Treated plants had far fewer numbers of aphids and were significantly taller. No one is suggesting four treatments, he says. The key is timing-to get control before aphid numbers peak. Garden-variety aphids fly into a field en masse. Not so with soybean aphids.
Females fly into soybeans in small numbers and begin dispersed colonies.
The colonies might be missed during scouting, and with high reproduction rates they can explode in number literally overnight. Wedberg suggests watching for infestations early, at the V-zero stage, and attacking early. Wedberg says the aphids appear to have three population spikes. Wedberg says it is unclear whether last year's late-season rescue attempts had a positive effect. The aphids find younger soybeans attractive.