General characterisation. By Dr. A. Seitz. 147 



7. Family: Lasiocampidse. 



The name Lasiocampidae is derived from tlie larva being covered with shaggy hair. The family com- 

 pri.ses about 800 species, some of which are again .'<plit up into a large number of subspecies on account of their 

 ready response to different geographical conditions, and also are very variable individually, some aberrations 

 being almost monstrosities. In this family dimorphism, which is not usual among Bombycids, is occasionally 

 very pronounced, e. g. in Selenophorn hiniqera-lohidina, so that if all the dimorphic, aberrational and local 

 forms are taken into consideration, more than a thousand forms are united in thim family, a number which is 

 only surpassed by the Arctiids and reached by the Liparids. 



They are more evenly distributed over the earth than other families. About 3.50 forms inhabit the 

 Western hemisphere, and 420 the Eastern. The Lasiocampids are by no means so much more abundant in the 

 tropics than in the temperate zones, as is the case with other groups of moths, the colder district of North Amer- 

 ica alone appearing especially poor with only 40 forms. The Arctic winter of Canada and the Xorthern States 

 of the Union with its blizzards and sharp frosts prevents the Lasiocampids, which nearly all hibernate as lar- 

 vae, from establishing themselves in these countries, and only single species are met with in the other districts 

 of the U. S. A., apart from the warmer south-western states, such as Arizona, New Mexico, etc. 



In Europe and temperate Asia also, where more than 200 forms of Lasiocampidae occur, only a few 

 go far north, and not one species has followed the Liparids to Greenland and North Siberia. Following the 

 degrees of longitude we find about 70 species in Europe and almost the same number in Anterior Asia and the 

 northern part of Central Asia, as the Avestern forms disappear in nearly the same proportion as new eastern 

 ones appear. In Amurland and the neighbouring temperate China there are about 25 to 30 well-characterised 

 main forms, which, if they were as rigourously separated into varieties as the European forms, would also result 

 in about 50, and in temperate Asia we find 15 species with a large immber of varieties. But they are absent 

 on many islands. 



The position assigned to the Lasiocampids in the different schemes of classification is somewhat un- 

 stable, as they show affinities with several other families of Bombycids. They agree with the Liparids in the 

 peculiar brushes which protrude from the first segment of the larva at the sides of the head, the moths also 

 showing some points of resemblance to the Liparidae, especially in the antennae. As in the preceding families 

 {Arctiidae, Liparidae, etc.) the larvae of the Lasiocampids are protected by the chemical and mechanical pro- 

 perties of their covering of hair, and likewise have the habit of weaving these hairs into the cocoons, whereby 

 the pupa is also protected. The sexual dimorphism, often so excessively developed in the Liparids, is again met 

 with in this family, and the extraordinary difference in size from which the Liparid Lymantria dispar derives 

 its name, we find in the same pronounced degree in the Lasiocampid Snana concolor. 



According to their anatomy nearly all the groups of Lasiocampids examined as yet are rather primitive 

 forms, only the antennae of the (^ being specialised, as is also the case in other groups of considerably more 

 generalized moths, e. g. the Cossids. In the Lasiocampids it is a result of the clumsiness of many $$ which 

 renders it necessary that the ^J is equipped with an acute sense of smell. The frons nearly always bears a dense 

 tuft of hair ; the palpi are often stumpy, but very frequently prolonged in nose-shape to a sometimes pointed 

 cone. Tongue always aborted; eyes small, strongly convex, often deeply hidden in the wool of the head. 

 Thorax, especially in the $, mostly very stout and woolly; legs short, strong, densely hairy. Forewing without 

 frenulum, often with dentate outer margin and strongly shortened inner margin, hindwing almost circular; ve- 

 nation very regular, cell often short, discocellular strong; all the branches almost equally distant from one 

 another at the margin. The mecUan veins fully and uniformly developed. A distribution of the veins as in 

 many Saturnids where the costal system seems to separate from the cubital veins and the inner marginal portion 

 becomes separate from the costal portion by the absence of the transverse vein, does not show itself to any 

 marked degree in the Lasiocampidae. 



The structure of the body, particularly the constancy of the venation which in spite of considerable differ- 

 ences between many genera is remarkably uniform, accounts for the fast but always unsteady and clumsy 

 flight of the Lasiocampids. The 99 of many species do not seem to fly much; but the ^^ are all the more 

 lively and often rush wildly about over brushwood and meadows even wliile the sun shines. The cj of Lasio- 

 cnmpa querctis, e. g., is decidedly diurnal, being most lively in the afternoon between two and four o'clock, 

 while I never met with the $ in daytime, but at 10 o'clock at night. The ^ of Macrothylacia rubi also fhes by 

 day, especially in the afternoon between half past four and six o'clock, the 9 however only flies bj- night, and 

 but very little. The ^ of Lasiocampa trifoUi, which species only flies by day when disturbed, is on the wing 

 between 7 and 10 p. m. and the 9 scarcely later. In Gastropacha both sexes often fly late at night. In some 

 groups the 99 cannot fly at all on account of the reduction of their wings, e. g. in Chondrostega and Lasio- 

 campa ( Lambessa) staudingeri. 



The colouring is much brighter and more varied than in the Lymantriids. Fiery red (in Odonestis pruni) 

 is replaced by a beautiful apple green (Trrtftr/ia vishnmi), co\)per-hro\vn{Gastrop.quercifolia) by slate-blue {Poecilo- 

 campa populi). In the markings there is usually a strong white discal spot on the forewing, beyond which a 



