25 

 PESTS. 



The pests in Peru affecting the sugar cane have been little studied. 

 It is to be said that those that are here may be kept under con- 

 trol if not entirely eliminated, provided there are united efforts in 

 this direction. This is true for the following reason: The cane belt of 

 a valley is that portion accessible to irrigation waters; outside of this 

 belt very little plant life exists. (A good example of this is the strip 

 of cultivated land in the Chicama valley lying between the large 

 barren tracts towards Trnjillo on one side, and towards San Pedro on 

 the other.) The pests must confine themselves to the fertile areas as 

 there are no other places for them to feed, and as these fertile areas are 

 practically isolated, the work of extermination is made easy, and a 

 valley once cleared of a pest would not often be revisited. 



The borer seems to be about the only in sect pest that has material- 

 ly influenced the growth and quality of the cane. There are occasion- 

 al local attacks of other insects. The presence of fungus has been 

 noticed on canes that were grown on wet soil and had fallen down. 



While the natural conditions are not favorable to the increase of 

 pests, they may get the upper hand if neglected. In the case of pests, 

 "an ounce of prevention is worth a pound of cure", and the best 

 preventative is strict regulations for all plants brought to the country. 

 An insect or a fungus harmless in its natural environment, may become 

 a dangerous pest in new feeding grounds. A careful inspection should 

 be made of all plants entering the country, and if diseased, they 

 should be rejected or subjected to treatment. This work cannot be 

 satisfactorily carried out without proper equipment and a trained 

 entomologist. 



Controlling pests. There are two distinct schools or methods for 

 the control or eradication of pests. One advocates the use of chemi- 

 cal mixtures for sprays; the other advocates the introduction of para- 

 sites to prey upon the pest. Both have their advantages and disadvan- 

 tages; in the case of chemical sprays, there is the danger of killing 

 beneficial as well as destructive parasites; in the introduction of 

 parasites, there is the danger of their becoming pests under new 

 environments. 



The cane borer in Peru. As cane has been grown in the country for 

 over three hundred years, it is probable that the borer has inhabit- 

 ed the cane fields for a long time. The effect of the borer on 

 Peruvian cane will not be as disastrous as in canes of many other 



