist Ontario Ministry of Agriculture, Food and Rural Affairs

A high level of concern was raised last spring regarding bee kills and corn planting in Ontario.  Many growers are asking what actions they can take to help reduce the risk of bee kills this spring during planting. We will try to clarify the situation, and give the best recommendations we can provide at this time.

In the spring of 2012, coinciding with corn planting, there were approximately 200 incidences of what was likely acute poisoning of honey bees in Ontario. Representatives from the Ministry of Environment (MOE), Pest Management Regulatory Agency (PMRA), and OMAFRA investigated affected bee hives, taking bee samples for residue analysis by PMRA. Though final results have not been released, PMRA’s initial lab results indicate “that pesticides used on treated corn seeds may have contributed to at least some of the 2012 spring bee losses that occurred in Ontario, however, there is still additional information being collected”. It is important to note that they have found no cases of off‐label use by growers. It is also important to note that, though the analysis indicates the presence of clothianidin (active ingredient in Poncho), thiamethoxam (active ingredient in Cruiser) breaks down to metabolites that include clothianidin.Virtually all corn seed sold in Ontario is treated with some form of the insecticides in question.

Many factors may have contributed to these incidences.  Environmental conditions and planting practices during the 2012 planting season may play a significant role. Unfortunately, without being present in each field at the time of planting to collect data, there may never be conclusive evidence as to route(s) of exposure to bees. However, results indicate that honey bees were somehow exposed to corn seed insecticides. So how can a bee come into contact with a seed insecticide during planting?

One of the more likely routes is dust.  Research from Purdue University and other jurisdictions in Europe have found evidence that dust coming from the exhaust of high pressure air‐assisted corn planters contained particles of neonicotinoid (eg. Poncho or Cruiser) seed insecticides.Many factors can contribute to the contamination of the dust including abrasion of the seed from the planter lubricant (eg. talc), quality and formulation of the polymer seed coating (sticker), and rough handling of the seed bags causing chaffing of the seed coat. Planting on dry, windy days may also help to carry the “fugitive dust” greater distances. Bees can come into contact with the contaminated dust while flying across the field during planting or from the dust settling on water sources or nearby flowers that they are foraging on.

What can corn producers do to help reduce the risk of bee kills when planting? The following are actions that should help reduce the production of contaminated dust during planting, and consequently (hopefully) reduce the exposure of bees to this dust. There is no guarantee that these actions will prevent bee kills from happening during planting. Many of these are best management practices that growers should be following anyway, given they are applying pesticides when planting treated seed.

1. Strengthen communication with local beekeepers.  Honey bees can forage up to 5km from their hives. Take an active role in finding out where the nearest hives are to your fields and let the local beekeepers know when you plan to plant. There may be steps that they can take to protect their hives during planting. Contact information for the local beekeepers’ association in your area can be found on the Ontario Beekeepers’ Association website at:‐beekeepers‐associations

2. Time of planting.  Keep in mind that during dry spring conditions, dust will travel further on windy days. If there is an opportunity to plant in the early morning or evening on windy days, when bees are less likely to be foraging, it may also help to reduce the risk of exposure. 

3. Manage dandelions and other flowering weeds in and around fields, prior to planting.  The warm March, followed by a very cold April of 2012 may have resulted in dandelions being the predominate flowering plant for bees to forage on during corn planting. Managing flowering weeds in and along field perimeters prior to planting may help to reduce the likelihood of bees foraging around your field at the time of planting. 

4. Minimize the amount of insecticide seed treatment used.  Growers planting corn on corn with moderate to high populations of corn rootworm should consider planting a Bt corn rootworm hybrid. Transgenic control has been proven to be more effective than using a high rate of seed insecticide. In addition, not every grower in the province has soil insect pest problems. It is time to get back to integrated pest management. Evaluate your fields and determine if soil pests are present at threshold levels. Even if they were in the past, it doesn’t mean they are now, especially if insecticide seed treatments have been used in the same field over multiple years. If the soil pests are not at threshold and impacting yield, a seed insecticide is not necessary. Most companies can accommodate orders for noninsecticide treated seed, as long as the orders are done well in advance. Test noninsecticide treated seed to see how they do on your farm. For information on how to monitor for soil insects and determine thresholds, refer to the Soil Insects and Pests section of the OMAFRA Publication 811, Agronomy Guide for Field Crops at:

5. Limit the amount of seed lubricant (eg. Talc) used at planting.  The amount of lubricant needed varies by planter.There has been a tendency to err on the “safe side” for planter performance, and apply at the upper end of the label rate. Experience from some growers would suggest that in low humidity situations, little to no talc is required. Follow label recommendations. A build‐up of talc on the blower exhaust indicates overuse. Take precautions to reduce the risk of inhaling talc, which can have serious health effects. Fortunately, there are promising new lubricants being developed that could greatly reduce the amount of dust produced. 

6. Exhaust dust towards the center of the field. When planting the outside rounds along the perimeter of the field, blow the air in.If your planter exhausts air towards the right side, plant in a counter‐clockwise direction. This will help direct the dust into the field rather than directing the dust onto the vegetation and water sources near the field’s edge. 

7. Modifying planters with deflectors.  Deflecting exhaust air directly at or into the ground will reduce the distance the contaminated dust is able to travel. Deflectors have been mandated in parts of Europe to reduce dust implications.  In North America, deflectors need to be tested for their impact both on planter performance and on efficacy to reduce dust concerns. Stay tuned. 

Again, following all of these recommendations does not guarantee that there will not be future bee kill incidences at planting. These are the best suggestions we can offer based on the information available to date. We will continue to modify these recommendations as more information is made available, and research and technology is developed to address the issue.  Updates will be provided on the Field Crop News site at: 

Note: Any suspected bee kill incidents in B.C. should be reported to:  
Paul VanWestendorp
BC Provincial Apiculturist
Phone:  604-556-3129

Corn Rootworm 2016.1 - Western Corn Rootworm in British Columbia - presentation November 2016

by Tracy Hueppelsheuser and Susan Smith, B.C. Ministry of Agriculture
November 2016

Western Corn Rootworm is a major corn pest in the midwest and eastern North America

It causes significant damage by:

  • Larvae feed on roots (spring and early summer) causing lodging and limits growth and tonnage.
  • Adults feed on silks (July-Sept) which limits pollination and cob development
  • Adults fly and search for pollen—will damage flower crops (i.e. dahlias)

First detection in B.C. was confirmed August 10, 2016 in Sumas Prairie.

