Vegetable Crop Insect Scouting

David Owens, Extension Entomologist,

Cole Crops

Recent heavy rains may be suppressing DBM and ICW egg hatch. Continue scouting for worm presence. Thresholds are 20% seedling or recent transplant infestation and 30% until beginning of reproductive stages or harvested structure formation (cabbage heads). Continue rotating two modes of action within a 30-day window followed by two different modes of action during the subsequent 30 day window. Also watch out for aphids. Aphids are establishing in recent transplants at Carvel, and so far our late summer weather is fairly similar to last year’s when aphid populations built up to large numbers in our plots. Aphid materials include neonics (useful for harlequin bugs), Closer, Sivanto, Fulfill, PQZ, Versys, Torac, Movento, Exirel, and Beleaf. Torac has worm activity on imported cabbageworm and on diamondback moth but NOT on cabbage looper. Exirel should have good to excellent worm activity.

Sweet Corn

Sweet corn trapping numbers have been on a gradual downward trend, but please note that we do not move traps to be immediately adjacent to silking sweet corn. With cool weather today and tomorrow, there is no need to tighten spray schedules based on temperatures until early next week. We recently harvested a sweet corn trial, and while we continue to analyze the data, preliminarily, we had very clean plots that were sprayed every 3 days alternating a diamide premix (Besiege, Elevest) with beta-cyfluthrin. This suggests to me that a 2-3 day spray schedule is conservative.

Trap counts from Thursday are as follows:


Trap Location BLT – CEW Pheromone CEW
3 nights total catch
Dover 2 145
Harrington 1 46
Milford 5 91
Rising Sun 2 80
Wyoming 1 49
Bridgeville 2 64
Concord 3 36
Georgetown 1 35
Greenwood 1 44
Laurel 4 64
Seaford 4
Millsboro 2 13

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