Squash bug

Anasa tristis (De Geer)

(Insecta: Hemiptera: Coreidae)

Adults are shield-like, dark grayish brown, and 14 to 16 mm in length. Eggs are elliptical, bronze, and about 1.5 mm long. Nymphs grow from 2.5 to 10 mm in length, and their coloration changes from a light green (first instar) to gray, getting darker with each instar.

Completion of the life cycle takes six to eight weeks. Eggs are laid in clusters of 20 to 40 eggs on the undersurface of leaves, with uniform spacing between each egg. Nymphs hatch in seven to nine days, and develop through five instars that tend to feed gregariously on the host plant foliage. Adults may live up to 130 days and are the overwintering life stage. One generation occurs per year.

Squash bug distribution spans from Canada to Central America and includes most of the United States.

Both nymphs and adults feed on members of the cucurbit family (squash, pumpkin, cucumber and melon).

Images 

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Adult of squash bug, Anasa tristis (De Geer)

(Photographer: Lyle Buss, University of Florida)

Eggs of squash bug, Anasa tristis (De Geer)

(Photographer: Lyle Buss, University of Florida)

First instars of squash bug, Anasa tristis (De Geer)

(Photographer: Lyle Buss, University of Florida)

Adult (top) and fifth instar of squash bug, Anasa tristis (De Geer)

(Photographer: John Capinera, University of Florida)