Alberta’s cool weather delays insect development
By Top Crop Manager
May 12, 2014 - While cool conditions in Alberta are delaying development of insect pests, provincial insect management specialist Scott Meers says the weather is unlikely to affect overall insect populations.
"A good example of what's happening right now is with the pea leaf weevil," says Meers, with Alberta Agriculture and Rural Development at Brooks. "Usually by this time of the spring, they are migrating into pea fields. But when it's cold, like it is this spring, they just go back to sleep."
Meers says pea leaf weevil will migrate into pea fields once the crop emerges and the weather returns to more normal levels. He expects the same thing is happening with alfalfa weevil in southern Alberta. "Alfalfa weevil had started some feeding but had completely stopped with the return of cold weather. They will resume activity when warmer weather returns."
Insects, like crops, are heat unit driven, adds Meers. "Since we've had virtually no heat units yet, insects like wheat midge, grasshopper and bertha armyworm, that are currently in the soil, waiting to emerge, are having their development slowed. They are fairly well protected for now; they are just going to be delayed a bit. "
Meers says there is good news on the diamondback moth front. "We have 35 sites across the province where we watch for the migration of diamondback moths. As of May 7, all we've caught is a total of two moths in those 35 trap locations. That's an extremely low number for this time of year."
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