Kudzu nymphs could create problems for soybeans

By MICHEL ELBEN
Staff Reporter

STUART, Va. — Adult kudzu bugs have been sited in soybean fields in 14 counties in Virginia.
“The good news is that there are no nymphs,” said Dr. Ames Herbert, Jr., the state integrated pest management coordinator and Extension project leader for the Department of Entomology.
“They haven’t reproduced,” Herbert said. “Nymphs are what cause damage.”
According to North Carolina State University Extension entomologists, the kudzu bug was introduced from Asia. The bug taps through the veins of plants to reach the phloem, using piercing sucking mouthparts. As a result, injury to plants likely results from nutrient and moisture loss, rather than a direct loss of biomass from removal of plant tissue.
Kudzu bugs have been found in Amelia, Brunswick, Dinwiddie, Greensville, Halifax, Henry, Isle of Wight, Lunenburg, Mecklenburg, Nottoway, Patrick, Pittsylvania, Southampton, and Sussex counties but “to date, no kudzu bug eggs or nymphs have been found. ... It is just a matter of time before we do,” Herbert said.
“The kudzu bug is a little bit different than the Brown Marmorated Stink Bug,” Herbert said
“BMSB has a related natural enemy but kudzu bugs, as far as we know, have nothing even close to it,” he said.
Theparasitoid wasp will attack BMSBs but not as effectively as those from China. A study is being conducted for introduction of the natural enemy in 2013. Herbert said the kudzu bug could cause significant damage.
He said foreign exploration should be investigated to identify a natural enemy of the insect.
Herbert is involved in several projects involving soybean pest management. He said the kudzu bug was first sited in Georgia in 2008 and spread in 2009.
It did not appear in Virginia until last September.
“I don’t think we’re going to see problems this year. We’re about one year away,” said Herbert.
Herbert said the bug might overwinter. “They don’t need the kudzu now, they go straight into the soybean,” he said.
The kudzu bug overwinters as adults near kudzu patches and soybean fields in plant debris and behind tree bark, but it will also attempt to overwinter in structures such as houses and other buildings.
Dr. Cerruti Hooks, assistant professor and Extension specialist in the Department of Entomology at the University of Maryland, said the kudzu bug is not yet present in central and southern Maryland.
“At this time, we have low numbers of kudzu bugs in soybeans,” Hooks said, adding that the main thing to be concerned about right now in Maryland is spider mites.
“Spider mites favor hot dry weather,” Hooks said. “Everything else is down — nothing like 2010. ... Farmers are happy to hear about that.”