38 U. S. NATIONAL MUSEUM BULLETIN 2 1 6 paut 3 



Apsilops contains only seven known species, the European Ichneu- 

 mon cinctorius Fabricius, 1775, and Trichocryptus aguaticus Thomson, 

 1874, the Oriental Cryptus scotinus Tosquinet, 1903, the three Nearctic 

 species described below, and a seventh species, presumably from the 

 United States, which is represented by a male in Washington labeled 

 only "Collection C. V. Riley." This specimen is unique in the genus 

 in having the clypeus and the front and middle coxae white. Its 

 general appearance suggests less aquatic habits than other species. 

 The name aquatica has not previously been referred to Apsilops (new 

 combination). We have not seen specimens but place it from 

 Thomson's description. 



Adults of Apsilops occur on emergent or floating aquatic vegetation 

 in lakes and marshes, or among bordering grasses and sedges. They 

 parasitize aquatic or subaqiiatic Lepidoptera. 



Key to the Nearctic species of Apsilops 



1. Seventh tergite with a white spot; hind tibia black; abdomen black except for 



the apical white spot; body rather slender .... 1. hirtifrons (Ashmead) 

 Seventh tergite without a white spot; hind tibia fulvous to dark brown; abdo- 

 men often partly or mostly ferruginous; body^stouter 2 



2, Propodeal spiracle subcircular to elongate oval; upper face of propodeum 



moderately convex; fourth and fifth tergites of male partly or entirely 



ferruginous, of female entirely ferruginous 2. bicolor (Cushman) 



Propodeal spiracle a long, narrow slit; upper face of propodeum almost flat in 

 female, more convex in male; fourth and fifth tergites of both sexes entirely 

 fuscous 3. sericata (Viereck) 



1. Apsilops hirtifrons (Ashmead) 



Cryptus hirtifrons Ashmead, 1890, Proc. U.S. Nat. Mus., vol. 12, p. 411; cf. 

 Type: cf, Texas (Washington). 



Front wing of male 3.6 to 5.2 mm. long, of female 4.5 to 5.8 mm. 

 long; body moderately slender, not depressed, the first abdominal 

 segment slender; hairs on thorax moderately dense; posterior meso- 

 sternal carina widely interrupted in front of each middle coxa; pro- 

 podeum moderately convex above; areola of male about 2.0 as long 

 as wide, of female about 1.1 as long as wide; median longitudinal 

 carinae of propodeum strong to its base; propodeal spiracle subcir- 

 cular; intercubiti approximately parallel; ovipositor rather slender, 

 about 4.5 as long from nodus to apex as it is deep at nodus. 



Black. Scutellum of female and sometimes of male with a white 

 spot; seventh tergite with a white apical spot; median part of sixth 

 tergite of female sometimes with a narrow white margin; coxae and 

 femora fulvous, the apex of femora fuscous; trochanters infuscate; 

 front and middle tibiae fuscous above, more or less fulvous below; 

 hind tibiae and all tarsi black; wings weakly infuscate. 



