The red-and-black bugs clustering on the sunny side of your house every fall are box elder bugs (Boisea trivittata), and they’re one of the most recognizable fall invaders in Leavenworth. They’re not dangerous and they don’t cause structural damage, but a swarm of hundreds on your siding — and the ones that inevitably find their way inside — gets old fast. Control is straightforward if you act at the right time.

Signs of a Box Elder Bug Problem

  • Masses of red-and-black bugs on south-facing walls — Box elder bugs aggregate on warm exterior surfaces in large groups each fall. They’re about half an inch long with distinctive red markings on their wings.
  • Bugs entering around windows and doors — They squeeze through gaps in weatherstripping, window frames, and foundation cracks to overwinter inside.
  • Bugs emerging indoors in late winter/spring — Overwintering box elder bugs become active when indoor heating tricks them into thinking spring has arrived.
  • Reddish staining on light surfaces — Their excrement can leave reddish-brown stains on drapes, upholstery, and light-colored walls.
  • Box elder or maple trees nearby — Box elder bugs feed almost exclusively on box elder trees (and sometimes maple and ash). If you have these trees on or adjacent to your property, expect box elder bugs every fall.

Why Box Elder Bugs Are Common in Leavenworth

Box elder trees (Acer negundo) are widespread throughout Leavenworth County and the greater Kansas City area. They’re a fast-growing native tree often found along creek corridors, in older neighborhoods, and along property lines. Leavenworth’s historic neighborhoods with mature trees, riverside terrain, and a mix of older and newer homes almost certainly include box elder or maple trees within range of your home.

The fall invasion pattern is predictable: as temperatures cool in September and October, box elder bugs that have been feeding on seed pods in trees all summer shift into overwintering mode. They seek warmth on sun-exposed building surfaces, then push inside through any available gap. The missouri river corridor creates humid, moisture-rich conditions year-round, and the hard freezes that follow make any warm building an attractive destination.

Homes with large box elder trees adjacent to south or west walls consistently get the worst infestations. The bugs don’t go far from their food source.

Our Box Elder Bug Control Process

Miller Pest Solutions uses exterior barrier treatments applied to siding, window and door frames, foundation areas, and other exterior surfaces where box elder bugs aggregate and enter. Timing is important — treatment in early to mid-fall, before heavy aggregations begin, provides the best results.

We also review and recommend exclusion improvements: sealing gaps around windows, doors, utility penetrations, and foundation cracks. For particularly heavy infestations, treating the box elder trees themselves may be recommended, though this is a supplemental measure rather than a standalone solution.

Bugs already inside can be removed by vacuuming. We don’t recommend crushing them indoors — the odor they release when crushed is mild but unpleasant, and it can attract more bugs.

Why Choose Miller Pest Solutions

We’ve been serving the Kansas City metro area from our local branch for years, with Joel Miller in pest control since 2007 and Miller Pest Solutions in business since 2001. QualityPro Certified, NPMA members. We know the seasonal pest pressures in Leavenworth and Leavenworth County and we’ll give you a straight answer on what control looks like for your specific situation.

Get a Free Phone Bid Today

Box elder bugs taking over your Leavenworth home this fall? Call Miller Pest Solutions at (816) 815-0498. Free phone bids — describe what you’re seeing and we’ll tell you what it will take to solve it. Visit millerthekiller.com.