Jan., 1906.] 
How to Collect Stylopidae. 
443 
HOW TO COLLECT STYLOPIDAE.* 
Charles Ditry. 
It is well known to entomologists that many genera of wasps, 
bees and insects of other orders, are at times affected with par- 
asites which live in their abdominal cavities. In the genera 
Xenos and Stylo ps, the adult female is larvaform and never 
leaves the body of the host, but the male when ready to pupate 
projects the end of the pupa case outwards, between the seg- 
ments, where it can easily be seen protruding. By examining 
wasps and bees when they frequent flowers, it can readily be 
observed as to whether or not they are parasitized. The female 
Xenos can be distinguished from the male by the broad flat 
projecting head. The male pupa case is rounder and separates 
the segments to a greater extent. When a wasp is found with 
male pupa, it may be secured and brought home alive. Confine 
it in a jellv tumbler with a cheese cloth cover over the top ; in 
the bottom of the glass there should be placed a round bit of 
blotting paper and a piece of screen wire, raised up from the 
bottom. This is necessary because the instant the Xenos hatches 
the wasp rushes after it, in an endeavor to catch, kill and bite it 
to pieces, an example of an interesting instinct. The move- 
ments of the Xenos are so rapid, that the wasp can not catch it 
until it falls exhausted in the bottom of the glass. By having 
the false bottom of wire, the Xenos falls through, the wasp not 
being able to follow, and the specimen can thus be secured. 
The wasp while confined in the glass must be fed. This may be 
done with jelly and water, putting it on the cheese cloth cover 
in one small spot, with a camel’s hair brush. Many fine spec- 
imens have been hatched by the writer in this way, from five 
genera of wasps, several of which are new host wasps, and the 
facts and species obtained are entirely new to science. There 
are yet some interesting problems in the life history of these 
curious insects that are unknown. In looking through some of 
the largest and finest collections of insects recently at Wash- 
ington and New York, only a few poor specimens in this family 
were found while in some otherwise valuable collections they are 
not even represented. In view of a monograph of these insects 
in course of preparation by W. D. Pierce, the publication of 
which will occur soon, material from all parts of the country is 
verv much desired. 
* Presented at the Ohio St. Acad, of Sci., Cincinnati meeting, Dec. 1, 1905. 
