It’s a strange topic to inject into a conversation, but Wist is used to it and expects it to happen.

“At least once at every show, someone goes, ‘well, you need to plant marigolds around your plants and (then) you won’t get flea beetles,’” said Wist, a field crop entomologist with Agriculture Canada in Saskatoon and a flea beetle expert.

Do marigolds repel pests?

Wist has heard the “marigolds repel pests” comment so many times that he decided to test the concept this growing season at Ag in Motion, held July 15-17 near Langham, Sask.

“I thought … if people are going to keep (telling) me this, I maybe should do this experiment,” Wist said.

“It’s (really) a demo plot. I wouldn’t call it an experiment.”

At the show, Wist has canola plots that are surrounded by marigolds to see if the flowers can deter flea beetles from chomping on canola plants. Every spring, striped or crucifer flea beetles will invade canola fields somewhere in Western Canada, devastating the crop and sometimes forcing farmers to re-seed their fields.

Wist is one of several Agriculture Canada scientists who have crop plots at Ag In Motion. In total, about two dozen companies and organizations have crop plots at AIM, where agronomists and crop management experts will talk about the latest varieties, disease management and methods to control annoying pests such as flea beetles.

Wist knows it’s unlikely that a commercial-scale farmer, with 8,000 acres of land, is going to plant thousands of marigolds next to their canola field.

Luring flea beetles into a trap crop

However, another cultural practice could be more feasible – seeding a trap crop near the canola. The basic idea is to lure the beetles into the trap crop and then hit them with an insecticide.

One possibility for a trap crop is radishes.

“When we (as researchers) try to grow colonies of flea beetles, we feed them various (plants),” Wist said.

“If you give them the choice between canola and radish, the adult flea beetles prefer to feed on radish.”

To test out this theory, Wist and his team planted a trap crop by his canola plots at Ag in Motion to see if flea beetles could be lured into the trap.

Wist emphasized that this isn’t a full-scale, replicated experiment. It’s a demonstration of using trap crops to control flea beetles and also a way to start a conversation with canola growers who are weary of battling flea beetles every spring.

Trap crops for other pests

Other scientists have studied trap crops for other pests, such as pea leaf weevils that attack field peas.

Meghan Vankosky, an entomologist who also works for Agriculture Canada in Saskatoon, did an experiment where she seeded a strip of field peas or fababeans in July so that the strip would attract weevils in late August or September.

“In the fall, the new generation of adults come out and they’re looking for anything green to eat…. If we had a trap strip along the edge of a field, that would attract those new generation adults,” she said.

“What we wanted to know … could we use trap crops in the spring or in the fall, to aggregate weevil populations and control them?”

The results? The trap crops performed as expected.

“(They) definitely worked to bring those weevils in,” Vankosky said.

A similar strategy might work for flea beetles, where a late summer trap crop could be used to kill flea beetles before they over-winter. Ideally, that would reduce the population of beetles for the following spring.

“If you have a trap crop growing at that point (in the summer), maybe you could draw in enough flea beetles,” Wist said.

“Give them something else (besides canola) … then spray those guys in a concentrated area.”

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On Sept. 17, Bayer announced that its Buteo start seed treatment has been registered for mustard in Western Canada.

“The damage caused by flea beetles at the start of the season impacts crop development long-term and can lead to significant yield loss,” Bryan Bryson, Bayer marketing portfolio lead for traits and licensing, said in a release.

The Group 4D, flupyradifurone-based product reached the Canadian market in 2020. Its label now covers early season control of flea beetles in canola, as well as soybean aphid and bean leaf beetle in soybeans, although promotional materials from the company heavily market the insecticide for its canola applications.

The company pitches the product for control of striped and crucifer flea beetles. Fact sheets published by the company cite canola trials done in 2019 in flea beetle-infested areas. Those trials found that a combination of Buteo start and the seed treatment ProsperEverGol (which is also registered for mustard), showed significantly less leaf damage from three to 17 days post-emergence, quicker crop progression and a thicker stand.

