Stink Bug Exterminator for Central NJ Homes, Before the Fall Invasion

The brown marmorated stink bug: an Asian import that made Central Jersey home

The bug lining up on your window screens each autumn is almost always the brown marmorated stink bug, Halyomorpha halys. Rutgers Cooperative Extension describes it as native to Asia and first collected in the United States in Allentown, Pennsylvania, in the fall of 1996, just across the Delaware River. A Rutgers vegetable program trap in Milford, NJ caught one in 1999, and by 2002 the insect was established in the northern and central parts of the state. It has been part of autumn here ever since.

Adults are about 17 millimeters long, a little over half an inch, and mottled brown. The Rutgers fact sheet points to a few marks that separate it from the native stink bugs in your garden: white or off-white bands on the antennae, darker bands across the thin, overlapping tips of the wings, and small coppery or bluish metallic pits on the head and the shield just behind it. The odor that gives the group its name comes from scent glands on the back of the abdomen and the underside of the thorax.

Outdoors this is a plant feeder with a wide menu. Rutgers reports it feeding on ornamental plants, fruit trees, legumes and vegetables in New Jersey and Pennsylvania, and leaving scarred, dimpled spots on fruit such as apples and peaches. Indoors it is a nuisance more than a hazard. The same sheet says it will not bite people or pets, and adults do not reproduce during the winter months.

Why stink bugs gather on siding in September and October

Rutgers compares the habit to Asian lady beetles and boxelder bugs. Adults congregate on the outside of houses in late fall and then work their way indoors to spend the winter. The extension service even asks residents who notice large numbers on their walls during mid-September and October to report it to their county office, which tells you exactly when the gathering peaks.

That gathering stage is the useful one. A bug sitting on clapboard in early October has not found its way in yet. Once it slips behind a window casing or into an attic vent, it is out of reach until it wanders into a room on its own. So our inspection concentrates on the walls where you have been seeing clusters, which is also where Rutgers says sealing does the most good.

• Cracks where window and door trim meets siding, brick or stucco.
• Window air conditioners. Rutgers calls them a common entry point and suggests pulling them out by mid-September.
• Torn screens on windows, attic gables and soffit vents.
• Gaps along the roofline where siding stops short of the soffit or fascia.
• Openings around cable lines, refrigerant lines, dryer vents and hose bibs.
• Worn door sweeps and thresholds, including the door between the garage and the house.

Inside the visit: what a stink bug exterminator actually does

A good part of stink bug control is carpentry and caulk rather than product. Here is how the work divides up when our technician arrives.

The outside walk and the gap list

We circle the house with a ladder where it is needed, checking each side for the openings above and noting which ones show bugs crowding at the edges. You get the list. We can close what we find during the visit, or you can take the list and do the caulking yourself if you are handy and the openings are within easy reach.

Exterior perimeter application, timed to the first arrivals

Rutgers notes that a perimeter spray on the exterior of the house may reduce numbers if it goes on when the insects first start to appear. We take the word may seriously. When a plan includes outside treatment, our technician applies a product labeled for that use to the exterior walls and openings, following the label, and aims for the weeks when the first bugs show up on the siding. Your technician will explain any steps to take before and after treatment, following the product label.

Why we leave the living room alone

Rutgers does not suggest using insecticides inside the home for this insect, and we agree with the reasoning. The bugs you see indoors are a small share of the ones resting quietly in wall voids and attic insulation, and a spray in a bedroom does nothing for those. Inside the house we rely on sealing and on a vacuum.

A homeowner's sealing checklist for late summer

Exclusion is the part of the work that keeps paying off year after year, because a gap you close in August stays closed the following fall. If you want to get ahead of us, these are the jobs to tackle before the middle of September:

• Run a bead of exterior caulk along window and door trim on the sunny sides of the house, where clusters tend to appear in your yard.
• Patch or replace any window screen with a tear, and add fine screening behind attic and gable vents.
• Take window air conditioners out, or seal the gaps around the unit and its side panels if it has to stay.
• Replace worn door sweeps and weatherstripping.
• Fill gaps around pipes, wires and vents where they pass through the wall.

Stink bugs that wake up on warm winter days

Plenty of people who sealed late still see a few bugs crawling on a window in January. Rutgers explains why: on warm days during the fall and winter, the adults that made it inside become active and show up in living spaces. They are not breeding in there. They are bugs that slipped in during the autumn and are stirring with the heat.

Rutgers suggests vacuuming them up and disposing of them, which is what we recommend too. A small handheld vacuum kept just for this job, emptied into a sealed bag outside, keeps the odor out of your main machine. Avoid squashing them, because the smell is released when they are disturbed or crushed. Keep a note of which rooms they turn up in. That record points us to the gaps on that side of the house when we come back before next fall.

Stink bug or spotted lanternfly?

Both are invasive, both are common in Central Jersey, and people mix them up in late summer. They are different problems. The lanternfly is a planthopper with spotted gray forewings and red hindwings that feeds on tree of heaven and other plants, and the New Jersey Department of Agriculture runs a statewide quarantine for it. It is not something we treat, but our spotted lanternfly guide sums up what NJDA asks homeowners to do.

The stink bug is the one trying to get into your house. A house with many windows and aging trim, whether a colonial in Monroe Township or a split-level in Bridgewater, simply offers more openings, but any home with gaps on a sunny wall can host a crowd.