Not all bugs are bad, says scientist

By Tim Kalinowski on December 4, 2020.

Submitted photo by Shelley Barkley A pesticide resistant Alfalfa Weevil confirmed in Rosemary area is just one of several insect issues farmers had to deal with in southern Alberta in 2020. This topic and more were discussed during the final afternoon of the Farming Smarter virtual 2020 Conference and Trade Show on Thursday.

LETHBRIDGE HERALDtkalinowski@lethbridgeherald.com

Farming Smarter wrapped up its two-day virtual 2020 Conference and Trade Show talking about bugs, fungus and the importance of farmer-led research on Thursday.
Insect scientist Boyd Mori kicked off the final afternoon of the conference by talking about how “Not all bugs are bad,” and went on to illustrate one of the good things that happened in 2020 for farmers that insect pests, outside of southern Alberta around Lethbridge, did not make much of a dent in the provincial agriculture industry.
Unfortunately, around Lethbridge this was not strictly true with localized outbreaks of cabbage seedpod weevils, wheat stem sawfly and grasshoppers, but Mori said the outbreaks were not really widespread enough to be greatly vexed about the situation.
After giving his update on the provincial pest situation in 2020, Mori pivoted toward a topic with a potential for longer-term concern for local farmers. His research team has confirmed what farmers in the Rosemary area have feared since 2015 — that there is a species of alfalfa weevil in the region which has become partially resistant to pesticide application.
“You can see we had very low mortality (in the first test); only around 25 per cent,” he said.
They ended up with a 60 per cent mortality overall when finished their tests in 2018 at the highest dosage, Mori explained.
“This seems to confirm we have pesticide resistance, at least in these populations around Rosemary, Alberta,” he stated.
In 2019 they tried different doses of pesticide to see if it might have a greater effect on the weevil.
“Even at 100 times the recommended active ingredient, we were still unable to kill even 40 per cent of the weevils from Rosemary,” Mori stated.
Mori said when bugs develop resistance to pesticide it greatly limits what response farmers can have in their fields, and they will become almost totally dependent on rotation and natural predators which feed or parasitize the insects. Mori said there are two known parasitoid wasps which do act as bio-control agents for alfalfa weevils, and they are testing the weevils to see if they can identify even more natural parasites.
“Part of our project is looking to see what is the parasitism level across southern Alberta? What can we do to help enhance these parasitism levels? Especially in light of this pesticide resistance. We are going to need to find either some other products we can use or other means of controlling those weevils.
Mori said thus far this type of pesticide resistance in insects does not appear to be widespread, but he admitted there is not enough data in the system to know for sure.
“Right now we are not really monitoring for resistance in many of our populations,” he said. “We know Colorado potato beetle has resistance to some insecticides, and that is monitored yearly. Alfalfa weevil is probably the big one we know of in Alberta.”
After Mori finished his presentation, Farming Smarter’s Lewis Baarda spoke about the “Spornado,” a commercial device which can cheaply and easily measure harmful fungal spore levels in fields. The Spornado is basically a wind catcher device with a cassette inside to capture the sample from the air. The cassette can be removed and then sent in for rapid testing to show if harmful crop spores are floating around in fields and at what level.
Farming Smarter is testing the device kit, which costs about $490 and about $120 per test, with 20/20 Seeds Inc.
Fungal pathogens are a severe problem in agriculture today with diseases like fusarium head blight, wheat rust and sclerotinia running a bit rampant and have to be treated at high cost. Unfortunately, they are also difficult to spot sometimes in their early stages, and often are weather driven in their severity. Baarda said knowing what level of spores are present in fields could help farmers make better management decisions.
“As far as pathogens go, we don’t really have a good sense of what our risk is,” he explained; “especially from an in-season standpoint. We may know some of the disease history of the field. We may know what has been planted here the year before or what is in neighbouring fields, but we really don’t know if that pathogen is present or not? What the Spornado does is it gives us that piece of information.”
Farming Smarter just began field testing the devices this year, but the preliminary results are encouraging, Baarda said.
“This is filling in a piece of information we are currently missing,” he explained, “as far as in-season scouting. Crop diseases can very quickly devastate crops. Crop detectors are one of our main strategies to combat this.”
The Farming Smarter conference ended the day with keynote speaker Brent VanKoughnet, owner of Agri Skills Inc., who made a presentation on the increasing importance of farmer-led research as carried out by both producers and organizations like Farming Smarter.
“We want to create a world where we can bring science and good sense together to support those (field-level) decisions,” said VanKoughnet. “In my experience, it is far easier to bring good science to the field than it is to bring good sense to a university or a researcher.
“Anybody who has worked in field trials on their own farm, or in a place like Farming Smarter, you know there are a lot of inconvenient processes and disciplines to do good science. And any places we can overcome those really sets us in good stead for capturing better information.”
VanKoughnet later stated he felt farmers had a vital role to play in helping to focus academic research, and verifying it at the field level.
“I don’t think producers taking a higher role in field verification and research is a compromise filling the role of what has been done before,” he stated. “It might be a stronger system than has ever been there before. I think we can generate better data through field trials with the kinds of tools we have (as farmers). The quality of the information per investment if we do fieldscale trials in the right way is spectacular.”

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