The infestation of kudzu bugs on early-season soybeans continues, but natural mortality of the overwintered adults is increasing. We might see numbers of this species decline on early-planted soybeans before increasing again when the F1 generation comes off of kudzu.
I sprayed some of these soybeans with insecticide yesterday and observed very high mortality today. We used Endigo at 4.5 oz/acre, but other selected pyrethroid insecticides and pre-mixed products would have done a fine job as well.
Look at what these adults left behind, though. I can count about 17 separate egg masses on this poor picture of a few trifoliates. These eggs will hatch within the week, and a new generation will be on its way. In my opinion, that will be the generation to worry about. I think that these young soybeans can take some injury from low-to-moderate infestations of adult kudzu bugs, but we had better not let the immatures develop on the crop! Think of it this way, deer often do considerable damage to our young soybeans, and we still can make a good crop, if it rains! However, when heavy infestations develop closer to reproductive stage soybeans, we definitely need to get them under control.