46 INSECTS AND MAN 



able changes in form ; and, to a certain extent, it assumes 

 the shape of the cavity in which it is deposited. In a few 

 days the young larva hatches from the egg, and, at first, 

 it is as inconspicuous as the egg from which it came, except 

 for its brown head and mandibles. About ^ ^ an i ncn ^ n 

 length, this legless grub (fig. 4, A) is crescentic in form and 

 white in colour, modified, however, by the dark-coloured 

 body contents, which show through the almost transparent 

 body wall. As the larva feeds and grows it enlarges the 

 cavity in which it dwells, and, at the same time, the larval 

 castings are spread thickly over the walls of the cavity, 

 and, becoming firmly compacted by the frequent turning 

 of the grub, form a cell in which, after the third moult, 

 pupation takes place. The pupa (fig. 4, B) is creamy or 

 pearly white in colour, gradually becoming darker as the 

 adult stage is neared. When the final moult is about to 

 take place, the pupal skin splits open over the head and 

 slips down over the proboscis and thorax, but it adheres 

 to the antennae and tip of the proboscis, till the back has 

 been laid bare and the legs kicked free. Then the skin is 

 violently pulled with the fore legs, and so the tip of the 

 snout and the antennae are freed; finally, with the hind 

 legs, the shrunken and crumpled skin is kicked off the tip of 

 the abdomen. The whole operation lasts for about half an 

 hour. The newly emerged adult is soft, helpless, and quite 

 unable to walk, so it remains for a time within the cavity 

 where it emerged. It is light coloured, the proboscis, 

 which is the darkest part, being yellowish brown, and the 

 elytra or wing cases pale yellow. After about two days 

 the beetle (fig. 3) has become hard and more active, and has 

 also attained its normal colouring, so it escapes from its 

 voluntary prison by cutting with its mandibles a hole just 

 the size of its body. The coloration and size of the adults 

 vary considerably. As a general rule, the greater the 

 supply of larval food, the larger the size of the adult, and 

 the larger the adult, the lighter its colour. The largest 



