Accidental Invaders in the Spring

Boxelder Bug

Early spring is the time many homeowners notice an increase in the number of boxelder bugs and Asian lady beetles that "mysteriously" appear inside their homes. All accidental invaders found inside at this time entered the building last fall through cracks and openings, and spent the winter hibernating behind exterior siding and in attics, wall voids, window/door casings, and similar protected areas. With the onset of warmer weather, the bugs become active and emerge from their overwintering sites. As they attempt to escape to their natural habitat outdoors, some move inward into living areas, emerging from beneath baseboards, behind window and door frames, from within sash-cord openings, and around light fixtures and ventilators.

Besieged homeowners often seek immediate and complete relief from the annoyance of accidental invaders. Unfortunately, this simply is not possible, since the bugs are emerging from hidden areas that are inaccessible to insecticides. Household foggers ("bug bombs") will not penetrate and control pests in these areas. Residual sprays generally kill invaders too slowly to be considered successful.

The best way to dispose of ladybugs and boxelder bugs appearing indoors is with a vacuum cleaner. Both insects tend to emit substances that can stain surfaces, making a broom less desirable. Repeated vacuuming may seem inefficient and monotonous, but it remains the most practical control.

The frustration of invader insects is temporary as the nuisance will run its course as the weather warms. Ladybugs and boxelder bugs typically do not bite, sting, or carry diseases, nor do they infest food, clothing or wood. They do not breed (reproduce) indoors.

Read more on the Asian Lady Beetle in Iowa.

This article originally appeared in the April 13, 2001 issue, p. 39.


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