Invasion of the stink bugs has begun

The annual stink bug invasion has begun around homes and other buildings. Here are 10 things to keep in mind about them.

1. These are brown marmorated stink bugs, and they are native to Asia. They supposedly originated in a shipment of goods at a Walmart store in Pennsylvania sometime before 1998. They were first recorded in Lynchburg in 2005. Now they are in 33 states.

2. They want to come into our homes for the winter, where they can stay warm and crawl across the walls and buzz around lamps at night.

3. The best way to control them is to prevent them from coming inside. This is done by filling cracks around windows, doors and utility pipes with silicone caulk and by screening attic and crawl space vents. If your doors and windows are not covered by tight-fitting screens, keep them shut. Remove window air conditioners, as they offer easy access.

4. Insecticides sprayed on the exterior of your house may help control stink bugs if applied when the bugs first appear. Focus on areas such as doors, windows and attic vents, and be prepared to reapply because the pyrethroid products used on the bugs break down in sunlight.

5. Indoor treatments are possible with aerosols and foggers. Sucking the pests into a vacuum cleaner is a more popular, non-toxic alternative, though this will result in the machine having a peculiar odor that lasts for months.

6. The bugs’ natural enemies are back in Asia. However, the following have been observed eating stink bugs in Lynchburg: praying mantis, spider, daddy long-legs, ground beetle, house centipede, wheel bug, mouse, wren and cardinal.

7. Stink bugs feed on all kinds of fruits and vegetables growing in gardens in addition to trees and plants in general. While indoors they will be seen sucking juice from an apple, garlic clove, or other fresh food left sitting on the kitchen counter.

8. They do not bite people, according to experts at universities who study them. However, the insect’s sharp-edged shell can scratch your skin and cause lingering irritation.

9. Stink bugs breed by laying eggs, and this is done on plants outdoors. There are two generations a year in Virginia, compared to six in parts of China.

10. Buying a stink bug trap for your yard to control the bugs in your garden and also the ones moving toward your house is a positive measure that may help. However, I am skeptical about its ability to make much difference. The trap I hung next to my infested okra and tomato plants collected more than 50 stink bugs in a two-week period, yet the vegetables still had plenty of stink bugs. At the same time, hundreds of the bugs invaded my porch. Government research programs are currently underway to develop biological control methods and to determine the kind of light most attractive to these bugs so that an effective indoor trap can be developed.

Davis is a retired Lynchburg Extension agent. He can be reached at dodavis2@vt.edu.