Home / Canola Watch / Insects / Page 34
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Some fields may have a variety of green worms feeding, including bertha armyworm, diamondback moth larvae, imported cabbageworm and alfalfa looper. Here's how to tell them apart…
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We don’t have scientific evidence to combine thresholds, but where an “additive” effect of multiple species can make sense is when more than one species are feeding on key yield-producing areas — flowers, buds or pods — at the same time…
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Lygus, bertha armyworm and diamondback moth have a number of natural enemies that will keep populations in check. These beneficial insects may not control an immediate insect threat — growers will still have to spray if economic thresholds are reached — but beneficials can keep a lid on populations. The key to preserving beneficial insects is to follow thresholds and…
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Include nymphs (shown above) when doing lygus sweep net counts. Bertha risk rising. Zebra caterpillers are usually confined to small areas within a field. (Photo source: Roy Ellis)…
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Keep in mind pre-harvest intervals for fungicides and insecticides now that many early seeded crops are less than a month from swathing. Pre-harvest intervals vary widely from product to product…
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An AAFC study has shown very clearly that with continuous canola, there is a statistically significant increase in crop damage by root maggots. No insecticides are available to control root maggot in canola, but providing a one year break seems to make a significant reduction in root maggot losses, the study found…
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Our current economic threshold tables for lygus in canola may be too low when applied to current canola production systems across the Prairies. If a canola stand is healthy and growing fast, growers are reportedly doubling or tripling thresholds. Say the threshold is 10 per 10 sweeps, some growers are doubling that to 20 per 10 sweeps as the action…
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Leafhoppers are more plentiful and carrying more aster yellows phytoplasm this year, but spraying is rarely effective. Bertha counts are starting to spike in some locations. Cutworms are still feeding in some locations, but the threat should be over for most regions…
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If you have lygus bug and cabbage seedpod weevil in the same field and if they are both at 50% or more of their economic spray thresholds, spraying may provide an economic benefit…