200 Illinois State Laboratory of Natural History 



Genus Chilaspis Ma^r. 



C. ferrugineus n. sp. 



This genus has hitherto had no recognized representative 

 in this country. Dr. Gustav Mayr, in his paper on " Die euro- 

 paischen Arten der gallenbewohnenden Cynipiden," gives a sin- 

 gle species, C. nitida Gir., for Europe. Giraud's species is given 

 as producing galls on the leaves of Quercus cerris^ while the spe- 

 cies here described is either a guest or a parasite, as two of 

 them were captured in the act of ovipositing in immature 

 galls, one of Dryophanta lanata, described above, and one in a 

 very similar gall of an undescribed species; both were taken 

 1st Sep., 1890, at Ames, Iowa. 



I have never seen a specimen of C. nitida, and it is possible 

 that the species here described will require a new genus, but by 

 the use of Mayr's synopsis these flies are readily traced to 

 Chilasiiis. 



Flies. — Females. — General color yellow-rufous, abdomen 

 shading into black on apical dorsal portion, tips of mandibles 

 black, posterior tibiae "and tarsi somewhat infuscate, length 

 2 mm. 



Head: face finely rugulose and having the appearance of 

 being covered with scales like the body of a fish, a few scatter- 

 in c hairs, clypeus in the upper and middle portion sculptured 

 like the rest of the face but with a broad polished margin 

 below, mandibles punctate, vertex and occiput covered with a 

 fine net-work of depressed lines and blackish in color; antennae 

 13-jointed, 3d and 4th joints equal in length, last joint twice 

 as long as the preceding, ferruginous, reaching to the middle 

 of the abdomen. Thorax: mesothorax ferruginous, quite dark 

 in one specimen, sculptured like the face, parapsides distinct 

 throughout but in the middle showing as broad shallow grooves 

 without well-defined sides, median groove absent, parallel lines 

 from the collar plainly marked, lateral grooves distinct and 

 reaching to opposite the bases of the wings; pleuriB covered 

 with a net-work of slightly raised lines; scutellum with pol- 

 ished basal groove crossed by many shining ridges, coarsely 

 rugose posteriorly and with a narrow blackish rugose margin; 

 raetathorax coarsely rugulose and with three longitudinal 