The insecticide “delivers rapid uptake and systemic translocation from cotyledon to leaf margins, enabling a quicker-growing canopy and uniform flowering, even in dry conditions where flea beetles thrive,” the Sept. 17 release said.

Mustard growers face many of the same agronomic challenges as canola growers do, the company noted, and that includes flea beetles.

The insects have been a perennial problem for canola growers. Several years of difficult spring conditions led to stalled stands while plants were vulnerable. Significant and sometimes repeated applications of foliar spray were needed once seed treatments wore off.

According to the Canola Council of Canada, heavy flea beetle infestation can cause a 10 per cent yield reduction even when insecticides are applied.

“A yield reduction of one per cent per acre results in a total crop loss of about 25 million to 35 million dollars,” the council’s website states. “Annual crop losses in North America from flea beetles potentially exceed 300 million dollars.”

According to the manual put out by the Saskatchewan Mustard Development Commission, “damage is most severe when the beetles attack the growing point of the plant. In cool moist conditions, scouting should include observing the underside of cotyledons for pitting and the stem for notching or girdling. Feeding on pods can result in premature shattering and grade loss.”

The post Western mustard growers get new flea beetle seed treatment option appeared first on Country Guide.

Jennifer Otani, a pest management scientist with Agriculture and Agri-Food Canada in the Peace River region, says there were reports of high numbers of adult flea beetles aggregating on the pods or collecting on machinery during last year’s harvest in some areas of the Prairies.

Otani says that although the presence of newly emerging adults in late summer is normal, “we know that when it’s easy to find late-season flea beetles, we should anticipate a higher level of risk for the following spring. It does elevate the prioritization of spring scouting.”

She says several factors influence overwintering survival, including adult movement, reproductive capacity and survival of larvae to pupae in the soil, along with emergence and dispersal of the newly emerging adults. If flea beetle densities are indeed high early in the spring, it may be critical to scout daily, especially if seedlings aren’t growing quickly.

Zero-till advantage

Rotation reduces some flea beetle risk. “In some years, we’ve seen producers end up with canola-on-canola rotations and the concern here is that flea beetles and other insect pests of canola really have a continuous buffet,” Otani says. 

James Tansey, provincial pest management specialist for the Saskatchewan Ministry of Agriculture, says there’s some evidence that zero till can help with flea beetle control, as they prefer open habitat. This may be due to better accumulation of heat and/or the effect of debris impeding their movement. 

Manitoba Agriculture entomologist John Gavloski says the insects prefer environments that are exposed to bright sunlight and are relatively warm. “Direct seeding into standing stubble provides a microclimate which is less ideal for flea beetles. This seeding method often produces larger plants early and may reduce the producer’s dependence on insecticides, except under conditions of intense flea beetle pressure.”

Theoretically, cover crops with their extra debris could also impede the movement of flea beetles. Last summer, there were reports that a Manitoba field of canola seeded into a terminated rye cover crop was hardly touched by the insects. 

Otani says more work needs to be done to address which crops might work, what rotations might prove beneficial in overall flea beetle management, with regional differences to be expected.

Tansey says there’s some evidence that higher seeding rates can provide some flea beetle control. Treated seed is expensive, but he notes that seed treatment in addition to in-season overspray was often required in 2021 and may be needed again in 2022, especially if it’s another warm, dry year. 

“We certainly saw a need for spraying last year and in some cases, multiple spray treatments were needed, but hold to the economic thresholds. If you’re seeing 25 per cent defoliation in canola, that’s the threshold and act quickly. 

“But if your canola is past the four-leaf stage, the plants can tolerate a lot of defoliation, and spraying for flea beetles may not be useful. Keep an eye on the populations, though. If numbers are very high and great damage is accumulating, control may still be needed even at this stage.” Otani says that an early, dry spring could mean that seeding can be started early, but overwintering insects like flea beetles would also become active early. 

