ICHNEUMONID FINAL INSTAR LARVAE — SHORT 505 



f\ — '\-<ij-r\—rv^ A — ■ 



r\ ^ /\ r\ 



Olmm 



Figure 64. — Cryptinae:Hemitelini, head sclerites: Atractodes sp. (1, antenna; 2, spiracle; 



3, skin.) 



the tissues of the host and hberating air from the tracheae. If the 

 spiracle is open there is possibly some biological advantage in having 

 the closing apparatus situated close to the atrium. If one function of 

 the closing apparatus is to prevent the entry of body fluids of the host 

 into the tracheal system, then it is best situated to perform this func- 

 tion when it adjoins the atrium. If, however, such a precaution were 

 necessary, one would more readily expect to find hydrofuge structures 

 at the opening of the tracheal system, as in many aquatic insects. 



The setae of the sldn of endoparasites are reduced. 



It should be noted that the Cryptinae, which contain both ecto- 

 parasites and endoparasites of prepupae and pupae, show larval 

 characters which are relatively uniform within the group. 



Just as some similar adults have different larvae, so do some different 

 adults, such as the Metopiinae and Anomalinae, have similar larvae. 

 These similarities may be correlated with larval habits. The Meto- 

 piinae, Anomalinae,^'^ Ichneumoninae, and Pimplini all have large, 



30 Except Anomalon. 



