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. moechus 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, 
but 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 larve at the time they 
hatch and drop into the water. As the eggs of so many of our 
species are deposited over water and the larve drop down into 
the water when they hatch, | am of the opinion that more strik- 
ing results may be obtained from the use of kerosene on the sur- 
face of stagnant water in destroying larve than in destroying 
adults. 