“Spring growing conditions, and especially soil moisture levels, will factor heavily in the ability of canola seedling to pop up, grow and quickly get past that most vulnerable growth stage,” she says. “Once it’s seeded, growers really must scout. It’s always best to never assume anything when it comes to spring flea beetles.” 

Know your hoppers

Gavloski says there are five main species of grasshoppers that are potential crop pests on the Prairies, and they all have different food preferences. Therefore, knowing the dominant species on your farm can determine which crops may be affected. 

“For example, clearwinged grasshopper is primarily a grass feeder and seldom feeds on broad-leaved plants. Some crops, such as peas or oats, may be less preferred by some species … but grasshoppers will still feed on them.” 

Much of the egg hatch for the potential pest species is usually in late May or early June. Gavloski says that earlier-seeded crops can sometimes tolerate grasshopper feeding better than late-seeded crops. 

A Manitoba Agriculture factsheet says seed density can be increased along field margins. “For example, doubling the planting populations for a strip that is between 20 to 40 metres wide around the field edge. This increased plant stand should slow the movement of grasshoppers into the rest of the field, and compensate for lost seedlings.”

Spraying threshold

Tansey says the economic spray threshold for grasshoppers is 10-12 large nymphs or adults per square metre for most crops. Lentils and flax in boll are more sensitive so thresholds of two per square metre should be used. 

“There’s no economic benefit before that and negative effects to the natural enemies of grasshoppers can occur, so hold to the threshold. Don’t use a calendar spraying schedule, but instead scout and take timely action if you hit the threshold.” 

The Manitoba Agriculture factsheet says if timely rains keep the vegetation in and around hatching beds green, grasshoppers may not move to adjacent crops until later in the season. Early scouting should therefore focus on areas of anticipated egg hatch. 

In addition, remember that when grasshoppers are young, they can be confused with some of the larger species of leafhoppers which can be abundant in the vegetation around fields but are not crop pests.

Tansey says if 2022 is another warm, dry year, both flea beetles and grasshoppers will do well, and if it’s hot, grasshoppers can thrive. “Striped flea beetle activity starts to diminish at about 26 Celsius and crucifer flea beetle is more heat-tolerant but its activity is low in the mid-30s,” he says. 

“However, grasshoppers like it warm and the optimum temperatures for the activity for some of the pest grasshopper species is in the 30s. Effective scouting for both flea beetles and grasshoppers is your most powerful tool.”

More information:

• Updated Manitoba Agriculture grasshopper factsheet, including photos of the harmful species 
• Manitoba Agriculture flea beetles factsheet
• The Prairie Pest Monitoring network has weekly updates in the growing season, with information such as monitoring protocols, risk maps and a wind watch.
• In-season insect maps for Alberta

The post Hopper and beetle watch appeared first on Country Guide.

Days to maturity

Canola growers could use earlier-maturing hybrids on at least some fields to dodge challenging weather in spring, summer and fall. 

“Waiting for rain, then seeding a short-season hybrid, should mean faster establishment, which will help the crop grow through the flea beetle risk period a lot faster. Earlier-maturing hybrids also tend to flower earlier, which will beat the hottest summer days — most years, at least,” says Clint Jurke, agronomy director for the Canola Council of Canada. 

“And finally, they can be ready to harvest before later-maturing hybrids, which helps if fall frost and green seed are higher risks.”

Canola Performance Trials, funded by the provincial canola farmer organizations, compare leading hybrids based on several factors, including days to maturity. Find results booklets and the online comparison tool at canolaperformancetrials.ca.

Clubroot resistance

“Clubroot risk is everywhere across the Prairies,” says Autumn Barnes, agronomy specialist and clubroot lead for the CCC. “For this reason, we believe there is a case for all canola growers to choose clubroot-resistant hybrids, including those who have not yet discovered a clubroot problem.”

