THE STABLE FLY. 23 
PARASITES. 
Two species of small wasplike insects have been found to breed 
within the pupe of the stable fly. These insects deposit their eggs 
through the hard puparium, and instead of an adult fly the little 
parasite emerges. In some cases, where the immature stages of the 
fly were concentrated in great numbers, as high as 40 per cent of the 
pup were found to be destroyed by these parasites. At least one 
of these parasites, known scientifically as Spalangia muscidarium 
Richardson, appears to have a wide distribution in this country. 
It has been found in Massachusetts, Washington, D. C., southern 
Kansas, southern Louisiana, and a number of points in northern Texas. 
ARTIFICIAL CONTROL. 
As is the case with most insects, the destruction of the stage which 
is actually doing the injury is most desired by those concerned. 
With this species, as with many others, this is very difficult of accom- 
plishment, and we must determine some more easy way of securing 
the desired end. With the stable fly the natural point of attack is 
found in the immature stages, and there is every reason to believe 
that by properly caring for substances in which it breeds the insect 
may be kept well under control. 
PROTECTION OF LIVE STOCK FROM ATTACK OF THE STABLE FLY. 
When adult flies are present in great numbers it is necessary to 
devise some means of protection against them, especially since we 
know that every individual is capable of feeding a number of times 
before it dies. During the recent outbreak in Texas many different 
substances were tried with a view to repelling the flies from live stock. 
Most of the materials used were found to be ineffective, and although 
some gave a measure of protection for a time, none had a lasting 
effect. In addition to the temporary value of these substances, in 
many cases injury was produced by their application, especially if 
persisted in often enough to keep the flies away. 
Many malodorous mixtures, particularly of an oily nature, have 
some value as repellents, but in preparing these care should be taken 
that they are not made too strong, particularly when animals are 
being worked in the hot sun, as they are likely to cause overheating 
and often produce shedding of the hair. A mixture of fish oil (1 gal- 
lon), oil of pine tar (2 ounces), oil of pennyroyal (2 ounces), and 
kerosene (4 pint) was found to be very effective in keeping the flies 
off live stock when applied lightly, but thoroughly, to the portions 
of animals not covered with blankets or nets. 
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