Squash bugs have an elongated body shape and striped abdomen. Eggs are red and laid in clusters. Nymphs are gregarious, and progress in color from light gray to dark.

Anasa tristis is one of the squash bugs common in the PNW.

This pest is notoriously hard to detect, because they can hide on the underside of foliage, on plant stems, near irrigation lines, or even under fabric mulch.

Squash bugs use their piercing-sucking mouthparts to feed on leaf tissue and inject their saliva, which causes wilting of leaf tissue and, depending on the species, vectors cucurbit diseases.

Damage tends to be localized but can occur quickly because nymphs are gregarious, and feed alongside adults. If left undetected, vines eventually wilt and die.

Squash bugs have been a problem this year in the southeastern U.S., as noted by this news article.

According to a laboratory-based estimate, nymphal instars may be present in July, with a possible 2nd generation of adults in early August (model source: GDD58 single-sine, Fargo and Bonjour, 1988).

Consult this PNW Insect Management Handbook section for more info.

This page shows how to differentiate squash bug, BMSB, and other similar-looking bugs.

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