84 INSECTS AFFECTING DOMESTIC ANIMALS. 
road they have ready access to earth. But as some other forms can 
pupate successfully in the dung heap, it would seem worth while to 
subject the droppings of horses known to contain bots to some process 
that would destroy them and thus prevent maturity of the fly. 
REMEDIES FOR BOTS. 
The prescription of drugs for the removal of bots from the stomach 
when their presence is known or suspected belongs rather to the vet- 
erinarian than to the entomologist, but it may not be out of place here 
to call attention to a few of them. It is of course not an easy matter 
to determine during the life of the horse whether any particular dis- 
turbance of the digestive organs or lack of nutrition is due to tine 
presence of bots or to some other agency producing similar symptoms, 
and even a competent vetermarian may be puzzled in diagnosis. If 
occasional bots are noticed in the excrement of the animal together 
with poor condition, their presence in numbers may be inferred. It 
must be remembered that the bots are capable of withstanding almost 
any substance that the walls of the stomach can endure, and the safest 
plan, if intending to dose for them, is to employ a veterinarian. Tur- 
pentine is perhaps most generally given, but must be used with care. 
THE Ha:MORRHOIDAL BOv-FLY. 
(Gastrophilus hamorrhoidalis Linn.) 
While it is common to speak of the horse bot fly, it should not be in- 
ferred that there is but one kind parasitic upon the horse. Take the 
world over there are at least six well-defined species occurring on the 
horse, ass, or mule, and any of these are liable to be introduced into this 
country with imported animals. The above-named species is probably 
next to equi, the most generally distributed in this country. With the 
other allied species it was well known in Europe during the last cen- 
tury and received mention or more elaborate description from Linnzeus, 
DeGeer, Fabricius, and other leading writers on entomology. 
EXTENT OF INJURY. 
The losses to be referred to this species are similar to those of the 
other species, but from the accounts of various authors and what we 
have heard from persons who were plainly describing the actions of 
this particular form, it is evident that the excitement and consequent 
loss due to the attacks of the adult 4y are much worse with this species 
than the common one. This is described by Clark as follows: 
At the sight of this fly the horse appears much agitated, and moves his head back- 
ward and forward in the air to balk its touch and prevent its darting on the lips; 
but the fly, waiting for a favorable opportunity, continues to repeat the operation 
from time to time; till at length, finding this mode of defense insufficient, the enraged 
animal endeavors to avoid it by galloping away to a distant part of the field. If it 
still continues to follow and tease him, his last resource is in the water where the 
