David Owens, Extension Entomologist, owensd@udel.edu and Bill Cissel, Extension Agent – Integrated Pest Management; bcissel@udel.edu
Low populations of bean leaf beetles, grasshoppers, green cloverworm, bean leaf rollers and soybean leafminer, and thrips are being observed in soybeans. We are also seeing spider mite hotspots in a couple of the oldest fields. Levels are not yet of concern, but with warm temperatures, keep an eye on their populations. Interestingly, we have been seeing thrips hotspots in Kent County. In the experience of other university entomologists, 95% of the time, thrips do not cause yield reductions. There is a general guideline where if most of the leaves are injured, and there are more than 8 thrips per leaflet and the field is stressed, they can be significant. That is, are the plants being ‘held back’? Are they not growing? Soybean that is growing can tolerate a great deal of feeding.