134 U. S. NATIONAL MUSEUM BULLETIN 2 1 6 part 3 



1. Ischnus latus (Provancher) 



Front wing of male 3.8 to 6.1 mm. long, of female 3.6 to 6.5 mm. 

 long; body a little stouter than in /. cindipes; clypeus narrow; tyloids 

 on about 4.5 segments, extending about 0.90 or practically the full 

 length of the segments, narrow and sharp, parallel to the long axes of 

 the segments; mesoscutum mat, its lateral lobes subpolished, its punc- 

 tures rather small, weak, separated by about 1.2 their diameter; 

 scutellum carinate only at its basolateral corners; metapleurum shin- 

 ing, with rather close, moderately large but weak punctures that are 

 somewhat obscured by and confluent with weak, fine wrinkling ; apical 

 carina of propodeum complete, sharp and strong, its median 0.25 

 bowed forward; postpetiole weakly mat, with sparse or very sparse 

 weak punctures; punctures on second tergite medium sized, separated 

 by about 0.7 their diameter. 



Black. Palpi stramineous to fuscous, the second segment of max- 

 illary palpus white; scape of female often brown in front; flagellum 

 with a white band that occupies usually 4 or 5 segments, the band 

 usually incomplete below in the female; basal segments of female 

 flagellum usually brownish; tegula usually white, but sometimes 

 brown; sub tegular ridge often with a small white mark; coxae and 

 trochanters whitish, fulvous, or blackish, according to the subspecies; 

 femora ferruginous, the front and middle femora sometimes infuscate 

 basally behind and sometimes whitish at apex, the apical 0.18± of 

 hind femur fuscous; front and middle tibiae fulvous to brownish fer- 

 ruginous, often whitish at base ; hind tibia brown to blackish, its basal 

 or subbasal 0.2 ± white; basal 0.2 or more of hind basitarsus white, 

 the apical 0.8 or less fuscous; second segment of hind tarsus white, its 

 apex often brown or fuscous, or sometimes all but a narrow basal ring 

 fuscous; third and fourth segments of hind tarsus white to brown or 

 fuscous; fifth segment of hind tarsus fuscous; middle tarsus with a 

 pale repetition of the hind tarsal color pattern or the dark markings 

 more extensive; front tarsus brownish; abdomen ferruginous, the base 

 of its first segment, fifth and following tergites, and usually part or 

 all of fourth tergite black. Sometimes, in the subspecies latus, 

 the femora and first abdominal segment are more extensively infus- 

 cate than described above. 



This species is close to the European Ischnus alternator (Graven- 

 horst), 1829. In color the subspecies latus is particularly similar. 

 The European species differs structurally in the more strongly 

 mat and less punctate mesoscutum, more wrinlded and less punctate 



