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CHAPTER IX. 

 The Control of Insects. 



In the preceding pages, insect pests have been con- 

 sidered in four general groups : the insect pests of crops, 

 the insects which attack man, insect pests of domestic 

 animals, and household insects, including those which 

 attack stored products. 



In the matter of control, the same principles apply to 

 all these groups, and control measures fall under two 

 heads : one preventive, the other remedial. 



In dealing with insects of all kinds, preventive meas- 

 ures are those which aim at debarring insects, by the 

 destruction of their breeding places and of their food 

 supplies, from developing to troublesome numbers, 

 especially during, the breeding season. 



Remedial measures are those by means of which the 

 insects are destroyed after they become numerous. The 

 use of insecticides comes under this head. 



PREVENTIVE MEASURES. 



General. Preventive measures are prophylactic and 

 sanitary. In the case of field crops the methods employed 

 include rotation of crops, resting or fallowing the land, 

 the destruction of old plants after the crop is reaped, and 

 of all dead and rotten portions of plants which are likely 

 to furnish breeding places for pests. The clearing away 

 of wild plants in w r hich pests of crops develop is a part of 

 the clean cultivation which comes under this head. 



These dead and worthless parts of plants should be 

 burned or disposed of in such a way that all insects con- 

 tained in them will be destroyed. Sugar-cane stumps 

 often enable enormous numbers of weevil borers to breed 

 to maturity. Old cotton plants furnish breeding places 

 and food to scale insects, leaf -blister mite and other pests. 



