Boric Acid & Stink Bugs

Stink bugs are a family of insects best known for their infamous scent; they secrete a foul-smelling liquid they can release when frightened or disturbed. They are a nuisance to homeowners in some parts of the United States, especially in Maryland, Pennsylvania and New Jersey, where a species of stink bug new to the United States--the brown marmorated stink bug--was accidentally introduced in 1998, according to Penn State's College of Agricultural Sciences. Boric acid is a common insecticide sometimes used for ant infestations, among other problems; some stink bugs, however, are resistant to certain insecticides, and there are better solutions than boric acid available.

Boric acid is a chemical compound with the molecular formula H3BO3. It's been used as a pesticide in the United States since 1948; insects that ingest the chemical die because of its effects on their exoskeletons. Boric acid is less toxic than many other pesticides and is typically safe to use in kitchens; it is still poisonous to humans, however, and should be kept well away from pets and children. It's estimated that 3 to 6 g may be a lethal dose for an infant while 15 to 20 g may be enough to kill an adult. Boric acid is available in a variety of forms, including aerosol sprays, powders, dusts, baits and pellets.

Boric acid is generally used against cockroaches, termites, ants and other common household pests, the Environmental Protection Agency reports. Some formulations include a bait so that insects are lured to the poison. There's only limited evidence to suggest that boric acid is effective against stink bugs, however, and certain common species of stink bugs are resistant to some of the less lethal insecticides. Some people report having used boric acid successfully to deter stink bugs, and boric acid is certainly cheaper and safer than many other pesticides. If you are going to try boric acid against these invaders, it's best to treat the exterior of the house--the places where stink bugs would gather to enter--to prevent them from gaining access. There are other better methods to deal with stink bugs that have already entered your home.

Stink bugs live outside but sometimes creep into homes and buildings seeking shelter through the winter. They are herbivores with mouth parts designed to suck the juices from plants. They lay their eggs on plant leaves and do not typically reproduce inside your home. If disturbed or squashed, they exude an intense stench that may linger for a long time.

The best method to deal with stink bugs is to prevent them from entering in the first place. Keep doors and windows closed and seal cracks and crevices around windows or siding with silicone caulking; stink bugs can crawl or squeeze through surprisingly small spaces. Window air conditioners are another route the bugs can use to gain entry. Stink bugs are also attracted to bright lights at night, so drawing the shades may help. If there are only a limited number of stink bugs, you can remove them with a vacuum cleaner; be forewarned, however, that the vacuum bag will absorb the stench and should probably be changed afterward. If you're handling individual stink bugs, it's a good idea to wear gloves because their bite is painful, although not harmful.

Stink bugs are resistant to some of the less lethal insecticides. Many insecticides are toxic to humans and it's unwise to use large amounts of these chemicals indoors. If only a small number of the insects have infiltrated your home, there's no need to use an insecticide; even in the event of a more serious infestation, insecticides are a questionable solution, since the remains of the dead stink bugs may very well attract other insects like carpet beetles and cause an entirely new problem. Treating the exterior of your home with insecticide may mitigate the problem to some extent. Ultimately, the best solution is to seal up your home against these malodorous invaders as thoroughly as possible, according to the National Pest Management Association.