Each patch of Canada thistle needs a tray of weevils and there are 100 weevils in a tray. The insects overwinter in soil and leaf litter, emerge in spring to feed on thistles, and then lay eggs. After hatching, the larva tunnel down the stem, which kills the weed.

The association has seen significant impacts since it first began releasing weevils a decade ago in three districts, says an article in a recent Foothills Forage & Grazing Association newsletter.

To order trays, contact Karin Roen 403-664-3777 or cara3@telus.net.

The post Biological control for Canada thistle on deck appeared first on Alberta Farmer Express.

“All of the weeds here can come from other parts of the world, mostly Europe and some from Asia, and establish here without the organisms that keep them in check in their home range,” said De Clerck-Floate, an expert in insects and biological control of weeds at Agriculture and Agri-Food Canada’s Lethbridge research station.

But the tricky bit is making sure that introduced insects, also known as agents, are truly host specific and won’t feed on or damage other plants they aren’t supposed to.

“Most of the testing occurs overseas, where the insects that you’re testing occur naturally. That way they can test them outdoors, as well as indoors in cages,” said De Clerck-Floate, adding she and fellow insect ecologist Rob Bourchier collaborate with a Swiss agency that has expertise in biocontrols.

They are able to do their own testing because they have a quarantine facility.

“It’s specifically designed to keep these insects that we work with indoors and under wraps so they don’t get loose in the environment before they are tested and petitioned for release,” she said.

Petitioning is part of the process that includes submitting a detailed report to the Canadian Food Inspection Agency and a review by experts. If approval is given, the next step is helping the newcomers get established in their new homeland.

“Some of them don’t survive our winters well,” said De Clerck-Floate. “We also release them in different habitats and climatic areas. We get a good sense of where they’re going to establish, and what kind of impact they are going to have on the weed.”

Biological control is just one tool to handle weeds, along with herbicides.

“When you reach a point with the weed when you can’t contain it, or you can’t spray it because it is in a sensitive habitat, biological control is a potential tool — if we can find an agent that is really effective,” she said.

Currently, De Clerck-Floate is looking at agents for two types of toadflax (dalmatian and yellow).

“Both are a problem in rangelands, but yellow is also a problem in northern farmland in crops like alfalfa and even barley. It’s a problem in strawberries in Eastern Canada.”

Yellow toadflax grows in southern and central Alberta and around Edmonton.

Researchers (there are also American scientists working on biological controls) think they may have found a suitable agent for yellow toadflax. It’s a type of weevil that lays its eggs into the growing shoots of yellow toadflax, producing galls. The larvae sit in the gall, and all the nourishment comes to them, starving the plant.

Once again, it’s a case of getting the critters settled but the weevil is establishing well in cooler habitats.

“We have wonderful populations in the mountains. We released it in southeastern B.C. near Elkford, and it’s doing well in the Calgary area, near the foothills.”

De Clerck-Floate is also working on a new insect to combat oxeye daisy, a pasture invader from Europe that cattle won’t eat and can contaminate grass seeds like timothy or alfalfa.

“The agent that we’re petitioning is a moth whose larva feeds on the roots of the oxeye daisy,” said De Clerck-Floate. “Based on our testing, it’s pretty host specific, so it looks like a good agent, and it looks like it could be really effective.”

Common tansy is another big threat in parts of northern Alberta. Scientists are working to bring in a Russian weevil with larvae that feed on the stems of the common tansy.

However, with biocontrol, effective control doesn’t mean eliminating a weed.

That’s simply because it would be self-defeating if a type of agent killed off the weed that is its source of food.

“It’s like a predator/prey situation,” she said. “The predator is the biocontrol agent, and the prey is the weed. If you eliminate the weed, the insect doesn’t have enough food to feed on long term. Ideally, you want to take the weed below a damaging threshold. We try to reduce its number so it’s no longer a problem.”

Finding suitable biocontrol agents takes a lot of research and time, but provides control options that might not be possible otherwise, which is why the team is focused mainly on weeds that affect rangelands.

“Generally, it’s not cost effective for a farmer or rancher to be out there spraying all their weeds,” she said. “It’s costly in terms of the cost of the pesticide, but also the feasibility of getting out there and spraying. It’s damaging to the native forages, where they are grazing their cattle.”

The post There’s foreign workers in the bug world, too — and they attack weeds appeared first on Alberta Farmer Express.

The proud warriors are called stem gall flies and they’re available for sale.

“The gall flies act on a different portion of the Canada thistle than the weevils do,” said Rachael Nay, conservation agriculture and extension program co-ordinator with the West Central Forage Association.

The association has been selling Canada thistle stem-mining weevils for years — and has trouble meeting demand. Stem gall flies could be an attractive option for producers who are battling the invasive, and pernicious, weed.

