Anasa tristis is a species of bug in the family Coreidae. It is a major pest of squash and pumpkins, found throughout North America, and is a vector of the cucurbit yellow vine disease bacterium. These bugs can emit an unpleasant odor when disturbed. It is commonly known as the squash bug but shares this name with certain other species.
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DiurnalDiurnal animals are active during the daytime, with a period of sleeping or other inactivity at night. The timing of activity by an animal depends ...
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TerrestrialTerrestrial animals are animals that live predominantly or entirely on land (e.g., cats, ants, snails), as compared with aquatic animals, which liv...
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OviparousOviparous animals are female animals that lay their eggs, with little or no other embryonic development within the mother. This is the reproductive...
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starts withThe adult A. tristis is a greyish-brown, somewhat flattened insect reaching a length of about 1.5 cm (0.6 in) and a width of 0.75 cm (0.3 in). There is often a row of alternate brown and gold spots along the margin of the abdomen. Adults survive for three or four months.
In the southern part of its range, the adult female A. tristis lays two or three batches of about 18 eggs, but in the northern part of the range it just lays a single batch. The eggs are oval, somewhat flattened and bronze in colour, and are deposited on the underside of the leaves of the host plant. They may be clustered close together or more widely dispersed but are often regularly arranged. The eggs hatch after 7-9 days into nymphs which have five instars. The first instar nymphs are green and about 2.5 mm (0.1 in) in length. Each successive instar is larger and less hairy and grey. The fifth instar is grey, with developing wing pads and about 10 mm (0.4 in) in length. The complete nymphal stage lasts about 33 days.
