108 Psyche [June 
THE CHALCIDOID PARASITES OF THE COMMON 
HOUSE OR TYPHOID FLY (MUSCA DOMESTICA 
LINN.) AND ITS ALLIES.* 
II. ReconstrucTIoN oF THE GeENus Pachycrepoideus ASHMEAD OF THE 
Famity PreroMALipAE, WITH Description oF P. Dubius AsHMEAD, 
Sp. Nov., Irs Type Species. 
By A. A. GrrauLtt AND GEORGE ETHELBERT SANDERS, 
The University of Illinois. 
Introduction. 
This second of the series of papers on the chalcidoid parasites 
of the house fly and its allies considers a monotypical genus which 
occurred but rarely in connection with its host. We met with it but 
four or five times during the course of our rearing work and are not 
perfectly sure as to its réle as a parasite. The tribe to which it 
belongs is composed of genera supposed to be mostly hyperparasitic, 
but at the present state of our knowledge of the host relations of the 
group, this is no reason for classing the genus as the same. Our 
records lead us to believe that it attacks Musca domestica as a 
primary parasite, with the possible alternative of being secondary, 
its host Muscidifurax raptor Girault and Sanders MS.* or one of 
the species of Spalangia, also to be considered later. 
History and Description of the Genus. 
In a table of the genera of the Sphegigasterine tribe Pachyneu- 
rini published in 1904, Ashmead, in his memoir on the classification 
of the chalecid flies, briefly described the genus under consideration, 
merely naming the species Pachycrepoideus dubius Ashmead as 
type, without describing the species or even indicating that it was 
new to science. The genus was proposed as follows: 
“Table of Genera. 
Wee PBemales. |. scot sacs ee ieiae nes ester levers fereioiove 01s ‘a/ale.s steiniege hn in] eetey sueleleae = Steam 2 
IVUGUIES 5 dyes sin esshe ste Slob tele ope; wie s arate pi els 6.0 ele hie lore bie) walatelee ina /aiatn a) <eteis eee 7 
2. Mesothoracic furrows distinct, complete.............---seseseseees 3 
Mesothoracic furrows incomplete, indicated only anteriorly........-- A 
EEE 

1Continued from Vol. XVII, p. 28. 
2Described in the third paper of this series. 
