478 U. S. NATIONAL MUSEUM BULLETIN 2 1 6 part s 



1. Genus Xylophrurus 



Figure 324,a 



Xylophrurus Foerster, 1868, Verb. Naturh. Ver. Rheinlande, vol. 25, p. 169. 



Type: (Echthrus lancifer Gravenhorst) =dispar (Thunberg); included by 



Schmiedeknecht, 1888. 

 Nyxeophilus Foerster, 1868, Verh. Naturh. Ver. Rheinlande, vol. 25, p. 187. 



Type: {Nyxeophilus bimaculatus Thomson) =angustus (Dalman); designated 



by Viereck, 1914. 

 Macrocryptus Thomson, 1873, Opuscula entomologica, fasc. 5, p. 486. Type: 



{Echthrus lancifer Gra venhorst) = dzspor (Thunberg); monobasic. 

 Xylophruridea Viereck, 1912, Proc. U.S. Nat. Mus., vol. 42, p. 646. Type: Xylo- 



phruridea agrili Viereck; original designation. 



Front wing 5.0 to 10.0 mm. long; clypeus moderately small, with 

 a strong median apical tooth; sternaulus rather weak; pleural carina 

 present; transverse carinae of propodeum both sharp, complete or the 

 apical one interrupted medially, the apical carina forming very weak 

 sublateral crests; areolet moderately large, pentagonal but its front 

 side narrow; nervulus basad of basal vein by about 0.3 its length; 

 nervellus broken near its lower end; first tergite without a subbasal 

 lateral tooth, its spiracle near its apical 0.43, its median dorsal carinae 

 distinct, at least near spiracle; ovipositor sheath 0.3 to 0.65 as long 

 as front wing; ridges on ovipositor tip close together. 



Xylophrurus is a small genus, of Holarctic distribution. Specimens 

 are scarce in collections, and this, together with the fact that the 

 species have a rather uniform structure and color, has made it difficult 

 to work out the Nearctic forms. When more specimens are available, 

 modifications of the classification proposed below will Ukely be in 

 order. 



Adults occur mostly in spring and some in the fall; almost none in 

 the summer. They are usually collected around shrubby growth. 

 The species parasitize coleopterous borers in small branches of decid- 

 uous trees and shrubs, and a European species parasitizes Aculeata 

 nesting in twigs. 



Key to the Nearctic species of Xylophrurus 



1. Middle and hind coxae fulvous; abdomen entirely or mostly fulvous ... 2 

 Middle and hind coxae black 3 



2. Head about 0.88 as wide across temples as across eyes; wings faintly to strongly 



infused with brown, not distinctly banded .... 1. sitkensis (Ashmead) 



Head about 1.01 as wide across temples as across eyes; wings subhyahne, the 



front wing of female usually with a weak brown band at level of stigma and 



its apex weakly darkened 2. fasciatus (Ashmead) 



3. Punctures on second tergite rather small, separated by about their diameter. 



3. bicolor (Cushman) 



Punctures on second tergite moderately large, separated by about half their 



diameter 4 



