FLIES OF THE GENUS ODINIA — SABROSKY 225 



and will key correctly to genus in that famUy. Figure 4 on page 333 

 of that work illustrates the typical side view of the head of Odinia, 

 and figure 2 the typical wing venation. 



Generic diagnosis: Head bristles long and strong, with three pairs 

 of orbitals, the posterior two reclinate, the anterior mesoclinate and 

 cruciate at tips; both ocellars and postverticals widely divergent, the 

 latter weaker than the other head bristles; inner and outer verticals 

 strong; thoracic bristles equally strong, with 1 humeral, 1 + 1 noto- 

 pleural, 1 presutural, 2 supraalar, 1 postalar, 5 dorsocentral, 1 pre- 

 scutellar acrostical, 1 subapical and 1 apical pairs of bristles; meso- 

 pleuron bare; a short, fine propleural bristle present; 3 sternopleural 

 bristles in a straight line, the anterior long, the others shorter; pre- 

 apical dorsal bristle present on all tibiae, although short and weak; 

 hind femur of male strongly incrassate; wing venation as figured in 

 present paper, the costa broken at juncture of subcosta and ending 

 at or sUghtly beyond third vein, anal vein and anal cell present. All 

 species seem to have essentially the same color pattern on the legs 

 (cf. description of higuttata), but the color varies considerably in 

 extent. The two dark bands on the tibiae, one subbasal and the 

 other apical, are quite regular. 



Collin (1952) employs the presence or absence of small hairs on the 

 parafrontals between the posterior orbital bristle and the verticals 

 as one of the primary key characters in separating the species. I am 

 inclined to mistrust this character, having seen the hairs present, 

 present on one side only, and absent, in a series reared at the same 

 time and place from the same "host," and certainly appearing to be 

 the same species. However, presence or absence of the hairs may 

 well be characteristic of a majority of individuals of a species, and 

 I have utilized them to a certain extent. 



Key to the New World species of Odinia 



1. Wing with a few black spots on or enclosing veins, the wing membrane clear 



except in one species with two spots in marginal cell (figs. 1-4) 2 



Wing pattern reticulate, or with numerous dark spots most of which are 

 surrounded by a whitish corona (figs. 5-8) 5 



2. Marginal cell of wing clear, unspotted; mid tibia ventrally at apex with two 



strong bristles, subequal in length or unequal 3 



Marginal cell with two large, evenly spaced black spots between the smaller 

 spots at junctures of first and second veins with costa; mid tibia ventrally 

 at apex with only a single strong bristle 1. O. biguttata, new species 



3. Mesopleuron gray, at most a streak or trace of brown posterodorsally; wing 



markings strong, the spots covering the fore and hind crossveins broad 

 and dark, second and third veins with distinct brown clouds about their 

 apices; antenna entirely yellow, at most the apicodorsal margin of third 

 segment faintly browned; large species, typically the body and wing each 

 5 mm. long 2. O. conspicua, new species 



