Pall. 2. VII. 1924. 
EUPTEROTIDAE. By Dr. A. Seitz. 
417 
10. Family: Eupterotidae. 
The Eupterotids, having been dealt with but very briefly in Vol. II (p. 185—187) because they are 
represented in the palearctic region by only few boundary-forms, are a group of lepidoptera which has been 
consistently comprehended in its delimitation by hardly two authors. It is a group of genera being some¬ 
times more allied to the Saturniidae, sometimes approaching more the Lasiocampidae. Many systematizers 
have not acknowlegded them at all as a delimitable family, inserting them in one family or another. Kirby 
placed them to the Lasiocampidae ; Stattdinger and Rebel left them out altogether in their Catalogue, because 
Japan is no more regarded there as palearctic, but Rebel at another place states the number of the palearctic 
Eupterotidae to be 8, inserting them between the palearctic Endromidae and the American Ceratocampidae, 
neither of which, however, is allied to the Eupterotidae. 
The Eupterotidae are mostly very large lepidoptera with broad wings; the colouring is mostly rather 
monotonous, but some are also black and white or with silvery markings. The antennae are not very long, 
mostly bi-serrated, in some genera ( Cotana ) also in the male representing but very feeble, short, atrophous, 
thin threads, sometimes scarcely attaining 1 / i of the length of the costa. Besides they mostly exhibit a remarkably 
short discal cell on all the wings, the upper wall of which often hardly projects beyond the basal quarter of 
the wing (Palirisa, Pseudojana). The Eupterotidae differ from the Saturniids by vein 8 in the hindwing nearing 
the upper wall of the cell or being fused with it for some distance, whereas in the Saturniidae it runs separately. 
From the Bombycids we can easily distinguish the Eupterotidae by the frenulum which is absent in the Bombycicls. 
In the Drepanidae which are also mostly much smaller except the Cyclidia-growp than most of the often gigantic 
Eupterotidae, the origin of the middle radial is invariably nearer at the lower than the upper angle of the 
cell on the forewing, whereas this vein (vein 5) in the Eupterotidae comes from the middle of the transverse 
vein. The most difficult is the separation of the family from the preceding Lasiocampidae, so that in catalogues 
and faunistic enumerations there is frequently no separation at all, though the genuine Lasiocampids are always 
without the frenulum by which the Eupterotidae are recognized. 
Thus, the family is confined to the continents of Asia and Africa with their islands, but very few species 
penetrating from the north into Australia. All the species except very few are tropical; they preferably inhabit 
the hottest countries of the globe and are fond of districts with vast, continuous forests. Many are of an almost 
inexhaustible variability and beside a considerable number of geographical races they also exhibit an inclination 
to individual deviations chiefly in the ground-colour which sometimes turns from yellow into greyish or brownish. 
Bark-coloured shades may be a protective colouring which, as often also in other families, is presumably 
adjusted to the changeable background of the resting insect. The Eupterotidae are apparently not protected 
by somatic properties; when they — though rarely — fly in day-time, they are keenly pursued by birds and 
at night, when they fly to the light, by bats. I coidd observe an Eiipterote undata being pursued by a 
bird and taking refuge in a thorny hedge of Opuntia, where it slipped in between two of the thick, thorny 
discs, whereupon its pursuer desisted from the pursuit. The flight of the $$ is slower than that of the EE, 
but owing to the large wings it is not so unwieldy; the EE dash along in a plunging and whizzing flight, 
somewhat like a <$ of Philosamia cynthia or Saturnia pyri. 
Of the larvae not many are known, although the very large, black, long-haired larvae of Eupterote 
fabia are not rare at the skirts of the forests, where they settle down in day-time on branches and are to 
be seen from afar. I have not noticed a burning effect of their hair, as in many Saturniids ( Automeris 
and others), but it is easy to understand that such long and dense hair (as in our Arctia- larvae) may be protective 
against many enemies. Many genera, particularly the Papuan Cotana and Melanergon, mostly contain species 
discovered of very late; the large species of India, Java and Ceylon have mostly been known long ago. 
X 
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