210 U. S. NATIONAL MUSEUM BULLETIN 216 



FEMALES 



1. Apical tooth-bearing part of lower valve of ovipositor about 4.5 as long as deep 

 (fig. 331,e); ovipositor sheath about 1.6 as long as front wing; second tergite 



about 1.25 as long as wide 1. mediator (Fabricius) 



Apical tooth-bearing part of lower valve of ovipositor about 2.5 as long as deep 

 (fig. 331,f); ovipositor sheath about 1.0 as long as front wing; second tergite 

 about 1.05 as long as wide 2. divinator (Rossi) 



1. Perithous mediator (Fabricius) 



Figure 331,e 



Front wing 4.5 to 9 mm. long in male, 6 to 10 mm. long in female; 

 body form slender; second segment of middle tarsus about 4.2 as long 

 as wide; second tergite about 1.50 as long as wide in male, about 1.25 

 as long as wide in female; ramellus short; ovipositor sheath about 1.6 

 as long as front wing; lower valve of ovipositor with about 12 ridge- 

 like teeth, the apical tooth-bearing part of the valve about 4.5 as 

 long as deep. 



This is a Holarctic species with four subspecies, as keyed out below. 

 Some of the subspecies are colored very much like P. divinator, others 

 rather differently. 



1. Mesopleurum entirely black; hind tibia and tarsus blackish brown, the tibia 



medium brown beneath; front and middle coxae of female ivory, fulvous 

 beneath; punctures on abdomen of female moderately coarse and dense; 



range: Japan Id. mediator japonicus Uchida 



Mesopleurum mostly or entirely ferruginous; hind tibia and tarsus partly or 

 mostly pale (white to fulvous) 2 



2. Hind tibia and tarsus of female dark fulvous, the apex of the tibia and of the 



tarsal segments a little infuscate; front and middle coxae of female entirely 

 fulvous; punctures on abdomen of female rather fine and sparse; male rather 

 similar to male of P. mediator neomexicana; range: Europe. 



lc. mediator mediator (Fabricius) 



Hind tibia and tarsus of female whitish to stramineous, with dark fuscous 



markings; front and middle coxae of female partly ivory; punctures on 



abdomen of female moderately coarse and dense; range: North America . 3 



3. Apex of hind femur infuscate for a distance about equal the depth of the femur, 



the extreme apex of femur whitish (fig. 322, j) ; hind tibia of female whitish 

 or stramineous between its subbasal swelling and its base, the extreme base 

 sometimes brown; range: temperate North America east of Rocky Moun- 

 tains la. mediator pleuralis (Cresson) 



Apex of hind femur weakly and narrowly infuscate, the extreme apex whitish 

 (fig. 322,i) ; hind tibia of female brownish on front and back sides between 

 its subbasal swelling and its base; range: temperate North America in 

 Rocky Mountains and westward . lb. mediator neomexicanus (Viereck) 



