This is the time of year when people can get some exotic and never-before-seen pests in their homes, often in large numbers. There several different outdoor insects that will move into buildings in the fall to spend the winter. Most of these are plant-feeding insects that we never notice when they are high up in trees or feeding on crops in the field across the road. But when they find their way into our homes, we can’t help but wonder what they are and why and how they got in.

Invading Plant Bugs in Massachusetts and New Hampshire

These are some of the more common plant insects that invade homes in the fall in our region. See the links below for photos and more information on each pest.

1. Asian lady beetles – These colorful, beneficial beetles are also known as multicolored ladybird beetles, or more commonly, ladybugs. They are almost circular, mustard yellow or orange with black spots. Lady beetles don’t feed on plants but are found on plants where they feed on garden pests like aphids. See Lady Beetles Will Soon Move Into Homes.

2. Brown marmorated stink bugs – These plant bugs are shield-shaped and mottled brownish-gray with white banded antennae. They feed on a variety of fruit trees and field crops. See How to Keep Stink Bugs Out!

3. Western conifer seed bugs – These bugs are fairly large and dull brown in color, with flattened leaf-shaped projections on the hind legs. They feed on the seeds and needles of conifer trees. See Seed Bugs – Another Home Invader Revealed!

4. Boxelder bugs – These bugs are black with red eyes and red-orange markings along sides, on the back and along the wing borders. They feed on female boxelder trees or on silver maples. See Boxelder Bugs Are Overwintering Pests.

5. Elm leaf beetles – These beetles have soft wing covers that are dull yellow to olive green with a broad black stripe on each side. They feed on elm trees, especially the Siberian elm. See Elm Leaf Beetles Indoors.

Take Steps to Keep Plant Bugs Out Next Year

These plant pests don’t bite or sting and won’t damage anything in your home. Some can stain fabrics if crushed or may give off a defensive odor if handled. Once they are inside, these insects generally go into hiding and may not be seen again until spring or on very warm winter days. See It’s Time for Insects Wintering in Your Home to Wake Up!

There are two primary ways to keep fall plant pests out of your house: (1) a pesticide treatment around the perimeter of your home in fall before the pests start to move indoors. The insects often congregate on sunny exterior walls for several days before they move inside, and (2) pest-proofing your home to seal doors, screens, and openings around the roofline where these pests often enter. See Keep Fall Pest Invaders Out! and contact Colonial Pest for more information.