THE DIPTERA 



315 



around domestic animals because of their size. Many of the smaller kincb. 

 have wings banded with dark. Some of these are called ^i;ccn-heads 

 because of the bright green color of their eyes (Fig. 331). Their attacks 

 irritate and disturb the animals and, in the case of milch cattle, this 

 may reduce the amount of milk produced. 



As these insects attack domestic animals only for their blood, any 

 repellent measures which prevent this are sufficient. Fly-nets covering 

 the greater part of the animals are sometimes used for this purpose: and 

 smearing the ears and legs with substances having an odor objectionable 

 to the flies is also practiced. One of several materials often applied is 

 fish oil either alone or mixed with tar. The following mixture has proved 



{Original.) 

 twice natural 



Fig. 330. ^^^^- '^^^ 



Fig 330.-Large Horse Fly {Tabanus stygius Say), slightly reduced 

 Pj^; 331. —Small Horse Fly {Chrysops vittatus Wied.), over U 

 {Original.) 



effective against those Tabanids which preferably attack the ears and the 

 region around the eyes of the animals: pine tar, 1 gal.; fish oil or crude 

 carbolic acid, 1 qt.; powdered sulfur, 2 lb- These materials are thoi-- 

 oughly mixed and rubbed on the parts most hable to be attacked. As so 

 many Tabanids pass their early stages in stagnant water, the reat.nent 

 of such breeding places with kerosene will destroy the larva, as they hatch 

 and enter the pools. 



Fanuly SimuUd* (The Black Flies or Buffalo Gnats) -The small flies which 

 compose this family feed upon the blood of man and other ammals, attackmg 

 hZ at all exposed places. As in the Tabanids. only the females are concerned 

 and these are active only during the daytime. The eggs are la,d in such places 

 Lt the larv. can enter water, and in most cases, swiftly runmng streams whee 

 they feed on small animals. They usually anchor themselves to some object m 

 he water and have a pair of fan-shaped structures at the mouth which are used 

 to produce currents toward the mouth. In the South, all domestic animals .uffer 

 severely from the attacks of these insects, and many *«'^.^™" '""''''. ^/'^™- 

 There are usually two or three generations each year, particularly in the South. 

 The best control methods known are the use of repellent materials on the animal, 

 such as fish oil three parts, kerosene one part, applied about twice a day. Ani- 

 mals kept in dark stables are not attacked while there. 



