ICHNEUMON-FLIES, PART 2\ XORIDINAE 451 



18. Fifth segment of hind tarsus about 1.4 as long as second segment; fi»st segment 



of flagellum about 1.4 as long as second segment; segments of flagellum 



rather short 12. mellipes (Say) 



Fifth segment of hind tarsus 0.95 to 1.2 as long as second segment; first 

 segment of flagellum 1.0 to 1.25 as long as second segment; segments of 

 flagellum rather long 19 



19. Hairs on median part of second tergite sparse and irregularly distributed, the 



hair sockets separated by about 1.5 to 3.0 the length of the hairs; basal 

 0.25 ± of second tergite with moderately strong wrinkles; mesepimeron 

 with hairs on its entire length except its lower 0.1 ±; nervellus broken 

 usually near its middle; hind femur ferruginous with apical 0.1 ± infuscate. 



20. albotibiale (Bradley) 

 Hairs on median part of second tergite moderately dense and evenly distrib- 

 uted, the hair sockets separated by about 0.7 the length of the hairs; basal 

 0.15± of second tergite with rather weak wrinkling; mesepimeron usually 

 lacking hairs from part or all of its lower half; nervellus broken usually 

 near its lower 0.38 20 



20. Mesepimeron with hairs on about its upper 0.5 ± (on upper 0.4 ± near front 



edge, on upper 0.6 ± on hind edge) ; hind femur about 2.3 as long as deep, its 

 hairs moderately long and moderately sparse, the setiferous punctures 

 near its lower 0.3 separated by about 2.5 their diameter; hind femur with 

 its apical 0.35 ± often distinctly infuscate. (Not all specimens can be 

 distinguished with certainty from strangaliae on these characters.) 



21. ochropus, new species 

 Mesepimeron with hairs on its upper 0.7 or more; hind femur about 2.1 as 



long as deep, its hairs unusually long and sparse, the setiferous punctures 

 near its lower 0.3 separated by about 5 times their diameter; hind femur 

 uniformly fulvous or with a weak apical dorsal infuscation. 



22. strangaliae (Rohwer) 



21. Punctures on mesoscutum and second tergite of medium size, sharp, and 



rather dense, those on second tergite separated by about 0.7 their diameter; 

 hind femur unusually robust; head about 1.04 as wide across temples as 



across eyes 22 



Punctures on mesoscutum and second tergite small, rather weak, rather 

 sparse, those on second tergite separated by at least 1.0 their diameter; 

 hind femur not unusually robust; head 0.95 to 1.04 as wide across temples 

 as across eyes 23 



22. Hind femur without a distinct apical infuscation; hind tibia ferruginous or 



fuscoferruginous 10. punctatum (Cushman) 



Hind femur with its apical 0.12 ± distinctly infuscate; hind tibia fuscous. 



11. canadense (Provancher) 



23. Propodeal teeth usually more than 0.3 as long as their basal width; abdomen 



entirely black or more or less ferruginous; front wing 3.4 to 10 mm. long. 

 (Not always distinguishable from the species parvam and sierrae.) 



17. dichrous (Rohwer) , most specimens 



Propodeal teeth usually less than 0.3 as long as their basal width; abdomen 



entirely black; front wing 3.2 to 5.7 mm. long 24 



24. Second tergite except basally and all of third tergite almost or quite polished; 



metapleurum with strong wrinkles; lower part of trough of pronotum 

 crossed by several rather long horizontal ridges . 14. sierrae, new species 



