Photos and text by Debbie Roos, Agricultural Extension Agent.
The kudzu bug (Megacopta cribraria) was introduced to the U.S. in 2009 and is now found in most North Carolina counties. A true bug roughly the size of a lady beetle, it uses its piercing sucking mouthparts to rob plants of water and nutrients and can cause significant yield loss.
The kudzu bug is primarily a pest of legumes such as kudzu, wisteria, beans, and soybeans. Some growers have observed them feeding on sunflowers and they may be observed congregating on many different plants. We are still learning about its hosts and potential damage here in North Carolina. Market farmers will primarily be concerned about kudzu bug damage on edamame and all types of beans. They can cause up to 75% yield loss in soybeans. They also seem to like congregating on figs and grapes but as far as we can tell they don’t seem to be feeding on these crops. However, this is a new pest so we don’t yet know all its hosts, and it may acquire new hosts here in the U.S.
Fall 2012: The cooler weather of fall has prompted many calls from farmers and gardeners asking about their kudzu bug invasion. I visited a few farms last week and observed kudzu bugs all over figs, pole beans, scarlet runner beans, redbuds, roses, peppers, and other plants. I had never seen anything quite like it. The bugs are looking for places to spend the winter and in the fall they will often invade homes seeking overwintering sites. Some beekeepers have even reported seeing kudzu bugs congregating near the entrance to hives looking for a warm place to spend the winter (they do not present any threat to honey bees)! Entrance reducers will help the guard bees keep out unwanted visitors in the fall.
Spring 2013: I am getting lots of calls again from folks seeing kudzu bugs amassing on figs, magnolia, bronze fennel, and other plants. They can also been seen on the exterior of houses. These bugs have emerged from their overwintering sites and are looking for reproductive hosts (kudzu and soybeans).
We do not yet know of organic control strategies for controlling this pest. Because the bugs usually feed in groups, small-scale farmers and gardeners can brush them into a pail of soapy water when faced with infestations during the growing season. Growers are advised not to squish the kudzu bugs with their bare hands because they release a yellow substance that can cause welts and inflammation. Some of our beneficial insects have discovered this new pest – both assassin bugs and predatory stink bugs have been observed feeding on kudzu bugs.
According to NC State University Entomologist Dominic Reisig, “the kudzu bug is incredibly prolific, and has gone from nearly undetectable to overwhelming in a few generations.” Dr. Reisig expects kudzu bug populations to be much worse in 2013 than in previous years. He is part of a team of NC State University researchers working on biological control of the kudzu bug. Next year they plan to release a parasitic wasp that targets kudzu bug eggs in hopes of reducing populations.
For more information:
Kudzu bugs on edamame. They feed on stems and leaves (not on beans).
Kudzu bugs on edamame.
Close-up of kudzu bug.
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