The flies become adults in early June and lay eggs on the thistle in early summer. The larvae then develop and feed on the tissue of the plant and form a gall.

“The gall becomes a nutrient sink, directing nutrients away from the plant’s normal metabolic and reproductive functions,” the association notes on its website.

Forced to focus all its energy on the gall, the thistle stops reproducing properly. The flies overwinter in the gall as mature larvae and emerge as adults in spring.

It’s all very nasty for Canada thistle, but a boon for farmers suffering from infestations of the weed, which is a huge pest because it reproduces from both seed and rhizomes. Even an inch-long piece can send out new shoots.

“A density of 20 Canada thistle shoots per square metre can cause an estimated yield loss of four per cent in barley, 26 per cent in canola, 36 per cent in winter wheat and eight per cent in alfalfa seed,” said Nay. “Field infestations can reach 170 shoots per square metre.”

West Central Forage began selling stem gall flies in 2016, but doesn’t have a lot of data on how well they work.

“So far, on our test sites, we haven’t been able to see any galls forming, but we’ve had some producers say that they’ve seen lots of galls and had good success with them. We’re still learning as we go,” said Nay.

“I think people are also a bit worried because flies will pick up and take off from where they have been deposited. I can’t guarantee that they won’t do that. As long as they are deposited in an area with a lot of thistle, they should stay there, as they don’t have to look for a new food source.”

The gall flies are greenhouse raised, so their numbers are guaranteed.

“If you already have weevils out in an area, the stem flies work well because they both target different portions of the plant,” added Nay.

One tray costs $145 plus GST and can be ordered from Nay (at 780-727-4447 or conservationag@westcentralforage.com).

The post Tiny warriors get nasty on Canada thistle appeared first on Alberta Farmer Express.

“They especially love cereal crops and food crops like carrots and potatoes big time. Right now, they’re not killed by pesticides. So your only chemical control option for wireworms right now is your neonicotinoid seed treatments,” Haley Catton of AAFC in Lethbridge told the audience at FarmTech.

These seed treatments don’t actually kill wireworms. They just put them to sleep for a while so the crop can get established.

“That same population of wireworms will be back next year.”

There’s a potential phase-out of neonicotinoid pesticides, so that chemical control could be lost.

“Although I’m hearing from several companies that there are new products in the pipeline that they say will kill wireworms, but I don’t know more than that,” Catton said.

There are hundreds of natural species of wireworms across Canada. Most don’t pose a problem, but 20 to 30 species are pests that eat cereal and vegetable crops.

The pests on the Prairies are native species, unlike British Columbia and the Maritimes, where invasive species are the problem.

“The wireworms that we are dealing with here on the Prairies are very well adapted to our winters and our soils, and survive well in the grasslands, which is bad for us,” said Catton.

In Alberta, there are five to seven problem species. Anyone who has a wireworm problem and digs around in their field will find a variety of wireworm species.

Click beetle offspring

Wireworms only live for a year in adult form as click beetles. They have a bullet-shaped body and the hind end of their thorax has little hooks. They leverage the little hooks underneath the top of their wings to create tension and snap, making a click. Click beetles lay their eggs in the spring.

“We don’t know a lot about how they decide to lay their eggs, but where they do is pretty important for the future wireworm problems down the road,” said Catton.

Once the eggs hatch, wireworms spend up to two to seven years in the soil. They can overwinter and move up and down in the soil to feed on whatever crop is planted, but can survive without eating for a year if they don’t like that particular crop.

After they are big enough after several years in the soil, they pupate, come up in the fall and nest.

In any wireworm-infested field, there will be a variety of sizes of worms of overlapping generations and species.

“Some of them are hard to study because they live so deep in the soil,” Catton said.

Wireworms can create bald patches in a crop or even wipe out an entire field.

“If you have a dead patch in your field, it can be for various reasons. Maybe you have a chemical spill, or maybe it was a low, wet spot during seeding. But dig around the edge of that patch — there are still some live plants and that’s where you will find a wireworm.”

Searching for research fields

Catton is working on a long-term project called ‘Wireworms and beneficial insects in wheat,’ co-funded by the Western Grains Research Foundation and the Alberta Wheat Commission. There are also several Canadian Agricultural Partnership projects with other researchers collaborating. Another project involves looking for wireworm pheromones (sexual attractants) by using a monitoring tool to attract and track click beetles.

“In B.C. and P.E.I., they have pheromones that have been synthesized and identified for those species. Here in the Prairies, we haven’t identified the pheromones for those species yet.”

Catton is also leading the third and final season of a project to investigate wireworms, crop rotations and beneficial ground beetles. She is still looking for fields for the third year. They should be dryland fields with a wireworm problem less than two hours from Lethbridge and seeded to spring wheat in 2019.