Click here for pdf presentation with photos.

Corn Rootworm 2016.2 - Western Corn Rootworm Lifecycle

Corn Rootworm 2016.3

Source: (read entire article here)

Corn rootworm larvae are cylindrical worms with a white body, brown head and 6 small legs behind the head. They are 3 mm to 1.5 cm (1/8- 3/5 in.) long when fully grown.  Adults have hard shells and are roughly 6 mm (1/4 in.) long. The Western corn rootworm is yellow with black stripes on the wing pad. The Northern corn rootworm is pale green-yellow.

Both the adults and the larvae attack sweet corn. Larvae feed on root hairs and tunnel into the roots resulting in poor water and nutrient uptake, as well as a loss of structural support to the stalk. Indications of infested fields include poor root formation, plants with curved stalks (goose necking) or a high proportion of lodged plants. Corn rootworm damage affects both yield and harvestability.

Later in the season, adult rootworm feed on fresh corn silks. Severe feeding may affect pollination of sweet corn if the silks are clipped prior to seed set, resulting in a barren cob.

The corn rootworm over-winters in the soil as an egg. Adults lay their eggs in the fall in corn fields. Eggs must go through diapause (winter chilling) before they hatch. Development begins once the soil temperatures reach 10°C (50°F). The larvae emerge and feed on corn roots for 3- 4 weeks. Pupation takes 1- 2 days.

Corn rootworm complete only one generation per year. After emerging, adults will look for corn fields on which to feed and lay the overwintering eggs.

Sweet corn fields planted after sweet corn or field corn have the highest risk of infestation. A new variant of the corn rootworm is present in Ontario and across the U.S. mid-west. This variant lays its eggs in soybean crops. While this variant is currently present at very low levels in Ontario, it is important to scout all sweet corn fields for the presence of corn rootworm. Control may be necessary in the future should this variant establish itself in Ontario soybean fields.

Period of Activity
Corn rootworm larvae emerge in late May to mid-June. Feeding continues through mid-July. Damage symptoms may not become noticeable until the crop reaches the early-tassel stage. First generation adults emerge in late July through early August.

Scouting Notes
It is difficult to scout for this pest prior to the onset of symptoms. To diagnose symptomatic plants, dig around the plant and remove its root mass. Place it on a dark surface (garbage bag) and break apart the soil looking for the white larvae. Also inspect roots for feeding injury. Rootworms may occasionally be found under the leaf collar. Inspect plants in several different areas, as populations tend to be variable across the field.

Corn Rootworm 2017.1 PEST ALERT!! Western Corn Rootworm in B.C. (Jan 2017)

Western Corn Rootworm (WCRW), Diabrotica virgifera, Family: Chrysomelidae, a major corn pest, was confirmed in the central and eastern Fraser Valley in August 2016. Surveying in August and September revealed varying levels of infestation in fields, in both silage corn and sweet corn. WCRW has also been confirmed in a dahlia crop adjacent to corn fields.

western corn root worm adult beetle

Life cycle: One generation per year, eggs laid in established corn in late summer in soil cracks. Eggs overwinter, hatch in spring, and larvae are attracted to and feed on corn roots of planted corn fields for 1 month. Larvae pupate in soil, and adults emerge in July. Adults feed on corn foliage and pollen, and mate. Beetles are active fliers and will feed on many plants. Females feed for two weeks, and then lay eggs in corn fields. Both males and females live for about 1 month.


  • Root pruning by larvae, decreasing corn plant growth and causing full or partial lodging
  • Feeding on silks, affecting cob fill, and cob contamination
  • Feeding on flowers (i.e. dahlia), affecting marketability If you see this pest in your corn or flowers, management may be necessary.

Management includes: Crop rotation out of corn every 2-4 years, use of seed treatments or in-furrow sprays at planting, foliar spray for adults in July-August.

If you have questions, contact: British Columbia Ministry of Agriculture
Abbotsford Ph: 604-556-3001
Kelowna Ph: 250-861-7681

CLICK HERE for entire pdf article and photos!

Corn Rootworm 2017.2 - Western Corn Rootworm Update January 2017

Western Corn Rootworm (WCRW) Diabrotica virgifera – A New Pest in British Columbia In August 2016, a new pest was detected in the Lower Fraser Valley, Western Corn Rootworm (Diabrotica virgifera). From preliminary surveying in August-October, WCRW has been seen in forage corn and sweet corn in the Abbotsford area, Matsqui, Chilliwack, Mission, and Agassiz. WCRW is not a quarantine pest. It is native to North and South America, and has been a significant pest for over 50 years in major corn growing regions of the mid-west USA, and has been present for some time in Ontario and Quebec. It is estimated that rootworm species cause over $1 billion in corn yield loss and control costs in the USA. Affected BC agriculture sectors include fresh market sweet corn, silage corn for dairy including organic producers.

Damage Caused by Pest: Adult beetles feeding on the silks of developing corn ears can negatively affect pollination and fill of the cobs and also be a contaminant at harvest for the fresh market sweet corn crop. Rootworm larvae are the most damaging stage, as they feed on corn roots, causing goose-necking or lodging of the plant.

Management: If WCRW is detected in a field the best management option is crop rotation out of corn every 2-4 years. Other measures include: at-plant insecticides targeting the larvae stage, spraying for adults, and use of Bt corn hybrids.

For information about what to look for, see the Factsheet located at: ….. (put the BCAGRI factsheet link here)

Useful websites include: Ontario:

Utah State University:

Penn State:


Coast: Tracy Hueppelsheuser, Entomologist, Plant and Animal Health Branch, British Columbia Ministry of Agriculture, 1767 Angus Campbell Road, Abbotsford, British Columbia, V3G 2M3, Ph: 604-556-3031,

Interior: Susanna Acheampong, Entomologist, Plant and Animal Health Branch, British Columbia Ministry of Agriculture, 200-1690 Powick Road, Kelowna, British Columbia, V1X 7G5, Ph: 250-861-7681,

Corn Rootworm 2017.3 - It's time to check your corn fields for rootworm damage so plans can be made for management/rotation next year (2017)

Lodging, tipping over, instability or ‘goosenecking’ is evident now in fields with rootworm.

corn damage


The photo below shows severe rootworm larvae damage to roots.  Brace roots are completely destroyed and larvae are present on plant crown. 

rootworm larvae

On July 24, 2017, beetles were emerging from the soil and were present on leaves in the Fraser Valley. 

