Seeing dimpling on your canola leaves? Stem feeding? Chances are, it’s flea beetles causing the damage.
This year in the southern prairies, flea beetles are becoming a significant issue, most likely in part due to dry conditions. And with neonicotinoids continuing to hit headlines, flea beetle control could become even more difficult in the coming years.
Hector Carcamo, research entomologist with Agriculture and Agri-Food Canada says in this episode of RealAgriculture’s Canola School, that although neonic insecticides still provide the best protection when it comes to spraying for flea beetles, foliar insecticides are an option producers may want to look at.
“Although the studies are preliminary, we have research around foliar insecticides in Beaverlodge [Alberta], Saskatoon [Saskatchewan], southern Manitoba, and southern Alberta. We see a lot of variabilities but sometimes we do see an increase in the yield by using foliar insecticides,” he explains.
Carcamo says that although many producers have been upset with the amount of protection that the seed treatments actually provide, this is normal, as seed treatments only protect up to a certain point in the growing season.
“For the insecticides to work, the flea beetles have to feed on the plant. So if you have a very large amount of flea beetles, taking a small amount of the plant, you are going to see the damage. So I don’t necessarily think there’s a case of the flea beetles developing resistance to the insecticide,” he says. “Most years there’s a multiple of factors that make it worse, such as landscape, and the weather. There’s so many factors that make it difficult to pinpoint to one and say ‘this is why we have large flea beetle numbers.’”
When it comes to beneficial insects, Carcamo notes that the most dominant ones you will see eating flea beetles are spiders, and ground beetles, but there is still research to be done in the area.
Canola School videos are produced by Real Agriculture.