Dichromodes ainaria

Appearance

The adult moths of this species have forewings that are brown, with zig-zag markings bounding areas of different shades. The hindwings are yellow with broad brown margins. The females have threadlike antennae. The males have antennae with a feather-like fringe on one side. The wingspan is about 2 cms.

Naming

Guenée,1857

Distribution

Australia: NSW, ACT, Victoria, Tasmania, South Australia and Western Australia

Behavior

The name "Geometridae" ultimately derives from Latin geometra from Greek γεωμέτρης ("geometer", "earth-measurer"). This refers to the means of locomotion of the larvae or caterpillars, which lack the full complement of prolegs seen in other lepidopteran caterpillars, with only two or three pairs at the posterior end instead of the usual five pairs. Equipped with appendages at both ends of the body, a caterpillar clasps with its front legs and draws up the hind end, then clasps with the hind end (prolegs) and reaches out for a new front attachment - creating the impression that it measures its journey. The caterpillars are accordingly called "loopers", "spanworms", or "inchworms" after their characteristic looping gait. They are gregarious.

Food

Some eat lichen, flowers, or pollen.

Defense

Geometer moth larvae tend to be green, grey, or brownish and hide from predators by fading into the background or resembling twigs. Many inchworms, when disturbed, stand erect and motionless on their prolegs, increasing the resemblance. Some have humps or filaments, or cover themselves in plant material.

History and timeline

In 2019, the first geometrid caterpillar in Baltic amber was discovered by German scientists. Described under Eogeometer vadens, it measured about 5 mm (0.20 in), and was estimated to be 44 million years old, dating back to Eocene epoch. It was described as the earliest evidence for the subfamily of Ennominae, particularly the tribe of Boarmiini.