A MONOGBAPH 



OF THE 



BRITISH 



PHYTOPHAGOUS HYMENOPTEEA. 



VOL. I. 



INTRODUCTION. 



THE term " Phytophagous " is applied to the Insects 

 described in the present work to signify that most of 

 them are plant-feeders, and not that they form a homo- 

 geneous section of the Order Hymenoptera to which 

 they belong. Nor, indeed, is the term strictly correct, 

 for many of the species in one group the Cynipidce 

 are animal parasites ; while this family differs 

 structurally from the other families described, in 

 having the abdomen attached to the thorax by a narrow 

 pedicle only having it appendiculated or petiolate 

 the abdomen in the other section, that containing the 

 Tenthredinidce and Siricidce, being joined to the thorax 

 by its entire width, or sessile. The latter groups, 

 furthermore, differ from all other Hymenoptera (includ- 

 ing the Cynipidce) in the peculiar structure of the 

 ovipositor, and in the larvae having legs on the thorax. 



The four families of Tenthredinidce, Siricidce, Ce- 

 phidce, and Oryssidce (Holonota, Foerster*) form thus 



* Ueb. d. syst, Wertli d. Fliigelgeaders b. d. Hymen., p. 19. 

 VOL. I. 1 



