no. 2068. NEW SPECIES OF INSECTS— OAH AN. 167 



The following key is believed to include all of the known species of 

 Tetrastichus from the United States having only one bristle on the 

 dorsal side of the submarginal vein. 



Key to some North American species of Tetrastichus. 



1. Legs all pale; antennae unusually long, the flagellum twice the length of the face 



euplectri, new species 



Femora, at least, black or blackish; antennae shorter 2 



2. Antennal club short, scarcely longer than the last funicle joint and distinctly wider; 



first funicle joint nearly twice as long as the pedicel; propodeum strongly punc- 

 tate scolyti Ashmead. 



Club much longer than the last funicle joint and scarcely wider 3 



3. Abdomen slender, narrower than the thorax and produced apically, longer than the 



head and thorax productus Riley. 



Abdomen as broad as the thorax, not especially produced apically and rarely longer 

 than the head and thorax 4 



4. Lineolation of the thorax indistinct, very fine and shallow ; first funicle joint appar- 



ently not much longer than the pedicel theclae Packard. 



Lineolation of the thorax deeper and more distinct; first funicle joint distinctly 

 longer than the pedicel 5 



5. Face obscurely sculptured, nearly smooth; body black, femorae dull brownish 



johnsoni Ashmead. 



Face distinctly finely sculptured and with a number of large shallow round punc- 

 tures on the frons and along the inner orbits; body metallic blue or green; 

 femorae black "or tinged with metallic 6 



6. Third funicle joint not much longer than wide; scape and pedicel metallic blue- 



black; body deep blue; marginal vein somewhat thickened. 



asparagi Crawford. 

 Third funicle joint nearly twice as long as broad and equal to the second; 

 scape and pedicel yellowish; body color green; marginal vein scarcely 

 thickened hylotomae Ashmead . 



TETRASTICHUS EUPLECTRI, new species. 



Female. — Length, 1.5 mm. Antennae elongate, cylindrical, the 

 club not enlarged; ring- joint minute; pedicel about half as long as 

 the first funicle joint; funicle 3-jointed, the first joint about three 

 times as long as wide, second a little longer than the first, third 

 shorter than the first; club 3-jointed, the first joint about twice as 

 long as wide, second a little shorter, third small. Head obscurely 

 lineolate ; mesoscutum and scutellum with fine shallow lineolation, 

 more apparent than on the face, parapsidal grooves deeply impressed, 

 median groove of mesoscutum distinct; propodeum strongly and 

 closely punctate with a median carina, the lateral folds present but 

 not deep; submarginal vein with a single stiff bristle above, post- 

 marginal vein obsolete ; abdomen smooth, conic-ovate, about as long 

 as the head and thorax. Head, thorax, and abdomen blue-green; 

 antennae dark brown or black, the scape a little paler below; all 

 coxae concolorous with the thorax, remainder of the legs pale yellow, 

 the apical tarsal joint dark. 



Male. — Similar to the female except that the antennal club is more 

 elongate, being about as long as the funicle, its last joint as long and 



