Vegetable Crop Insect Scouting

Vegetable Crop Insect ScoutingDavid Owens, Extension Entomologist, owensd@udel.edu

Sweet Corn
Fall armyworm is active, be sure to scout tassel-push corn. If more than 15% of tassel-pushing whorls are infested by worms, a treatment is advised. Corn earworm trap counts are up a bit in most places, with the last holdout for low counts being in central Sussex. Trap catches from Thursday are as follows:

Trap Location BLT – CEW Pheromone CEW
3 nights total catch
Dover 1 147
Harrington 0 71
Milford 1 101
Rising Sun 0 117
Wyoming 0 63
Bridgeville 1 96
Concord 2 27
Georgetown 0 25
Greenwood 0  
Laurel 2 91
Seaford 1 89
Lewes 192
Millsboro 4 11

Cucurbits
Be on the lookout for aphids and signs of worm feeding. I sprayed a small plot with pyrethroids earlier this year to prevent squash vine borer from destroying my pumpkin pies only to have a large aphid outbreak 3 weeks later. You will see cast skins, even on the top of leaves. New, infested leaves will have a bit of a curl or cup to them. Spider mite reproduction is going to be slowed by recent rains but keep an eye on them. Beneficial fungal pathogens have a much harder time establishing in vegetables than in field crops.

Peppers
Continue scouting for beet armyworm. In areas with high earworm trap counts, some suggest 20 or more per night, regular treatments may be necessary.

Tomato
Once tomatoes have small fruit on them, regular treatments for earworm may be necessary. Also scout for spider mites. If you see 2-4 mites per upper leaflet, a treatment may be advised.