Planting clubroot-resistant (CR) hybrids before the disease gets established will slow the pace of spore reproduction. “This will help keep spores low and local,” Barnes says. “Growers who wait until the disease has taken hold in a field before choosing CR could be stuck with challenging levels of clubroot for a long time.”

Hand-in-hand with CR is a minimum two-year break between canola crops (one in three-year rotation). This also helps keep spores low and protects the CR trait from natural selection of more virulent clubroot pathotypes that can overcome the CR trait. Dozens of CR hybrids are on the market for 2022. Find the list and more tips on clubroot prevention and management in the diseases section at canolaencyclopedia.ca.

Pod-shatter resistance

Cutting canola at or after 60 per cent seed colour change on the main stem will usually lead to higher yields compared to cutting earlier. Hybrids with pod-shatter resistance can be cut even later — at 80 per cent seed colour change or straight combined — with lower risk and higher yield potential. 

“Thinner crops like we have in 2021 always raise questions about harvest. Should I swath to prevent losses from standing crops whipping in the wind? Or should I leave it standing because swaths are going to roll without good tall stubble to anchor them?” says Shawn Senko, agronomy specialist and harvest management lead for the CCC. “Pod-shatter resistance can be especially helpful in reducing wind losses for standing crop, which adds to the yield benefit.”

Increased yield potential makes pod-shatter resistance something to consider in 2022.

Flea beetle seed treatment

After 2021, many western Canadian canola growers might be wishing for a flea beetle resistance trait. In a recent CCC survey of 1,000 growers, flea beetles ranked as the number one pest among those surveyed, and 2021 was no exception. Flea beetle resistance is not on the ticket for 2022 — or anytime in the near future — but enhanced seed treatments are an option.

“If foliar spraying is becoming regular practice on your farm, consider booking seed with an enhanced insecticide seed treatment for 2022,” says Keith Gabert, agronomy specialist and insect management lead for the CCC.

Enhanced insecticide seed treatments are not perfect, but they should make flea beetles somewhat more manageable when used in combination with other practices. These other practices, Gabert says, include higher seeding rates and seeding into standing stubble — both of which can factor into seed orders and harvest management this fall.

The recommended canola stand is five to eight plants per square foot. “Targeting eight plants per square foot allows for some plant loss without sacrificing yield potential,” Gabert says. “It also means fewer flea beetles per plant and more seed treatment per acre.”

As for stubble, Gabert says the wind protection from standing stems should trap snow, conserve moisture and may even reduce flea beetle risk. “Without that wind protection, flea beetles can take shelter at ground level and start feeding on stems instead,” Gabert says. “This stem feeding can be much more damaging than leaf feeding.”

Every farm and field will have their own challenges to productivity and profitability of canola. Seed decisions can play a big role in risk management, with successful canola crops often starting with the right traits, treatments and rates.

The post Four canola seed considerations for 2022 appeared first on Country Guide.

This year, many producers had to decide how firmly to respond to pest pressures hovering around the economic threshold. Scott Meers, Alberta’s provincial entomologist, says this was the case for flea beetles in canola in the province.

“If the crop is not doing well, we have to be more sensitive about control — be more aggressive in applying the economic threshold, rather than waiting for things to develop,” he said in an interview. “I think what happened was that a lot of fields were below threshold, and then we came back a few days later and things were bad.”

Scott Hartley, the provincial entomologist in Saskatchewan, says the same was true for aphids in Saskatchewan cereals. “This year, there were aphids in everything, almost every crop,” he said.

Aphids are uncommon in cereals, and this year, they either arrived too late or populations did not reach economic levels until late in the year. “In the later cereal crops, control would have been worthwhile, but in many, by the time the aphids were noticed, the crops were too advanced to warrant control,” he said.

Across the Prairies, aphids and grasshoppers emerged as the most significant general pest threats, affecting almost all crops, particularly in Alberta and Saskatchewan. In Manitoba, cutworms were also a significant problem for most crops, according to John Gavloski, the province’s head entomologist.

