548 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 90 



metathorax darker, infuscated with brown. Abdomen pale, dull 

 yellow, the dorsum with a brownish infuscation on the second seg- 

 ment and also a little before the apex. Genitalia (fig. 24, J.) : Basal 

 segment of clasper large, brown, its length slightly more than twice 

 its greatest width; inner edge uneven, with a large concavity in the 

 apical third; two large bristles of unequal length inside, just below 

 the apical joint; dorsal plate broad, with a broad V-shaped emar- 

 gination forming two broad lobes each having a deep rounded 

 emargination that forms two small lobes, the outer one more pointed 

 and slightly lower; the ventral plate somewhat elliptical, the apical 

 end with a deep rounded emargination forming two small, slightly 

 oblique lobes; the style very narrow, rounded at the tip and con- 

 siderably longer than the basal segment of the clasper. Wing (fig. 

 24, D) hyaline, costa brown: three long veins; petiole at base of 

 wing long and narrow. Halteres dark brown, base of the stem pale 

 yellow. Legs nearly uniformly dark brown, femora paler ventrally. 



Female. — Length 1 to 1.25 mm. Very similar to the male. In 

 some specimens the yellow of the abdomen is a little deeper in color 

 and sometimes faintly reddish. Antenna with 13 segments, the 

 fifth (fig. 24, G) with the stem about three times as long as its 

 diameter; basal enlargement twice as long as its diameter; the cir- 

 cumfili pale, more distinctly marked in some specimens than in 

 others. Ovipositor a little longer than broad, the terminal lobes 

 pale. 



LastAnstar larva (fig. 24, E, ventral view; F, dorsal view). — 

 Length 1.75 to 2.5 mm. Body composed of 12 segments in addition 

 to a small, slightly rounded, retractile head ; anterior three segments, 

 especially the first and second, tapering sharply anteriorly; anterior 

 two segments much shorter than the following; posterior two seg- 

 ments tapering slightly toward the caudal end. Color white. Breast 

 plate Y-shaped, flat, pale amber-yellow ; each side of the fork broad, 

 with a slight narrowing near the base ; main stem slightly constricted 

 below the fork. Antenna cylindrical, about twice as long as its 

 diameter; located on a broad, flattened tubercle. Posterior segment 

 with a large pointed tubercle at each posterior angle; below these 

 a pair of smaller tubercles that are less widely separated than the 

 others; on each side of the last segment, anterior to the large 

 tubercle, a pair of pale bristles. The ventral side of segments 2 to 

 10 each with an ambulatory area having minute spines, arranged 

 in about four transverse rows. 



Type locality.— Chsigrm Falls, Ohio, June 20, 1938. Other 

 specimens are from Chagrin Falls, Ohio, June 20 to August 29, 1938, 

 August 8 to September 19, 1939; Wooster, Ohio, June 29, 1936, 

 August 9 to 29, 1937, June 25 to July 4, 1938 ; Canton, Ohio, July 1 