The photos below show a beetle feeding on leaves and window-paning” and sawdust.

rootworm beetle







Corn Rootworm 2017.4 - Flight is taking off this week August 8, 2017

Corn rootworm flight is really taking off this week in Sumas and south Abbotsford and probably elsewhere. There are loads of beetles flying; they are really active in some locations. Corn silks are getting snipped, leaves look bleached out from feeding, and nearby flowers seem to be aggregation places for beetles, in particular, in melon flowers. The beetles seem to like eating red-root pigweed.

They are attracted to anything yellow, including our traps. Besides logging the flight pattern over time, traps can be used to anticipate the risk for the next year in the field. Once we have some counts done we will have a better idea of how this will work for BC growers.

Growers are concerned and some want to spray the beetles to prevent silk damage. The only insecticide registered for this use is Sevin (Carbaryl). In 2016, Sevin was used successfully for beetle control on at least one farm. If fields are still short enough to drive equipment through this is an option. A spray won’t entirely prevent egg laying in the field but will help prevent silk damage.

Prepared by: Tracy Hueppelsheuser, B.C. Ministry of Agriculture

corn silk


corn rootworm


rootworm damage


melon flower damage

Corn rootworm on melon flower.

Filed under: 

Corn Rootworm 2018.1 Fact Sheet

Click here for FACT SHEET PDF (with photos)

Western Corn Rootworm

  • Detected for the first time in the Fraser Valley in 2016 and reached record levels in local corn fields during the 2017 season.
  • Single most important factor contributing to economic loss and shifting management practices in corn growing regions in North America.


Adults:  clip corn silks which interferes with pollination and may result in poorly-filled cobs.  Beetles and frass can contaminate fresh market sweet corn.  They feed on the top layer of leaf tissue and eat the flowers of a variety of crops, including cucurbits.

Larvae:  feed on corn roots reducing structural integrity and nutrient uptake resulting in weak, unstable plants.


Larvae:  White, 3-15mm long; brown head capsule, 6 legs, with a dark patch at the end of the abdomen.

Adults:  Yellow, ~ 6mm long beetles with 3 black parallel stripes (females) or a solid black patch (males).


Adult beetles:  Active in late July-August.  Visually inspect 20 plants at 5 locations for adults and feeding damage.  In sweet corn, consider a foliar spray if there are more than 10 adults per plant.  For forage corn, damage by beetles is of less concern – however presence of adults is an indicator that larvae will be present in the next season and will cause damage.

Larvae:  Monitoring for larvae is useful to determine if the insect is present in a field.  Sample weak-looking areas in the field by digging around the roots and lifting it onto a dark plastic sheet.  Search through corn plant roots and crowns for larvae.  For fields where whole plants are missing, the cause is more likely due to wireworm than western corn root worm.


Entire Fact Sheet contains more information on management.

Field Crop and Forage Pests and their Natural Enemies in Western Canada (2015)

Identification and Management Field Guide

NEW! Field Guide to Support Integrated Pest Management (IPM) in Field and Forage Crops Field Crop and Forage Pests and their Natural Enemies in Western Canada: IDENTIFICATION AND MANAGEMENT FIELD GUIDE

Whether you’re a new or experienced producer, agrologist or field scout in Western Canada, “What’s ‘bugging’ this crop?” and “Does it need to be controlled?” are typical questions raised when scouting for pests in a field of grain, oilseed, pulse or forage.

This new, 152-page, full-colour field guide, now available online, is designed to help you make informed decisions in managing over 90 harmful pests of field and forage crops in Western Canada. Better decision making helps save time and effort and eliminates unnecessary pesticide applications to improve your bottom line. The guide also helps the reader identify many natural enemies that prey on or parasitize pest insects. Recognizing and fostering populations of natural enemies will enhance their role in keeping or reducing pest populations below economic levels.

FREE download

What you’ll find inside:

Description of over 90 economic pests and 30+ natural enemy species or species groups:

  • diagnostic characteristics
  • life cycle
  • damage
  • monitoring/scouting techniques
  • economic threshold
  • control options: biological, cultural and chemical

Large full-colour photos depicting various life stages of featured pests and natural enemies

Overview of Integrated Pest Management (IPM) strategies

Natural enemy and pest relationships


Book Description 

Author: Hugh Philip, 2015
Published by: Agriculture and Agri-Food Canada, Saskatoon, SK [with funding from the Pest Management Centre’s Pesticide Risk Reduction Program]
Pages: 152
Downloadable formats: pdf and pdf-enhanced [features internal hyperlinks allowing the reader to quickly jump to referenced pages]
Languages: Available in English and French
French title: Guide d’identification des ravageurs des grandes cultures et des cultures fourragères et de leurs ennemis naturels et mesures de lutte applicables à l’Ouest canadien
Dimensions: 27.9 x 21.6 cm (landscape)
Document numbers – regular pdf

  • ISBN: 978-1-100-25768-6
  • Catalogue Number: A59-23/2015E-PDF
  • Department Number: AAFC No. 12327E

Document numbers – pdf-enhanced

  • ISBN: 978-1-100-25952-9
  • Catalogue Number: A59-23/2015E-PDF1
  • Department Number: AAFC No. 12346E

Price: FREE download from

For more information, reach us at, by email at, or by calling toll-free at 1-855-773-0241

Fraser Valley Pest - Enhancing Information and Collaboration for Managing Emerging Pests (2018)

CLICK HERE to read entire document in pdf format.


In 2014-2015, the Fraser Valley Adaptation Strategies planning process brought together the Fraser Valley’s agricultural producers and local and provincial government partners to evaluate climate change impacts on local agricultural production, and to develop strategies and actions to address the associated challenges. 

During 2016, a project was implemented to accomplish the identified priority action to undertake “an assessment of immediate and near-term [pest] threats to the sector.” Initiated in 2017, this project builds on the completed assessment by addressing additional actions including strengthening partnerships and collaboration to improve pest monitoring and management, and increasing the availability of “effective informational materials for producers for pest identification, management and control options.” (Climate Action Initiative 2015, pp. 26) 

As the climate changes, regional weather patterns are shifting (Beddington et al. 2012; Vermeulen et al. 2012), altering the growing conditions and creating the potential for changing population patterns of agricultural pests across the Fraser Valley (Climate Action Initiative 2015). This is likely to make some pests more challenging to manage, and proactive planning and action are needed across the agricultural sector. 

