By BRUCE HOTCHKISS
(Aug. 15, 2017) For the first time, University of Maryland entomologists have verified sightings of kudzu bug adults and egg masses feeding and reproducing on Maryland soybeans.
This was not the initial sighting of the pest in Maryland, however. Before this it had either been found only on patches of the bug on kudzu vines or, if reported on soybeans, it had not been confirmed by either the Maryland Department of Agriculture or the University of Maryland Extension.
According to Dr. Bill Lamp, UME entomologist, the kudzu bugs were collected in Beltsville soybean plots. They have been moving north for several years because they have been able to survive the mild winters.
“Typically,” Lamp said, “we only see high numbers when we scout in the fall.” And he warned that “our previous research suggests this is a pest problem for both the current growing season and next year.”
If kudzu bugs successfully overwinter in areas adjacent to soybean fields, the bugs may invade fields regrown with soybeans next year, Lamp cautioned. And the bug may infest snap bean fields as well as soybeans.
“We recommend growers use an insect sweep net to frequently scout for kudzu bugs during the remainder of this year,” Lamp said.
The bugs are typically found near edges of fields. The threshold for spraying is currently set at one immature per sweep. “Without a net,” the entomologist advised, “growers can look at the stems of plants, focusing particularly on leaf nodes. Large populations of kudzu bugs also often produce a distinct odor, similar to stink bugs.”
Removal of kudzu vine patches and other overwintering sites near soybean fields can help to reduce migration from these areas.
Lamp offered this advise should the kudzu settle on your fields.
“If kudzu bug numbers exceed the economic threshold of one immature per sweep, and plants appear stressed, an insecticide may be necessary. However, applying insecticide should be limited as it may increase outbreaks of other pest species or decrease natural predators.”
All insecticides rated for soybean use are effective on kudzu bugs.
The kudzu bug was first discovered near Atlanta, Ga., in 2009 and has since spread northward into South Carolina, North Carolina, Alabama, and southern Virginia.
Like the stink bug, the kudzu bug was introduced from Asia.
It is very distinctive looking, about the size of a pea — 1/6 of an inch to 1/4 of an inch — olive green with brown speckles and flat across the back end.
The kudzu bugs love the kudzu plant and are a rare example of an invasive feeding on another invasive.
In climates where they can overwinter and where the kudzu vines have taken root, it is expected that the bug will continue to spread. In addition to soybeans, the critter feeds on the leaves and stems of a wide variety of other legumes including other beans, wisteria, and some vetches.
In addition to farmers, the kudzu can be an enormous pain in the neck for homeowners.
Like the Brown Marmorated Stink Bug and Asian Lady Beetles, kudzu bugs don’t like to spend the winter outdoors. In the fall, they often congregate on light colored surfaces, such as siding, fascia boards and the like before moving into structures.
They will enter buildings under siding, gaps around windows, doors, vents, or pretty much any entry point they can find. Like the stink bugs come spring time they will try to get back outside in search of food. Needless to say they can be a real nuisance to people.
The best method of dealing with them in residences is basically the same as other home invaders. Seal your home or building up as tight as possible to prevent entry.
For more information about the kudzu bug in Maryland, visit the website: http://mdkudzubug.org/. Or if the kudzu bug is observed in a field of soybeans, farmers are asked to contact Lamp and his staff at: http://mdkudzubug.org/contact-us/.