Kudzu bugs are responding to the warm temperatures, and activity is increasing. The bugs are looking for food sources, such as wisteria and kudzu, but there is very little foliage available. You will find the kudzu bugs congregating on light colored surfaces. They are simply hanging out rather than feeding.
Kudzu bugs are small insects (4 to 6 mm long) with mottled olive-green and brown color. They have piercing-sucking mouthparts and are considered strong flyers. Plants are damaged when the insect removes plant juices, which include nutrients and moisture from the veins.
Besides kudzu, the bugs are known to feed on soybeans, other bean species, wisteria and some vetches. In counties to our east, kudzu bugs are congregating on but not feeding on many different types of plants. Gardeners have reported thousands gathered on fig and willow trees.
Entomologists from several southern states are working together to find more detailed information about control and host plants. Kudzu bugs are producing several generations per year. In Georgia, they can complete development from egg to adult in six to eight weeks.
When temperatures warm, the strong-flying adults emerge from overwintering sites and move into kudzu or wisteria where they reproduce. The insects do reduce kudzu biomass just as they do in Asia. In the southeast, the new generation of kudzu bugs will move onto soybeans in June and July, where they can become an economic problem.
You may be tempted to use chemicals to spray the exterior of your house. Do not have high expectations of success. There is a big difference between killing individual bugs and controlling them. These bugs are a moving target searching the great outdoors for food and a place to lay eggs. Spraying large aggregations will kill a bunch, but it is not going to make them go away.
Remember, safe application of a pesticide includes making sure the product is labeled for use on the target. If spraying up over your head, do not forget to remove items such as children’s toys, pet food or water bowls. Fish ponds, grills, outdoor furniture and hard surfaces need to be avoided when pesticides are used.
Products available include bifenthrin, permethrin and lamda-cyhalothrin. Wettable powder formulations of insecticides may produce better results. Treating is difficult without the proper equipment, and care must be exercised.
Peg Godwin is horticulture agent, Lenoir County Cooperative Extension Center. Reach her at Peg_Godwin@ncsu.edu or 252-527-2191.