Facts About Stink Bugs

In the New England states like Vermont or Massachusetts, residents encounter both green stink bugs, Acrosternum hilare and the emerging brown marmorated stink bug, or Halyomorpha halys.

Also called shield bugs for the distinctive flat, shield-like appearance, the insects feed on fruits, vegetables, and other farm crops, causing both cosmetic damages and reduction in overall food quality.

Both stink bug species possess large stink glands on the underside of the thorax which may release a foul-smelling liquid whenever disturbed, to ward off predators, or when squashed. The insect may invade homes in order to overwinter, as well.

Quick Facts

• Does not like the cold weather therefore will enter the home through cracks and crevices
• Will not survive in your home, needs to feed on trees
• These Bugs are completely harmless to people and their possessions
• Not a destructive bug they feed on green pine cones
• They return in the Springtime

Reproduction & Life Cycle

The reproductive cycle and lifespan tends to depend on the species of the insect.

The brown marmorated stink bug typically emerges from its overwintering state in early May and mates through August. The eggs are elliptical in shape, typically light yellow in color, harbor tiny spines, and are usually attached side by side to the underside of host leaves in masses of up to 30.

Hatching into nymphs, the species goes through five instars before becoming an adult.

The green stink bug remains similar in most ways, with the entire life cycle taking up to 45 days to complete and eggs hatching within a week of oviposition.

Nymphs pass through five instars, with each passing molt bringing the young to look more like adults.

Typical lifespans may reach up to one year, depending on the overwintering patterns of each species, with weather patterns and predation playing a significant role in how many insects survive to the next spring.

As spring approaches and temperatures begin to rise, overwintering stink bugs emerge from hiding to begin the reproduction process. The insects typically mate and produce eggs from May to August. Female stink bugs lay batches of 20 to 30 barrel-shaped eggs on the undersides of leaves.

Eggs hatch into tiny black and red nymphs that measure less than an eighth of an inch. Nymphs progress through five instars before reaching adulthood.

Fully grown stink bugs measure about one inch in length. Stink bugs usually produce one or two generations per year. However, temperatures influence reproduction rates, and warm spring and summer seasons can result in three to four generations in a year.

Sub-tropical regions can see as many as six generations of stink bugs in one year. New England's temperate climate usually limits stink bugs to one generation per year.

Stink bug populations spike as summers progress. During the fall, typically between September and October, the insects begin searching for overwintering sites.

Outdoor stink bugs overwinter in piles of leaf litter and become active again when temperatures increase. Stink bugs may also enter homes to overwinter, often invading in large numbers. Warm temperatures inside the home keep stink bugs active, making them winter-long nuisances.