Scoliid wasps are a family of beetle hunters. Large, rather hairy solitary wasps, some species are handsomely colored. The female digs in soil, finds a beetle grub, stings it, and lays an egg on it. The young eats the beetle grub. The name is pronounced sko-LEE-ud.
Coloration includes the typical wasp colors: bodies are usually dark or black, often with a bluish sheen, and the markings may include yellow stripes or other patterns of white, yellow, orange, or red. The precise pattern helps identify the species.
Specialists use wing vein patterns and details of the antennae, reproductive organs, and other anatomy to make precise identifications. In some species, the females and males look very different, which can complicate IDs.
Scoliid wasps are large, with hairs visible on their abdomen. The wings have distinctive corrugations: lengthwise, roughly parallel wrinkles on the outer half or two-thirds of the wings.
These wasps also have a rather bent or curled posture. The family name comes from the genus name Scolia, which has the same root meaning “bent,” or “crooked,” as in scoliosis, or curvature of the spine.
Most North American scoliids occur in the Southwest, Florida, or other desert, tropical, or subtropical areas. Some common Missouri species include:
- The blue-winged wasp (Scolia dubia) has a wide range in North America. The colors on its abdomen are distinctive: a large, fuzzy, rich rusty patch with two ovals of yellow. This quickly distinguishes it from other large wasps with shiny blue-black bodies and wings.
- The double-banded scoliid (Scolia bicincta), with its two cream-colored bands on the front half of the abdomen, resembles a mason wasp. Like other scoliids, it is hairy and usually seen visiting flowers.
- Scolia nobilitata (no common name, but you could call it the noble scoliid) has a wide distribution in the United States. It is small for a scoliid, just over ½ inch long. Legs are reddish, and the wings are dark. Females have 2 or 3 pairs of yellow or orange spots on the front part of the abdomen. Males are variable and frequently have yellow-banded abdomens.
- Pygodasis quadrimaculata (formerly in genus Campsomeris) is very large, and females have four large, yellow ovals on the abdomen. It looks like a huge, black-legged version of Scolia nobilitata. The color pattern of males can vary; they are frequently banded. It occurs in the eastern United States.
- Dielis plumipes (formerly in genus Campsomeris) is another very large, heavy-looking, hairy wasp. It has amber wings and cream-colored or yellow bands on the abdomen. It might easily be mistaken for a cicada killer wasp.
Similar species: There are many other families of large wasps that have similar colorations, including the spider wasps and thread-waisted wasps. Hairs on the abdomen, thorax, and legs, and typically bent-over posture help to distinguish the scoliids.