The 2016 assessment developed an inventory that documented pest-related activities in the Fraser Valley, as well as perceived pest threats across 30 agricultural commodities. This resulted in documentation of over 300 pest-related projects that have been conducted in the Fraser Valley over the past five years. Interviews with specialists, growers and producers helped to identify priority pests of concern, particularly those perceived as having a changing presence in the Fraser Valley. Following the completion of the inventory, results were shared through a cross- commodity workshop in December 2016 which also enabled pest specialists and leaders from across the agriculture sector to share priorities and acknowledge common goals. 

The project summarized through this report moved forward with several next steps to encourage cross-sector connections and to apply the information gathered in the 2016 inventory. The project analyzed inventory results to prioritize near-term pest threats and their associated management challenges. This enabled the selection of particular pests and management topics as a focus for fact sheets and additional strategic planning. The catalogue of pest-related projects created in 2016 was updated, ensuring it provides an accurate list of projects completed and underway (to facilitate linkages and avoid unnecessary repetition of research). 

Two focus groups held in 2017 brought together relevant individuals to define actions needed to address specific pests of concern (spotted wing drosophila and helminths). These sessions encouraged participants to define initiatives to enhance monitoring, management, research, or education related to the pest of concern. A cross-commodity workshop was held in December 2017 to share overall project results, to continue to strengthen the focus on common solutions, and provide an opportunity for networking. 

The analysis of the Fraser Valley Pest Assessment Inventory has allowed for development of new knowledge transfer resources (seven fact sheets) as well as the initiation of more focused strategic collaboration. This project is not an end point, but a starting point for a shared approach to addressing the challenges of emerging pest threats in the Fraser Valley. Through analysis, outreach and collaboration the two completed projects provide a foundation for a cohesive and coordinated approach to shared pest threats. 

Project objectives 

  1. Analyse 2016 inventory to identify pest (animal, plant and disease) priorities. 
  2. Develop fact sheets for several pests or pest groups that are identified as high priority from Objective 1. 
  3. Update project list from 2016 inventory. 
  4. Plan and implement two group sessions focused on developing short and long-term solutions for monitoring, management, education or research of specific pests identified in Objective 1. 
  5. Plan and implement a cross-commodity workshop to foster collaboration and communicate project findings. 


See link at top of page to read entire document.



Fraser Valley Pest Assessment Inventory - Pest Analysis 2017

Complete document in PDF Format


As our climate changes, weather patterns are expected to shift (Beddington et al. 2012; Vermeulen et al. 2012), which could significantly alter growing conditions and therefore the populations of insects, weeds, pathogens and invasive species across the Fraser Valley (Climate Action Initiative, 2015). These changes are likely to increase the complexity and challenges associated with pest management.

In 2016, an inventory was created that documented pest-related activities in the Fraser Valley, as well as perceived pest threats across 30 agricultural commodities. The pest-related activities included research, outreach, monitoring, and surveillance, and resulted in a list of over 300 projects that have been conducted in the Fraser Valley over the past five years. In addition to this information, interviews were conducted with specialists, growers and producers to establish top priority pests or pests that were believed to be an increasing threat to each commodity. This is a wealth of information for the region and further analysis would be valuable for identifying key areas for future attention and investment. The additional analysis of the Fraser Valley Pest Assessment Inventory undertaken below is intended to assist in focusing activities and research to mitigate pest-related impacts on the agricultural community in this region. This initial assessment could provide a platform for a cohesive and coordinated approach to shared pest threats, and will inform a series of fact sheets that will improve the availability of relevant management information for Fraser Valley producers.

This analysis below focuses on the pests of importance that are identified through the inventory. It is important to note that ‘pest’ refers to any living organism that causes economic damage to a crop or livestock commodity, and therefore encompasses diseases, plants, and animals. The objective of the inventory analysis is to identify emerging pest threats, as well as to categorise established pests for which attention is needed. The categories utilized for analysis of the inventory are: pests affecting multiple commodities; pests with potential for cross-commodity research; pests affecting just one commodity; and emerging pests.

Following this analysis, fact sheets on a selected short-list of pests will be created to improve knowledge and promote management. A communications plan has been included with this analysis to ensure that the fact sheets are distributed using the preferred methods of communication that were identified in the inventory.

To continue reading, open pdf link at top of page.

Grey Tortrix Moth

Grey tortrix (Cnephasia stephensiana) caterpillars caused damage to alfalfa in the Williams Lake and Kersley regions of B.C. in 2009, 2010 and 2011. Since 2011, damage by this pest has been reported in Lumby, Sparwood, Creston and Fort Fraser. Farmers are asked to report any suspect damage in new regions to the B.C. Ministry of Agriculture offices. 

This species has most recently been noticed in Fort Fraser, BC.  Based on samples provided by area producers, entomologists with Agriculture and Agri-Food Canada and BC Ministry of Agriculture have provisionally identified the caterpillars as Grey Tortrix Moth (Cnephasia stephensiana); identification is provisional because the larval stage lacks some of the characters required for 100% confirmation.  Some of the caterpillars are being kept in hopes that they will mature and allow for final identification. 

Here is a Pest Alert notice for this species:  Pdf Document with photos.

Native Pollinators and Agriculture in Canada (AAFC 2014)

Pollinators are animals, mostly insects, and primarily bees, but also birds and bats and a few other animals that help plants produce fruit and seed. Pollinators transfer pollen between the male and female parts of flowers more or less accidentally while they are collecting food in the form of pollen and nectar. We say “more or less accidentally” because it turns out that in the long run, doing so is beneficial to both the pollinators and the plants.

