ICHNEUMON-FLIES, PART 2\ ACAENITINAE 569 



The Nearctic species all have a subcircular blackish spot in the apex 

 of the front wing. The similar-appearing Nearctic species of Arotes 

 also have a dark spot in the apex of the front wing, but in these the 

 spot is paler, and crescentic rather than subcircular. 



Genotype: Spilopteron franclemonti, new species. 



This genus includes a number of species in Japan, Formosa, and 

 China, and the four Nearctic species described below. 



Key to the Nearctic species of Spilopteron 



1. Hind femur fulvous, its extreme base brown, sometimes its apex with a weak 



infuscation 2 



Hind femur mostly or entirely black, or sometimes fulvous with a conspicuous 

 subapical blackish area 5 



2. Males 3 



Females 4 



3. Flagellum with a broad postmedian yellowish band; mesopleurum mostly 



blackish or fulvous 3. vicinum (Cresson) 



Flagellum without a yellowish band; mesopleurum mostly yellow. 



4. oceiputale (Cresson) 

 -I. Third and following tergites dark brown and fulvous, the markings not sharply 



contrasting 3. vicinum (Cresson) 



Third and following tergites black and yellow, the markings sharply contrasting. 



4. oceiputale (Cresson) 

 5. Front wing without a fuscous spot over base of radius, except rarely for a 

 small faint spot in some females (fig. 319,i); punctures on metapleurum 

 separated by 0.2 to 1.0 their diameter; apical 7± segments of flagellum black- 

 ish; scutellum with indistinct lateral carina extending most of its length. 



1. franclemonti, new species 



Front wing with a fuscous spot over base of radius, small in males, larger in 



females (fig. 319,j); punctures on metapleurum dense, subadjacent; apical 



13 ± segments of flagellum blackish; scutellum with lateral carina only at base. 



2. formosum (Cresson) 



1. Spilopteron franclemonti, new species 



Figures 319,i; 328,c 



Front wing 11 to 14 mm. long; head about 0.91 as wide across mid- 

 length of temples as across eyes; punctures on metapleurum of 

 moderate size, separated by about 0.5 to 0.8 their diameter; scutellum 

 with indistinct lateral carina extending most of its length; ovipositor 

 sheath about 1.04 as long as front wing. 



Black. Head yellow with the top of head, frons except laterally, 

 and occiput black. In the female the central part of face is usually 

 partly or entirely black or dark brown, a common pattern being a 

 median longitudinal and a sublateral, concentrically curved, dark 

 brown stripe. Antenna with a subapical broad pale yellow band, 

 the apical 7 ± segments blackish, and more or less pale yellow beneath, 

 basad of the band. Thorax with more or less of lower part of pro- 



526527—60 37 



