6 BOARD OP AGRICULTURE. 



differences in their transformations, and peculiarities in their 

 habits. The most obvious distinctions are found in the 

 structure of the organs composing the mouth, and in the 

 wings, when these exist. Their names are derived from the 

 character of their wings. The orders are as follows : 



I. Hymenoptera, (membrane-winged). This order includes 

 the bees, wasps, ichneumon-flies, saw-flies (figures 7, 7 a), etc. 



Fig. 7 a. 

 Fig. 7. 



They have four small but strong membranous wings, the front 

 pair largest. The body is compact, the head large, and the 

 three regions of the body very distinct. The head (figure 8) 

 usually has three simple eyes Fig. 8. 



in front, forming a triangle ; a 

 pair of slender antenna3 or 

 feelers, and a pair of very large 

 compound eyes ; connected 

 with the mouth we find a pair 

 of powerful, often toothed, 

 mandibles or jaws; a pair of 

 orceps-like maxillce, bearing 

 near the base a jointed palpus 

 or small feeler ; and finally the 

 labium or lower-lip, which bears 

 a pair of palpi or feelers, and 

 the. ligula or tongue, which is 

 long and highly developed and 

 covered with hairs in the bees. 

 They have, therefore, all the 

 parts of the mouth symmetri- 



FIGURE 7. The Pear-slug or Saw-fly (Selandria cerasi Peck), enlarged. Color 

 black, with white spots on four anterior legs and feet. 



FIGURE 7a. Larvae of the same on leaf of pear, natural size ; and a, enlarged. 

 It is covered with sticky slime. Both from Packard's Guide. 



FIGURE 8. Head of wild Bee (Anthophora), much enlarged ; a, compound 



