NORTH AMERICAN TETRASTHCHUS — BURKS 589 



with one irregular row of bristles at each lateral margin; submar- 

 ginal vein of forewing with two or three dorsal bristles; apex of 

 hindwing acute, fringe at posterior margin one-third width of wing 

 at hamuli. Surface of propodeum smooth, and with only a vague 

 median carina; median length of propodeum slightly more than one- 

 quarter length of mesoscutellum ; propodeal spiracles round, sepa- 

 rated from anterior margin by a space equal to diameter of a spiracle; 

 gaster one and one-third times as long as thorax. 



Male. — Length, 1.2 mm. Scape with a darkened anterior carina 

 on its apical two-thirds; first funicle segment two-thirds as long as 

 pedicel, second segment slightly longer than first, third and fourth 

 equal in length and each as long as pedicel, funicle segments bearing 

 setae as long as the segments, club as long as last three funicle seg- 

 ments; gaster equal in length to thorax. 



Type locality. — Rosslyn, Va. 



Types. — U.S.N.M. No. 41333. (Specimens in rather poor condition.) 



Host. — Larvae of goldenrod leaf miner, Microrhopala xerene (New- 

 man). 



Distribution. — Virginia. 



TETRASTICHUS CHLAMYTIS Ashmead 



Tetratichus ohlamytis Ashmead, Trans. Amer. Ent. Soc, vol. 23, p. 231, 1896. 



Dark iridescent blue; scape of female usually, pedicel, bases and 

 apices of femora, tibiae, and basal segments of tarsi light yellow or 

 white. 



Female. — Length, 2.0 mm. Antennae inserted slightly ventrad of 

 level of ventral margins of compound eyes ; apex of scape not reaching 

 level of ventral margin of anterior ocellus ; second and third funicle 

 segments equal in length, first segment slightly shorter than either, 

 club longer than two distal funicle segments; length of malar space 

 two-thirds as great as height of compound eye ; length of postocellar 

 line twice as great as ocellocular line. Pronotum with well-marked 

 femoral groove, as in figure 17, e ; median longitudinal groove of meso- 

 praescutum almost entirely obliterated, mesopraescutum as long as 

 wide and usually bearing one row of bristles at each lateral margin, 

 occasionally with one or two bristles mesad of each lateral row near 

 anterior margin ; submarginal vein of forewing with two dorsal bris- 

 tles, marginal vein two and one-quarter times as long as stigmal vein ; 

 hindwing blunt at apex, width of fringe at posterior margin slightly 

 less than one-fourth as great as width of wing at hamuli. Surface of 

 propodeum smooth, or very faintly roughened, paraspiracular carinae 

 wanting; mesal length of propodeum slightly less than mesal length 

 of metanotum and one-fifth as great as length of mesoscutellum; 



