A 



FARM PESTS 23 



ailments is bound to be usef ul,and so we shall here examine 

 a few farm pests that belong generally to the insect world. 

 These divide naturally into two sections, viz. insects 

 injurious to stock and those harmful to field crops. 



The numerous diseases of stock are due to the attacks of 

 many other creatures besides insects. For instance 

 anthrax, swine fever and erysipelas, foot and mouth 

 disease, glanders and tuberculosis are caused by bacteria 

 or viruses. Ringworm is an animal fungus ; so is the 

 trouble called hard tongue or lumpy jaw in cattle. Husk 

 or hoose in calves is caused by worms in the tubes of the 

 lungs, whilst the disease called redwater is due to the 

 presence of a minute germ or protozoon in the blood. We 

 are here, however, chiefly concerned with insects, and 

 stock pests under this head_are„_dmost.dw^^^ 

 oF'twx> winged., flies . 



We may take as our first example the Horse Bot Fly 

 [Gastrophilus equi), which is yello\^dsh in colour and some- 

 what Uke a Blue-bottle in appearance, in fact it has been 

 called the Yellow-Bottle. It lays its eggs on the hair of 

 the fore-legs, mane and neck, and the maggots which 

 hatch from them find their way down the horse's gullet 

 and so to the interior, where they finally attach themselves 

 bp the walls of the stomach and feed upon the juices 

 lierein. When full-fed they leave go, and pass out to 

 Sange into glossy brown pupae, which hatch as complete 

 Yellow-bottles in due course. After being out at grass 

 all animals should be examined for the eggs, and also, if 

 the Bot Fhes are thought to be estabHshed, a draught 

 of linseed oil and turpentine will be found beneficial once 

 a fortnight. 



The Gad-fhes and Forest-flies are insects of the same 

 tribe and similar in appearance to house flies. These do 

 not infest horses during the larval state, being aquatic, 

 but the females come in the hot weather to suck their 

 blood, and cause great suffering in some years. The 

 draught horse is ui^ortunately too often deprived of his 



