HORSEFLIES OF THE SUBFAMILY TABANINAB 7 
The Genus CHLOROTABANUS Lutz 
Chlorotabanus Lutz, Inst. Oswaldo Cruz em Manguinhos, p. 30, 1909; Internati. 
Hyg. Ausstellung Dresden, 1911: 35; Brazil-Medico, 27 (45): 487, 1913; 
Mem. Inst. Oswaldo Cruz 6: 71, 167, 1914; Kréber, Zool. Anz. 87: 14-15, 
1930. (Genotype, Tabanus mexicanus Linnaeus.) 
Ommallia Enderlein, Deut. Ent. Ztschr. 1923: 545; Mitt. Zool. Mus. Berlin 11: 
388, 1925. (Genotype, Ommalia viridis Enderlein=Tabanus  inanis 
Fabricius. ) 
Generic characters.—Rather small, stout, yellow or green; no ocelli, ocellar 
tubercle, frontal callus, or median callus; first antennal segment about as long 
as thick; third with five divisions, the first with a distinct dorsal angle but 
no forward-projecting process; palpus not unusually stout; short stump from 
vein R., usually present. 
This genus is placed as a subgenus of Tabanus by Krober (17) 
in his catalog, but it is the present writer’s opinion that 7’. meaicanus 
and related species form a group that is sufficiently well defined 
and striking to deserve generic rank. 
There is a single Nearctic species, Chlorotabanus crepuscularis 
(Bequaert). 
CHLOROTABANUS CREPUSCULARIS (Bequaert) 
(Big. 9; A) 
Tabanus sulphureus Palisot de Beauvois (in part), Insectes recueillis en Afrique 
et en Amerique, p. 222, 1813-1820. 
Tabanus flavus Macquart, Histoire Naturelle des Diptéres, v. 1, pp. 200-201, 
1834. (Preoccupied by Tabanus flavus Wiedemann.) 
Tabanus mexicanus of authors (not Linnaeus) (in part), Osten Sacken, Mem. 
Boston Soe. Nat. Hist. 2 (pt. 4, No. 4): 459460, 1876; Hine, La. 
Agr. Expt. Sta. Bull. 93: 52, 1907; Jones and Bradley, Jour. Econ. Ent. 17: 
48, 1924; Schwardt and Hall, Ark. Agr. Expt. Sta. Bull. 256: 26, 1930. 
Tabanus crepuscularis Bequaert, Harvard Inst. Trop. Biol. Med. 4: 234, 1926. 
Tabanus (Chlorotabanus) crepuscularis Krober, Rey, Ent. 4: 296, 19384. 
=o = 
Figure 9.—Antenna, front view of head, and palpus of (A) Chlorotabanus crepuscularis 
and (B) "Anacimas dodgei. 
Rather small, stout; pale greenish yellow; frons narrow; no frontal calli. 
Female.—Length 13-15 mm. Eye bare. Whole body pale yellow, in fresh 
specimens the antenna, proboscis, femora, and most of abdomen bright green. 
Frons very narrow, more than five times as high as width at base, somewhat 
widened above, without ocellar tubercle or ealli. Basal portion of third 
antennal segment large, width at base about three-fifths its length, dorsal angle 
prominent, a shallow excision directly distad of angle and a Slight convexity 
just basad of annulate portion; ventrally not strongly convex; length of an- 
nulate portion equal to greatest width of basal portion. Second palpal segment 
rather elongate, decidedly tapering, about two-thirds length of proboscis. 
Wing hyaline, the costal cell yellowish; veins yellow; rather faint brown 
spots at furcation and on cross veins; vein Ry with short stump; cell Rs wide 
open; no spots on hind margin of wing. Legs uniformly yellow; hind tibial 
fringe well developed, yellow. 
Male.—Hye bare, distinetly differentiated into areas of large and small facets, 
the upper surface somewhat flattened. Coloration of body as in female. 
