Common Summer Pests of the Midwest

By Julie Bawden-Davis

The Midwest's summer heat, humidity and rains attracts a variety of insatiable pests. The following critters are the most likely to show up in your backyard during the warmest months of the year.*


In its adult stage, this pest is a moth that lays eggs on the stems of squash plants in the late spring and early summer. The eggs hatch into fat, white caterpillars with brown heads that feed on the stems of squash vines, causing the plants to wilt and die. As the name suggests, the squash vine borer prefers squash, but will also attack melons and cucumbers.

  • Designation: nuisance and harmful
  • Remedy: Extract borers from wilted vines by slitting the vines open with a sharp knife and pulling out the caterpillars.1 Cover the cut portion of the vine with moist soil, and it may re-root and resume growth.Finally, remove vines as soon as the growing season is over.


Like its relative, the tomato hornworm, the tobacco hornworm is a large, green caterpillar with a horn on its head. In adult form, it is known as the hawkmoth or sphinx moth, a large moth that is sometimes mistaken for a hummingbird.2 The moth feeds on nectar, but its larvae defoliate plants in the Nightshade (tobacco) family, including tomato, pepper and potato.

  • Designation: nuisance and harmful
  • Remedy: Pick tobacco hornworms off of plants by hand, and then destroy them. CABBAGE WORM:

The cabbage worm adult is a white butterfly that deposits eggs on the underside of leaves of plants in the cabbage family, including cabbage, kale, kohlrabi, broccoli and Brussels sprouts. When the eggs hatch, the resulting cabbage worms feed on the leaves of these crops and can decimate entire plants.3 The cabbage worm butterfly doesn't damage plants.

  • Designation: nuisance and harmful
  • Remedy: Hand remove worms when they appear and then destroy them.

Amdro Quick Kill is a registered trademark of Central Garden & Pet Company.


1. Susan Mahr, "Squash Vine Borer, Melittia curcurbitae," The Wiscosin Master Gardener Program, July 26, 2013.

2. "Tobacco Hornworm," University of Nebraska Department of Entomology.

3. W. D. Hutchison, et al., Imported Cabbageworm, University of Minnesota, March 4, 2013.

* For a quick remedy for most of the pests listed, treat with the wide-reaching Amdro Quick Kill Outdoor Insect Killer (RTS). This ready-to-spray product kills more than 500 landscape pests, making it your go-to summer pest control for any region. Remedy time will vary, depending on the size of the garden or yard. Most control measures involve taking simple steps. Follow all product label recommendations to ensure the greatest chance of pest control.