LASIOCAMPIDAE. By Dr. C. Aurivillius. 
205 
8. Family: Lasiocampidae. 
The Lasiocampidae form one of the most interesting families of the Bombyces and are very well distinguish¬ 
ed in all their stages. Their size varies between small and very large. The $$ of some species of Gonometa, owing 
to the volume of their body, number among the largest lepidoptera known. The 99 as a rule have a stout abdomen, 
much stouter than that of the They consequently fly in a very unwieldy way or very little, and are sought 
for by the <$<$ being provided with a very highly developed sense of smelling from great distances. The sexes 
do not only differ in size, but often also in the formation of the antennae, in the shape of the wings, and in 
the colour and marking of the forewing. The antennae in both sexes almost invariably exhibit two rows of 
pectinations which, however, are longer in the $ than in the $ and often much longer before the middle than 
beyond the middle, whereas in the $ they gradually shorten towards the apex of the antenna. The fore wings 
are in the often much longer and narrower, and the hindwings smaller and more triangular than in the 9$. 
The marking and colouring of the forewing may also be extraordinarily different in the sexes of the same species, 
as in many species of the genera Lechriolepis , Chrysopsyche, Taragama, Pacliypasa etc., where the sexes can 
only be ascertained by breeding. The breeding of the Lasiocampidae from the larvae is also otherwise of the 
greatest importance for the increase of our knowledge of this family. The imagines are only rarely chanced upon 
in the open air and are then often damaged; the <3$ fly very swiftly and are therefore very difficult to capture, 
and the $9 keeping in hiding are still more difficult to discover. The large hairy larvae, however, with frequently 
bright colours and living very gregariously are generally easy to find and can be bred in numbers. Every lepiclo- 
pterologist may therefore be highly recommended to breed Lasiocampidae, and whoever will occupy himself 
with it, will surely find great pleasure and gain important disclosures. In every consignment from Tropical 
Africa containing larvae there are such that evidently belong to still unknown species of Lasiocampidae. If 
one wishes to render a great service to science, it is important to preserve the larvae in alcohol or inflated. 
Systematically, the Lasiocampidae form a very natural and sharply defined family which can be easily 
distinguished from other families. They are characterised by the following marks. Spiral tongue absent. Palpi 
rarely stunted, usually of medium length, sometimes long, projecting far beyond the frons and together forming 
a conical apex. Abdomen hairy, often densely clad with long hair. Hindwing at the base of the costal margin 
lohately projecting; costal margin of hindwing in the resting insect projecting beneath the costal margin of 
the forewing which is folded in the shape of a roof. The discal cell in both wings is narrow and short, not or 
hardly reaching to the centre of the wing; discal cell rarely open, generally closed up by the median cross-vein 
alone, the upper and lower cross-veins being almost invariably quite absent; vein 5 thus proceeds from the 
posterior angle of the discal cell and vein 6 from the anterior angle of it. The majority of the genera are besides 
distinguished by vein 8 of the hindwing being united with the anterior edge of the discal cell or with vein 7, 
whereby a smaller or larger basal cell is formed, from the anterior edge of which generally one or several 
veins (so-called ,,accessory veins“) are despatched towards the costal margin of the hindwing. Such a basal 
area with ,,accessory veins“, so far as I know, does not occur in any other family. These ,,accessory veins“ 
have either been explained as formations intended to support the basal lobe of the costal margin or as real 
though stunted veins. A. Jefferis Turner, in his meritorious revision of the Australian Lasiocampidae , has 
joined this opinion and therefore counts in the hindwing 12 veins just like in forewing. It must be owned that 
among the genera of the Gastropachinae and of the American Malacosomatinae there are many facts in favour 
for this opinion, as the ,accessory veins“ are developed exactly like real veins. If we take the hindwing of the 
genus Estigena as an example, according to Turner the anterior edge of the basal cell would be formed of the 
united and then gradually separated veins 12 to 9 (besides the preoostal vein) and the shutting up of the basal 
cell caused by vein 8 proceeding from the anterior edge of the discal cell and anastomosing for some distance 
with vein 9. According to Turner, the Lasiocampidae have kept up a primeval formation of the neuration 
of the hindwing, but by general consent it is rather to be regarded as a highly differentiated family. As it is 
