Soybean Insect Management
Over the past few weeks I have captured corn earworm moths in the blacklight trap that I operate in Camden, with nightly catches picking up steam around the first of August. As moth catches increase in this local trap, the likelihood of moths flying into and laying eggs in your soybean fields increases as well. Trap data is published every Monday on the Camden Extension Center website under the Camden Crop Data tab on the left side of the page. Furthermore data from traps across the state will be reported on the NC State Extension Trap Data site.
Dr. Dominic Reisig has noted that corn earworm numbers have been extremely high in corn this year. While this is not a guarantee that they will be high in soybeans, we should definitely be scouting. Note that previous research does not support treating corn earworm in flowering soybeans. Therefore it’s important to hold off until pods are present to make a treatment decision.
Thresholds
-For foliage feeders (ex.soybean looper, green cloverworm, armyworms, and bean leaf beetle) the defoliation threshold is 30% defoliation up to two weeks prior to bloom, and 15% defoliation from two weeks prior to bloom until the pods have filled(R7-R8). Note that this includes a defoliation estimate throughout the entire canopy, not just the top visible leaves. Also, loopers tend to defoliate from the bottom up. See defoliation images below.