Almost three-quarters of all the flowering plants in the world rely, at least to some degree, on pollinators to play this role (CSPNA 2007). In fact, we can call it a “service” because from both the plant’s perspective and ours, that is what it is. And because of this, entire terrestrial ecosystems, within which these flowering plants grow and interact, depend on this service – from Amazon forests (most tropical tree species are insect pollinated (Michener 2007)) to the native grasslands in the North American Great Plains, to the vegetated “green” zones along prairie streams in western Canada. And if that wasn’t enough, pollinators are vital to agriculture (Table 1). Most fruit, vegetable and seed crops (about 70 percent) are pollinated by animals (Klein 2007) as are some fibre crops (e.g., flax and cotton) and major forage-seed crops like alfalfa and clover (Michener 2007). Some crops are entirely dependent on insect pollination for seed and fruit production while others benefit from higher yields, better quality produce, or more uniform maturation (Corbet 1991; Delaplane 2000). In fact, roughly 35 percent of global crop production depends on pollinators (Klein 2007), and even more, these plants tend to be nutritionally very important to our diet – they provide about 90 percent of our vitamin C, all of our lycopene, almost all of the antioxidants b-cryptoxanthin and b-tocopherol, most of the lipid, vitamin A and related carotenoids, calcium and fluoride, and a large amount of the folic acid intake (Eilers 2011). In the case of honey bees, which provide the majority of agricultural pollination done by bees, they also produce useful and economically important products: wax and honey.

Table 1: Major crops grown in Canada that depend on or benefit from insect pollination.

  •  Legumes and relatives - Bean, Lima Bean, Soybean
  • Vegetables - Cucumber, Peppers, Pumpkin, Squash, Tomato
  • Vegetables (seed) - Asparagus, Beet, Broccoli, Brussels Sprouts, Carrot, Cauliflower, Celery, Lettuce, Onion, Parsnip, Radish, Rutabaga, Turnip
  • Fruits, berries and nuts - Apple, Apricot, Blueberry, Cherry, Cranberry, Melons, Peach, Pear, Plum/ Prune, Raspberry, Strawberry, Watermelon
  • Oils, seeds and grains - Alfalfa, Buckwheat, Canola, Flaxseed, Mustard Seed, Sunflower
  • Clover and relatives (seed) - Alsike Clover, Red Clover, White Clover, Yellow Sweet Clover, White Sweet Clover

The number of honey bee colonies in Canada has been increasing over the last five years from about 570,000 in 2008 to more than 706,000 in 2012 (Agriculture and Agri-Food Canada 2013) as beekeepers import more and more bees to fulfill increasing demands for pollination services as requested by farmers. For wild bees, there are indications that their abundance and diversity is declining and that some species are already at risk (COSEWIC 2010; CSPNA 2007). For the domesticated and agriculturally-important European honey bee, annual losses in the range of 15-30 percent of colonies in North America, primarily due to over-winter kill, appear to be typical (van der Zee 2012; vanEngelsdorp 2012). However, since 2006, a phenomenon termed Colony Collapse Disorder has been reported in the United States where entire colonies are lost because of what appears to be a combination of factors that are difficult to gauge, thereby adding to the vulnerability of pollination services to agriculture (Dainat 2012).

While the causes of all of these declines (wild and managed bees) can be hard to pin down, the following are among the culprits:

  • declines in the diversity of flowering plants (Di Pasquale 2013);
  • loss, fragmentation and degradation of habitat due largely to agriculture and urban development (Grixtia 2009; Kremen 2002; Larsen 2005; Richards 2001);
  • the introduction of invasive non-native plant species (Potts 2010);
  • the toxicity and widespread use of pesticides (Desneux 2007; Kevan 1975; Pettis 2013);
  • air pollution (Girling 2013);
  • climate change (Potts 2010); and
  • diseases and parasites (Potts 2010).

Fortunately, beekeepers have been able to increase the number of honey bees that they import from other countries, not only to compensate for over- winter kill and colony collapse disorder, but to respond to the increase in demand from farmers for pollinators for their crops and from the demand for more honey. Honey production increased from ~29,500,000 kg to over 41,000,000 kg between 2008 and 2012 (Agriculture and Agri-Food Canada 2013). It is also true, however, that for the majority of species, we don’t know very much about the habitats they depend on, their interdependencies with other species, the trends in their populations, or how changes in the environment affect them. This booklet is the story of the pollinators as we know it, what we know about why they are important to agriculture in Canada and some ideas on how we think they can be protected.

Link to entire document:  Native Pollinators and Agriculture in Canada (AAFC publication)

Pest Degree Days to Predict Insect Development

Temperature plays a major role in the growth and development of insects. There is a threshold temperature for each insect where no development occurs when temperatures are below that level and a maximum temperature (termed upper cutoff) above which development stops. In between is an optimum temperature range in which insects grow rapidly. These temperatures can be used to predict insect activity.

Degree days are used to predict insect development. One degree day results when the average temperature for a day is one degree over the threshold temperature. The Farmwest website maintains a Pest Calculator that calculates degree days for several pests at many locations across the province.  Currently you can monitor degree days for Apple Clearwing Moth, Codling Moth, Leaf rollers, fruit flys and more.

Following degree days will allow you to become more accurate in your pest management. This in turn can result in reductions in pesticide use and better control through more accurate timing when pesticides are required.

Rats! Black Rat spreads to BC Interior (2014)

by Margaret Holm, Okanagan Similkameen Conservation Alliance

Unfortunately, the sailing ships that brought explorers and settlers to British Columbia also brought rats and mice. For a hundred years or more the large Norway Rat and Black Rat species were confined to coastal areas, but in the past decade, the smaller Black Rat has spread to the interior of the province and is a new problem in urban and rural areas.

The black rat, or roof rat, has a tail that is longer than its body. It nests in sheds and attics and is an excellent climber, using pipes, wood siding and wires to clamber into small holes and chew through plastic vent covers and screens to gain access.

A pair of black rats can produce six litters a year so you definitely want to be prepared if you have heard that rats are living in your region. Trapping is effective for small populations and is the preferred method over the use of poisoned bait, which can harm non-target animals such as domestic pets, hawks, owls and snakes. Since snakes and raptors are doing us a favour by preying on rodents, we should make sure that our pest control methods are not harming these native animals.

Rodent control for all species involves controlling food attractants, limiting access to building for nesting and shelter, and having snap traps set in key locations. Snap traps are a safer and a better choice than using poisoned bait. Rats require the use of a larger snap traps designed for their body size. Ideally the trap is placed in corners along inside walls. Ideally the traps are enclosed in plastic tubing or a wooden box. Two traps facing out are effective but make sure the space is large enough for the mechanism to snap and to be easily set again.

