12 THE JOURNAL OF THE 



COLLECTING STYLOPID^. 

 By E, P. Austin, 



There are certain degraded forms of Coleoptera which 

 are found as parasites on other insects, and which are 

 therefore very rarely found in collections, although they 

 are, no doubt, not rare in certain localities, and it only 

 requires a little careful collecting to secure them. The 

 StyloijidcB are found in the bodies of Hymenoptera, Two 

 genera occur in the United States, one of which [^enos) 

 is sometimes quite abundant in the common paper wasp 

 (Polistes metrica.) 



On August 20, 1879, while collecting in the vicinity of 

 Readville, Mass., my attention was called to a wasp which 

 had a distorted abdomen. When I captured it, it proved 

 to be " stylopized," and contained no less than seven 

 specimens, although several had made their escape. 



It may be of some interest to give the result of my 

 captures that day. Of fourteen male wasps, two were 

 '^ stylopized," and of thirty-six females seven were " stylo- 

 pized." Besides these I caught about twenty additional 

 specimens which I released, after examining them. It 

 will be seen that a considerably larger percentage of the 

 females than of the males were infested. But when we 

 come to the number of the specimens of Xenos the dis- 

 proportion is very much greater. Of the seven female 

 wasps taken, three escaped from the box in which I had 

 them; of the four remaining, one contained a single female 

 Xenos, the second a male only, the third two males, and 

 the fourth no less than seven males. It will be seen by 

 this that the number of male Xenos is very much greater 

 than that of the females, there being eleven of the former 

 but only two of the latter. 



The female, which never leaves the body of the wasp, 

 has a very thin flat head and does not cause as much 

 distortion as the male, so it is possible that one or more 

 females may have been overlooked in a cursory examina- 



