Fall's Insect Invasion

Week of October 31, 2022
Kathleen Cue, Nebraska Extension Horticulture Educator in Dodge County

 Fall’s Insect Invasion

As nights cool, it’s not unusual to see an increase in the number of insects and spiders (collectively known as arthropods) inside the home. On average, homes have 200+ species of arthropods living there.  Keep in mind this isn’t a total of 200 insects and spiders, but instead of 200 species, with multiples of each not being at all unusual. There are reasons why arthropods make their way indoors.  Some, like crickets and millipedes, are seeking warmth, with heated homes offering a reprieve from cool temperatures. Other arthropods are predators, like ground beetles and spiders, following the prey indoors.

What can be done to minimize the number of arthropods found indoors?  First and foremost, seal all entry points. The smallest crack or opening is an easy access point for insects, wolf spiders, millipedes, centipedes, and leaf-footed bugs.  Close openings with a silicone-based caulk as this shrinks less than latex types do.  Next, look at the lighting over the front, side, back, and garage doors. Use yellow-colored lights or warm LED bulbs to discourage insects congregating around outdoor lights and allowing easy access every time a door opens. 

Adopt a cleaning strategy to discourage hiding places and food sources.  Clear away fallen leaves around the foundation and indoors frequently sweep to remove bits of food found on floors. A final strategy is to use boxed sticky traps (found in hardware stores) inside the home to catch these occasional invaders and monitor what’s found inside the home.

The Asian lady beetle, dermestid beetles, and boxelder bugs like to overwinter beneath a structure’s siding. These insects are not readily found indoors until spring, when warmer weather induces activity that results in them moving through wall voids to the inside of the home. These insects are best cleaned up with the aid of a vacuum cleaner. If an insecticide is used, it should be applied in September with a perimeter spray outside of the home to discourage access to the home’s siding. 

Remember that most of the arthropods we find indoors come from outside. Considered nuisance pests, most of these arthropods cause no harm to structures or people.

Boxelder Insect Image

Photo: Boxelder image from Oregon State University  (nipc.orst.edu)

Find more horticulture information at Trees, Plants and Insects