142 U. S. NATIONAL MUSEUM BULLETIN 216 



11. Dolichomitus flexilis, new species 



Male: Unknown. 



Female: Front wing 10 to 13.5 mm. long; face of moderate width, 

 with moderate-sized punctures that are separated by about twice 

 their diameter; upper end of prepectal carina above midheight of 

 hind edge of pronotum, curved forward toward front edge of meso- 

 pleurum, the upper part of the prepectal carina often weak; median 

 longitudinal carinae of propodeum rather strong, strongly divergent, 

 extending about 0.6 the length of propodeum; propodeal punctures 

 rather small, crowded sublaterally but elsewhere rather sparse; hind 

 femur about 6.0 as long as deep, its front face with numerous small 

 weak punctures that are separated by about twice their diameter; 

 bristlelike hairs on middle tibia small and weak; first tergite about 

 1.65 as long as wide; second tergite about 1.35 as long as wide; third 

 tergite with weak transverse rugulosity, its tubercles moderately 

 prominent, without distinct rugulosity, covered with rather small 

 punctures whose interspaces are about equal to their diameter; ovi- 

 positor sheath about 2.7 as long as front wing; tip of ovipositor rather 

 similar to that of D. messor (fig. 330,f). 



Black. Clypeus and mandible stained with ferruginous; maxillary 

 palpus brown, its basal segment dark brown; labial palpus dark brown; 

 tegula and hind corner of pronotum whitish; mesosternum and lower 

 part of mesopleurum sometimes light brown ; front and middle coxae, 

 trochanters, and femora fulvous, the apex of the femora pale yellow- 

 ish in front; front and middle tibiae fulvous, somewhat infuscate 

 above (especially the middle tibia), their basal 0.12 and apex in front 

 pale yellowish; front and middle tarsi fulvous, the middle tarsus a 

 little darker; hind coxa and trochanters fulvous; hind femur rather 

 dark brown, its base somewhat fulvous or sometimes the basal half 

 mostly fulvous; hind tibia and tarsus fuscous, the basal 0.12 of the 

 tibia stramineous above. 



The dark brown hind femur and the long ovipositor (2.7 ± as long 

 as the front wing) distinguish this species. The male is unknown but 

 presumably has the hind femur dark, which would distinguish it from 

 all other known Nearctic members of the irritator group except D. 

 pygmaeus. 



Type: 9, Gillam, Man., July 17, 1950, J. F. McAlpine (Ottawa). 



Paratypes: 9, Great Slave Lake region, N. W. T., July 31, 1927 

 (Townes). 9, Snag, Yukon, Aug. 1943, Beresford Smith (Ottawa). 

 9, Yukon (Pittsburgh). 



This is a species of northern Canada, 



