wasp, Any of more than 20,000, usually winged, insect species in the order Hymenoptera. The abdomen is attached to the thorax by a slender petiole, or “waist,” and the female’s abdomen has a formidable stinger. Most species are solitary; about 1,000 species are highly social; and some may be either social or solitary. Adults feed primarily on nectar. Most solitary wasps nest in tunnels in the ground and feed larvae with paralyzed insects or spiders. The paperlike nest of social wasps (family Vespidae) consists of chewed plant material mixed with saliva and arranged in adjacent hexagonal cells. The female lays one egg in each cell and provisions it with a macerated caterpillar. Successive generations may enlarge the nest and care for the young.