272 



The Orders of Insects 



plant-tissues and lays her eggs there. The larvje are caterpillars 

 with six well-developed thoracic legs and many, sometimes sixteen, pro- 

 legs on the hind-body (fig. 150). Most of them feed openly on leaves, 

 but in some genera they are concealed and protected within swellings 

 or galls which arise in the tissues of the food-plant. The pups are 

 enclosed in cocoons which are often buried in the ground. About 

 2000 species of Sawflies are known ; the family is widely distributed, 

 but is much more numerous in North America, Europe and northern 

 Asia than in tropical or southern countries. 



Sub-Order B. Petiolata. 



In the Petiolata which comprise the vast majority 



of the Hymen- 

 optera the first 

 abdominal seg- 

 m e n t is in- 

 timately con- 

 nected with 

 the thorax, and 

 the second seg- 

 ment (some- 

 times also the 

 third) is very 

 narrow in 

 diameter form- 

 ing a marked 

 "waist" or 

 "stalk" be- 

 tween the 

 (apparent) 

 fore- and hind- 

 bodies. In 

 cases where 

 this waist is 

 short as well 

 as narrow, the 

 hind-body 

 seems to be 



Fig. 150. — a. Pear Saw-fly, Enocaia/'Oidts hinacina 

 (Retz.), Europe. /. larva without and c. with its 

 slimy coat ; e. cocoon ; f. larva before pupation ; g. 

 pupa, magnified 4 times ; d. leaves with larvae, 

 Natural size. From Marlatt, Circ. 26 (2nd sen), 

 Div. Ent. U.S. Dept, Agr. 



