NORTH AMERICAN TETRASTICHUS — BURKS 575 



TETRASTICHUS POLYNEMAE Ashmead 

 FIGURE 20, f 



Tetrastichus polynemae Ashmead, Ent. News, vol. 11, p. 616, 1900. 



Aprostocetus polynemae (Ashmead) Gikault, Proc. U. S. Nat. Mus., vol. 51, p. 130, 



1916 (not Aprostocetus polynemae Ashmead). 

 Ootctrastichus mymaridis Gibaui>t, Proc. U. S. Nat. Mus., vol. 51, p. 130, 1916. 



(New synonymy.) 



Bright, iridescent green ; abdomen varying from brown to iridescent 

 green ; legs, except coxae, anterior tarsi, and apical segments of middle 

 and hind tarsi white. 



Female. — Length, 1.0-1.2 mm. Antennae inserted slightly dorsad 

 of level of ventral margins of compound eyes; scape short, its apex 

 not reaching level of ventral margin of anterior ocellus ; first f unicle 

 segment one-third longer than pedicel, second and third segments equal 

 and each slightly shorter than first ; club as long as second and third 

 f unicle segments ; length of malar space two-fifths height of compound 

 eye; postocellar line equal in length to ocellocular. Mesopraescutum 

 as long as wide and bearing two or three bristles at each lateral margin ; 

 submarginal vein of fore wing with two or three bristles ; apex of hind- 

 wing acute, width of fringe at hind margin equal to width of wing 

 at hamuli; first bristle of hamuli one-half as long as width of wing 

 (fig. 20, /). Surface of propodeum slightly reticulated; inconspic- 

 uous paraspiracular carinae present ; propodeal spiracles minute, not 

 quite contiguous with anterior margin ; gaster one and one-half times 

 as long as thorax. 



Male. — Unknown. 



Type locality. — Lake Forest, 111. 



Types.— -U.S.N. M. No. 5323. 



Host. — Eggs of damselfly, Lestes sp. 



Distribution. — Delaware, Illinois. 



TETRASTICHUS OECANTHIVORUS var. COMPAR Gahan 



Figure 16, e 



Tetrastichus oecanthivorus var. compar Gahan, Ann. Ent. Soc. Amer., vol. 25, 

 p. 743, 1932. 



Thorax and apex of abdomen iridescent green ; variable areas of head 

 and antennae, tegulae, and dorsal sector of metapleuron, legs (except 

 coxae of female), and base of gaster yellow; all tarsi light brown. 



Female. — Length, 1.3-1.4 mm. Antennae inserted at level of ventral 

 margins of compound eyes ; apex of scape reaching level of vertex, first 

 funicle segment one and one-third times as long as second, second and 

 third equal in length (fig. 16, e) ; club two and one-quarter times as 

 long as third funicle segment; malar space one-half height of com- 

 pound eye ; postocellar line one-fourth longer than ocellocular. Meso- 



