Sept., i9i6.] Felt: New Western Gall Midges. 189 



Gall. — ^These are green, glabrous, cortical stem swellings which, as they 

 age, become brown and present a very close resemblance to a group of 

 Lecaniums. The gall has a height of about 2 mm. and a diameter of 3.5 mm., 

 the midge escaping through a circular apical orifice. 



Exuvium. — Very similar to that of R. chrysothamni. 



Female. — Length 2.25 mm. Antennae extending to the fourth abdominal 

 segment, sparsely haired, brown, the two basal segments blackish; 16 seg- 

 ments, the fifth with a length two and one-half times its diameter, the distal 

 segment reduced, with a length about twice its diameter. Palp consisting of 

 a moderately short, broad segment having a length about twice its diameter. 

 Mesonotum grayish black, with the lateral margins and median line black ; 

 abdomen dull red with the sclerites, the last two segnVents and the base of the 

 ovipositor grayish black. Halte^es pale yellowish. Anterior and mid legs fus- 

 cous, the hind legs, except the cox?e, pale yellowish gray ; claws strongly 

 curved, the pulvilli decidedly longer than the claws. Ovipositor with a length 

 about one-half that of the abdomen, the terminal lobes narrowly oval and 

 rather thickly setose. Type Cecid. 1615. 



Rhopalomyia erigerontis new species. 



The one male described below was reared by Mr. P. H. Timber- 

 lake in April, 1913, from a gall fouiid on a plant provisionally identi- 

 fied as Erigeron fragilis and collected at Whittier, Cal. 



Gall. — This is an oval apical bud deformation with a length of 10 mm. 

 and a diameter of 7 mm., the modified leaflets being thickly clothed with a 

 short white pubescence. 



Exuvium. — Length 2.75 mm., mostly whitish transparent, the denser por- 

 tions of the head and thorax brownish. Antennal horns short, stout, tapering to 

 a broadly excavated apex ; antennal cases hardly extending to the base of the 

 abdomen, the wing cases to the third abdominal segment and the leg cases to 

 the sixth abdominal segment ; posterior extremity broadly rounded the dorsum 

 of the abdominal segments dotted with very minute, chitinous points. 



Male. — Length 2.25 mm. Antenna; extending to the third abdominal seg- 

 ment, sparsely haired, pale yellowish brown; 18 segments, the fifth with a 

 stem as long as the cylindrical basal enlargement, which latter has a length 

 about one-fourth greater than its diameter ; terminal segment irregular, oval or 

 subcylindrical and tapering to an irregularly rounded apex. Palp consisting 

 of one segment composed of a narrow, oval basal portion and a slender, finger- 

 like apical part. Mesonotum reddish brown. Scutellum and postscutellum a 

 little lighter. Abdomen fuscous yellowish. Genitalia darker. Halteres yel- 

 lowish transparent. Coxae yellowish brown, the legs a nearly uniform pale 

 straw ; claws slender, evenly curved, the pulvilli as long as the claw^. Geni- 

 talia ; basal clasp segment long, stout ; terminal clasp segment very irregular, 

 excavated internally and slightly recurved at the slender apex ; both dorsal and 

 ventral plates long, broad, broadly and roundly emarginatc, the former broader. 

 Harpes stout, tapering to a narrowly rounded apex ; style short, stout. Type 

 Cecid. 1629. 



