NOTES ON SOME GENERA AND SPECIES OF CHALCID- 

 FLIES BELONGING TO THE APHELININAE WITH DE- 

 SCRIPTION OF A NEW SPECIES. 



By A. B. Gahan, 



Of the Bureau of Entomology, United States Department of Agriculture. 



In attempting to place the species described below as new, some 

 interesting facts were developed which it is believed will serve par- 

 tially to clear up one or two mooted questions in the classification 

 of the subfamily Aphelininae. Since these observations deal princi- 

 pally with the identity of a species lately shown to be parasitic on the 

 Hessian fly, their publication at this time appears to be advisable. 



Genus CENTRODORA Foerster. 



Centrodora Foerster, Verb, natiirh. Ver. preussisch. Rheinland, vol. 25, 



1878, p. 66. 

 Paraphelinus Perkins, Bull. I, Hawaiian Sugar Plant. Assoc, 1906, p. 264. 



The genus Centrodora was described in 1878 with C. amoena Foer- 

 ster designated as the genotype. Both the genus and the species have 

 apparently remained unrecognized since that time. 



While examining specimens of Paraphelinus speciosissiwius Girault 

 the writer was impelled to compare them with the description of C. 

 amoena^ with the result that he is thoroughly convinced that Girault's 

 species belongs to the genus Centrodora and is very likely synonymous 

 with the type-species. The only point of disagreement between 

 my specimens and the generic description of Centrodora is found in 

 the reference to the postscutellum (Hinterechildchen) as completely 

 covering the metanotum and reaching the base of the abdomen and 

 this is explainable. A slide mounted specimen under poor illumina- 

 tion will easily give one an impression similar to that indicated by 

 Foerster, due to the fact that the phragma is very conspicuous, re- 

 sembling a greatly produced postscutellum. The probable correct- 

 ness of this supposition can hardly be questioned, in view of the fact 

 that the specific description of amoena agrees very closely with speci- 

 mens of speciosissimus — so closely, in fact, as to make it seem highly 

 probable that they are the same species. Practically all of the 

 known European parasites of the Hessian fly are now known to 

 occur in the United States, and there is no good reason why this 



Proceedings U. S. National Museum. Vol. 55— No. 2279. 



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