Rats like fresh foods and will reject spoiled or rancid food. They are also smart and find ways to steal from traps. Rodent food bait, such as a slice of fruit or vegetable with peanut butter, should be placed securely on the trip mechanism or even wired on. Check the traps daily and leave them in place as a preventative measure even after rodents are trapped out.

The best practice is to make your property unattractive to rodents by being aware of food sources and building access points. Keep garbage and edibles in containers with tight-filling lids. Place traps under lumber, pallets and debris which are common nest spots as well as sheds. Based on field tests, ultrasonic devices have insufficient repellency to merit use.

If preventive control measures and trapping are not adequate, poison baits may be necessary. Treated baits should be placed in in covered, tamper-resistant bait stations or in locations not accessible to children, pets, wildlife or domestic animals. Bait stations can be built or may be purchased commercially. Entry holes should be sized for target animal, no larger and interior baffles or small openings should prevent people from touching the bait. Lastly, anchor the bait stations to the ground and flag. Never scatter bait outside a bait station or rodent burrow.

Make sure the bait stations are checked regularly and dispose of dead animals daily to prevent other animals from being attracted to and eating the carcass. To reduce exposure of non-target birds and other wildlife to poisoned carcasses, dead rodents should be securely wrapped and placed in closed containers for disposal or buried to a depth that will make them inaccessible to scavengers.

Sadly, recent studies of Great Horned Owl and Red-tailed Hawk carcasses found in locations across Canada, showed significant levels of anticoagulant rodenticide chemicals in the livers of the dead raptors. Researchers estimate that use of rodenticides is an unintended but significant threat to hawks and owls. Since rodents may need several feedings of bait before they succumb, they can become a poisonous meal for snakes and raptors. Some rodent populations have become resistant to certain poisons. Snap traps may require a bit more effort but it’s safer and supports species doing rodent control the natural way.

Check out “Living with Wildlife”, a series of nine wildlife management guides for agriculture published with the support of the BC Agriculture Council at “Living with Wildlife” pages.

Rodents - Living with Wildlife in BC (2014)

 Click here for pdf version of complete article.

  • Northern Pocket Gopher
  • Coast Mole
  • Yellow-bellied Marmot
  • Columbian Ground Squirrels
  • Mice & Rats
  • Voles

Many rodents have no impact on crops while others cause from minimal to significant damage. Proper identification and assessment of damage is important for rodent management. Trapping is effective for small populations and is the preferred method over the use of poisoned bait, which can harm non-target animals such as dogs, hawks, owls and snakes.

Spotted Wing Drosophila (2016)

Lower Mainland Growers see more Spotted Wing Drosophila
by Ronda Payne February 16, 2016

Spotted Wing Drosophila (SWD) has been harassing Lower Mainland berry growers for five years and Tracy Hueppelsheuser, entomologist, Plant and Animal Health Branch with the BC Ministry of Agriculture, noted that 2015 was an even more exceptional year for the persistent pest.

Research has been ongoing to find and approve the tools farmers need to defend crops against SWD with no current biological control recommended by Agrifood BC and few chemical controls. Chemicals listed by the ministry are Delegate WG, Entrust SC, Mako EC and Malathion 85E. Mako and Malathion were both emergency registered for treatment of SWD in 2015, Entrust is OMRI approved for organic production and treatment guidelines for all products are available on the ministry production guide site.

Few tools to choose from means growers must be aware of all possible ways to manage SWD and Hueppelsheuser feels 2015 was a great example of preparedness and action.

“Winter and spring trapping along edges of Fraser Valley raspberry and blueberry fields from December to May has been done for the last five years,” she says. “The winter of 2014 to 2015 was warm and dry, resulting in much less SWD mortality than in previous years. Over this winter and spring, we caught six to nine times more flies than in previous winters.”

Summer was even worse with trapping showing seven to 122 times more flies in blueberry and raspberry fields when compared to previous summers. Hueppelsheuser says the numbers ramped up earlier and were exceptionally high in both summer and winter. Wild fruit saw heavy SWD infestations in 2015 even though previous years saw light infestations in wild fruit.

“The berry industry was bracing for the worst, and I think that was a good thing,” she says. “Growers were therefore more prepared to deal with the pest in a timely and proactive manner.”

This early preparedness combined with the hot, dry summer (SWD thrives in humid environments) allowed the programs of management to be implemented more accurately in terms of spray and harvest schedules. This didn’t necessarily keep SWD out of sight, but it certainly kept it at bay. A far better outcome than anticipated.

Hueppelsheuser is hoping more emergency registrations will be approved for the 2016 season. She encourages growers to stay on top of the activities outlined on the ministry site including traps, elimination of culled and old fruit from all areas, watching host plants in neighboring fields and most importantly is to pick early, clean and often.

“SWD is anything but routine,” she says. “The story has played out differently each of the five years we have had this pest and we would encourage growers to keep up to date with the information available.”

In summary, Heuppelsheuser’s biggest advice can be taken from how the 2015 season played out – anticipate SWD and plan for it to avoid being unprepared.


Spotted Wing Drosophila Factsheet (2018)

Click here for entire factsheet in pdf format.

Spotted wing drosophila (SWD) is a major insect pest of small fruit and tree fruit crops, as they lay eggs in ripe fruit. Infestation risk factors include high canopy humidity, and ripe and over-ripe fruit (hanging, dropped or rejected). Following the guidelines below will help to achieve the best possible SWD management.

Early Season

  • Before new plantings, select varieties carefully.  Advantages for SWD management include earlier ripening berries and even berry development for uniform harvesting.
  • Manage Himalayan blackberries, which provide habitat for SWD.  Try to remove prunings to avoid regrowth, and be aware of bylaw and label restrictions regarding herbicide use.
  • Record hot-spots based on previous high trap catches and infested fruit.
  • Learn to use a degree day model to predict when SWD will become active in the spring.
  • Prune bushes to open the canopy, decrease humidity, improve harvest efficiency, and improve spray coverage and penetration.

Growing Season to Harvest

Cultural Management

  • Cut back and/or prune flowers or green fruit from any Himalayan blackberries near fields.
  • See BCBC IPM Newsletter for spring and summer SWD trap catches, which will help determine level of SWD risk in the area, and whne insecticide treatments could optimally begin.
  • Harvest berries early and often leaving as little ripe fruit as possible.
  • Cool or freeze fruit as soon as possible after harvest to slow growth or kill eggs and larvae.
  • Sample for larvae in fruit by using the 'float out' method to determine infestation level.

