Synopsis. Head largely yellow but upper half of 
frons blackish; mesonotum matt gray, scutellum 
yellow, legs entirely yellow; squama and fringe 
whitish; wing length 2-3 mm, costa extending to 
M 1+2; male unknown. 
Host/Early Stages. Unknown. 
Distribution. District of Columbia; new record: 
California, Alameda Co., Berkeley, 1 f . , 16.V.15 
(M. C. VanDuzee, USNM). 
References. Malloch, 1924: 192; Frick, 1959: 356. 
All body bristles black £ 
(5). Mesonotum yellow or brownish 7 
Mesonotum gray a. aristata Malloch 
(If arrangement of dorsocentral bristles is con- 
sidered to be 3+1, see couplet 34.) 
Synopsis. Frons yellow in front, blackish on upper 
half; antenna yellow, rather large, arista very 
short; legs, including coxae, bright yellow; 3+1 
or 3+2 dc, anterior ones small, sometimes little 
differentiated from acr; abdomen black; wing 
length about 2.3 mm, costa ending shortly after 
vein R 4+5; male genitalia with aedeagus as in 
figures 357, 358. 
Host/Early Stages. Ulmus americana (not Celtis as 
suggested by Frick, 1959: 354). Larva forming 
initially long, narrow linear mine, which in final 
instar develops into a blotch (fig. 359 ); 
larval posterior spiracles each with 8-10 bulbs. 
Distribution. Illinois, Indiana, Iowa, New York, 
Ohio, Pennsylvania, Virginia; new record: 
Arkansas, Hot Springs, empty leaf mines on Ulmus 
americana , 17.V.79 (KAS). 
References. Malloch, 1915b: 13; Frick, 1959: 354; 
Spencer, 1969a: 38. 
( 6 ). 3d antennal segment and mesonotum yellow 
“ A. diversa Johnson 
Synopsis. Frons narrow, equal to width of eye, 
black, orbit distinctly paler, yellowish; scutel- 
lum largely yellow, legs entirely yellow; abdomen 
basically yellow but tergites sometimes darkened, 
almost blackish centrally; squama and fringe yel- 
low; wing length from 2.5 mm in male to 3 mm in 
female; male genitalia with aedeagus as in figure 
360 (resembling A. pseudoreptans , fig. 399). 
Host/Early Stages. Unknown. 
Distribution. Illinois, Indiana, Iowa, Massachu- 
setts, Vermont; new records: New York, North 
Carolina, Virginia; Canada. 
References. Johnson, 1922: 26; Frick, 1959: 355; 
Spencer, 1969a: 41. 
3d antennal segment and mesonotum darker, brownish 
or blackish brown A. canadensis Malloch 
Synopsis. Closely resembling A. diversa but frons, 
3d antennal segment, and mesonotum matt blackish 
brown; somewhat larger, wing length up to 4 mm; 
male genitalia with aedeagus as in figures 361, 
362. 
59 
