■NORTH AMERICAN TETRASTOJCHUS — BURKS 545 



Dark, iridescent blue-green or green; antennae usually, apices of 

 femora, tibiae, and bases of tarsi white or light yellow. 



Female. — Length 0.75 mm. Antennae inserted at level of ventral 

 margins of compound eyes ; scape short, its apex not reaching level of 

 anterior ocellus ; all f unicle segments equal in length, and each three- 

 quarters as long as pedicel, club as long as f unicle; postocellar line 

 twice as long as ocellocular. Mesopraescutum wider than long and 

 bearing one row of bristles at each lateral margin ; submarginal vein 

 of f orewing with one dorsal bristle ; apex of hind wing acute, fringe at 

 posterior margin one-half as wide as wing at hamuli. Surface of 

 propodeum almost smooth, only very faintly reticulated ; paraspiracu- 

 lar carinae wanting; mesal length of mesoscutellum three and one- 

 half times as great as mesal length of propodeum ; propodeal spiracles 

 contiguous with anterior margin ; length of gaster equal to length of 

 thorax, gaster somewhat rounded, and flattened in dry specimens. 



Male. — Length, 0.65 mm. Scape with a minute anterior carina; 

 pedicel one-third as long as scape and greatly enlarged at apex, sec- 

 ond, third, and fourth funicle segments equal, first segment one-half 

 as long as second ; funicle segments bead-like and without long bristles, 

 club as long as three distal funicle segments. 



Type locality. — Parma, Italy. 



Types. — Probably in the Pondani collection in Parma, Italy. 



Host. — Eggs of Galerucella xantliomelaena (Schrank), the elm 

 leaf beetle. 



Distribution. — Western and central Europe; Massachusetts, New 

 Jersey, New York. 



TETRASTICHUS COMPSIVORUS Crawford 



Tetrastichus compsivorus Ckawfobd, Insecutor Inscitiae Menstruus, vol. 2, p. 

 180, 1914. 



Very dark brown, almost black; trochanters, apices of femora and 

 tibiae, and basal segments of middle and hind tarsi white or light 

 yellow. 



Female. — Length, 1.0 mm. Antennae inserted at level of ventral 

 margins of compound eyes ; apex of scape not reaching level of ante- 

 rior ocellus, pedicel slightly less than one-half as long as scape, first 

 and second funicle segments equal and each slightly shorter than 

 pedicel, third segment slightly shorter than second, club equal in 

 length to scape, malar space three-fifths height of compound eye. 

 Mesopraescutum with one row of bristles at each lateral margin ; sub- 

 marginal vein of forewing bearing one dorsal bristle, outer margin 

 of forewing with a fringe of long setae; apex of hindwing acute. 

 Surface of propodeum almost smooth, slightly reticulated, median 

 carina vague, paraspiracular carinae wanting; mesal length one-third 



