64 PROCEEDINGS ENTOMOLOGICAL SOCIETY 



tance to apex and with a median longitudinal carina extending two- 

 thirds of the distance ; ovipositor about 4 mm. long. 

 Male: Length 6 mm. Similar to the female. 



Secured from the cells of larvse of the family EucnemicUe. 



Type locality : Female, Silver Spring, Md. ; male, Lynn- 

 haven, Va. Both collected by Mr. R. W. Van Horn. Paratypc 

 female, Plummer's Island, Md., May 31, 1908, E. A. Schwarz, 

 collector; paratype male, Silver Spring, Md., Van Norn, col- 

 lector. 



T\>/>c No. 12584 U. S. National Museum. 



EXPLANATION OF PLATE V. 

 Vcmhornia eucnetnidarum Crawford. 



1. Adult female. 



2. Head of female. 



3. Abdomen of female. 



On behalf of the author. Professor Webster read the fol- 

 lowing paper : 



HOW LYSIPHLEBUS FASTENS ITS APHID HOST TO 



THE PLANT. 



[Hymenoptera, Braconidae.] 

 BY E. O. G. KELLY. 



During the fall of 1908, in connection with his investigations 

 of Toxoptera graminum, the writer carefully bred and reared 

 several hundred parasites belonging to the genus Lysiphlebus 

 Foerster. 



In order that some careful interbreeding could be done, 

 individual aphids, upon turning brown (caused by the para- 

 sites), were removed from the host plant to small homeopathic 

 vials stoppered with cotton, in which the adult Lysiphlebus 

 emerged. In removing these brown aphids from the plant 

 they were observed to be securely fastened to it by silken 

 threads enmassecl in a glutinous substance which had become 

 dry and hard. The glutinous substance and silk are more or 

 less brittle and numbers of cocoons (as they really are cocoons) 

 were broken open on the ventral side at the point of attach- 

 ment, while being removed from the plant. The breaking 

 open of the cocoon was nearly always fatal to the parasite, in 

 fact, it proved to be inconveniently so; consequently another 