For canola, cereals and pulses, a variety of pest pressures across the Prairies kept all three entomologists on their toes in 2015.

Canola

In canola, flea beetles emerged as the pest of greatest concern across the Prairies.

In Manitoba, Gavloski said seed treatment to manage early-season flea beetle populations is common in the province, but feeding damage affected crops at or above threshold levels in early-season canola once treatments wore off, forcing producers to spray. “Late May through June, they were a big issue,” he said.

Hartley said that due to Saskatchewan’s early spring, flea beetle populations were higher than the province had seen in years.

“Even though we did get some good heat, we had cool nights, dry conditions and slow growth for a while, which meant that canola seedlings were more vulnerable to flea beetle,” Hartley said. “When you have higher numbers than you’ve seen in a while, producers have to refresh themselves on control options and scouting for certain pests.”

Meers said flea beetle pressure was high in Alberta for similar reasons. “The canola crop was not growing aggressively — this year it was very slow to develop,” he said.

Across Saskatchewan and Alberta, producers saw a significant northern range expansion for cabbage seed pod weevil. The weevil survey indicated significant populations as far north as Kindersley. It is also established as far east as Indian Head.

Cabbage seed pod weevil is a perennial issue in Alberta, but the pest pushed a surprising distance north. “Numbers were more or less normal in the established range, which is essentially Highway 1 and south, but we saw a fairly substantial range expansion into the Lacombe area,” Meers said.

Bertha army worm counts were low in Alberta and Saskatchewan, and remained below threshold in 2015 in Manitoba. Diamondback moth similarly remained below threshold levels in all provinces.

Swede midge, an invasive pest first detected in Ontario in 2000, was found in Saskatchewan in 2007, according to Hartley, but was picked up in significant numbers only in 2012.

“Surveys by AAFC found that it has a broad distribution across the northern Grain Belt from Nipawin and Carrot River across through Prince Albert toward Lloydminster and North Battleford,” Hartley said. Swede midge was detected this year just across the Alberta border. Only very low levels of swede midge have been detected in Manitoba.

Cereals

In Manitoba, the biggest pest threat facing cereals was army worm, which blows in from the south. But this year Gavloski noted an uprising against the pest from a surprising source — a small back parasitic wasp known as Cotesia.

“In mid-July I was getting a lot of people sending photos of what they suspected were egg masses on top of the cereal plants. They were actually clusters of pupal cases for Cotesia,” Gavloski said. “The army worm population was heavily parasitized. We do often get a second generation of army worms, but we didn’t notice much of a second generation this year, so the parasitism knocked things back quite a bit.”

Army worm was less of an issue in Saskatchewan and Alberta, where grasshoppers presented a bigger threat.

Meers said grasshoppers presented a greater problem this year than last year in Alberta. “It’s a double-edged sword — in dry springs, the crops don’t do as well and the grasshoppers do very well, so the damage is worse than the numbers would indicate. We’re poised for a big increase in grasshopper numbers if we get another dry spring next year.”

Grasshopper numbers built up through the southwest, west-central and east-central areas of Saskatchewan, Hartley said.

In both Saskatchewan and Alberta, there were large populations of English grain aphid that although normally green was pigmented orange this year, likely due to environmental conditions.

Pulses

By far the greatest pest threats facing Saskatchewan pulse producers this year were aphids and grasshoppers, according to Hartley.

Grasshoppers have been sprayed for the last few years in lentils, where threshold levels are extremely low — two grasshoppers per square metre.

“Economic thresholds tend to go down any time the insect is feeding on the yield component, such as lentil pods, where there’s a direct effect on yields,” Hartley said.

Alberta saw a range expansion for pea leaf weevil. “We’ve always considered it a southern Alberta pest, but we had very serious high numbers into the Lacombe area, and we were finding it on fababeans as far north as Edmonton in the fall, so it’s made a major jump north,” said Meers.

