Article by Jack Bacheler
We are beginning to see the major kudzu bug flights into soybean in our southern counties, in most cases so far with very few nymphs present. All producers should be advised to tolerate even significant levels of adults in soybean fields and base treatment decisions on the finding of 15 immature fuzzy kudzu bug nymphs per 15 sweeps taken from 6-8 locations at least 50 feet in from field edges. If a grower waits until this nymph threshold is met, yields are still protected; plus the odds of a second or third follow-up spray are lower, according to data developed by Phillip Roberts (University of Georgia Extension) and Jeremy Greene (Clemson Extension) in 2010 and 2011.
This past Tuesday, Dominic Reisig, his graduate student, myself and others were taking data in a maturity group/planting date test (April, May and June “full season” plantings and another June planting behind wheat) in Scotland County. We observed many kudzu bug adults per plant in the April and May plantings beans, but almost no nymphs. Very few adults were found in the June-planted “full season” and “wheat beans”. The same trend was also seen the same day in an identical test at the Sandhills Station in Montgomery County.
We realize that some producers may be hard pressed to hold off on waiting until the nymph threshold is met. However, the best current information strongly suggests that a nymph-based treatment threshold provide producers their best odds of avoiding unnecessary sprays while protecting yields.