Sept., i9i6.] Felt: New Western Gall Midges. 187 



possible that the galls are produced by the same species. This insect 

 runs in our key to R. crassulina Ckll., from which it may be easily 

 separated by its distinctly larger size and also by well marked struc- 

 tural differences. 



Gall. — Ovoid, hypertrophied leaf buds, length lo to ii mm., diameter 7 

 to 8 mm., two or three frequently being confluent, monothalamous, green or 

 somewhat purplish and externally with short, recurved, aborted leaflets cov- 

 ered with a rather thick, gray arachnose pubescence. Apparently the same 

 species was reared from a similar more globose leaf bud gall at once distin- 

 guishable by the absence of pubescence. 



Male. — Length 3 mm. Antennae extending to the fourth abdominal seg- 

 ment, sparsely haired, grayish yellow, the first two segments black; 18 seg- 

 ments, the fifth with a stem three-fourths the length of the cylindric basal en- 

 largement, which latter has a length nearly twice its diameter; terminal seg- 

 ment with a length three times its diameter and tapering slightly to an ir- 

 regularly rounded apex. Palpi presumably biarticulate. Mesonotum shining 

 black. Scutellum and postscutellum probably dark reddish brown. Abdomen 

 probably dark brown, the pleurae fuscous yellowish. Halteres whitish basally, 

 fuscous apically. Legs pale yellowish or grayish, sparsely black-haired ; claws 

 moderately slender, evenly curved, the pulvilli as long as the claws. Geni- 

 talia ; basal clasp segment stout, broad ; terminal clasp segment rather stout, 

 long; dorsal plate broad, deeply and triangularly emarginate, the lobes broadly 

 rounded laterally ; ventral plate broad, broadly and roundly truncate. Harpes 

 moderatey long, slightly divergent and irregularly rounded apically ; style short, 

 stout. 



Female. — Length 3 mm. Antennae extending to the third abdominal seg- 

 ment, sparsely haired, dark grayish, the first two segments black; 18 subsessile 

 segments, the fifth with a length two and one-half times its diameter; terminal 

 segment slightly produced and narrowly oval. Palpi ; first segment somewhat 

 produced, subquadrate, the second irregular, tapering distally to an acute apex 

 and with a length about three times its diameter. Mesonotum and dorsal 

 sclerites of abdomen shining black. Scutellum and postscutellum probably 

 dark brown ; pleurae yellowish gray with a slight reddish tinge. Ovipositor 

 short, with a length probably less than half that of the abdomen, the terminal 

 lobes broadly oval and sparsely setose. Other characters practically as in the 

 male. Colors mostly after Timberlake. Type Cecid. 1608. 



Rhopalomyia chrysothamni new species. 



This midge was reared in May, 1913, by Mr, P. H. Timberlake 

 from a pubescent, variable, conical, stem gall on rabbit brush, Chryso- 

 thamniis gravcolcns, collected in the vicinity of Murray, Utah. The 

 species approaches closely R. utahensis, from which it may be most 

 easily separated by its decidedly smaller size, the fewer antennal seg- 

 ments and particularly by the peculiar type of gall. 



