48 



NATURAL HISTORY OF INSECTS. 



Their transformations are complete, and the legs, etc., of 

 the pupa are enclosed in separate sheaths (such as the pupa 

 of the Strawberry Saw-fly, Fig. 137, i and 2 ). The larva) gene- 

 rally change to pupae in their nests, or in whatever substance 



Fig. 189. 



Fig. 138. 



they happen to live; others spin cocoons around their bodies, 

 usually first concealing themselves beneath fallen lea.ves, or 

 entering the earth. 



COLEOPTERA ( Beetles). These insects are usually provided 

 with four wings, but in a few species the hind wings are want- 

 ing. The fore wings (elytra) are of a hard, horny texture, and 

 meet in a straight line (suture) along the back, except in the 

 genus Meloe, where the overlap each other; in a few species 

 the wings, are united at the suture (as in several kinds of 

 Darkling Beetles, Fig. 119). The posterior wings, when 

 present, are membraneous, and when not in use are usually 

 folded both lengthwise and crosswise, and concealed beneath 

 the elytra. (The Beetles which belong to the same family as 

 the Flat-headed Apple-tree Borer, Fig. 138, have the hind 

 wings folded lengthwise only.) The mouth-parts are fitted 

 for biting. Transformations complete. 



The larvae are commonly called grubs-, and are sometimes 

 furnished with six legs, which are placed beneath the fore part 



