- Inchworm redirects here. For the motor, see Inchworm motor.
The Geometer moths or Geometridae are a family of the order Lepidoptera. A very large family with around 26,000 species described (over 300 of which occur in the British Isles), it notably includes the peppered moth, Biston betularia.
Many Geometrids have slender abdomens and broad wings which are usually held flat with the hindwings visible. As such they appear rather butterfly like but in most respects they are typical moths: The overwhelming majority fly at night, they possess a frenulum to link the wings and the antennae of the males are often feathered.
The name Geometer (earth-measurer) refers to the means of locomotion of the larvae or caterpillars. Equipped with claspers at both ends of the body, a caterpillar will clasp with its front legs and draw up the hind end, then clasp with the hind end and reach out for a new front attachment. The impression that it is measuring its journey is inescapable. The caterpillars are accordingly called loopers or inchworms.
Species
