ICHNEUMON-FLIES, PART 2: EPHIALTINAE 409 



Sierra Ancha of Arizona April 30 to May 5, which is rather early spring 

 for that area. There is also a record for October 1 at Wallace, Idaho. 



One male was reared from Sirex areolatus at Berkeley, Calif., and 

 a number of specimens have pin labels indicating rearings from various 

 conifers, but without the name of the host insect. The conifers thus 

 recorded are: Abies balsamea, A. concolor, Pinus edulis, P. ponderosa 

 P. scopulorum, and Pseudotsuga taxijolia. 



This species is transcontinental in the Canadian zone. It occurs 

 also in Eurasia, where it is the commonest member of the tribe. 



2. Genus Rhyssella 



Figure 303,a 



Rhyssella Rohwer, 1920, Proc. U. S. Nat. Mus., vol. 57, p. 422. Type: Rhyssa 

 nitida Cresson; original designation. 



Front wing 5.5 to 15 mm. long; tergites 3 to 6 of male depressed, 

 polished, with fine sparse punctures, without a median apical sub- 

 membranous area, their apical margin broadly concave; tergites 3 to 

 6 of female covered with transverse aciculation except ventrally; male 

 clasper evenly convex, its apex rounded and containing a rounded 

 notch, without grooves as described for Megarhyssa males. Structure 

 otherwise similar to that of Megarhyssa. 



This genus contains the two Nearctic species treated below, Ich- 

 neumon approximator Fabricius 1793 and Rhyssa obliterata Graven- 

 horst 1829, of Europe, and Rhyssa jurannus Matsumura 1912, of 

 Japan. The species approximator, obliterata, and Jurannus have not 

 before been referred to Rhyssella (new combinations) . Rhyssa dubiosa 

 Matsumura, 1912, is a synonym of jurannus; and Rhyssa curvipes 

 Gravenhorst, 1829, is a synonym of approximator (new synonymies). 

 So far as known, all species of Rhyssella parasitize Xiphyriidae. 



Key to the Nearctic species of Rhyssella 



1. Thorax and abdomen without white spots (fig. 318,a); metapleurum black; 

 upper part of pronotum with rather dense fine punctures. 



1. nitida Cresson 



Thorax and abdomen with conspicuous white spots (fig. 318,b); metapleurum 



and often additional areas on thorax fulvous; upper part of pronotum with 



very sparse fine punctures 2. humida (Say) 



1. Rhyssella nilida (Cresson) 



Figure 318,a 



Rhyssa nitida Cresson, 1864, Proc. Ent. Soc. Philadelphia, vol. 3, p. 119; d". 



Type: d\ Virginia (Philadelphia). 

 Rhyssa canadensis Cresson, 1868, Canadian Ent., vol. 1, p. 35; 9 • Type: ? , 



"Quebec" (Philadelphia). 



526527—60 27 



