44 MEANS OF DEFENCE OF LARVJ1. 



It has been shown by recent researches that the 

 coloration of caterpillars is protective, and that the 

 coloration is of two kinds. On the one hand it has 

 been shown that larvae which are readily eaten by 

 insectivorous animals are always coloured to resemble 

 their surroundings, and that they conceal themselves as 

 much as possible; while on the other, it has been 

 proved that larvae which are inedible through possess- 

 ing bad secretions, &c., are brightly coloured, and are 

 often more or less hairy. The same law of coloration 

 applies to the larvae of the Tenthredinidce ; and the simi- 

 larity in coloration between them and the caterpillars 

 (especially with the edible larvae) is not unfrequently 

 very close. This is more particularly the case with 

 those which feed on narrow-leaved plants like pines 

 and grasses. 



The larvae possess various means of escaping from 

 their numerous enemies. A large number escape by 

 the colour of their bodies harmonising with the sur- 

 roundings ; thus they are not readily seen, especially 

 as they are inactive and solitary in habits. Those with 

 flat bodies feed on the underside of the leaves 

 (Nematus luteus, Camponiscus, &c.), in which they eat 

 holes, and many feed only at night. They are all 

 green, save that the head may bear blackish, or 

 brownish markings, and, as a rule, the tinge of green 

 agrees with that of the leaf e. g. Nematus pallescens. 

 Many of the larvae with cylindrical bodies are attached 

 to narrow-leaved plants such as grasses, pines, &c. 

 They also are green like the flat larvae, but they bear, 

 either on the back or down the sides, white or, more 

 rarely, pink stripes. The green larvae, which feed on 

 broad-leaved plants (willows, &c.), eat along the edge 

 of the leaf, eating in it semicircular indentations, the 

 form of which they follow with the body, which is kept 

 closely pressed to the edge. Those larvae are never 

 hairy, but some of the green flat larvae bear over the 

 legs, or over the whole body, soft pale hairs, the object 

 of which seems to be to prevent the body throwing a 



