Green Stink Bugs

General Information

Named for their distinctive color as well as the malodorous fluid they secrete when crushed or disturbed, green stink bugs form a group of sucking insects with specially developed mouthparts designed for extracting the juices of various plants. The commonly encountered insects belong to the family Pentatomidae and are distributed across the United States. Within the U.S., the New England states generally represent the northernmost range of the green stink bug, scientifically named Acrosternum hilare. Green stink bugs rank as the most common stink bug species found on the entire North American continent. Though harmless to humans, the green stink bug feeds on and damages crops of fruit, vegetables, and other plants commonly grown in New England .

Appearance & Identification

What does a green stink bug look like?
Flattened and distinctively shaped, the body of a green stink bug resembles the physical outline of a traditional shield. The frequently encountered pests are bright green in color and roughly 2/3 to 3/4 of an inch long as adults. Mature green stink bugs possess functional wings that, during periods of inactivity, remain partially concealed by a protective covering shaped like a triangle. Prior to adulthood, green stink bugs complete multiple nymphal stages in which the developing insects are wingless and range in color from black and red to yellowish-orange yet otherwise closely resemble adults.

Habits/Habitat

Active primarily during warmer weather, green stink bugs in New England emerge to feed and mate in late spring or early summer when the outdoor temperature reaches 70 degrees Fahrenheit or higher on a daily basis. The herbivorous pest insects are often found on fertile land supporting the growth of trees, weeds, cultivated crops, and other plants. Wary of natural predators like birds and spiders, green stink bugs react to the detection of motion and other disturbances by immediately dropping out of sight and hiding among vegetation. Strong flyers, the insects relocate when necessary in order to find adequate sources of food. During the coldest weather of the year, green stink bugs overwinter under tree bark or leaf debris.

Diet

What do green stink bugs eat?
Featuring mouthparts capable of piercing the outer layers of various plants, green stink bugs feed on more than 50 different varieties of vegetation. Shrubs, vines, weeds, and native as well as ornamental trees regularly form part of the green stink bug diet. The agricultural pests also feed on commonly cultivated New England crops such as apples, beans, cherries, corn, peas, tomatoes, soybeans, and most other fruits and vegetables.

Reproduction

Mating season for green stink bugs generally takes place during the warmer weather of spring. Females lay as many as 150 eggs, often on the undersides of leaves or in other, similarly protected areas. Initially green in color, the eggs are typically deposited in batches of about 30. The eggs change in color from green to pink and the nymphs hatch in roughly a week. During the nymphal stage of the life cycle, green stink bugs grow and develop by molting several times. Also known as an instar, each molt brings the nymph progressively closer to becoming a fully mature adult. Green stink bugs reach adulthood after five instars. This process takes about a month to complete. Depending on the surrounding temperature, the green stink bug completes the entire life cycle in 30 to 45 days.

Problems Caused by Green Stink Bugs

Due to the types of food sources favored by green stink bugs, the insects rank among the most damaging stink bug species native to the United States. Green stink bugs often feed on commercial crops and compromise the economic output of New England farmers. The mouthparts of the green stink bug enable the insect to pierce the tissue of plants and extract the sap from blossoms, buds, fruits, or leaves. In addition to damaging plants cosmetically, the destructive eating habits of green stink bugs can reduce the overall quality and volume of a harvest. Plants affected by the pest insects may end up being discolored, shriveled, stunted in growth, or otherwise deformed. Like other stink bug species, green stink bugs also produce a foul odor when crushed or disturbed.

Signs of Infestation

Visible damage to plants generally serves as the most noticeable sign of a green stink bug infestation. Specifically, the mouthparts of the destructive insects often leave behind white or yellow spots on the surface of fruit. Green stink bugs may also cause bumps resembling warts to appear on other types of plants. Further signs of infestation include the dimpling or scarring of fruits and vegetables attacked by the damaging pests.

Prevention

Preventing a green stink bug infestation largely entails the elimination of ideal hiding places and overwintering sites. Farmers and gardeners should remove plant debris from the field after the harvest season and till the soil regularly to discourage green stink bugs from settling down for the winter. Finding and removing the barrel-shaped eggs of green stink bugs also helps prevent the pest insects from infesting. Natural predators like birds, spiders, and toads may assist in controlling localized populations of green stink bugs, as well. Often difficult to eliminate due to its propensity for going into immediate hiding when disturbed, the green stink bug sometimes invades areas in large enough numbers to require the services of a professional pest control expert.