DISEASES AND PESTS 67 



lived in the coco-nut are made of coco-nut fibres, which 

 are , usually transversely and quite compactly matted 

 ^together.* 



As already noted, the adult of Oryctes is provided 

 with jaws by means of which it can cut its way through 

 hard wood. Its practice, however, is to go through as 

 little* hard wood as possible. We are not concerned 

 here with the method of its entrance into other breeding 

 or feeding places. In entering a coco -nut tree, the 

 rhinoceros lands in the crown and then walks downward 

 until he is out of sight between the leaf sheaths, or 

 often not so far but that the place is visible when it 

 turns and begins to eat its way inward into the tree. 

 As a rule, it eats fairly directly inward. The only 

 certain object of the rhinoceros in visiting coco-nuts 

 is to obtain food. It does not seem, however, that 

 it eats any of the pieces which it chisels or tears from 

 the tree. It squeezes these pieces and consumes the 

 juice which is squeezed from them. The rate at which 

 the beetle can tear its way through such tissues as 

 those of the base of a mature petiole has been measured 

 by Banks and by the students of the Philippine College 

 of Agriculture, and in both cases found to be 1 milli- 

 metre a minute. 



So large a beetle, of course, makes a very large hole. 

 This would itself be conspicuous enough unless covered 

 by leaf bases outside the point where the hole begins, 

 but is made still more so by a plug or wad of torn- 

 up fibres which the beetle pushes out behind itself as 

 it digs deeper into the tree. If a fair watch be kept 

 over a coco-nut grove, as is done wherever a number 

 of nien are steadily employed to kill the beetles, these 

 wads will be readily seen while fresh, and it is then 

 easy to remove them and to remove or kill the beetle 

 by means of a sharp piece of iron, or even of bamboo. 

 In some places the practice is merely to kill the insect 

 by punching a hole through it ; in others, a spiral wire, 

 like a flexible cork-screw, is used, by means of which 

 the beetle is removed and killed. The catching and 



