Stink Bugs

Halyomorpha halys
Brown Marmorated Stink Bug  _L0O9225.jpg

Stink Bug Identification

Pest Stats

Color

Mottled grayish-brown

Legs

6

Shape

Triangular or shield

Size

3/4" long

Antennae

Yes

Region

Found in the eastern half of the U.S., as well as California, Oregon, Washington, Arizona, New Mexico and Texas

What Do Stink Bugs Look Like

Stink bugs are described in several different ways. They are characterized as both “large, oval-shaped insects” and “shield-shaped insects.” Adult stink bugs can reach almost 2 cm in length. They are nearly as wide as they are long. Their legs extend from the sides, so this makes the adult bugs appear even larger. The brown marmorated stink bug is a brownish stink bug. It has lighter bands on the antennae and darker bands on the wings.

Adult stink bugs are good fliers and fold their wings on top of their body when they land. Nymphs do not have fully developed wings. The wings appear when the nymph becomes an adult. Fully developed wings are a way to identify adult stink bugs.

Immature stink bugs, called nymphs, are very tiny when they hatch from their eggs. Nymphs of the brown marmorated stink bug are yellow and red. As they grow, the yellow fades to white. They have bright red eyes during the nymph stage of their life cycle. The nymphs molt or shed their skin five times. Each time a stink bug nymph molts, it becomes larger. By the last molt, the nymphs are almost as large as adult stink bugs.

Signs of an Infestation

Homeowners often first detect stink bugs by their mass invasions in the fall. Finding large numbers of live or dead stink bugs is a telltale sign of an infestation. Stink bugs will turn up on sunny sides of homes where they warm themselves. Growers often detect an infestation by the damage they cause to their crops.

If an infestation has developed inside the home or building, contact a licensed stink bug control professional to evaluate and assess the severity problem and help to identify the access points for this invasive species.

Stink Bug Infestation

Stink Bug Control and Prevention

To prevent stink bugs from entering homes and buildings, seal cracks around windows, doors, siding, utility pipes, behind chimneys, and underneath the wood fascia and other openings. Typical entry points include around door and window frames, electrical outlets, light switches, ceiling fans, skylights and ceiling light fixtures. Use a good quality silicone or silicone-latex caulk. Damaged screens on doors and windows should be repaired or replaced. Stink bugs are attracted to light, so change exterior lighting to less-attractive yellow bulbs or sodium vapor lights.  
 
If you need to know how to get rid of stink bugs that have already entered a home or building, a vacuum cleaner can aid in the removal of live or dead stink bugs. The bag must be discarded to prevent odor from permeating the area. After stink bugs have entered the structure, it is best to isolate the affected room or rooms by sealing the bugs out. If an infestation has developed inside the home or building, a licensed pest control professional should be called to evaluate and assess the problem. A professional can also pre-treat for stink bugs in the late summer or fall just prior to bug congregation.

Stink Bug Odor

Stink bugs get their name from the unpleasant odor they produce when they are threatened. It is thought that this odor helps protect the bugs against predators. The stink bugs produce the smelly chemical in a gland on their abdomen. Some species can actually spray the chemical several inches. The smell has often been compared to strong herbs and spices like cilantro and coriander.

Interestingly, the composition of the odor is comprised of chemicals commonly used as food additives and is present in cilantro. This smell can linger for hours so, if possible, try to avoid stink bugs or carefully sweep or vacuum them up if they have entered your house. 

log.jpg

Stink Bug Education

Habits

In general, adult stink bugs feed on fruits and nymphs feed on leaves, stems and fruit. The life cycle of brown marmorated stink bugs generally involves mating, reproducing and feeding from spring to late fall. Upon the onset of cold weather, stink bugs seek shelter to spend the winter in a dormant phase known as diapause.

Stink bugs search for overwintering sites in late fall before the weather conditions drastically change. They spend the winter hiding inside homes or buildings, usually in the walls, attic or crawl space. However, entering into diapause may not be the complete end to their season of activity. If the weather warms up for a long enough period of time, indoor overwintering stink bugs might be misled into thinking it is time to exit their diapause period and become active again. Stink bugs reemerge in early spring and become active.

Brown marmorated stink bugs mate and create up to 3 generations per year depending on their habitat. Cooler zones see one generation per year, while warmer areas are likely to see 2-3. Female stink bugs typically lay 20 to 30 eggs. Egg laying generally occurs from May through August. The eggs are light green, barrel-shaped, and are attached side-by-side on the underside of the host plant’s leaves in a mass. 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.

The brown marmorated stink bug cannot sting and is not likely to bite. The stink bug’s mouthparts are grouped in the piercing/sucking category, but they do not use blood as a food source like mosquitoes, biting flies and bed bugs. Their mouths are not structured in a way that enables them to bite through human skin. Most species of stink bugs feed on plants. They suck the juice from leaves, stems and roots of plants. They attack everything from ornamental plants to weeds. The insects pierce the skin of the plant and extract the juice inside. 

Threats

Stink bugs have the potential to spread throughout the country, which could be harmful to the agricultural industry, as they destroy crops. Stink bugs can damage ornamental plants, fruit trees, and gardens, but they are more of a nuisance than a threat to people. They do not cause structural damage or spread disease.