RAVAGES OF CATERPILLARS. 



215 



pseudo-caterpillars of one of the saw-flies {Nematus 

 Ribesii, Stephens). The latter insect has a flat yel- 

 low body and four pellucid wings, the two outer ones 

 marked with brown on the edge. In April it issues 

 from the pupa, which has lain under ground from 

 the preceding September. The female of the goose- 

 berry saw-fly does not, like some of the family, cut a 

 groove in the branch to deposit her eggs ; — " of 

 what use, then," asks Re'aumur, " is her ovipositor 

 saw*?" In order to satisfy himself on this point, he 

 introduced a pair of the flies under a bell-glass along 

 with a branch bent from a red-currant bush, that he 

 might watch the process. The female immediately 

 perambulated the leaves in search of a place suited to 

 her purpose, and, passing under a leaf, began to lay. 



aaa. Saw-fly of the gooseberry (iVt'ffJo^ui Ribesii, Stephens). 

 h, its eggs on the nervuresof a leaf, dd, the caterpillars eating, 

 c, one rolled up. /, one extended. 



* See Insect Architecture, 

 curious instrument 



ch; 



for a description of this 



