There are hundreds of species of crane flies in North America. The larvae are essentially tan, gray, or greenish grubs: plump, segmented caterpillars with a definite head and with tiny, fleshy projections at the hind end. They lack legs. Sometimes you can see the dark line of their digestive tract under the translucent body covering.
The adults look like giant mosquitoes. They have slender bodies, very long legs, and one pair of wings that are often held out at a 45-degree angle to the body. Just behind the wings, attached to the body, are two small, antennae-like appendages called halteres. These function like gyroscopes during the crane fly’s weak and wavering flights. The mouthparts look like a snout.
Female crane flies have thicker abdomens, which have a pointed (and harmless) tip for egg-depositing. Males have pincerlike claspers at the tip of the abdomen.
Adult crane flies can be distinguished from mosquitoes by their lack of a piercing, tubelike mouth, a lack of scales on the wing veins, and a V-shaped groove on the thorax (the body part behind the head, from which the wings emerge).