Expansion in pea leaf weevil range seems to be following fababean acreage expansion, but Meers said it’s too soon to tell what is causing the increase.

Manitoba’s only significant pest concern in pulses was soybean aphid. “But overall it was moderate — we have seen much worse,” Gavloski said. “A lot depends on when they arrive. And once again we noticed a lot of natural enemies in soybean fields, and quite a few people let the natural enemies take care of aphids.”

Gavloski believes producers are becoming much more aware of natural enemies of insect pests, and at times willing to let them regulate potential pests. “Many producers are willing to wait and see if natural enemies can regulate pest levels, rather than quickly resort to insecticides,” he said. “A lot of them get concerned when they have a high-value crop, but at the same time they would like to let nature take its course.”

The post Grasshoppers, aphids top crop pests in 2015 appeared first on Country Guide.

Bob Elliott, integrated pest management scientist with Agriculture and Agri-Food Canada (AAFC) in Saskatoon, saw a fivefold increase in adults captured in sticky traps in summer 2015 compared to summer 2014. This was on top of a significantly higher spring population.

Late-summer feeding is not usually an economic concern, even with big numbers, but the sight of these clusters had Canola Council of Canada agronomists wondering what 2016 will bring. Flea beetles that hatch and grow into adults through the summer are the generation that overwinters and emerges in the spring looking for young canola plants to eat.

“Flea beetles are the most important — the most costly — insect pest in canola, with just about every acre getting protection through seed treatment and a percentage of those same acres also getting in an in-crop application,” says CCC agronomy specialist Keith Gabert. “The in-crop protection decision seemed especially common in 2015, with widespread cool and dry spring conditions that delayed crop establishment and left the crop vulnerable for longer.”

The Canola Watch agronomy e-newsletter regularly addressed the heavy flea beetle situation during crop establishment in May. Slow emergence or delayed emergence due to dry soil, cool temperatures and repeated frost stretched the length of time plants needed protection from flea beetles. Unthrifty plants were extra vulnerable. Many fields needed to be reseeded, and many others with just enough plants to make it through had to be sprayed.

“Lower populations of surviving plants meant growers had to pay closer attention to thresholds and were more likely to spray this year to protect that minimum stand,” Gabert says. “So with the high summer population, what will growers face in 2016?”

Entomologists are careful not to read too much into fall numbers. Past research did not show a strong correlation between fall numbers and the spring threat. However, Alejandro Costamanga at the University of Manitoba is leading a Prairie-wide grower-funded research collaboration focused on an integrated approach to flea beetle management. This research will provide improved economic thresholds for flea beetles in different ecozones, identify natural predators, and develop predictive models based on overwintering flea beetle populations, weather and other variables. The researchers believe advances in genomics and data analytics may make this modelling realistic. Results will not be available for 2016.

Plan for 2016

Best management practices for flea beetles remain seed treatment, followed by good agronomy to provide a minimum stand of seven to 10 plants per square foot, and in-crop scouting up to the four-leaf stage to see if foliar insecticide is required.

Even though current seed treatments are not as effective on striped flea beetles as they are on crucifer flea beetles, seed treatment is still an important investment, Gabert says. “And I can’t emphasize enough the value of a well-established stand. A fast-growing even stand is one of your best defences.”

Seed treatment and rapid, even stand establishment set up the crop to withstand most foliar flea beetle feeding that may occur. Thin stands, delayed emergence, and stress such as cool and dry conditions increase the likelihood that a foliar application is needed.

“I don’t know if there are currently any better ways to manage flea beetles than what canola growers are typically doing,” says Manitoba Agriculture, Food and Rural Development provincial entomologist John Gavloski. “Assessing defoliation to make spray decisions can be tricky, and damage can progress very quickly when weather is hot and calm and flea beetle populations are high. So management strategies that may reduce the need for foliar insecticide applications would be welcome.”

Hopefully in the future new strategies such as incorporating resistant varieties or enhanced control through natural enemies could be part of the management program, Gavloski says.

