274 



Arthropoda. 



chhb 



lai-va of 1. tapezella, -wMoli is somewhat larger, spins on tte outside of the fm-, a 

 long thin- walled tube within which it can move about; the portion of fm- or 

 woollen material covered by the case, is eaten away from the sui'face. 



2. The "Leaf -rollers" (Tortricidx) axe, on the 

 whole, somewhat larger than the Tineidse, the wings 

 broader, with a shoi-ter marginal fringe. The larvse very 

 frequently — ^but by no means ia all foi-ms — live in and 

 upon leaves which they have spun together. A larva, 

 which is often found in the core of " wonn-eaten " apples, 

 belongs to one species of this division {Tortrix pomo- 

 nana), other species are injui-ious forest pests (Tortrix 

 huoliana, etc.). 



3. The "Wood-borers (Xylotropha). A small 

 family, the members of which are usually distinguishable 

 from other Microlepidoptera by their much larger size. 

 Here belongs the Goat-moth (Cossus ligniperda), 

 a large, brownish-grey moth (about 80 m/m. across the 

 wings) ; the larva which is almost naked, and rose-red 

 dorsally gnaws passages in poplars, osiers, and other 

 trees. Further, the wasp-like Clearwings (Sesia,) 

 with transparent, almost soaleless wings, the whitish 

 larvsB of which live in trees or in the stems of shrubs. 



4. The Oase-bearers (Psyche), are charac- 

 terised by great sexual dimorphism, the females ai-e 

 grub-like, wings and legs are absent, whilst the males 

 look like ordinary moths. The laiwa is suiTOunded by 

 a sac spun out of fragments of plants or grains of sand, 

 the female remains within this larval case. One species 

 of the genus. Psyche helix, which forms a spiral case of 

 fine particles of sand, usually reproduces partheno- 

 genetically, males only appear now and again. 



Sub-Order 2. Macrolepidoptera. 



The prolegs of the larvae have a unilateral 

 series of hooks, the head turns downwards; 

 they lead a free life upon plants, feeding on 

 leaves. The pupse have no transverse rows 

 of spines on the abdomen. The adults are 

 usually of considerable size. 



1. The Bombycidse are bulky forms with dull faded 

 colours, usually of somewhat indistinct patterns; the 

 wings are broad and overlap when at rest ; the antennss of the male are pectinate 

 on each side, those of the female bristle-like or denticulate ; the proboscis is 

 small. The lai-vse are usually hairy, often, indeed, very hauy. The pupa lies; 

 within a cocoon formed either of spun thi-eads alone, or of these together with 

 haii-s thrown off from the larva, etc. The BombycidsB are nootm-nal, the males 

 flying about to seek for the inactive females ; in some species the latter have 

 only rudimentary wings. To the Bombycidse belong the Silkworm (Boinhyx 

 mori), which came oi-iginally from China, and the cocoons of which afford the 

 chief supply of the silk used in industries ; the imago is white, the larva 

 naked, and (unlike all other Bombycidse) provided with a small horn at the 

 hinder end of the body. Silk is also obtained from several other species. 



Fig. 223. Psyche, a 

 male, 6 male pupa, c 

 female, d female pupa, 

 e sac containing female, 

 / sac containing male 

 larva. — After Taschen- 

 berg. 