“Because wireworms live for multiple years in the soil, if we trace the characteristics and population structures with the rotation it was before, it may give us insight into how to use rotation to at least slow it down a bit,” she said.

Catton only studies 12 fields a year because the study is so in depth. Her team samples the field by taking soil cores to about 10 centimetres down. The soil is packed into a container and taken back to the lab.

“Wireworms don’t like light or heat. We put the soil in this funnel and then we shine a light down on it. Wireworms don’t like the light, so they fall to the bottom of the funnel, where we have a little vial that will preserve them for us so we can identify them in the fall and winter months,” she said.

The adult click beetles are monitored using pit ball traps. The click beetles just fall into the containers where they are collected.

There are still no recommendations for management practices to control wireworms. Catton advised farmers to know their field history.

“If you have a wireworm field, it’s probably going to be patchy,” she said. “If you think you have wireworm damage, dig down around the edges of your live plants and see if you can find some wireworms. If you do, you can send them to us.”

If you want to be a participant in the 2019 field study, email haley.catton@canada.ca.

The post Seeking options for wireworm control appeared first on Alberta Farmer Express.

“It’s a biological control and it’s been going great,” said Rachael Nay, conservation agriculture extension co-ordinator with the West-Central Forage Association.

The association began the project to import stem-mining weevils four years ago as a way to combat Canada thistle, which can devastate the productivity of pastures if it gains the upper hand. The noxious perennial weed is hard to control, and difficult to attack. Each thistle produces thousands of seeds and individuals send up numerous shoots — as many as 170 shoots have been found in a single square metre, with just a fraction of that causing major productivity losses.

However, while cattle won’t eat thistles, stem-mining weevils will.

The insects lay their eggs in thistle rosettes and the larvae live up to their name by munching their way down the stem of the thistle as it grows. After exiting and pupating in the soil, the adults emerge and feed on thistle leaves.

“It’s a great alternative to herbicide,” said Nay.

The weevils are non-invasive (they only eat Canada thistle and some types of plumeless thistles) and were first approved as a biological control agent half a century ago.

Each tray, containing 105 weevils, costs $200 plus GST. How many you need varies.

“It really depends on how big of an area they have to cover,” she said.

West-Central Forage suggests three methods. An aggressive approach is the most costly — buying as many as you can afford and topping them up with one or two releases in following years. But you can also release a tray or two in the worst area of Canada thistle infestation and release one or two more in following years. Or just release one tray and wait for them to slowly spread. (One Canadian study found the insects took six years to spread 90 metres, but a Montana study found that after a slow start, they had travelled nine kilometres from the release site a decade later.)

Producer interest in the weevils has spread much faster. The association gets daily calls from producers who are interested in purchasing the insects, said Nay.

“The program is getting bigger every year,” said Nay, adding her association has been working with other forage groups to get the word out and producers from all over the province have been placing orders.

Producers need to order them in spring with trays arriving at the end of August, which gives time for the adults to adjust and successfully overwinter. For more information, contact West-Central Forage at manager@westcentralforage.com or 780-727-4447.

The post There’s a reason why stem-mining weevils are the priciest livestock in Alberta appeared first on Alberta Farmer Express.

“Beneficial insects play a vital pest control role in cropping systems. It’s time to give them more awareness and attention,” explains Pat Flaten, research programmer with WGRF. She notes that the need to promote the importance of beneficial insects was identified at a Prairie Pest Monitoring Network working group meeting. Producers and agronomists have been asking members of the network for more information.

Allowing beneficial insects to help control yield-robbing pests is an important part of integrated pest management. Beneficials can reduce spraying, lower cost of production, save time in the field and protect the environment.

“Healthy populations of insects like lady beetles, ground beetles, lacewings, damsel bugs, and many parasitoids can often keep crop-feeding insects at insignificant levels,” says entomologist John Gavloski of Manitoba Agriculture. “With good management decisions and the proper environment, this free biocontrol can help maximize the value of a crop.”

Beneficial insect photos, scouting techniques and best management practices are available from various sources across Western Canada. WGRF has compiled key information online at www.fieldheroes.ca. A series of print and online ads will also run throughout the 2017 growing season to get the word out.

WGRF is asking other stakeholders to get on board and support the beneficial insects awareness campaign by visiting FieldHeroes.ca and following @FieldHeroes on Twitter (like, share and comment) for great agronomic information and timely, relevant content.

The post Website identifies your insect friends appeared first on Alberta Farmer Express.

“Biologicals are huge right now in greenhouse production and we’re seeing people introduce them and monitor them carefully for pests but at the same time aren’t quite sure where to take it from there,” said provincial horticulture specialist Dustin Morton.

