DISEASES AND PESTS 49 



result that it is snapped off a few feet from the ground 

 whenever a gale occurs. In more sheltered positions 

 the tree remains standing, but weakens and gradually 

 dies as the work of the borer progresses. The disastrous 

 effects produced by this pest are quite well understood 

 locally, and attempts are made in some districts to 

 check its devastation by digging out the insect in the 

 early stages of its attack on the stem, and also occa- 

 sionally by plastering the exposed wood with clay. The 

 borer seldom or never enters the trunk of the tree 

 through live bark, the latex cells providing efficient 

 protection against its depredations. Two species of 

 borer are found in Brazil ; they are not unlike in 

 appearance, but differ very much in size. 



Another constant source of damage is from the white 

 ant (termes). Every district in the rubber-producing 

 area is infested with this pest, and no effort is made to 

 check its ravages in connection with the wild rubber- 

 trees in the forest or those set out in plantations. 



One of the worst enemies to any agriculture develop- 

 ment in the Amazon Valley is the red ant (JBcodoma 

 cephalotes), known locally as sauba. This plague 

 attacks the foliage of rubber-trees of all ages, whether 

 in the forest or in planted areas. It strips off the 

 leaves and carries them away, leaving nothing but bare 

 branches, and in the case of young plants, in addition 

 to the foliage, it cuts off the tender growing shoots. In 

 a single night a field of several acres of young beans, 

 maize, or other foodstuffs, is frequently ruined by this 

 pest. The sauba is stated by Bates, in his " Naturalist 

 on the Amazon," to be the most destructive insect in 

 South America, and experience confirms his description 



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