Overview
The family has sometimes been referred to the Bombycoidea because of larval characters. Rothschild and Jordan (1903) recognised 5 subfamilies and Hodges (1971) 2 with 5 tribes; the latter view is accepted here. D'Abrera (1986) illustrated most species of the family.
Description
Large; ocelli and chaetosemata absent; antennae usually thickened, sometimes clavate or hooked apically, ciliate, serrate, or shortly pectinate in male, filiform in female; proboscis usually strong, often long; maxillary palps 1-segmented; labial palps thick, ascending, appressed to frons, with unscaled areas on inner surface, basal segment often with patch of sensory hairs on inner surface; epiphysis present, tibial spurs 0-2-4 or rarely 0-2-2; fore wing long, narrow, CuP absent, one other vein usually absent, 1A + 2A forked at base, retinaculum rarely absent; hind wing much shorter than fore wing, with anal lobe, frenulum usually strong, Sc connected to Rs by R
1
at middle of cell, Sc + R
1
approaching Rs beyond cell, CuP absent, 2 anal veins; tympanal organs absent; abdomen large, fusiform, posterior margins of segments usually with flattened spines or stiff, modified scales. Egg of flat type. Larva without conspicuous setae, abdominal segment 8 usually with spine-like dorsal horn, sometimes rudimentary in final instar, crochets biordinal, in a mesoseries, anal prolegs massive; feeding exposed in daytime. Pupa fusiform, mouth-parts displaced anteriorly, cremaster prominent, rarely armed; in cell in soil, or in flimsy cocoon amongst detritus.
Distribution
This mainly tropical family includes fast-flying species, often with long proboscis used for ingesting nectar as the insect hovers before flowers. Twenty-four genera occur in Australia, most of which are found also in New Guinea and the Orient; a few species are almost cosmopolitan.