THE BOT FLY.

Wairarapa Daily Times, Volume XV, Issue 4365, 11 March 1893, Page 3

THE BOT FLY.

Tho following from Professor T, W. Kirk's pamphlet on the bot fly will ba of interest to farmers and horset owners" The eggs aro deposited . on tho hair of tho horse, usually on . the inner side of the knee and foreleg, , on tho shoulder, the mane, and on the j long hairs under the lowor jaw, They , aro very (irmly attached to tho coat , by a strong glutinous substance, and ' remain so, till hatched hy the warmth [ of the horse's body, aided by tbe , moisture of his tongue as lie licks [ himself, The tiny maggots aro taken into j tbe mouth by tho tongue, and are swallowed with the food. They then, by means of the hooks, attach tbem- , solves firmly to tho lining of the stomach. In this position they remain for about nine months, at the , end of which timo they are nearly full grown, and about fill long. In the spring they loose their hold, and are voided along with the excreta. By means of tbe bristles attached to their sides they immediately burrow under the manure, into the oarth or under any other shelter, where tho change to chrysalis is undergone, Prom the chrysalids the perfect flies emerge in about six weeks, during the summer, Symptoms —Horses suffering from a severe attack of the parasytic larvs Usually show some of the following symp oms: They loto flesh, go off their feed, and sometimes bite their sides, cough, have difficulty in breathing, and stiffness of the joints, followed in some instances by convulsions, No case of the death of a horse has evei been posi i • el> proved .s directly due to hots. In eveiy instance \vb> re veterinary surgeons have hold post mortems some undoubted immediate cause of death, such as rupture, has always been found. It would therefore be well if those whose horses are attacked by the fly and die will take steps to have a post mortem made by a qualified veterinary surgeon, and this examination should take place as soon after the dealh of tho animal as pos- ' sible. 1

Remedies.—lt is generally believed that there are no real cures, but the following bavo been tried with more or less success, and ore given on llio authority of those whose names are attached Mr H, Thompson, M,R,C,V.S„ says "I have never seen the atomaoh entirely perforated, but the irritation induced by the development of the larva causes in many cases a great wastiDg of flesh in the horse, " I know of no medicine that will destroy them, or make them leave their winter quarters until fully developed, A good feed of grass in the early spring causes them to detach themselvoß the soonest; hut I am. inclined to think the larva will hold on till fully developed before leaving, "As a medioine, 2oz, turpentine and 20oz, raw linseed oil, mixed and given as a draught once a fortnight, is the beet remedy—i.e., if it ia thought the loss of flesh and condition of the horse is duo to the presence of bots,"

If in doubt whether a horse is infested with the bot-fly larva. Dr. Frankish, of Cliristchurch, recommends, " A quarter of an ounce of aloes mixed with half an ounce of shag tobacco, moistened with treacle, made into a ball and given to the animal." He saya that if any of tho lam are present soino will become detached, and will be seen in the droppings. The larger dose he prescribes below should then be administered

"Three ounces of elwg tobacco, moistened with a little glycerine or treacle, to which half a teaspoonlul of oil of cajoput has been added, should be made into balls, and the whole given as a dose, Two hours afterwards half a pint of linseed oil in a pint of (jruel should be administered. If notice be taken of the evacuations, the larvte of the bot-fly will be easily seen, The above is for a buck. Half, the quantity is a dose for ut pony, doubie for a draught-horse, This syat- m of treatment has been found succe-sful when tried early, and is therefore beyond the region of experiment,"- -Dr Frankish,

Prkventive Measures.— Even if a really reliable remedy w»re available, it is bi'tior to prevent an attack than to cure it, Therefore every precaution should be taken to protect horses from the fly, of which they appear to have a great dread, generally becoming very excited when the insect is hovering about, Should this restlessness be observed, the animals ought to be examined to ascertain if the egga have been deposited, and, if so, the wash horein suggested should be at once applied. Several mechanical contrivances, such as kneecaps, aprons for fitting closely under the horse's throat, etc,, have been invented, and in some instances patented. It is very doubtful, howefer, if any purely mechanical applicaace will prove efficacious, That, luckily, is not of great moment, for the following precautions will, ifi carefully carried out, prove effectual in preventing the deposition of sggs on the coat of horses

It is desirable that the long hairs on the legs and under the jaw should be cut off,

Working horses should, after boing groomed, be rubbed ovor with carbolised oil, kerosene emulsion, or other substance obnoxious to fließ. Tfca beet agent for this is Little's dip, one part of dip in from twenty to twentyfive of water,

Whoro horses aro kept in numbers the wash may be applied by yarding tho animals and using a spraying machine with oyolono nozzle, such as is found in every well-managed orchard. The mist-like spray will pormeato the coats of the horses, and while its effects last, no fly will attempt to deposit her eggs on them. One application per week will in most cases prove sufficient. In paddocks where affected horses are kept it is a very good plan, if larvte are observed in the droppings, to Collect and burn the excreta, the i only sure way to kill the larvw, thua.

provfnting tlio emergence of numerous flies, and tbe iaying of many hundreds of eggs. The markings of the perfect flies captuiedinNfw Zealanddifferßlightly from thoseof English specimens, This will bo investigated when a larger series of specimens has been collected. In the meantime it is sufficient for all practical purposes tn know that the life-history and modo of attack are identical. Dragon flies, and a species of Ascitun occasionally attack hot flies, but there is at present no known "natural enemy."