Chemical Management

  • (see Fact Sheet pdf)

Post-Harvest to Dormancy

  • Destroy all culled fruit
  • Clean equipment and fruit processing areas
  • Repair leaking irrigation lines, and/or modify to drip irrigation, rather than over-head, to reduce humidity.
  • Apply or repair weed mats - in summer, they may kill SWD that drop onto the hot surface
  • Install or repair trellis wires - Crop training allows better spray coverage and fewer berries are knocked off bushes during spraying
  • Place SWD traps in hedgerows and field edges.  Monitor for over-wintering hot spots to predict SWD movement inot field for next season.

Rotating Between Pesticides (see pdf)

Degree Day Model (see pdf)

Links and Resources (see pdf)


True Armyworm 1. Information for BC Growers July 2017

True Armyworm (Mythimna unipuncta, formerly Pseudaletia unipuncta) is a North American insect in the family Noctuidae which is introduced annually, in April, to southern Canada on wind currents from the southern USA and Mexico. Southern areas of Manitoba and Ontario do experience outbreaks of this pest periodically.

Hosts: grass crops, including cereals, forage, and corn are the primary hosts, but true armyworm larvae will feed on broad leaved plants as well, included peas and canola.

Damage: Larvae feed on leaves of grass and less frequently on developing seed heads. Feeding occurs mostly at night, or during cool mornings. Once the area is defoliated the growing larvae move in groups to other grass stands to continue defoliation. Damage in a field can be spotty and variable, and quickly result in devastation if the population of larvae is high. The first generation (larval feeding in June and July) is the worst, and the second generation in August is less destructive.

Biology: Adult moths ‘blow in’ to BC in April, in unpredictable numbers, and then begin laying eggs in grass. Eggs are laid densely, and then larvae feed in close proximity to each other; distribution of eggs and consequently larvae is highly clumped or aggregated. Larvae have 6 instars, with the last two instars resulting in the most feeding damage. The larval stage lasts about 1.5 months, depending on temperature, and they grow to about 35 mm before pupating. The larvae burrow into the soil just below the surface to pupate, within an earthen cocoon, and remain there for 1-2 weeks. The adult moth emerges from the pupae and a second generation of eggs and larvae occur in late summer (August). Adults are brown delta-shaped heavy-bodied moths (3 cm long) that may be seen flying around outdoor lights at night. During the day they hide at the base of plants or other dark protected places.

Monitoring for True Armyworms: Adult moths can be watched for around lights at night, but also by using pheromone baited bucket-type traps (‘uni-traps’) from April-May and in late July and August. Trapping for adults is useful to show when the moths are present and if numbers could be high enough to be of concern. Additionally, trapping moths is useful for predicting when and where larvae will occur. Set traps in areas of concern, such as beside a field that had heavy larvae infestation earlier in the summer.

Field scouting for larvae should being in mid to late June by checking at least 5 areas of a field. During the day, larvae will be down low on the plant or in the thatch. Scout after sunset and larvae will be up on the plants, where they may be easier to count. Larvae can be dislodged by shaking plants over a drop-sheet or panel and then counted. Get an average number per square foot (30x30 cm) over the 5 sampling sites for an estimate of the field density.

Management: Insecticides are available for control of armyworms. Modifying harvest plans may be necessary to limit losses. Consider cutting, baling, or grazing earlier, as well as irrigation and fertilization to encourage regrowth will help limit losses in hay fields. Cereal crops or corn will face yield reductions if they are defoliated early, but will not be as impacted if feeding occurs later in plant development.

The working threshold for insecticide treatment in forage grass/hay is 5 larvae per 30x30 cm. The threshold is lower for annual cereals: 2-4 larvae per 30x30 cm. For the application to be most worthwhile, apply before most of the larvae reach 25 mm in length.

There are naturally occurring biological control agents that feed on or kill true armyworm larvae, including parasitic wasps and flies, ground beetles and rove beetles, and fungal, bacterial, and viral diseases. As well, several bird species will feast on the larvae. These agents do not prevent an outbreak but can curtail damage to a limited extent.

More information:

Insecticides registered for control of armyworm in forage, grass, corn, July 20, 2017
Labels searched on PMRA Label Search site:

PCP #Product nameActive IngredientCropsPre-harvest or grazing interval# applications/year
Group 28
corn (field, sweet), grass forage, fodder, and hay group, non-grass animal feed group, oilseeds and cereals forage grasses: 0 days PHI; forage corn: 14 day PHIup to 4 apps, 7 days apart; use high rate 
5821Malathion Malathion
Group 1 
cereals, grasses, legumes, alfalfa, clover for hay 7 days 1 app 
27876Sevin Carbaryl
Group 1A 
forage, pasture, cereals 1 day up to 2 apps, 8 days apart 
Group 3 
cereals, corn corn for silage: 14 days; cereals: 28 days; sweet corn: 1 day up to 3 apps, 4-7 days apart 
28778Delegate Spinatoram
Group 5 
cereals, field/forage corn cereals: 21 day PHI; forage corn 7 day PHI up to 3 apps, 5 days apart 

Compiled by Tracy Hueppelsheuser, BC Ministry of Agriculture, Abbotsford
phone: 604-556-3031

True Armyworm 2. Update August 28, 2017

Moth traps were set up during early August near fields that experienced damage during the first generation of caterpillars/armyworms. Moths have been seen in fields and caught consistently in traps in Port Alberni, Courtenay/Comox, and Cowichan valley locations. Traps are checked approximately weekly and number of moths recorded.

moth trap 




It is time to scout for armyworm larvae (caterpillars) in the lush regrowth of the grass fields. Check in areas near or adjacent to the earlier armyworm-damaged fields. Moths will be looking for lush green growing grass to lay new eggs in August. Larvae will be feeding now in those areas. Scout by laying down a ruler or meter stick, and estimating a square foot or quarter meter square and count the larvae you see feeding in the grass. You will need to be down on your knees where you can look closely for larvae up to 1.5 cm long (3/4 inch). Do the first count this week, and then count again in one week. If, on average, more than 5 larvae per square foot are found, you can expect damage from feeding to the grass crop. Do counts in several locations (at least 20) in a field each time before deciding if and where to treat. It may be that only edges or part of a field need to be treated, as the population may be localized or spotty. Armyworm larvae may be green or darker, and have a brown or mottled head capsule. We do not expect to see as many as in July, but is worth counting larvae in areas of concern to know for sure what is happening in the fields.

