CHAPTER IV. 

 THE CYNIPIU.^ AFFECTING THE OAK. 



SixCKthe Cynipidge are such interesting and remark- 

 able insects, a few pages will he devoted to a very 

 brief description of the imagines and their early stages. 

 More than a mere outline of these facts is not desir- 

 able, since the present volume is designed to treat of 

 the galls they produce ; nor, indeed, is it possible to do 

 this much without quoting largely from two works 

 frequently mentioned in previous and subsequent pages, 

 both of which works contain exhaustive and detailed 

 information concerning these gall-wasps. There is 

 practically no feature of great importance that can be 

 added. 



But there may be many collectors, students, and also 

 readers who have not access to other works on the 

 subject of oak gall producers, and they would welcome 

 some information concerning the Cynipid^. For their 

 assistance this chapter is inserted. 



The name of Cynipidse was given to this group of 

 the aculeate Hymenoptera by Linnaeus. 



They are very interesting insects in several ways. 

 Almost all of them are either gall producers or are 

 parasitic upon other insects. The distinguishing 

 features of the family, according to Cameron (' Brit. 

 Phyto. H^^men.,' vol. iii, p. 142), are shown in eleven 

 particulars, an important one being that the 

 abdomen is petiolated and laterally compressed. 



The imago has many ])oints of great interest. So 



