94 



GENERAL ZOOLOGY 



quently become so very abundant that they destroy all the 

 leaves of currant and gooseberry bushes in the early spring. 

 Definition of Hymenoptera (Gr. hymen, "membrane"; 

 pteron, "wing"). The insects which we have been consider- 

 ing in this chapter all agree in possessing mouth parts 



Fig. 61. Metamorphosis of sawfly. (Natural size) 



adapted both to biting and lapping, and four membranous 

 wings with few veins. The order is called Hymenop'tera. A 

 structural peculiarity is the union of the first abdominal 

 somite to the thorax. Consequently what appears to be the 

 division between the thorax and the abdomen really comes 

 after the first abdominal somite. The Hymenoptera undergo 

 complete metamorphosis. 