Flea beetle management in the future

“We do have new management tools in development that will further help growers with flea beetle management and we hope to bring some of those to market in time for the 2017 planting season,” says Ted Labun, Western Canada seedcare technical lead for Syngenta, the company that makes Helix seed treatment.

Elliott and his team at AAFC have been field testing new chemistries currently under review by the Pest Management Regulatory Agency (PMRA) and are preparing three scientific papers that will be submitted for publication once the products are registered. The papers will describe seed treatments and mixtures that provide the best control, protection and agronomic improvements when crucifer and/or striped flea beetles are a problem. They will also describe the impact of temperature and soil moisture on the efficacy of the products against each species.

“Once these new products are available, it will be helpful for flea beetle management if growers are able to choose the most appropriate active ingredient or combination based on their local conditions or their pesticide rotation,” Elliott says.

Jay Whetter is communications manager and Canola Watch editor with the Canola Council of Canada. To read Canola Watch flea beetle management articles, go to canolawatch.org. While at the site, sign up to receive the free agronomy email newsletter.

The post A busy year for flea beetles in canola appeared first on Country Guide.

One of agriculture’s big challenges is dealing with different insects in different geographies, and doing the best you can to hedge your bets. Like the markets, however, insects are subject to a fair bit of detailed analysis, and every year the entomologists from the three Prairie provinces meet at the Western Pest Forum to present their version of the year that was, and to get a handle on the year that might be.

There are a number of factors that come together to make insects behave the way they do. Weather is one of the big ones, and the insects’ reproductive ability is another. The right number of egg layers surrounded by the right food and enjoying the right weather is a recipe for a perfect storm. When it all comes together, that’s when you get a plague.

On the other hand, you can also get a population crash, even when everything looks like it’s breaking in the insects’ favour. For instance, with grasshoppers, a well-timed rainfall could make the difference between a quiet year and an explosion.

Grasshoppers building

“Well-timed is when the grasshoppers are first emerging,” says Alberta’s Scott Meers. “Raindrops are like little bombs on them, so they get bombarded by rain. Now I don’t think a raindrop would kill them directly, but it makes it cool and damp and they become susceptible to predation, starvation and diseases. If they’re not feeding regularly, which they can’t do when it’s wet and cold, they tend to die off.”

Wet and cold were last spring’s operative words for the Prairies, with melting, drying and seeding all behind schedule. Grasshoppers prefer a warm, dry spring, so 2014 should not have been a grasshopper year. Yet in some places on the eastern Prairies, grasshoppers were a major story.

“It was an interesting year, not what I would call ideal,” says Manitoba’s John Gavloski. “I think there were a lot of eggs in the ground from the previous summer because they had good egg-laying conditions. We got a decent hatch so there was a lot of edge spraying going on. Certainly some fields were sprayed.”

Gavloski also attributes the greater numbers to warmer and drier weather later in the summer.

Hoppers have been building for a couple of years, so they could be headed for some kind of a peak if conditions line up. If Manitoba farmers have a dry spring this year, they may want to keep an eye on their ditches and be ready.

Scott Meers in Alberta agrees, and he advises farmers that grasshoppers may not be gearing up for an explosion on par with 2002 but they could be on the upswing and farmers should watch for larger hatches in the spring.

In Saskatchewan, however, Scott Hartley isn’t calling for big numbers. Last summer’s wet conditions kept hopper populations down over most of the province except for some areas around Maple Creek, off toward the river and west of the sand hills where there was some spraying. But cutworms were another story.

“After a three-year decline, we were expecting it to continue in 2014 but actually it went the other way,” Hartley says. “Early on, cutworms were probably one of the biggest issues. Maybe not as big as four years ago but it still surged much over what it was in 2013.”

Mixed cutworm threat

As with many of our pest species, cutworms aren’t easy to predict and any of several things can affect their numbers. As if that’s not bad enough, there are upwards of five different species.

