Identification and Life Cycle
The more common species of the stink bug is the Brown Marmorated Stink Bug (Halyomorpha halys). The first reported occurance in the United States came from Allentown, PA in 1998. The name “stink bug”, refers to the foul-smelling odor it emits from its thoracic gland, which they use in self-defense.
The adult Brown stink bug is approximately 3/4 – inch long and has a distinctive shield-shaped body. It has different shades of brown on both its upper and lower body surfaces with patches of a coppery or metallic blue color “puncture holes” on the head and pronotum. They feed mostly on cultivated plants and animal prey such as caterpillars.
In early spring, the adult female stink bug will mate and then seek a suitable plant to lay her eggs. She will lay tightly packed rows of barrel-shaped eggs (approximately 20 to 30 eggs), on the underside of leaves. From May through August, stink bugs do not go through a metamorphosis stage, but are hatched from the eggs without sexual organs or wings. After hatching, the nymphs will huddle together near their empty egg shells and will molt 5 times before dispersing as adults. In September and October months, the adults begin to search for locations to hibernate during the winter. The adults tend to live between 6 to 8 months.
Habits and Damage
Stink bugs can be a big nuisance in homes and a major agritcultural pest that feeds, and damages soft fruit and vegetables as well as commerical crops including soybeans, cotton, cabbage, apples, and tomatoes. Although they can assist farmers with feeding on such problem pests as catepillars, the monetary loss of a harvest does not make up for it. The stink bug does have some predators of its own such as spiders, birds and carnivorous insects that will make a meal out of it.
Stink bugs are not known to be harmful to humans or cause structural damage to homes or buildings. They live and feed outdoors in fields, orchards, forests, and gardens. In the late fall, they will work their way under your siding, sofits, and attic vents looking for a warm place to hibernate during the winter. During this time, they do not feed or reproduce. The females are incapable to reproducing until the early spring. Once inside a warm environment, they will be active during the cold months.
Typically stink bugs will emerge inside your home from cracks under or behind baseboards, around windows and door trim, exhaust fans or lights in ceilings. They can become an annoyance to homeowners when they noisily fly around and their smell can be quite apparent if crushed. Even if simply handled, you can trigger it to release an unpleasant odor.
Prevention and Management
The best strategy to manage stink bugs is to prevent them from entering your home or building. An Integrated Pest Management (IPM) program can help maintain stink bugs for a pest-free environment.
The best way to prevent them from getting in is to seal them out. Their flat, shield-like shaped body enables them to squeeze through the smallest openings to get into your home such as in cracked siding, holes in window screens, spaces around window-unit air conditioners, baseboards, dryer vents, chimneys, attic vents, etc.
You can eliminate them inside your home by gently picking it up with a tissue and flushing it in the toilet, or sucking them up in a vacuum. A dead stink bug can leave an odorous residue in your cleaner, so empty the canister after use.
The following steps can be taken to help prevent or reduce a potential problem with stink bugs.
- Seal cracks around windows, doors & siding, and underneath wood fascia.
- Install weather stripping around windows & doors. Replace any worn weather stripping.
- Install screens over chimney & attic vents.
- Repair holes in window screens & make sure that screens & windows close tightly.
- Seal all cracks around foundation, utility pipes and wires that can provide entry indoors.
- Seal spaces around window-unit and wall-unit air conditioners.