Facts, Identification & Control
Stink bugs belong to the order of true bugs called Hemiptera. They have piercing sucking mouthparts and straight antennae. Most stink bugs have a characteristic shield shape. Many are plant feeders and some are even predatory. This article focuses on the brown marmorated stink bug (Halymorpha halys).
The adult brown marmorated stink bug is about 12 to 17 mm long. Like other stink bugs, its body is nearly as wide as it is long. The adult is mottled brown in color. There are lighter bands on the antennae and dark bands on the front wings.
The immature bug, called a nymph, is yellow and red with red eyes. As it grows, the yellow lightens to off-white.
Behavior, Diet & Habits
Like many of the other stink bugs, the brown marmorated is a pest of fruits and vegetables. It has been found feeding on apples, peaches, blackberries, tomatoes, corn, soybeans, lima beans and green peppers.
Like other stink bugs, this pest pierces the skin of the fruit in order to feed. After feeding, the insect leaves. As the fruit continues to grow, it often develops a scar that resembles the face of a cat.
Besides being an agricultural pest, the brown marmorated stink bug is often a pest in homes. In late summer, the adult bugs gather on homes. The bugs are seeking sheltered places to spend the winter.
The bugs move inside the home through cracks and other openings. They spend the winter hiding inside the walls or in the attic or crawl space. When spring comes, the stink bugs become active. As they begin to move around, some of them emerge into the living space.
Inside the home, the bugs often gather on walls and windows seeking a way out. Homeowners are usually upset to find these bugs inside the home. Their size and unpleasant odor make them very unwelcome.
Females typically lay 20 to 30 eggs which she secures on the underside of the host plant in the summer. Eggs hatch four to five days later and the nymphs will begin to feed. They undergo a series of molts until they become adults by fall.
Signs of a Stink Bug Infestation
Homeowners often first detect stink bugs by their mass invasions in the fall. They turn up on sunny sides of homes where they warm themselves. Growers often detect them by the damage they cause to their crops.
The brown marmorated stink bug (Halyomorpha halys) is native to Asia. It has been an agricultural pest in China, Japan and Korea.
It was first collected in the United States in 1998. It is now found in many parts of the country from Maine to Mississippi and from Oregon to Florida.
Homeowners can discourage the brown marmorated stink bug from entering the home by sealing as many entryways as possible. Cracks around doors and windows can be sealed with caulk. Vents in attics and crawl spaces can be protected with screen. Any torn or damaged window screens should also be repaired. Weather stripping can help seal gaps under exterior doors.
Unfortunately, once stink bugs invade the voids of the home to overwinter, they can be difficult to remove. While overwintering, they do not feed or reproduce. However, they will become active again on a warm winter day or in the spring. When the spring arrives, they disperse from the home and will not return until the next fall. If a homeowner is experiencing overwintering stink bugs, contact pest professionals who can select the most effective materials and determine the best course of actions to prevent a recurrence.