IPM Crop Survey - Insect Update (06/17/21)
Cereal aphids continue at low levels in North Dakota, while Minnesota is seeing higher levels in the west central to southern area of the state. Continue scouting from stem elongation to the end of heading stage. Temperatures will be more favorable for aphid reproduction next week, with temperatures in the low to mid-80s F.
See last week’s Crop & Pest Report #6, June 10th for the scouting protocol.
Grasshoppers are getting larger, 3rd - 4th instar nymphs, and they will start to move around and feed more. Field reports of nymphs moving into field edges at some locations with higher populations were observed. Some farmers have sprayed ditches or field edges early to reduce overall populations. However, early insurance insecticide spraying also comes with several negatives – killing the natural enemies, resurgence of secondary pests like spider mites or pyrethroid resistant soybean aphids, and increased crop inputs (respraying the field for a 2nd time because grasshoppers are re-infesting fields).
IPM maps on insect pests and diseases are available on the IPM website: