CSPW timing: When is it too late?

Grasshoppers. If populations are significant and crop feeding has begun, a spray or bait application around field edges may be enough to reduce the threat. Grasshoppers are easier to manage when they’re small — less than the third instar. Except in cases where there are extremely high populations feeding on crop along the edges, ideal…

With earliest canola fields starting to flower in southern Alberta and southwest Saskatchewan, cabbage seedpod weevil scouting season begins. Here is the forecast map for 2018 based on 2017 surveys. This map comes from the Prairie Pest Monitoring Network 2018 forecasts. Alberta Agriculture is asking agronomists and farmers to help with their survey for 2018.…

Cabbage seedpod weevils do most of their damage by laying eggs in young pods. Larvae emerging from these eggs eat seeds inside the pods, causing the yield loss that can make cabbage seedpod weevil (CSPW) a costly pest in canola. Keys to the spray decision are scouting and timing. The economic threshold is 20-40 CSPW…

Cabbage seedpod weevils will feed on buds, but spraying is rarely recommended before 10% bloom. That’s because (1) economic loss from cabbage seedpod weevils (CSPW) is due almost entirely from weevils laying eggs in young pods. These eggs then hatch a couple weeks later, with larvae feeding on developing seeds. (2) Weevils move very easily…