— Wing length in male 1.85 mm M . radicicola Steyskal 
Synopsis. Essentially as in M. min imo ides ; male 
genitalia with aedeagus having distinct pigmenta- 
tion distally (fig. 128). 
Host/Early Stages. Unconfirmed, single available 
specimen obtained in rearing container with roots 
of Urtica but no pupal case found. 
Distribution. Maryland. 
References. Steyskal, 1981: 40; part 2, 246. 
59 (50). Minute species, wing length in male less than 2 mm- 
M. caribbea Spencer 
Synopsis. Shining black; gena narrow, 0.12 height 
of eye; male genitalia with aedeagus as in figures 
129, 130. 
Host/Early Stages. Unknown. 
Distribution. Florida; Costa Rica, Dominica. 
References. Spencer and Stegmaier, 1973: 34; part 
2, p. 244. 
Larger species, wing length 2.3-3 mm 60 
60 (59). Gena exceptionally narrow, 0.08 height of eye 
M. ultima Spencer, n. sp. 
Synopsis. Wing length in male 2.4 mm; frons 1.5 
times width of eye, not projecting above eye; 2 
ors, 2 ori; mesonotum and abdomen moderately 
shining black; squama gray, fringe black; male 
genitalia with aedeagus as in figures 131, 132. 
Host/Early Stages. Unknown. 
Distribution. Virginia. 
Reference. Part 2, p. 247. 
Gena broader 61 
61 (60). Frons only slightly wider than eye; (costa normal- 
ly ending at vein R 4+5, couplet 3) 
Ophiomyia similata (Malloch) 
Frons broader, 1.5 times width of eye 62 
62 (61). Mesonotum and abdomen shining black — M. tetrica Spencer 
Synopsis. Generally resembling M. setifrons (coup- 
let 8) but with only 2 pairs of dc; male genitalia 
with aedeagus as in figures 133, 134. 
Host /Early Stages. Unknown. 
Distribution. Colorado (new record); Canada. 
References. Spencer, 1969a: 76; part 2, p. 247. 
Mesonotum and abdomen matt — . M. marellii (Br&thes) 
Synopsis. Frons 1.5 times width of eye, not sig- 
nificantly projecting above eye; 2 ors, 3 ori; 
ocellar triangle ill defined; gena broad, 0.25 
height of eye, this bare in both sexes; mesonotum 
matt black, with 2 dc, abdomen entirely black; 
squama pale gray, fringe dark, ochreous to black; 
wing length 2. 3-2. 7 mm, last section of M 3+4 
distinctly shorter than penultimate, inner cross- 
vein at midpoint of discal cell; male genitalia 
with aedeagus as in figures 135, 136. 
Host/Early Stages. Achyranthes ( =A1 ternanther a ) 
philoxeroides . Larva forming conspicuous stem 
galls (fig. 137); puparium yellowish orange, 
posterior spiracles (fig. 138) each on stout 
33 
