DESCRIPTIONS OF THIRTEEN NEW SPECIES OF PARA- 

 SITIC HYMENOPTERA AND A TABLE TO CERTAIN SPE- 

 CIES OF THE GENUS ECPHYLUS. 



By S. A. RoHWER, 



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



The following paper, which is a contribution from the Branch of 

 Forest Insect Investigations, Bureau of Entomology, deals with the 

 descriptions of certain parasites on forest insects. Some of these 

 parasites appear to be of importance, and it is necessary that names 

 should be made available in the near future. A table to most of the 

 Nearctic species of Ecphylus is also included. 



One of the species, namely, Caenopachys scolytivora, was labeled as 

 a new species by Mr. H. L. Viereck, and has been described by the 

 author, so should be credited to Viereck and Rohwer. 



ATANYCOLIDEA APICALIS, new species. 



This species differs from rugosiventris Ashmead in its smaller size, 

 in having the fifth tergite coarsely sculptured (in rugosiventris the 

 fifth tergite is practically impunctate and smooth), in having the 

 embossed area of the second tergite very short (in rugosiventris the 

 embossed area of the second tergite is at least two-thirds of the 

 length of the segment), and in having the sixth tergite yellowish. 



Female. — Length 4 mm. Front with a strong median furrow which 

 divides at the anterior ocellus forming a Y ; thorax smooth and shining; 

 transverse median of the fore wings nearly squarely interstitial with 

 the basal vein; embossed area of the first tergite rounded anteriorly 

 and with a few longituduial stride, not smooth, sharply defined as in 

 rugosiventris; the lateral areas of the first tergite with short, irregular, 

 poorly defined striae, and with short longitudinal furrow; the apical 

 lateral sides of the first tergite sharply angled and curved basally; 

 second to fifth, tergites inclusive, longitudinally striate; the embossed 

 area of the second tergite Y-shaped but not one-third the length of 

 the tergite; no defined embossed area laterally on second tergite; 

 sixth and seventh tergites smooth, shining, impunctate. Black; 

 apical joint of the palpi piceous; abdomen dark red except a yellow- 



Proceedings U.S. National Museum, Vol. 45— No. 1991. 



533 



