NEW PARASITIC imiENOPTERA BELONGING TO THE 

 TRIBE XORIDINI. 



By S. A. RoHWER, 

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



This paper, which is a contribution from the Branch of Forest 

 Insects of the Bureau of Entomology, United States Department of 

 Agriculture, contains descriptions of all the new species of parasitic 

 Hymenoptera belonging to the tribe Xoridini which have been accu- 

 mulated by the above-mentioned branch of the bureau, and also those 

 which have been found in the coDections of the National Museum. 

 The types of all the species here described are in the collections of the 

 United States National Museum. The paper is presented at the 

 present time so the names of some of the species here described may 

 be available for economic purposes. 



Genus XYLONOMUS Gravenhorst. 



According to the material at hand Xylonomus may be separated 

 into three groups by the following table. These groups, as well as 

 some others, are considered by Schmiedeknecht as subgenera. The 

 recognition of subgenera on the position of the transverse median of 

 the fore wings would necessitate the making of additional subgenera 

 to include species in which the transverse median is squarely inter- 

 stitial with the basal. 



Table to subgenera of Xylonomus. 



Antennae of both sexes hairy, the female only toward the apex (female antennae 

 ringed with white, male antennae not banded; first dorsal abdominal segment 

 with two complete carinas; second dorsal abdominal segment wider than long; 



abdomen coarsely sculptured) Sterotrichus Foester. 



Antennae not hairy although female may have short bristles apically 1. 



1. Second dorsal abdominal segment not as long as or subequal with its apical width. 



Xylonomus Gravenhorst. 

 Second dorsal abdominal segment much longer than its apical width. 



Masrophora Foester. 



Proceedings U. S. National Museum, Vol. 45— No. 1986. 

 80459°— rroc.X.M.vol.45— 13 23 353 



