Loopers, Measuring Worms, Span Worms, Inch Worms, Twig Caterpillars, Arches, Emeralds.
There are approximately 1,300 named Australian species in GEOMETRIDAE. Here the notable species are listed in their subfamilies.
Many of the Caterpillars of GEOMETRIDAE pull their bodies into loops as they move. These Caterpillars lack the first two or three pairs of ventral prolegs, so that looping is their best means of progression. This movement gives them some of their names. Their latin name means "earth measurer". They are often called Inch Worms because they measure off one inch at a time as they progress. This method of progression has been suggested as being specially suitable for moving over rough terrain.
Some Caterpillars of this family are also called Twig Caterpillars because they can raise themselves and stand on their claspers, sticking straight out at an angle, and so looking like a twig.
They mostly pupate in leaf litter or in the soil in a flimsy cocoon.
Many of the adult moths are remarkable for their camouflaged wing patterns. These patterns, often wavy lines, extend across both fore and hind wings. These moths rest with wings outspread, and tightly pressed against the surface on which they are sitting. The curved markings may be the origin of their common name: "Arches": eg
A large group of the GEOMETRIDAE have green wings: these are called "Emeralds": eg