Squash Bug (Anasa tristis) overwinters as an adult in sheltered places such as plant debris, weeds, under rocks and around buildings. In spring, adults move onto squash, pumpkins and other cucurbits to feed and lay clusters of bronze to reddish-brown eggs, usually on the undersides of leaves. The eggs hatch into pale grey-green nymphs that darken as they mature.

Both adults and nymphs pierce plant tissue and suck sap. Feeding causes yellow speckling that can turn brown, and heavy infestations can cause leaves and young plants to wilt and die. Squash bugs particularly favour pumpkins and winter squash. Later in the season they may also feed on fruit and fruit stems.

How to Fix It
Check under leaves: Look regularly for clusters of bronze or reddish-brown eggs, especially along leaf veins.
Destroy the eggs: Scrape or crush egg masses before they hatch.
Remove bugs: Hand-pick adults and nymphs and drop them into soapy water.
Use board traps: Lay boards or pieces of newspaper beside plants overnight. Squash bugs often shelter underneath and can be collected in the morning.
Remove hiding places: Keep weeds and plant debris down during the growing season.
Clean up in fall: Remove old cucurbit vines and crop debris that can shelter overwintering adults.
Avoid heavy straw mulch where they are a problem: Straw can provide additional hiding places for squash