We have rapidly become accustomed to dealing with kudzu bugs in our soybeans throughout the season. So the question is, where are they now?
I have been slow to join the bandwagon, but am now on board. I think the cold winter has knocked our populations back. Many folks have noted dead bugs in overwintering spots. Furthermore, spots where kudzu bugs are showing up now are near traditional “hot spots” where they have overwintered. Because of this, I think our greatest chance for kudzu bug infestations are going to be localized around these traditional hot spots. You probably shouldn’t expect kudzu bugs to show up at threshold levels in new spots this year.
Believe it or not, the kudzu bug migration into soybeans is in full-swing. It is really wimpy compared to previous years. From what I can gather, our population levels are 10-20 times lower than last year. Right now, kudzu bugs are moving into soybeans, mating and laying eggs. I have noticed nymphs within the past weeks. We can expect a few fields to hit threshold within a couple weeks. If you don’t find kudzu bugs at one nymph per sweep (one per “swoosh” of the net), you don’t need to treat.
It is especially critical to use a sweep net in situations like this year. We can expect most of our fields at risk for kudzu bug (which aren’t many) to be borderline situations. Many fields in the past were obvious treatment situations. Those fields were so full of kudzu bugs that you could smell them through the AC system pulling up to the field. This year, you will find one nymph per sweep a lot easier and quicker using the sweep net than you will walking into a field and parting the canopy. Small hairy green nymphs blend in with the stems and will be difficult to spot. Most fields won’t need to be treated for this insect!