40 INSECUTOR INSCITI^ MENSTRUUS 



gether toward base of wing. Legs moderately slender; fore 

 tarsus on outer lower surface of tip with a distinct curved 

 tooth. 



Abdomen slightly wider than pterothorax, smooth ; segment 

 10 long, acute, fully 1.5 times as long as 9, not divided above ; 

 bristles moderately long, pale. 



Measurements of holotype: Length 0.996 mm.; head, length 

 0.105 mm., width 0.131 mm.; prothorax, length 0.105 mm., 

 width 0.175 mm.; pterothorax, width 0.216 mm.; fore wing, 

 length 0.648 mm., width near base 0.063 mm., at middle 0.040 

 mm. ; abdomen, width 0.252 mm. 



Antennal segments : 12345678 



Length {\i) 24 36 38 31 29 40 7 14 



Width (n) 27 24 20 20 19 20 8 6 



Male ( macro pterons). — Length about 0.9 mm. Color and 

 structure essentially as in female; ninth abdominal tergite 

 with two pair of short, stout, approximate spines close to pos- 

 terior margin ; posterior pair about half the length of anterior 

 pair, much more slender, and very slightly more widely 

 separated. 



Measurements of allotype : Length 0.90 mm. ; head, length 

 0.102 mm., width 0.124 mm. ; prothorax, length 0.099 mm., 

 width 0.168 mm. ; pterothorax, width 0.215 mm..; fore wing, 

 length 0.624 mm., width near base 0.054 mm., at middle 0.033 

 mm. ; abdomen, width 0.210 mm. 



Antennal segments : 1234 5 678 



Length (|i) 24 36 41 36 29 38 7 12 



Width (ji) 28 23 21 21 18 20 9 6 



Total length of antenna, 0.223 mm. 

 Described from 26 females and 20 males, from Branchville 

 (type locality), Beltsville, and Cabin John, in Maryland; and 

 from Four Mile Run, Great Falls, and Vienna, in Virginia. 

 All the specimens were collected from Pinus virginiana and 

 P. tceda in April and May, by R. A. Cushman, W. L. McAtee, 

 L. O. Jackson, and the author. 



