Brown Marmorated Stink Bugs

General Information

The insect, Halyomorpha halys, commonly referred to as the brown marmorated stink bug first began being reported/sighted in the U.S. in the early 2000s. The small insect originally from East Asia but has since spread to nearly 30 states across the country. The brown marmorated stink bug is common throughout the United States, where reports of the insect first originated. The insect continues to migrate across the United States and populate areas in the Midwest.

Appearance & Identification

What do brown marmorated stink bugs look like?
On average, brown marmorated stink bugs measure around one-half inch to an inch long and consists of rich marble colorations, predominantly in hues of brown. Unlike other species of stink bugs, marmorated versions of the insect possess white-striped antennae and blunt heads. Brown marmorated stink bugs also possess striping at the bottom of the abdomen near the wings and dark banding on the legs closest to the thorax. The body of the insect closely resembles what many refer to as the shape of a shield. Brown marmorated stink bug nymphs appear red and black in coloration, with patterns along the abdomen differentiating the instars from the adult form of the insect. Although invisible to the naked eye, the insect possesses a special gland that emits a foul odor if crushed.

Habits/Habitat

Brown marmorated stink bugs spend a majority of their life cycle reproducing and eating. Often referred to as a pest, stink bugs generally inhabit large crops and feed on the vegetation. Most active in the late spring and summer months, brown marmorated stink bugs later dwell on the sides of buildings or on the trunks of trees closely resembling the insect’s colorations in the fall. The insect overwinters in cracks, crevices, or under tree bark and goes into a form of reproductive hibernation called facultative diapause. The lifespan of a typical brown marmorated stink bug lasts about a year. Stink bugs historically produce one to two generations per year; however, warmer climates may allow for as many as six generations per calendar year.

Diet

What do brown marmorated stink bugs eat?
The primary diet of brown marmorated stink bugs includes a wide variety of plants. Preferred food sources range from tree fruits, like peaches and apples, to several types of ornamental or show plants typically found in domestic gardens, specifically the seed pods and fruits of these plants.

Reproduction

The reproductive life cycle of the brown marmorated stink bug includes four instars beginning with small, tick-like nymphs and subsequent molts resulting in larger versions of the insect until full maturation. Each instar bears slightly darker colorations and larger proportions. The early instars feature more red and black patterns, while the later instars become browner as they near adulthood.

Female brown marmorated stink bugs lay eggs in bunches of roughly 20 to 30. Over a lifetime, females may lay as many as 500 eggs, depending on climate and adequate access to food. After reaching adulthood, stink bugs spend up to two full weeks eating before mating. Brown marmorated stink bug mating primarily takes place in the spring.

Problems Caused by Brown Marmorated Stink Bugs

Classified as a pest insect, brown marmorated stink bugs do not cause any physical harm to humans, as the insect does not bite, feed on blood, or possess a stinger of any type. Reproduction indoors rarely occurs. However, the diet of stink bugs makes the insects severe nuisances in gardens and crop fields when feeding on commercial agriculture and decorative garden plants. The insect bruises and damages the fruits and other portions of the plants, which leaves the crops or garden plants unsightly or unsellable. According to a 2011 survey of Mid-Atlantic States taken by U.S. Apple Association, local agriculture suffered an estimated $37 million seasonal loss in 2010 due to brown marmorated stink bug feeding habits.

Signs of Infestation

Clusters of the insect found on trees and on the sides of buildings are glaring common indication of a brown marmorated stink bug infestation. Indoors, stink bugs are most likely seen around light fixtures or exhaust fans. The insects also prefer to live in crevices or cracks, such as runners in floors or spaces between boards, which often exist in older homes.