LYMANTRIIDAE. Bv Dr. E. Strand. 109 



5. Family: Lymantrlidae. 



Tho Lymantriids, better known under the name of Liiiaridae, are a family not very numerous in 

 species, which in the Palearctic region is widely distributed, especially in the south and east, while the number 

 of species quickly diminishes as we go north; scarcely one-fourth of the species found in South Scandinavia 

 occurring north of the Arctic circle. The Lymantriids are an exception in purely Arctic districts; there 

 occurs for instance only one species of Das?/cfttVa in Greenland and another in Arctic America. In the frontier- 

 districts of the Indian region the number of species is considerably increased because here true Palearctic 

 forms are intermixed with Indian ones which extend northward, and on account of this many species 

 must be dealt with as Palearctic whose true home is India. The nearest relatives of the Lymantriids 

 must be looked for among the Noctuids, and since these come very near to the Arctiids, as is well known, 

 also among that family. The larvae also show close affinity with the large Noctuid stirps, while the 

 larvae of the Notodontids for instance, the moths of which in many points resemble Lymantriids, strongly 

 deviate from the latter. There occur therefore immistakable transitions to the Noctuids, e. g. the African 

 genera Homalotneria Wallgr. and Synogdoa Auric, which in facies are Lymantriids, but in venation Noc- 

 tuids. Lymantriids which strongly resemble Arctiids are for instance Numenes, while Cisjna resembles 

 the Hypsids. The Pterothysanids also belong to the alhed families, although they are easily recognised 

 by the absence of a frenulum. In deducing the relationship of the families of Lepidoptera the position 

 of vein 5 in relation to 4 and 6 is particularly important. 



The Lymantriids are usually small or medium-sized moths, inconspicuous in colour, being generally 

 white or yellow, more rarely grey, brown or black; often they are entirely without markings or only bear 

 single spots or streaks; more rarely they are vividly marked with black and white {Lymantria), or with 

 reddish yellow on a dark brown gi'ound (Orgyia). The hindwings are usually without markings. The fore- 

 wings are broad, rounded at the apex, most species being hairy at the inner margin. When the insect 

 is at rest the wings are placed flat in roof-shape, and in the $ are sometimes aborted. Even when they 

 have wings the $$ are always more sluggish than the c?c?. the latter sometimes flying by day {Hypo- 

 gymna, Aroa, Orgyia). 



The head of the Lymantriids is small; the eyes naked; ocelli sometimes absent; tongue very short 

 or quite vestigial; antennae not long, in the <? bipectinate to the tip (the teeth also sometimes with long 

 bristles at the end), in the $ with short pectinations or only serrate. Palpi never large, but usually with 

 a distinctly separated end-segment. Legs usually short, with long woolly hair, and iiearing median and 

 apical spurs or only apical ones. Thorax strong and hairy. Abdomen of S usually slender, not extendmg 

 beyond tho anal angle or only a little, with anal tuft; in tho $ often clumsy and stout, with much anal 

 wool, and never extending far beyond the anal angle. In the forewing vein 1 c is absent, while 1 a and 

 1 b do not anastomose, 5 originates near the hind angle of the cell, therefore nearer 4 than 6 (by which 

 it is distinguished from the Notodontids for instance), 7, 8, 9 and 10 usually stalked, an areole often 

 present. Hindwing with two inner marginal veins, 5 originating nearer 4 than 6, 8 free from the base, 

 almost touching the cell in the middle and being connected with 7 by a transverse vein. Frenidum always 

 present. 



The almost globular eggs are usually nearly or quite smooth, not so liigh as they are broad, flat 

 or slightly hollowed at the top; they are often deposited in batches covered with the anal wool. Many 

 larvae are distinguished by bearing a funnel-shaped wart dorsally on segments 9 and 10 which 

 can be reversed in cone-shape. These larvae (larvae mobilituberosae) have 4 well-developed prolegs and 

 anal claspers, on the middle segments brushes of hair and 6 or 8 warts with radiating hair on each seg- 

 ment, beside the funnel-warts mentioned above. The larvae of European Lymantriidae may be classified 

 as follows: a) those with large star-shaped knob-like warts (Hypogymna, Lymantria, Ocneria); b) with 

 brushes on the middle segments and pencils at both ends of the body {Orgyia, Dasychira, Laelia); 



c) without brushes but with tufts of hair and long lateral hairs or scutiform spots {Stilpnoiia, Arctornis); 



d) with small hairy warts and with a smaller hairy tubercle on segments 4 and 11 {PorDiesia). 



