Stink Bugs in Your NJ House This Fall: Why, When and What to Do

Brown marmorated stink bugs start moving onto Brick and Ocean County houses in September, and the search for winter shelter runs through October. Penn State Extension says adults begin looking for overwintering sites starting in September through October, and University of Maryland Extension describes adults congregating in late summer and early fall to seek safe sites, especially inside buildings. No primary source gives a single temperature that sets them off, so watch the calendar, not the thermometer.

Rutgers' New Jersey fact sheet says the adults behave like Asian lady beetles and boxelder bugs: they congregate on houses in late fall and eventually move indoors. This guide is for homeowners and rental owners in Brick and nearby Ocean and northern Monmouth County towns who are seeing the bugs now and deciding what to do next: remove the ones inside, seal the house, or call a licensed pesticide applicator.

Brown marmorated stink bugs in a Brick or Ocean County home are a nuisance, not a threat to people, pets, or the structure. Rutgers calls the insect a plant feeder that will not bite humans or pets, and University of Maryland Extension says the bugs do not sting, suck blood, spread disease, or eat or bore into wood. Penn State adds that the stink bug will not reproduce inside structures or cause damage.

The real downsides are the smell and irritation. Rutgers explains that scent glands on the abdomen and thorax produce the pungent odor, and Maryland notes the bugs release it when threatened or crushed. Penn State warns that crushing them against exposed skin can produce dermatitis, and that the airborne defensive chemicals can cause allergic rhinitis or conjunctivitis in some people. This is general information, not medical advice; ask a health care provider about any skin reaction that does not clear up.

Stink bugs already inside a Brick house are best removed with a vacuum or a container of soapy water, not by crushing them. Penn State says both live and dead stink bugs can be removed from interior areas with a vacuum cleaner, and Maryland calls a dry or wet vac efficient. Rutgers Cooperative Extension staff in Monmouth County gave the same advice in 2008: sweep them up or vacuum them up and take them outside.

For the soapy-water method, University of Maryland Extension says to fill the bottom quarter of a container with water mixed with a teaspoon of liquid detergent or soap, then sweep the bugs into it. Check the places Penn State says they emerge from: cracks under or behind baseboards, around window and door trim, and around ceiling lights and exhaust fans. Rutgers' fact sheet sums up the non-chemical approach as vacuuming and disposing of the insects.

Spraying insecticide inside a New Jersey home does not solve a fall stink bug problem, and every extension source used for this guide advises against it. Penn State says it is not advisable to use an insecticide inside after the insects have gained access, Rutgers does not recommend using insecticides inside the home, and University of Maryland Extension says aerosol-type foggers are not recommended indoors to kill stink bugs.

Local experience matches the extension advice. In a 2008 Asbury Park Press report reprinted by Monmouth County, a Rutgers Cooperative Extension staff member in Freehold said homeowners told her they spray the bugs with insecticide and it does not affect them at all. Removal indoors and sealing outdoors do the real work, which is why the rest of this guide focuses there.

Keeping stink bugs out of a Brick home means closing entry points in early September, before the bugs start congregating. Cornell's New York State IPM Program says overwintering pests take refuge in south- or west-facing cracks and crevices to catch the warm sun, and it recommends inspecting where wires, pipes, and other utility lines enter, especially on those sides of the building. Start the walk-around on the south and west walls.

Penn State lists cracks around windows, doors, siding, utility pipes, and behind chimneys as spots to seal with good-quality silicone or silicone-latex caulk. Rutgers adds a step that matters for any Ocean County home or rental that runs window units: remove window air conditioners in mid-September, because they are a common source of entry. The fall mice guide on this site covers gap-sealing materials in more depth.

A local example shows what the pressure can look like. In an October 2008 Asbury Park Press report reprinted by Monmouth County, a Holmdel homeowner described seeing perhaps 25 to 30 stink bugs on her house's cedar-shake siding, and a Rutgers extension staff member advised caulking openings and removing or covering window air-conditioning units.

Not every brown bug on an Ocean County house in fall is a stink bug; the western conifer seed bug is the usual look-alike. Penn State describes it as 3/4 inch long and reddish-brown to dark brown, with a leaf-like expansion on the hind legs and alternating yellow or light orange and black patches along the edge of the abdomen. Stink bug adults are about 0.66 inch long, with lighter bands on the antennae.

The look-alike matters here because Ocean County is one of the seven counties with land in the New Jersey Pinelands, whose upland forests are dominated by pitch pine. Penn State says the western conifer seed bug feeds on conifers including pines, congregates on the outside of buildings in late summer and early fall, and is not considered a medical risk. The best control, Penn State says, is keeping it out through mechanical exclusion.

For a local, non-commercial second opinion on a bug you cannot place, contact Rutgers Cooperative Extension of Ocean County at 1623 Whitesville Road in Toms River. Its Master Gardener Helpline number is 732-349-1245, and the office lists hours of 8 a.m. to 4:30 p.m., Monday through Friday.

The quickest way for a Brick homeowner to decide what to do about fall stink bugs is to match the sighting to its cause. The table below pairs common Ocean County sightings with what the extension sources say they mean and the step that fits each one.

Exterior perimeter treatment by a licensed pesticide applicator makes sense for a Brick or Ocean County home that sees heavy stink bug numbers every fall even after sealing. Penn State says applications should be made by a pest control operator licensed for pesticide use in the fall just prior to bug congregation, and Rutgers says an exterior perimeter spray may reduce numbers if applied when the insects first start to appear. Timing matters, because indoor spraying after entry is not advised.

Guardian Pest Control's general pest control service covers stink bugs: a technician licensed for pesticide use inspects, explains what was found, and treats the source and the perimeter. Ask any applicator to show you the entry points, say what product goes where, and book the visit for early fall; the NJ exterminator license guide on this site explains how to check a pesticide license. Guardian offers a free quote and same-day scheduling when available, Monday to Saturday, 8 AM to 3 PM.