A new pest that looks like it may be with us for a while is kudzu bug on soybeans. Dr. Jeremy Greene, Clemson Extension Entomologist based at Edisto Research & Education Center in Blackville, SC has studied this pest extensively:
“This is the second year in a row that we have seen the kudzu bug occur in early planted soybeans. It was 2011 when we first saw this insect in large numbers in soybeans. It has certainly shown up early and homeowners have a lot of complaints about this bug and we have a lot of work to do this year.”
As most producers know, this is really only the second full season that kudzu bug has been a problem in soybeans, so as Greene explains, economic threshold is difficult to define:
“Economic thresholds remain something that we are continuing to develop and refine. We have only had this insect in soybeans in large numbers for this being the third year and in the first year it was at the end of the season. Last year is really when we had the full season to work with this insect. This year we are not even though the season so we are continuing to work on this problem and we have some pretty good ideas on how to control it. Most of those ideas revolve around controlling it in the immature stage.”
Greene has discovered that border spraying on over-wintered adults is affective, say one sprayer-width around larger fields.
The over-wintered adults are near completion of their life cycle and are dying off, and the immature they’re leaving behind are about to march right into soybeans says Greene:
“We are about to see an inflow of fresh adults into soybeans, including double cropped and full season beans. We will need to be a little more aggressive for this generation and maybe use the border spray approach for the first application and then see how this population develops. It seems to be something new every year in dealing with this insect.”
Greene points out that their research thus far has shown that one spray can create season-long control of kudzu bug:
“We have seen a lot of cases where one well timed spray can mitigate all losses to this insect. That pretty much is limited to the full season beans though.”
While kudzu bug is certainly something producers did not need, Greene says that most times chemicals that are already on-farm do a good job of control:
“A lot of the insecticides that we routinely use for other insects like worms and stink bugs will work, there are some subtle differences but we have a lot of options for control.”
Edisto Research and Education Center Entomologist Dr. Jeremy Greene.