Cutworms also like to live within the soil, which makes them harder to find and monitor. In fact, sometimes the only real sign that cutworms are a threat is actual crop damage.

“Whether or not they were a huge issue, it was certainly bigger than the year before, so it’s one that we’ll want producers to keep an eye out for in 2015,” Hartley says.

“Cutworms are regulated by natural enemies and particularly by diseases in Manitoba,” Gavloski adds. “The population goes through these cycles and we’re at that peak where we’ve got some higher populations. Sometimes we’ll get a few bad years in a row and populations drop and stay low for a few years and swing back up.”

The weevil risk

“Our cutworm numbers were actually down in 2014, but we really don’t know what that means year-to-year since cutworms are such a hit-and-miss thing,” says Alberta’s Scott Meers. “I expect that we’re still going to have trouble with pea leaf weevil and cabbage seed pod weevil in our traditional areas south of Highway 1.”

In its larval stage the pea leaf weevil feeds on the roots and root nodules of legumes while the adults feed on the leaves. It’s a relative newcomer and was first found in southern Alberta in 2002. It’s particularly fond of fababeans and this could be a serious problem with the growing popularity of faba. It’s a prodigious egg layer with individual females laying up to 1,500 eggs in the soil.

“We’re seeing pea leaf weevil as a problem primarily in southwest Saskatchewan, although it has shown some damage north of the South Saskatchewan River,” Hartley says. “It’s still primarily south of the river and east of the Alberta border to Swift Current.”

Hartley suggests if you had trouble with pea leaf weevil last year you may want to consider a seed treatment for this year. He also suggests looking for its cousin, the cabbage seed pod weevil.

“2013 was a banner year for cabbage seed pod weevil and it’s showing up at a latitude level with Kindersley and Outlook,” Hartley says. “It is north of the South Saskatchewan River now and it’s also well east of Regina. It’s still primarily in the southern regions and not quite to the Manitoba border yet but it’s now into the traditional canola-growing area.”

The seed pod weevil arrived in Canada in the 1930s and is a pest on canola, mustard and the cole crops like broccoli and cabbage. The adults emerge from the leaf litter in the spring and find their way to a plant where they feed on the floral buds and young seed pods. They lay their eggs on the pods where the larva continue feeding on the seeds. They cut their way out and drop into the soil where they pupate. They mature in August, emerge from the soil and overwinter in leaf litter.

Flea beetles and midge

Another canola pest, the flea beetle was not a big problem over most of the Prairies except in Manitoba. Flea beetles don’t like a cool wet spring but they still caused trouble in the eastern plains. It could be a result of the plants emerging slowly and remaining cool for a long period of time.

“That creates problems because the seed treatments eventually wear off and people are out doing foliar sprays in addition to seed treatments,” Gavloski says. “The plants had a hard time getting to that point where they were big enough to resist the flea beetles. The numbers were quite high so if we get a cool, wet spring again then flea beetles would probably be another one to watch.”

Flea beetles are a perennial problem in canola just as wheat midge is a perennial problem in wheat. Alberta and Saskatchewan both had trouble with wheat midge. In Alberta it was the Peace Region that was hardest hit.

“There was substantial damage in 2013 and in our soil survey the numbers were very, very high,” Meers says. “We’re still processing our samples from our fall survey. For the Peace it looks like the risk is going to be lower going into 2015, but we have had some individual sites that are fairly high in central Alberta so we may have midge issues we’ll have to watch in central Alberta.”

“It’s sort of our perennial pest in wheat and certainly the wheat midge forecast map had indicated that there was going to be a lot on the eastern side of Saskatchewan,” Hartley says. “Every year, midge is a problem somewhere in the province although we’ve got increased acreage of midge-tolerant wheat planted.

Those were the big insect problems encountered by Prairie farmers this year. Others that may be worth looking for include Bertha armyworm, diamond back moth and lygus bug. Farmers may also see the detailed reports from the Western Pest Forum at its website.

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