CHAPTER XX. 



INSECTS ATTACKING CATTLE. 



IN the most varied situations and under most adverse circumstances, 

 we find insect species which have adapted their life-history, their 

 habits and their structure to new and wholly distinct surroundings. It 

 is therefore not surprising that we find distinct branches of insect life, 

 wholly adapted to obtaining their food from living warm-blooded animals. 

 Though lacking the extraordinarily well-adapted life histories of the 

 parasitic worms, these insects are not behind others in the ingenuity of 

 the means whereby they overcome adverse conditions : their habits have 

 no parallel in other insects ; their structure is profoundly modified to fit 

 them to their surroundings, and they form an extraordinarily interesting 

 group. These insects are gathered from very diverse parts of the animal 

 kingdom ; the bird lice are Nturoptera ; the quaint West African rat 

 parasite is one of the Orthoptera ; the beaver parasites are Coleoptera ; most 

 parasites of cattle are Dipt era. The fleas are an abnormal group probably 

 near to the Diptera, and the common bug is one of the Hemiptera, whilst 

 finally the lice are abnormal erratic creatures which find no place in the 

 larger groups of insects. It is not possible here to discuss all of these ; 

 the fleas, flies and other creatures that affect men's welfare are beyond 

 the scope of this book, and we are concerned solely with those insects 

 which affect cattle and domestic animals, the fleas, house-flies, gad-flies, 

 biting-flies, bot-flies and flesh maggots, whilst we may include the ticks 

 which are not insects, though closely related. 



Pleas. 



Small laterally compressed insects, with imperceptible wings and great 

 leaping powers, which infest warm-blooded animals. They lay eggs in 

 dirty places, in corners, on the hair of animals, etc., from which hatch 

 white maggots, worm-like in appearance but with distinct head, which feed 

 on blood, animal matter, refuse, etc. These pass through a pupa stage, 

 emerging as the imago which leads a parasitic life on mammals and birds. 



The whole life-history occupies about one month at the shortest. 

 Fleas breed particularly in dirty places frequented by animals, laying 

 their eggs in places where animals lie down. Cleanliness is the greatest 

 check on them. Fleas should never be allowed to breed in a house and do 

 so only because there are domestic animals in the house which sleep in 

 the house and are not properly cared for. 



