A heavily-infested field in western Manitoba (south of Riding Mountain National Park) generated a lot of interest on Twitter in the past week. It prompted a lot of scouting, which is good. But what this one field and the ensuing scouting demonstrated is that bertha armyworm population spikes can be highly localized…
Insects
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Test your diamondback management skills with these four questions…
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Diamondback moth larvae have been found in canola fields across the Prairies this year. Of those fields with the larvae, counts in many (perhaps most) are below and often well below thresholds. Some fields are at thresholds. Some fields seem to be well above thresholds. The key is to the check each field. Diamondback larvae can vary in number from…
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Bertha armyworm adult moth counts were generally low across the Prairies in 2017. A few trap sites did enter the moderate risk level, but none was high. See provincial counts in the Prairie Pest Monitoring Network blog. However, as experienced with diamondback moth trap counts this year, egg survival could be higher in dry conditions and warm weather will promote…
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Grasshoppers can thrive in hot weather. The nominal threshold for grasshoppers in canola is 7-12 per square meter, with the low end more appropriate in dry conditions…
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In very dry conditions: If canola is $12 per bushel and spray costs $8 per acre, the threshold at the early pod stage is 5 lygus adults or late instar nymphs per 10 sweeps (0.5 per sweep). In moist and high-yield conditions: The economic threshold is quite a bit higher. At early pod stage, 50 lygus per 10 sweeps (5…