12 PROCEEDINGS ENTOMOLOGICAL SOCIETY 



faces of the leaves. Suddenly one of these individuals dashed at 

 a beetle, they grappled, the beetle rolled over upon its back. Then, 

 almost instantly, the fly disengaged herself, resuming the pose up- 

 on the leaf, preening her body with the hind legs. The beetle 

 rolled off to the ground and presently flew away. This was ob- 

 served several times and finally a fly and the beetle attacked were 

 captured for examination. The beetle was found to have a clean 

 hole punched through the center of one elytron. An examination 

 of the abdominal appendages of the fly (plate I, fig. 1) left little 

 doubt as to the origin of this puncture. By referring to the figure 

 it will be seen that the second abdominal segment is immensely 

 prolonged downward into a laterally compressed tubercle, the apex 

 of which is armed with short, flattened, somewhat pointed, spine- 

 like, processes, directed slightly caudad. Opposed to this, with 

 its base attached to apex of the abdomen, is a long curved, strong- 

 ly chitinized piercer. This is normally held with its tip ensheathed 

 in the posterior edge of the abdominal process described above. 

 In life it is easily visible with the aid of a hand lens. Figure 2 of 

 plate I shows the author's interpretation of the function of these 

 two appendages. 



The contact of the fly with the beetle is much too brief and the 

 conflict too strenuous for the eye to observe what actually takes 

 place. But taking into consideration the position of the punc- 

 tures on the elytra of the beetle and the conformation of the 

 puncturing apparatus, together with the fact that the beetle is 

 turned upon its back during the conflict, this hypothetical figure 

 seems quite plausible. 



Several punctured beetles were collected and placed in a breed- 

 ing jar and on July 10 one fly puparium was found therein. This 

 resembles the puparium of Celatoria quite closely in that it is cov- 

 ered with short, spine-like processes. Owing to the writer's pro- 

 longed absence from the city, further results of this rearing were 

 lost. But the facts outlined above indicate conclusively the para- 

 sitism of this fly on Diabrotica. 



When first observed it was naturally supposed to be Celatoria 

 diabroticce Shimer. In size and general appearance it closely re- 

 sembles that species but a careful examination revealed important 

 structural differences which make it necessary to propose not only 

 a new species but also to erect a new genus for its reception. This 

 latter action becomes necessary because the first vein is spiny 

 for almost its entire length. It seems quite apparent that this 

 character is wholly artificial, but as it has been utilized extensively 

 as a primary generic and even group character, and is of undoubted 

 convenience in spite of its apparent artificiality, the name Neoce- 

 latoria ferox n. gen. n. sp. is herewith proposed for this curious fly. 



