cana . Larva internal stem borer (details not 
recorded) in plants growing beside streams. 
Distribution. Illinois, Indiana, Maryland (new 
record) . 
References. Malloch, 1920: 147; Frick, 1959: 364 
(as M. diantherae ) . 
21 (19). Mesonotum bluish black 22 
— Mesonotum greenish black 25 
22 (21). Frons almost twice width of eye 23 
— Frons 1.5 times width of eye 
M. walleyi Spencer, n. sp. 
Synopsis. Wing length in male 2.7 mm; last section 
of vein M 3+4 little more than 0.5 penultimate; 
frons less than 1.5 times width of eye; 2 ors , 3 
ori; eye in male with distinct pilosity at level 
of ors; gena narrow, 0.20-0.17 height of eye; 
male genitalia with aedeagus as in figures 44, 45. 
Host/Early Stages. Unknown. 
Distribution. Tennessee. 
Reference. Part 2, p. 249. 
23 (22). 4 ori M. hicksi Steyskal 
Synopsis. Large species, wing length 2. 7-3.5 mm; 
gena 0.25-0.20 eye height; eye in male with 
slight pilosity above; arista bare; male genitalia 
with aedeagus as in figure 46. 
Host/Early Stages. Althaea rosea , possibly other 
Malvaceae. No record of larva or puparium. 
Distribution. New York; Canada. 
References. Spencer, 1969a: 78 (as sp. 
(Steyskal)); Steyskal, 1981: 36. 
2 ori 24 
24 (23). Male genitalia with aedeagus as in figures 47, 48 — 
M. vernoniae Steyskal 
Synopsis. Wing length in male just less than 3 mm; 
2 ors and upper ori equidistant, distance be- 
tween upper and lower ori double that between 
upper 3 bristles; orbital setulae in 2 rows, row 
nearest eye margin sparse, reclinate, inner row 
more numerous, proclinate; gena relatively narrow, 
0.17 height of eye, this in male with patch of 
short pilosity opposite ors; arista long, 0.83 
height of eye, appearing bare; male genitalia with 
aedeagus having virtually no gap between basal 
sclerites and distiphallus complex (fig. 47). 
Host/Early Stages. Vernonia noveboracensis . Larva 
internal stem borer. 
Distribution. District of Columbia, Maryland. 
Reference. Steyskal, 1981: 41. 
— Male genitalia with aedeagus as in figure 49 
M. vernoniana Steyskal 
Synopsis. Essentially as in M. vernoniae , possibly 
smaller, wing length about 2.5 mm. 
Host/Early Stages. Vernonia noveboracensis . Larva 
internal stem borer. 
Distribution. District of Columbia. 
Reference. Steyskal, 1981: 41. 
25 (21). Frons distinctly projecting above eye 26 
23 
