Vegetable Insect Updates – July 27, 2018

David Owens, Extension Entomologist, owensd@udel.edu and Bill Cissel, Extension Agent – Integrated Pest Management; bcissel@udel.edu

Watermelon
by David Owens
The various ‘rindworm’ complex members (various Lepidoptera and cucumber beetles) are present in fields. We have also seen some injury from Leps that normally feed on weedy hosts such as pigweed that may be present in fields. Have not yet heard of beet armyworm complaints; this species is more difficult to control with pyrethroids and can be identified by the black spot above the second pair of legs behind the head. Even with the wet weather, continue scouting for spider mites. Due to frequent fungicide applications, fungal mite pathogens tend to be suppressed in vegetable fields. Wet humid weather reduces egg laying, but in my experience, mite populations in vegetables will continue to grow despite rain events.

Sweet Corn
by Bill Cissel and David Owens
Corn earworm populations are somewhat similar to last week’s. Monday trap capture (http://agdev.anr.udel.edu/trap/trap.php) indicated similar populations in some traps, higher in others, and slightly lower in still yet others. As a reminder, what is reported on the web is on a per night basis, the table below is cumulative over Monday, Tuesday, and Wednesday night. The one trap location with a significant difference (Dover) still captured enough moths that any inference based on yesterday’s or Monday’s trap capture is not going to change. Earworm activity is moderate, trending up statewide.