176 CONNECTICUT GEOL. AND NAT. HIST. SURVEY. [BuU. 



ICHNEUMONOIDEA. 



From the standpoint of economic parasitology this is one of 

 the most important groups of insects. It is represented in Con- 

 necticut by many species. Many of these will, no doubt, prove 

 exceedingly useful in the hands of man when he has learned to 

 breed and manage them for the purpose of controlling injurious 

 insects. 



The greatest care must be exercised in classifying the insects 

 of this group, because the multiplicity of species and their close 

 relationship make their recognition a difficult subject indeed. 

 This group is so homogeneous that in order to classify its com- 

 ponents a knowledge of the general appearance and character of 

 the insects as a whole, or habitus, is quite essential. Habitus al- 

 though sufficiently tangible to the experienced eye can not be sat- 

 isfactorily described, so the beginner must have access to an 

 authoritatively determined collection, or, such not being avail- 

 able, recourse must be taken to a study of the figures of von 

 Vollenhoven in his two works, the Schetzen and Pinacographia. 



Inasmuch as the Icheumonoid fauna of this state is imper- 

 fectly known, the keys in the following pages cannot be regarded 

 as final, although in many cases they will lead the student to a 

 satisfactory conclusion. 



