14 OHIO STATE ACADEMY OF SCIENCE. 



In Chrysops the apex of the wing beyond the cross-band 

 is marked the same in both sexes even though the difference in 

 coloration between the male and female is striking. This is notice- 

 able in C. mdechus in which the female is largely marked with 

 yellowish while the male is entirely black. The base of the wings 

 of the males of nearly all of the species of Chrysops have more 

 black than do the females, and in some species like celer the 

 female has the sides of the thorax densely clothed with yellow 

 pile while the same parts in the male are less densely clothed with 

 black pile giving the two sexes a very different appearance. 



In the female of Tabanus stygius the dorsum of the thorax 

 is clothed with white pollen, while in the male this is largely 

 lacking, thus giving the sexes a very different appearance. 



The sexes of Goniops chrysocoma are notably different in 

 appearance, because of the fact that the whole body is black in 

 the male and light yellowish in the female. 



ARTIFICIAL REMEDIES. 



Various species of the family are very annoying to stock, 

 hut although their biting habits have been known for years no 

 generally practical remedies have been suggested for their con- 

 trol. Work horses may be protected by the use of fly-nets, and 

 burlap blankets are often used on cattle and horses, but these 

 blankets have their objectionable features, and it is doubtful if 

 they come into general use in the near future. Kerosene emul- 

 sion, carbolic acid, fish oil and a variety of substances have been 

 used, and beneficial results have been obtained from a number 

 of them, but the benefits derived from a single application are 

 of such short duration that to many their use is thought to be 

 impracticable. 



The most valuable results in destroying horse flies were ob- 

 tained by Porchinski in Russia, and are described by Howard 

 in a paper published in Bulletin number 20, new series, of the 

 U. S. Division of Entomology. The method employed consists 

 in applying kerosene to the surface of stagnant water for the pur- 

 pose of coming in contact with the adults when they come to 

 drink. It may be added from my own observations that the same 

 application, is of consequence in killing larvae at the time they 

 hatch and drop into the water. As the eggs of so many of bur 

 ■species are deposited over water and 'the larvae drop doAvn into 

 the water when they hatch, I ani of the dpihioh that more strik- 

 ing results may be obtained frdni the use of kerosene on the sttr- 

 f?ce of stagnant water in destroying darVse than in 'destroying 



adults. ■ ■■!■}■■■:■:' ■:■'.:■: '•>..:. . -."'■' ,;:.'. ■■ .' 



