Agronomic Crop Insect Scouting

David Owens, Extension Entomologist,

Continue scouting for stink bug, corn earworm, and defoliators. I have not received any reports of significant podworm, but be looking out for them in double crop beans, especially those at R2 and R3. Stink bugs will aggregate in fields, often near edges that have attractive host plants. These aggregations may exceed the threshold of 5 bugs per 15 sweeps, but stink bug aggregations can be spot treated without treating the entire field. Bean leaf beetles are also active, and will feed on both leaves and pods, but by themselves, you may need to see 2-4 per sweep to warrant treating. Soybean looper, green cloverworm and grasshoppers are the main defoliators active right now. Fungal and viral diseases are also working on the worm complex, aided by the recent rains. Defoliation thresholds for R-stage soybean is 15% with defoliators present. Once we reach R6, defoliation thresholds can be relaxed a bit.

Continue scouting for earworm and sugarcane aphid. Aphid activity is still spotty, most fields have very low numbers, but even in these fields there can be isolated hot spots where entire leaves are covered in aphids. Warm weather next week will stimulate aphids to reproduce rapidly.