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36 INSECTS AFFECTING DOMESTIC ANIMALS. 
females once gorged with blood do not and can not return, copulation and the depos- 
iting of eggs must take place very soon after emerging from the water. These points 
have as yet to be investigated. 
All species of the genus Simulium, the life histories of which have been studied, 
are single-brooded. * * * 
PREVENTIVES. 
Smudges have thus far proved the best method of protecting animals in the field 
against buffalo-gnats. Thoughtful planters are in the habit of collecting and stor- 
ing during the year all kinds of material that will produce a dense and stifling 
smoke; such materials are old leather, cast-off clothing, dried dung, etc. As soon 
as large swarms of gnats appear, and the stock is threatened by them, fires are 
started in different parts of the plantation, and are kept burning as long as the 
danger lasts. Anything that will produce smoke is thrown upon the smoldering 
logs, and the most offensive is considered the most useful. If the time for plowing 
has arrived, smudges are located in the fields in such a manner that the smoke is 
drifted by the wind over the teams at work. Such smoke-producing fires are also 
kept burning in the cities, and they are found in front of every livery and street-car 
stable, as well as of such stores as employ draft horses or mules. If these animals 
have to be upon the roads, they may usually be somewhat protected by tin pails in 
which some smudge is kept, and which are suspended from their necks and from the 
wagons. 
Animals may also be protected with a layer of mud or a coat of sirup. It has been 
found that animals which have shed their rough winter coat of hair and have 
become smooth are not as much troubled as others still covered with long hairs. 
The gnats find it much more difficult to obtain a foothold upon a smooth skin, and 
the clipping of the hair in early spring is therefore advisable. 
Buffalo-gnats have a great aversion to entering dark places, and stables thoroughly 
darkened are safe places for stock of all kinds in a gnat season. The odor of ammo- 
nia prevailing in such stables may also to some extent prevent the insects from 
entering. Planters with a small acreage, therefore, prefer to keep their horses and 
mules in the stable instead of working them in the field. For the same reason the 
owners of livery stables will not allow their animals to be taken outside the city 
limits if gnats are numerous enough to be dangerous. 
But the great majority of planters can not wait for the disappearance of the pest, 
and have to resort to other defensive means. Various external applications have 
been used to this effect: Decoctions of alder leaves, tobacco, pennyroyal, and other 
herbs, have been tried with a view of preventing gnats from biting mules while at 
work; but all of them have proven ineffective. Atatime when small swarms of 
turkey-gnats were tormenting mules plowing in the field one side of the animal was 
moistened by Mr. Lugger with various insecticides, while the other side was not 
protected at all. By following the animal and watching the gnats it was soon 
observed that any offensive smelling substance would drive the gnats from the pro- 
tected side to the unprotected one. Kerosene emulsion, pyrethrum powder sus- 
pended in water, diluted carbon-bisulphide, and dissolved tobacco soap were all 
used in turn, and all seemed to produce the same effect. Several times the whole 
animal was carefully sponged with the one or the other of the above substances. 
For a time the gnats would not settle upon the animal; but in the course of two 
hours the beneficial effect of these insecticides was gone and the insects were no 
jonger kept away. 
Experience shows that the best preventive is grease of various kinds. The follow- 
ing kinds are the most important: Cotton-seed oil alone, or mixed with tar, fish oil, 
gnat oil; a combination of stinking oils alone, or mixed with tar or kerosene oil, 
crude coal oil, kerosene oil, kerosene oil mixed with axle grease, and others. To be 
effective, the grease must be used at least twice during the day, because as soon as 
