486 



OTHER BLOOD-SUCKING FLIES 



Fig. 225. Mouthparts of a tabanid; hyp., 

 hypopharynx; lab., labium; label., labellum; 

 labr, ep., labrum-epipharynx ; mand., mandible; 

 max., maxilla; max. p., maxillary palpus. 



deliberate and persistent in their feeding and are not easily dis- 

 turbed when they have begun to suck blood. The thorax is 

 relatively long, and the wings are large and expansive and usually 

 held at a broad angle to the body, as shown in Fig. 227. The 

 markings of the wings usually give the easiest means of identi- 

 fication of the genera. Of 

 the four most important 

 genera as human pests, 

 Tabanus (Fig. 224) is of 

 large size and has clear 

 or smoky wings, with no 

 spots or a few small scat- 

 tered ones; Pangonia 

 (Fig. 226) also has clear 

 or smoky wings but can 

 be distinguished by the 

 long proboscis; Hcematopota is of moderate size and has wings 

 with profuse scroll-like markings; and Chrysops, the species of 

 which are often small, even smaller than a housefly, has a con- 

 spicuous black band on 

 the wing (Fig. 227). 



Life History. — All the 

 tabanids breed in water 

 or in damp places. The 

 eggs (Fig. 224C), several 

 hundred in number, are 

 laid in definitely shaped 

 masses on the leaves of 

 marsh or water plants, 

 on the leaves or twigs 

 of trees overhanging 



water, or in crevices of Fig. 226. A long-beaked tabanid, Pmigonia 

 rocks along the sides of ''"PP^"**i oi eastern Africa. X 2. (After Castel- 

 , _-, lani and Chalmers.) 



streams, ine eggs are 



white when laid, but soon turn dark. They are deposited during 

 the summer and under favorable circumstances hatch in from five 

 to seven days. The newly hatched larvae fall into the water or 

 to wet ground or decaying vegetation such as occurs around the 

 edges of marshes, in sphagnum bogs, in decaying logs, etc. The 

 larvae (Fig. 224D) are cylindrical legless creatures, pointed at 



