Stink Bugs, Cluster Flies and Other Fall Invaders: Seal Before They Move In

On the first sunny afternoon after a cold night in October, the south side of a house at the Shore can be covered with insects crawling toward cracks. These are fall invaders, pests that are not looking for food or a place to breed. They want a sheltered spot to sit out the winter, and your walls, attic and window frames fit the description. Resolve Pest Management takes calls about them every fall from homeowners in Ocean and Monmouth County who found a dozen in the window on Sunday and a hundred on Tuesday.

Who is moving in

The brown marmorated stink bug is the one most people know. It is a shield-shaped, mottled brown insect that gathers in large numbers on warm walls in fall, slips in through small gaps, and settles into wall voids and attics. It releases a sharp odor when crushed, which is why vacuuming or sweeping them into a cup of soapy water beats squashing them. They do not breed indoors and they do not damage wood, but on a warm winter day they wake up and wander into your living space.

Cluster flies look like slightly larger, slower house flies with a dull, golden-haired look. The larvae develop in earthworms outdoors during summer, and the adults head for attics and wall voids in fall, where they gather in groups. On a sunny winter day they crawl out and buzz sluggishly against windows. Boxelder bugs and multicolored Asian lady beetles are other overwinterers that follow the same habit. Lady beetles also stain surfaces when disturbed.

None of these is a health risk in the way that rodents or roaches are. What they do is annoy, stain, smell and show up in volume, often in rooms nobody uses until spring.

How they get in

They use the same weak points a mouse would, only smaller ones. If you find the gaps, you stop most of the problem before it begins.

• Gaps around window and door frames, where old caulk has shrunk or cracked
• Torn or missing window screens and loose weatherstripping on doors
• Siding seams, utility penetrations and the gaps around outdoor faucets and lines
• Attic and gable vents without screening, and ridge vents with loose ends
• Chimney flashing, soffit edges and the joint where a deck or porch meets the house

Sealing before the cold arrives

Fall invaders work by numbers, so seal early. The best window is September through October, before the insects start gathering. Replace worn caulk on the south and west sides of the house first, because those walls get the afternoon sun that draws the bugs. Repair screens, check door sweeps, and cover vents with fine mesh. Turn off or shade porch lights that stay on all night, since the lights draw insects toward your walls.

A professional treatment of the outside of the house, applied to the foundation and around openings before the insects arrive, is a standard fall step. Spraying a wall after the insects have crawled inside is much less useful, since the ones in the wall are out of reach. If they are already in, vacuum them up, do not crush them, empty the bag outdoors, and plan to seal gaps in spring when they have left.

What a seasonal plan covers, season by season

Fall invaders are a good example of why pest control follows the calendar. The pests that matter change as the year turns, and a plan that keeps pace with the seasons catches each one at its weak point. Resolve builds a seasonal plan around what is active when:

• Spring: ants, termites, spiders and rodents, as the ground warms and colonies and swarmers become active
• Summer: mosquitoes, wasps and ants, when yards are busy and the stinging insects build up
• Fall: rodents, spiders and overwintering pests such as stink bugs and cluster flies, as everything looks for shelter
• Winter: roaches and rodents, the indoor pests that stay active when the weather drives everything else away

Ask for the details of how each season is handled at your property. Houses differ, and a ranch on a slab near the bay has different weak points than a two-story with a crawl space inland. The quote is free and carries no obligation, and an inspection at the start shows what your house needs.

What helps right now

If you are reading this in October, you still have time to do three things. Walk around the house on a sunny afternoon and note where the insects are gathering, since that shows the gaps for you. Seal those gaps with exterior-grade caulk or fine mesh. Then clear the leaf litter and mulch that has piled against the foundation, because a thick layer gives overwintering insects more places to hide.

If they have already moved in, keep the vacuum handy, wait for warm days, and do not bother with sprays inside living spaces. For help with the outside of the house, or a plan for the year ahead, call Resolve at (732) 527-5770 or stop by the office at 792 Atlantic City Blvd in Bayville. The treatments are family and pet-conscious, and the work comes with a 100% satisfaction guarantee: if you are not satisfied, Resolve will come back and retreat your home at no additional cost to you.