PHYLUM ARTHROPODA 



275 



The wasps are very diverse, belonging to two entirely 

 different series, one of which (the digger wasps) is closely 

 related to the bees. The ants are not closely related to 



From Bulletin 67, U. S. National Museum 



FIG. 92. A sawfly, the so-called pear-slug (Caliroa cerasi} : a, adult ; b, c, larva 

 (enlarged) ; d, larvae on leaf. 



From Bulletin 67, U. S. National Museum 

 FIG. 93. A chalcis fly (Spilochalcis maria} ; enlarged. 



the bees, and have acquired social habits quite inde- 

 pendently. All Hymenoptera have the metamorphosis 

 complete. 



