ICHNEUMON-FLIES — GELINAE : MESOSTENINI 457 



Mesoslenus tnacrurus Dalla Torre, 1901, Catalogus hymenopterorum, vol. 3, p. 



544. New name for M. longicaudis. 

 Nematopodius exclamans Viereck, 1905, Trans. Kansas Acad. Sci., vol. 19, p. 318; 



?. Type: 9, Clark Co., 1,962 ft., Kans. (Lawrence). 



Front wing 4.5 to 9.3 mm, long; clypeus very wide, rather strongly 

 convex, its apical margin almost straight; temple strongly convex; 

 prepectal carina sharp dorsad to just above midheight of pronotum, 

 more dorsad obsolescent or absent; punctures on mesopleuruin rather 

 small, separated by about 1.5 their diameter; apical carina of male 

 propodeum complete, of even strength throughout, its central portion 

 bowed forward; apical carina of female propodeum complete, thin but 

 sharp, in some places often irregular or almost obsolete, its central 

 part extending far forward; second hind trochanter about 1.2 as long 

 as first hind trochanter (both trochanters measured on dorsal edge, 

 where fu-st trochanter is longest and second trochanter shortest, the 

 second hind trochanter of all other Nearctic species except angustus 

 less than 0.35 as long as first hind trochanter); areolet about 2.2 as 

 wide as high; second tergite of female subpolished, with small, weak 

 punctures that are separated by about 7 times their diameter; oviposi- 

 tor sheath about 3.2 as long as front wing; tip of ovipositor narrowly 

 lanceolate, about 4.2 as long from nodus to apex as it is deep at 

 nodus. 



Male: Black. Head and thorax marked v/ith pale yellow as in 

 figure 337, g, the marks on mesopleurum of variable size, sometimes 

 confluent as an oblique stripe and sometimes the front spot lacldng; 

 palpi yellowish to pale brown; scape often ferruginous or yellow in 

 front; flagellum black; front and middle legs fulvous, their fourth and 

 fifth tarsal segments brown; hind coxa, trochanters, and femur fulvous, 

 the coxa with a whitish area dorsally and first trochanter fuscous 

 above; hind tibia brownish fulvous, brown at base and toward apex; 

 segments 1, 4, and 5 of hind tarsus dark brown; segments 2 and 3 of 

 hind tarsus whitish, brown apically or on apex; wings subhyaline to 

 light brown; abdomen fulvous. 



Female: Ferruginous. Flagellum blackish, fulvous basally, with an 

 incomplete median white band that covers about 4 segments; area 

 above wing bases and thoracic sterna more or less infuscate; tarsi 

 brown apically; wings light yellowish brown to medium brown. 



Specimens from California tend to have the whitish markings of 

 the male reduced, white mark on flagellum of female reduced or 

 absent, fuscous markings on thorax enlarged, coxae and all first 

 trochanters of male partly black, and wings darker than usual. This 

 tendency toward darker coloration is at its extreme in a male and a 

 female from Mount Hamilton in Santa Clara Co., Calif, 



589900 — 62 30 



