324 THE CANADIAN ENTOMOLOGIST. 



A NEW SAW-FLY OF THE GENUS XYELA. 



BY T. D. A. COCKERELL, BOULDER, COLORADO. 



Xye'a negundinis, n. sp. — 9 . Length 3 mm., or counting ovipositor, 

 about 4 ; body entirely black ; front dullish subsericeous ; antennae very 

 dark brownish, the thick part a trifle longer than the filamentous ; 

 abdomen shining ; ovipositor black ; wings large, hyaline, iridescent, the 

 large stigma and the nervures dilute sepia : venation agreeing with 

 typical Xyela ; femora black except the knees, which, with the tibife and 

 tarsi, are dull ferruginous. Readily known by its black body and dark 

 fennora. 



Hab. — Boulder, Colorado, April 10, 1907; collected by Mrs. Cora 

 Bennett on flowers of Acer negundo. This is the third true Xyela from 

 North America (cf. Canad. Entom., Aug., 1902, p. 194). 



A GALL -GNAT OF THE PRICKLY- PEAR CACTU.S. 



BV T. D. A. COCKERELL, BOULDER, COLORADO. 



Mr. E. Bethel, of Denver, in the course of his botanical excursions, 

 has noticed that the ])rickly-pcar cacti, Opuntia, sometimes bear large 

 oval galls, containing Dipterous larvee. He recently collected some of 

 these at Boulder, and was able to breed many of the flies, which prove to 

 belong to an undescribed species. 



Asphondylia Betheli, n. sp. 



$ . — Expanse, 9 mm ; wings grayish-hyaline, with coarse hair; second 

 longitudinal vein reaching tip of wing ; third longitudinal forked near its 

 middle; fold very distinct; head and thorax slate-gray; abdomen dark 

 olivaceous gray, with copious pale hair ; legs varying from pale yellowish 

 to pale grayish ; antennae 2 -f 12-jointed, the joints cylindrical, sessile, with 

 coarse short hairs; measurements of joints in /x (3) 289, (4) 272, (12) 204, 

 (13) 195, (14) 195. 



Pupa about 5 mm. long ; pupa-shell bright ferruginous. 



Gall a swollen fruit of Opiiniia, collapsing after the exit of the flies. 



Hab. — Boulder, Colorado; flies emerging May, 1907. 



Like other species oi Asphondylia, this is not marked by any strong 

 peculiarities in the adult state, unless it be the comparatively large size. 

 It is closely related to A. mentzelicR, Ckll., which infests Mentzelia in New 

 Mexico. 



Mailed September 16th. 1907. 



