Soybean aphids have found their way into Indiana. That's the word recently issued by Christian Krupke and John Obermeyer. However, so far entomologists and crop consultants and agronomists who have reported to the entomologists say the levels are fairly low. Rumors say some fields have been treated and were at economic levels, but those rumors have not been confirmed.
What the entomologists recommend for now is to stay alert but don't panic. Rely on proper pest management scouting skills rather than bailing and opting to treat the field just because you're worried about aphids.
The entomologists report finding aphids in many fields in Tippecanoe County, and others have found them in other parts of Indiana, but in each case , the numbers are relatively low and do not justify treatment.
One reason the entomologists say it's not time to panic is that there has not been a big outbreak of aphids in the upper Midwest, When there is an outbreak, winged adults sometimes are brought to Indiana by air currents. So far, that's not the scenario that's playing out this year.
The other factor that should encourage you not to panic, but instead to wait and see, is that aphids don't reproduce well in extremely high temperatures. Some areas have received enough rain to cool things down to where reproduction is more likely, but in areas that remain very hot and dry, reproduction will likely proceed at a slow space. The field that the entomologists have seen would have to have a big build-up in population before spraying would be justified.
The third factor is simply that plants can stand a large number of aphids on the plant before economic damage occurs. If you sample carefully and find more than 250 aphids per plant, and the plants are in the R4 or R5 reproduction stage, making pods and filling pods, then treatment would be justified. If you find a sizable number but less than 250 per plant, the entomologists still advise waiting. However, they would suggest resampling the field and staying on top of the situation in case the population builds.