Full grown larva

Close up of netted pattern and "V" on head of larva.

Armyworm pupa in soil. 


grass damage
Use a ruler, measuring tape, or yard stick, and count the larvae in 1 square foot.  This photo is from the first generation, when there were many larvae per 1 sq.ft. (and lots of damage).

 grass damage
Look for feeding damage in grass.  This is fairly significant feeding by caterpillars during July (first generation of larvae).

Larvae may also feed on corn, but the corn will be able to withstand some feeding and no control actions are expected to be necessary.

corn damage
Larval feeding damage and their frass pellets on young corn plants (July).

If you meet or exceed the larval threshold for grass crops, control may be warranted.

Options for your consideration:

  • Foliar spray if possible or desired
  • Cut hay early to minimize damage (get the crop before the caterpillars do)
  • Graze sooner rather than later (caterpillars are not hazardous to livestock)

More information:


Prepared by: Tracy Hueppelsheuser, B.C. Ministry of Agriculture, 604-556-3031

True Armyworm 3. Confirmed in Abbotsford Grass Hay Fields August 2017

True Armyworms have been confirmed in Abbotsford grass hay fields. Growers should check hay fields for armyworms (caterpillars) not only on Vancouver Island, but also in the Fraser Valley.

For more information: Tracy Hueppelsheuser Entomologist, Plant and Animal Health Branch, British Columbia Ministry of Agriculture
Phone: 604-556-3031

True Armyworm 4. Pest Alert September 7, 2017

True Armyworm (Pseudoletia unipuncta or Mythinma unipuncta) second generation larvae have been observed severely damaging grass hay and forage corn in the Fraser Valley and Vancouver lsland.

General Locations confirmed with heavy larvae feeding and damage to grass hay and corn:

  • Vancouver Island locations seeing damage on grass fields: Saanich, Duncan, Chemainus, Port Alberni, Comox, Courtenay, Black Creek 

  • Fraser Valley locations seeing damage on grass fields and forage corn: Delta, Abbotsford, Sumas, Chilliwack, Deroche

Scout your fields for larvae activity. If you can easily find larvae, the damage threshold has been reached, and management options should be considered. Significant foliage loss can occur in a few days, either in spots, edges, or throughout a whole field. Moist, lusher areas are preferred, i.e. low areas, shady, and greener areas. Larvae will move to new feeding sites en masse once an area is consumed. They can be seen on roads and in yards, searching for new feeding areas. Significant damage can happen quickly, within a few days. 

Feeding mostly occurs from sunset through until mid-morning when temperatures warm up. During the warmer mid- day times, the larvae take refuge under plant bases, foliage on the ground, under plant crowns, and even under dirt clods and stones. 

The larvae go through 6 instars (stages), and the last 3 stages are when they feed the most and do the most damage. Currently, there are a range of sizes being observed, from 0.5 to 1 inch in size (1-3 cm). Larvae will continue to feed and cause damage for at least another couple of weeks.

Management options include (not necessarily in this order!): Harvest: get the crop off before the larvae devour it. 

Cultivate: and then wait 10-14 days before planting a new fall crop to ensure larvae have either starved or moved on. 

Spray: there are insecticides registered for grass hay and corn. Decision to treat will depend on the field, plan for the crop and how many larvae there are in the field (if you find larvae and damage you are already over the action threshold!). One to two applications may be needed; check the field 2 days after the first spray and then scout regularly to determine if a second spray is needed. Suitable rates are on the labels for armyworm, use the higher rates of the rate range if possible. 

Prepared by Tracy Hueppelsheuser, 604-556-3031, B.C. Ministry of Agriculture, Abbotsford


True Armyworm 5. June 2018

True armyworm (Mythimna unipuncta, formerly Pseudaletia unipuncta) is a North American agricultural pest in the insect family Noctuidae. During April and May, true armyworm moths may migrate from southern USA and Mexico on wind currents to parts of Southern Canada including B.C., Manitoba, and Ontario. True armyworm is not known to overwinter in Canada. 


True armyworm prefers grass crops such as cereals, pasture, grass hay and corn. However, under high populations, true armyworm larvae may also feed on broad leaf plants. Adults feed on flower nectar or other sweet sources. 


Young larvae will skeletonize grass foliage and eat small holes in leaves. From the third instar and older, larvae will devour entire leaves. Larvae will also sometimes feed on developing seed heads and corn tassels and ears. Once an area is sufficiently defoliated, larvae will move in a group to other grass stands to resume feeding. True armyworms can cause significant but often patchy crop damage in only a few days, and can cause rapid crop devastation when the larvae population is high. In southwest B.C., the first generation of larvae, feeding in June and July, can cause significant crop loss to grass hay and cereals. The second generation of larvae in August and September can be even more destructive, affecting both grass and corn crops. 2017 was the first year damage was recorded for this pest in B.C. 


True armyworm moths may migrate to B.C. in April-May in unpredictable numbers, influenced by weather, temperature, winds, and conditions in their originating locations, which are more southerly locations in North America. Moths can live for weeks, and seek lush green grass for egg laying. Eggs are laid deep within folded grass blades and are nearly impossible to find in fields. Both egg masses and larvae can be abundant in localized areas. 

There are 6 larval instars, with the last two instars causing the majority of feeding damage (Figure 3). The larvae stage lasts approximately 1.5 months, depending on temperature, in which time the larvae grow from 4 mm up to 35 mm. Young larvae mostly feed during the day and are well hidden by grass blades. Older larvae are nocturnal feeders and move up the plants, and rest at the base of plants and under grass canopy during the heat of the day. Larvae are marked with stripes running the length of their body, with a yellow/brown head capsule with a netted appearance (Figure 5), while the body colour ranges from pale green while young, to nearly black when full sized. When larvae are ready to pupate, they burrow into the soil just below the surface where they remain for 1-2 weeks (Figure 6). 

Adult moths emerge from the soil and a second generation occurs in late summer (August-September). Adult moths are about 2cm long with brown, delta-shaped bodies and have a distinguishing white dot on each wing (Figure 4). Adult moths are nocturnal and may be seen flying around outdoor lights at night, while hiding at the base of plants or other dark protected areas during the day.