I have not yet discovered what the critical identification features are for placement in this family. The family was previously considered monospecific containing only Endromis versicolor, but several non-British species, formerly placed in Family: Bombycidae have now joined it. Dissection of E.versicolor reveals the following distinctive features: eyes glabrous; proboscis absent; labial palps present, hairy and appear to be composed of a single segment; maxillary palps rudimentary; hindwing lacks a frenulum and appears to lack any secure wing-coupling mechanism; hindtibia with a small apical pair of spurs (no mid-tibial pair); midtibia identical to hindtibia; foretibia with a very long epiphysis; valvae of male genitalia very heavily sclerotised.
67.001 Endromis versicolora (Kentish Glory)
fw: m27-30mm, f34-39mm; late Apr - mid-May; silver birch (Betula pendula); NS-A central & eastern Scottish Highlands
ID: Unmistakeable. Male and female have similar forewing markings, but the female is larger and paler than the male. Male hindwing is orange-brown, female hindwing is brownish-white
Dissection
Male genitalia
Female genitalia
§1 Dinnet, Aberdeenshire; 01/05/2018; male
§2 Dinnet, Aberdeenshire; 01/05/2018; male
§3 Dinnet, Aberdeenshire; 01/05/2018; male; fw 27.2mm
§4 Dinnet, Aberdeenshire; 03/05/2018; male
All images © Chris Lewis
§2 Dinnet, Aberdeenshire; 01/05/2018; male
§3 Dinnet, Aberdeenshire; 01/05/2018; male; fw 27.2mm
§4 Dinnet, Aberdeenshire; 03/05/2018; male
All images © Chris Lewis
Page published 10/05/2018 (§1-4) - dissection images added 03/06/2018