HORSEFLIES OF THE SUBFAMILY TABANINAE 149 
as the lectotype. Three cotype females, Boston Society of Natural 
History. 
Type locality —Miulford, N. H. 
Distribution.—British Columbia and New Brunswick south to 
Montana and Maryland. May 21 (Mount Lehman, British Colum- 
bia) to August 27 (Fort George, James Bay, Quebec). In the 
United States National Museum, 29 females, 3 males. 
TABANUS TRISPILUS Wiedemann 
(Fig. 72, A) 
Tabanus trispilus Wiedemann, Aussereuropaische zweifliigelige Insekten, v. 1, 
pp. 150-151, 1828; Osten Sacken, Mem. Boston Soc. Nat. Hist. 2 (pt. 4, 
No. 4) : 464-465, 1876; Philip, Minn. Agr. Expt. Sta. Tech. Bull. 80: 34, 
118, 1931. 
Tabanus sodalis Williston, Kans. Acad. Sci. Trans. 10: 189, 1887. (New 
synonymy. ) 
FIGURE 72.—Antenna, front view of head, and palpus of (A) Tabanus trispilus and 
B) T. illotus. 
Medium sized; abdomen with a prominent middorsal row of white triangles; 
wing subhyaline to dark brown. 
Female.—Length 13-16 mm. Eye purple, with four bright-green bands and 
short, fine pile. Frons gray tinged with yellow, about three and one-half times 
as high as width across basal callus, with parallel sides; basal callus chestnut 
brown to black, square or slightly transverse, rounded above and not touching 
eyes; median callus concolorous with basal callus, slender, tapering at both 
ends, somewhat longer than basal callus and only rarely connected with it; a 
well-defined, orange, ocellar tubercle at vertex; subcallus, clypeus, and genae 
gray, the supraantennal crescents strongly tinged with orange; some black hair 
on clypeus, the genae below with yellowish hair. First and second antennal 
segments orange, with black hair, the first often with gray pollen; basal portion 
of third orange brown, usually blackened apically and dorsally beyond dorsal 
angle, which is distinct, the excision moderate; annulate portion black, shorter 
than basal portion. Second palpal segment creamy white to yellowish, with 
concolorous and black hair, moderately stout at base and tapering to a blunt 
apex. 
Mesonotum blackish, with faint gray lines in usual pattern; prescutal lobe 
black to reddish brown. Pleura, sternum, and coxae dark gray, with mostly 
yellowish hair. Wing more or less strongly tinged with orange brown, in some 
specimens almost black. Legs generally brownish black, the middle tibia and 
base of fore tibia palest. 
Abdomen above black, with a median row of white spots consisting of a very 
small one on first tergite, a large triangle on second reaching length of tergite, 
and somewhat smaller ones on 3 and 4, which are narrower but reach length 
of tergites; tergite 5 without or with only a minute spot; very narrow, white, 
posterior borders on tergites 2-4 or 2-5; venter gray, with a broad median band 
of dark brown. 
Male.—Kye with dense, short, gray pile; facets almost uniform in size. Palpus 
yellowish orange, with black hair. Thorax and legs blacker than in female, the 
hair of pleura, except that below wing base, black. Sides of tergites 24 tinged 
with orange; no white spot on first tergite; triangles on tergites 2 and 3 broad 
but usually not reaching anterior margin, that on tergite 4 very small; venter 
mostly dark, so the median stripe is usually indistinct. 
