430 ENTOMOLOGICAL NEWS. [Dec., 07 



On the Phorid Genera Plastophora and Pseudacteon. 



BY CHARLES T. BRUES. 



In a recent paper published in the Canadian Entomologist* 

 Mr. D. W. Coquillett describes a remarkable new species of 

 Phoridae parasitic on ants. He has erected a new genus for 

 its reception, naming the species Pseudacteon crawfordii. It 

 was discovered in Texas ovipositing on the heads of the ant, 

 Solenopsis geminata, after the manner of the related Apocepha- 

 his pergandei Coq. , which is a parasite of various species of 

 Camponotits in this country. 



In examining Mr. Coquillett's description and figures I was 

 struck by the similarity between Pseudacteon and the genus Plas- 

 tophora Brues,f and have recently obtained through the kindness 

 of W. D. Pierce two paratypes of Pseudacteon for comparison. 



I find that the two genera are extremely similar and not 

 separable by any characters which I consider to be of generic 

 value. The only differences which I have been able to detect 

 are the more slender legs, less prominent mouthparts, and 

 larger pyriform antennae of Pseudacteon. Differences of the 

 same magnitude occur in other genera, for instance in Aphio- 

 chaeta and Hypocera where they cannot be utilized for generic 

 separation on account of the species which occur with inter- 

 mediate characters. In the Genera Insectorum (Fascicle 44, 

 Fam. Phoridae, p. n, 1906) I have placed Verrall's Phora 

 formicarum in Plastophora with some doubt, but now feel 

 assured that it properly belongs here as it seems more closely 

 related to P crawfordii than to the type of the genus. The 

 genus therefore should now contain the following three species : 



P. beirne Brues, Ann. Mus. Nat. Hung, iii, p. 551 (1905), 

 New Guinea (type of genus). 



P. formicarum Verrall, Journ. L/inn. Soc. Zool. xiii, p. 258 

 (1877) England. 



P. craivfordii Coq., Can. Eut. xxxix, p. 208 (1907), Texas. 



This note is presented at the present time in order that the 

 change may be incorporated in the generic tables of Phoridae 

 for Professor Williston's forthcoming manual. 



* June, 1907, p. 207. A New Phorid Genus with Horny Ovipositor. 

 (Ann. Mus. Nat. Hung., Ill, p. 551 (1905). 



