In very dry conditions: Threshold tables for lygus indicate that 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,…
Insects
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Clover cutworm damage has been confirmed in a few fields around Weyburn, Saskatchewan. They are a climbing cutworm and can be easily confused with bertha armyworm. The most distinct difference between the two species is the wide stripe along each side; it is yellowish pink on clover cutworm and yellowish orange on bertha armyworm…
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Earliest canola fields are just coming into flower in southern Alberta and southwest Saskatchewan, the highest-risk areas for cabbage seedpod weevil in Western Canada. Cabbage seedpod weevils tend to cluster in fields that are first to flower, so farmers with early fields will want to check them closely…
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Growing degree days across most of the Prairies have reached the threshold for adult bertha armyworm (moth) emergence from overwintering pupae. That is 7-10 days ahead of normal. Egg laying begins shortly after adult emergence and young worms emerge about a week after that. Based on 2017 results, 2018 is not expected to be a bad year, but local flare-ups…
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Include cutworms on the scouting checklist for the first one to three weeks after emergence. Any later and management becomes more difficult because (i) spraying a registered insecticide is useless because the cutworms have developed beyond the feeding stage, and/or (ii) reseeding options are starting to be limited…