148 PROG. ENT. SOC. WASH., VOL. 20, NO. 7, OCT., 1918 



and second combined; fourth subequal in length to the third and similarly 

 sculptured; fifth approximately one-half as long as the fourth and sculp- 

 tured; following tergites mostly concealed from above. Color as in the 

 female but with the tibiae less brownish medially and the middle and 

 front femora barely stained with blackish at base. 



Type locality. Tempe, Arizona. 



Type. Cat. No. 21832 U. S. N. M. 



Host. Asphondylia sp. 



Type, collotype and a large series of paratypes reared by V. L. 

 Wilderamth from stem galls on Pluchea borealis and recorded 

 under Tempe No. 2742. Also a large series from the same 

 locality reared bv Wilclermuth from galls on Suaeda sp. under 

 Tempe No. 2741. 



The length of this species varies from 2 to 2.5 mm. and the 

 color of the legs is also variable to some extent. 



Rileya cecidomyiae Ashmead. 



Rileya cecidomyiae Ashmead, Bui. 3, Kansas State Agri. College, 1888, 

 p. 3, Appendix. 



Female. As represented by the female allotype, the head, as viewed 

 from above is more than three times as broad as long, the postocellar line 

 distinctly longer than the ocellocular line; face below the eyes distinctly 

 striate with some of the striae extending upward along the eye-margin 

 above the base of antennae; antennal depression distinctly margined; 

 cheeks separated from face by a distinct carina which extends along the 

 posterior eye-margin and narrowly separated from it nearly to the top 

 of the eye; malar space equal to about twice the width of mandible, shorter 

 than the eye; pronotum as long and as wide as the mesoscutum; pro- 

 podeum with a distinct transverse carina which is curved forward but 

 not sharply angulated medially, the area before this carina rugulose with 

 some rather indefinite striae, the area behind the carina distinctly stri- 

 ated; first tergite nearly circular; exposed margin of second approximately 

 one-third the length of first; third about twice the length of second; the 

 three basal tergites together constituting about one-third the length of 

 abdomen; fourth tergite large; fifth about equal to the third; following 

 tergites short; ovipositor tip exposed. 



Male. Abdominal petiole about as long as broad, weakly sculptured 

 above; first tergite beyond the petiole broader than long; second very 

 narrow; third fully as long as the first and second combined and extend- 

 ing to the middle of abdomen; fourth somewhat longer than the third; 

 fifth shorter than the first; following very short, practically concealed 

 from above. 



