ENTOMOLOGY

CHAPTER XXXIControl of Ticks 1F. C. BillJWppMethods of destroyiIig ticks may be divided into two general headsstarvationand destruction with insecticides. The former is much morelimited in its practical application owing to the long life of many species.of ticks and the fact that many of them are capable of developing on anumber of different hosts. Furthermore, destruction with chemical agentsappeals to most stockmen owing to the fact that they can actually seethe destruction of individuals.Knowing the ill effects produced by tick infestation, both throughblood loss and the irritation due to gross infestations and by disease transmission,one would think there would be little difficulty in inducing peopleto proceed with control or eradication measures. However, this is notthe case. In practically all parts of the world it has been found thatstockmen will attempt to destroy ticks when they become grossly abundantbut their efforts relax when the numbers arc reduced to a considerableextent. In this connection it might be well to mention some of the benefitswhich arc derived from tick control or eradication. By keeping thenumber of ticks reduced to a minimum, thc growth of animals and the milkHow in cattle are increased. Death loss through gross infestation isavoided and, by accomplishing eradication, several of the most dangerousdiseases of live stock and some of those of man would disappear. Thiswould permit of more rapid agricultural development of many regionsof the world.By following either the method of repression or eradication, the bringingunder control of the herds of livc stock is an important consideration.This is greatly facilitated by fencing and clearing of brush lands. Clearingalso has a direct influence on the abundance of ticks, as the worstinfestations in the case of many species are to be found in lands more orless covered with woods and brush.It is important in many instances to maintain effective quarantinesto prevent the uncontrolled movement of stock and the consequent spreadof the ticks which transmit disease. The effectiveness of this procedurehas been fully demonstrated by the result of the quarantine maintained on1 This lecture was prepared especially fDr ihis edition.440