306 



THE STUDY OF INSECTS 



SERIES II. STRAIGHT-SEAMED FLIES WITH SHORT ANTENNA. 



(Brachycera) * 



Family Tabanid^e 



The Horse-flies 



The horse-flies are well-known pests of stock, and are often extremely 

 annoying to man. They appear in summer, are common in woods, and 

 are most abundant in the hottest weather. 



In this family the flagellum of the antenna; is 

 composed of from four to eight, more or less closely 

 consolidated segments and is never furnished with a 

 distinct style or arista (Figs. 530, 531). The vena- 

 tion is shown in Figure 532. 



The flight of these flies is very powerful, they are 

 able to outstrip the swiftest horse. The males feed 

 on the nectar of flowers and on sweet sap. The 

 _ mouth-parts of the female are fitted for piercing the 

 Antenna oiTab- skin and sucking the blood of men and quad- FlG __ 

 rupeds; the females, however, also feed on sweets Antenna 'of 

 of plants when they cannot obtain blood. 



The larger species, as well as some of moderate size, belong to the 



Fig. 530. 



Fig. 532. — Wing of Tabanus. 



genus Tabanus of which nearly two hundred species are listed from North 

 America. One of the most common of these is the 

 mourning horse-fly, Tabanus atratus. This insect is of 

 uniform black color throughout, except that the body 

 may have a bluish tinge (Fig. 533). The species of this 

 genus attack cattle and other farm animals 

 almost exclusively. 



To the genus Chrysops belong the smaller 

 and more common horse-flies with banded 

 wings (Fig. 534). The species of this genus 

 attack man as well as other animals. To this 

 Tabanus genus belong the well-known deer-flies familiar 

 to fishermen and hunters. The eggs are de- 

 posited in masses on plants or on exposed stones in the bed of a stream. 

 * Brachycera: brachy, short; ceras (nepas), a horn. 



