NORTH AMERICAN TETRASTICHUS BURKS 531 



antennal flagellum slightly darkened. Male may have thorax largely 

 yellow and abdomen yellow at base, with legs entirely yellow. 



Female. — Length, 1.4-1.6 mm. Antennae inserted slightly dorsad 

 of level of ventral margins of compound eyes ; apex of scape not reach- 

 ing level of anterior ocellus; pedicel globular, and slightly narrower 

 and shorter than first funicle segment, all three funicle segments equal 

 in length, club slightly more than twice as long as a funicle segment ; 

 length of malar space one-half as great as height of compound eye; 

 postocellar line twice as long as ocellocular line. Mesopraescutuin with 

 one row of bristles at each lateral margin ; submarginal vein of fore- 

 wing with from four to six dorsal bristles, marginal vein three times 

 as long as stigmal; apex of hindwing blunt, fringe at posterior margin 

 almost one-fourth as wide as wing at hamuli. Surface of propodeum 

 smooth, paraspiracular carinae wanting; spiracles contiguous with 

 anterior margin of propodeum; median length of propodeum almost 

 one-fourth as great as length of mesoscutellum ; gaster broad, varying 

 from as long as to one-fifth longer than thorax; apices of ovipositor 

 sheaths not quite reaching apex of abdomen. 



Male. — Length, 1.1-1.8 mm. Scape greatly enlarged, darkened an- 

 terior carina extending almost entire length of scape, pedicel small, 

 beadlike, slightly longer than first funicle segment but narrower than 

 it, second funicle segment one and one-half times as long as first, three 

 apical segments equal in length, club slightly more than twice as long 

 as fourth funicle segment ; length of malar space three-fifths as great 

 as height of compound eye; median length of propodeum one-third 

 as great as length of mesoscutellum; gaster varying from one and 

 one-tenth to one and one-quarter times as long as thorax. 



Type locality.— Williamson River, Oreg. 



Types.— U.S.N.M. No. 56238. 



Described from the female holotype, male allotype, and 35 female 

 and 15 male paratypes, reared from eggs of Coloradia pandora Blake, 

 on Pmus ponderosa, June 21-July 28, 1924, by J. E. Patterson, under 

 Hopkins U. S. No. 16247-C. 



TETRASTICHUS HYLOTOMAE (Ashmead) 



Figubes 17, a; 21, i 



Eyperteles hijlotomae Ashmead, Can. Ent., vol. 20, p. 105, 1S88. 

 Tetrastichus hylotomae (Ashmead) Schwarz, Proc. Ent. Soc. Washington, vol. 11, 

 p. 107, 1909. 



Iridescent green; antennae, mouthparts, trochanters, apices of 

 femora, tibiae, and tarsi white or light yellow; male antennae some- 

 times entirely brown ; female gaster often reddish brown, sometimes 

 lighter at base. 



Female. — Length. 2.0 mm. Antennae inserted at level of ventral 

 margins of compound eyes; apex of antennal scape reaching, or 



