Controlling Stink Bugs in the Vegetable Garden
Stink bugs and their cousins, the leaf-footed bugs, are common pests on many fruits and vegetables in the southeast. Gardeners most frequently notice these pests on tomatoes, where their feeding injury causes hard yellow spots to form just under the tomato skin. Populations of both of these difficult to control insects build up over the season, peaking in late summer and early fall. Control efforts taken now will help you stay ahead of these malodorous pests.
Recognizing Stink Bugs
Adult stink bugs are easy to recognize. They are relatively large, growing up to ¾” long, and have distinctive shield shaped bodies. They may be green or brown. When held or squished they emit a foul smelling fluid, hence the name stink bug. Young stink bugs are smaller, rounder, and more colorful, with highly patterned black, red, white, and green colored bodies.
Adult leaf footed bugs are slightly larger than stink bugs, with longer bodies that are dark brown and may have a white line across the middle. Flat, leaf like attachments grow from the lower end of their back legs. Young leaf footed bugs are bright red with long, spidery looking black legs.
Both leaf footed and stink bugs feed on plant sap using their needle like mouthparts. They can be found in large numbers feeding on the buds, flowers, fruits, and seeds of many types of plants including beans, okra, tomato, pecan, peaches, eggplant, and blueberries. Their feeding damage often causes fruits and seeds to be misshapen or shriveled, and leaves behind a small pin prick injury on the fruit or seed skin. Pecans that have been damaged by stinkbug feeding will have hard, dark, bitter tasting spots within the kernel. On tomatoes, their feeding causes cloudy areas of hard yellow spots to form just under the skin.
Controlling Stink Bugs
Both stink bugs and leaf-footed bugs are challenging to control. They spend the winter in weedy areas like ditch banks and fencerows. Controlling weeds around vegetable gardens and orchards can help reduce bug populations, but both are strong fliers and can easily move into gardens from areas further away.
Birds and spiders are important predators of leaf footed and stink bugs. In addition there are several species of beneficial insects that feed on these pesky bugs. These include wheel bugs, assassin bugs, and predatory stink bugs. There are also parasitic insects that can help control these pests, but they are sensitive to pesticides. In areas where pesticides are regularly used the populations of these and other beneficial insects will be greatly reduced. You can encourage beneficial insects to move into your yard by minimizing pesticide use and planting a diverse variety of flowers, trees, and shrubs to provide habitat for beneficial insects and pollinators.
Even in diverse landscapes with thriving beneficial insect populations, leaf-footed and stink bug levels may build up high enough to cause significant damage to fruits and vegetables. Damaged fruits and vegetables can still be eaten, though their taste and texture may not be as good as unblemished fruits. In small gardens, these large bugs can be controlled by hand picking them from plants and either squishing them or drowning them in a bucket of soapy water. Keep in mind these bugs will not bite or sting, but they will live up to their name when handled or squished!
In larger gardens where leaf-footed or stinkbugs are a serious problem, pesticide application is often necessary. Very few organic pesticides have any effect on these bugs. One that has shown fairly good results is made from a white edible clay known as kaolin. This organic product coats plants and fruits in a white film, deterring pests. The film is washed off before eating. It is sold under the brand name Surround WP, though usually has to be ordered online or by mail since few local garden centers carry it. Conventional insecticides containing synthetic pyrethroids are relatively effective for controlling leaf footed and stink bugs, but must be sprayed every seven to 14 days. These include products containing permethrin, bifenthrin, or cyfluthrin as the active ingredient. When using any pesticide read and follow all label directions. Be sure to check the label for the pre harvest interval; this is the amount of time you must wait after spraying to harvest crops.
For more information contact me, Mary Hollingsworth, Extension horticulture agent, at the Extension Center, by phone at 910-875-3461, or by E-mail at Mary_Hollingsworth@ncsu.edu. For more information about Extension visit our website at https://hoke.ces.ncsu.edu.
Recommendations for the use of agricultural chemicals are included in this newsletter as a convenience to the reader. The use of brand names and any mention or listing of commercial products or services does not imply endorsement by North Carolina Cooperative Extension nor discrimination against similar products or services not mentioned. Individuals who use agricultural chemicals are responsible for ensuring that the intended use complies with current regulations and conforms to the product label. Be sure to obtain current information about usage regulations and examine a current product label before applying any chemical. For assistance, contact your county Cooperative Extension agent.