squash bug, name for a true bug, Anasa tristis, found throughout the United States and S Canada. It damages squash, pumpkin, and related plants by sucking the juices from leaves and stems. The adult is dark brown and measures about 2/3 in. (16 mm) long. The eggs are laid in the late spring and hatch in two weeks. The green larvae, or nymphs, soon turn brown or gray. Birds feed on both nymphs and adults, but the most effective natural enemy is the larva of a tachinid fly, which develops within the body of an adult or larval squash bug, feeding on and eventually killing the host. The squash bug is classified in the phylum Arthropoda, class Insecta, order Hemiptera, and family Coreidae.

or leaf-footed bug

Any of more than 2,000 widely distributed insect species (family Coreidae), including many important plant pests. Most species are dull-coloured and more than 0.4 in. (10 mm) long. Many have enlarged, flattened extensions on the legs. The North American squash bug (Anasa tristis) is an important pest of squash, melon, and pumpkin (plants in the gourd family). It is basically yellow but is covered with black pits that make it look black. The larvae feed underground, and the piercing and sucking mouthparts of the adults enable them to attack the parts of plants that insecticides rarely penetrate.

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