The hands-on workshop will be held at Thiel’s Greenhouses in Bruderheim. Suzanne Wainwright-Evans of Buglady Consulting will look at methods of applying them, and how best to treat incoming plants and hot spots.

To register, call 1-800-387-6030.

The post Learn about the good bugs appeared first on Alberta Farmer Express.

“You have to change your mindset from pesticides to biocontrol,” said Veronica Cervantes, technical adviser at Biobest USA.

“The first year you start your biocontrol program is the toughest one. It’s what we call the transition year. It’s the most expensive year and the most challenging one.”

But growers can make the first year easier by building a successful biocontrol program — one that uses beneficial bugs, or ‘bios’ — right from the get-go, Cervantes said at a recent Integrated Pest Management Day hosted by Biobest.

The first step is to “start clean.”

“Clean propagated material is key,” she said.

“This is a very difficult thing because a lot of the stuff that you bring into your greenhouses is propagated by someone else. You don’t have a lot of control over what’s going on there.”

Many plant propagators say they have “zero tolerance” for pests in their cuttings — but “how realistic is that?”

Not very, as it turns out. In a study conducted at the University of Guelph, researchers found that thrips were coming into the greenhouse with chrysanthemum cuttings — even though the cuttings looked clean during a visual inspection.

“They’re hitchhikers,” said Cervantes. “They come in with the cuttings, and they’ll start to reinfest your greenhouse. It doesn’t matter how much you clean up your greenhouse, the pests will be coming from somewhere else.”

So in most cases, a clean cutting is one that comes with “low pest pressure.”

“We know it’s going to be coming with something,” she said.

“If your cuttings come with some pests but no residues, we can still continue to move forward with a bioprogram, because what we’re going to be releasing afterwards is not going to be dying due to those chemical residues.”

Prevention and monitoring

Next, growers need to think about prevention.

“Being proactive and preventing is the best option. It’s sort of like a vaccination with biocontrol,” said Cervantes.

“You may be reluctant to put in money up front, but at the very end of the road, it’s the very cheapest thing you can do. It’s like buying insurance.”

And one of the easiest ways to do that is by hanging sticky cards or rolls before an infestation occurs.

“Mass trapping is something we normally do at the very end, when things are out of control and we have a high infestation,” she said.

“But I think it’s worth it to start right away with mass trapping, especially if you’re at propagation. That’s a time when we don’t have a lot of beneficials running around.”

In the case of fungus gnat — “which isn’t a very prolific bug” — females can lay about 150 eggs, a relatively low number compared to other insect pests.

“If we hang up sticky rolls and catch 100 fungus gnat females — preventing those females from laying eggs — and multiply 100 by 150, we would be preventing 15,000 new individuals in your crop. That’s just the first generation,” said Cervantes.

In the second generation, that number could climb to over one million fungus gnats — “in just six weeks.”

“And all you needed to do to prevent that was collect the first fungus gnats that were there,” she said.

If growers are proactive at the beginning of their crop cycle and introduce beneficial insects then, “you’re going to give the bios a chance to establish in your crop” within those two generations.

“Even if there are some escapees, they’re going to have a warrior giving battle in your crop. But you’re not going to have that at the very beginning.”

And finally, producers need to monitor their traps to make sure their biocontrol measures are working.

“Monitoring should be a key part of any pest control program, whether it’s biological or conventional,” said Cervantes.

Growers should be using their traps as “sentinels,” she said.

“Monitoring encompasses two things — what you can trap on the traps and what you will have to do visually.”

Normally, Cervantes recommends 10 traps for every acre as a minimum, but growers can get away with fewer if they commit to monitoring more.

“I’d rather have you putting fewer traps and monitoring them and having a ton and not doing anything with them,” she said.

And if you’re going to be using traps to count pest populations, it’s good to keep a record.

“Once you’ve got a record for a couple of years, you know roughly that your aphids pop up around March or that your thrips will come out in February. Year after year, you’ll know which are your most susceptible crops,” said Cervantes.

“It will allow you to anticipate the pest pressure and do something about it.”

The post Prevention is the best cure when managing greenhouse pests appeared first on Alberta Farmer Express.

The weed is particularly threatening in pasture and riparian habitats, but can also be found in disturbed soils and flower beds. Most livestock find it unpalatable, but some can ingest enough to cause serious poisoning or death.

Common tansy has small button-like flowers clustered at the top of the stem and a deeply divided, fern-like leaf structure. The multiple stem structure and yellow flowers often stand out among other green forage and can grow from one-half metre to 1.5 metres tall. Dense patches can form and outcompete native plant species resulting in a loss of forage and natural habitat.

Chemical control gives the best results, although repeated cutting can reduce the seed production abilities. Consult your local Agricultural Fieldman for more information on identification and control measures.

The post This poisonous invader is growing in numbers appeared first on Alberta Farmer Express.