Kudzu Bugs Beginning to Migrate Into Soybeans
Like last year, spots where kudzu bugs are showing up now in very small numbers 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.
The kudzu bug migration into soybeans will be in full-swing within the next two weeks. From what I can gather, our population levels are 10-20 times lower than last 2013, but right on par with 2014. We can expect a few fields around the state to hit threshold during mid-August. If you don’t find kudzu bugs at one nymph per sweep (one per “swoosh” of the net) away from the field edge, you don’t need to treat. In fact, a pyrethroid treatment in soybeans during July can eliminate beneficial insects, flaring corn earworm, which is our major pest in the state.
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 (2011-2013) were obvious treatment situations. This year, you will find one nymph per sweep a lot easier an quicker using the sweep new 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.