280 DYNASTIN.E. 



Type in the Uppsala University Museum. 



This is an extremely common beetle, familiar in many parts of 

 the East as the Ehinoceros Beetle or Black Cocoanut Beetle, and 

 is one of the two great enemies of the Cocoanut Pahn, the other 

 being the Palm Weevil or Red Cocoanut Beetle {Rhynchophorus). 

 The latter begin their attack at the roots and tunnel upwards into 

 the tree, but the Rhinoceros Beetle on the contrary always begins 

 at the top, the soft growing point of the tree, and works gradually 

 downwards, assisted by the decay caused by the entrance of water 

 at the opening made. Its depredations have been described by 

 Mr. L. C. Brown in the Agricultural Bulletin of the Straits and 

 Federated Malay States, 1903, p. 66, and more exactly by 

 Mr. Chas. S. Banks in the Philippine Journal of Science, vol. i. 

 1906, p. 143. The latter states that the beetles' attacks are con- 

 fined to the soft tissues near the top of the tree, and holes seen in 

 the trunk below this point date from the time when the growing 

 apex was here located. " The attacks always begin during the 

 night and by the following morning it will frequently have entered 

 so far into the burrow as to be protected from the light. It then 

 continues its feeding until a gallery of considerable size has been 



excavated Observation has shown that the males make 



burrows as well as the females and it is probable that they always 

 accompany the latter at the time of egg-laying, retreating from 



the burrow they have made to allow the female access It is 



rare to find a single Cocoanut tree anywhere in the Philippines 

 \\hich does not show one or more evidences of attack by this 

 beetle. It is the pest most frequently reported by farmers and 

 cocoanut growers, and in hundreds of trees which I have personally 

 examined large holes in the trunk, distorted leaf-stems, or ragged 

 leaves demonstrate the character of its work. The insect larva or 

 the adult, in its work inside the tree, frequently cuts off the tip of 

 the embryo leaf or the tips of the leaflets on one or both sides 

 of the midrib, so that when the leaf finally grows it appears as if 

 it had been trimmed with a pair of shears or as if a triangle had 

 been cut from one or both sides. The fibres severed by the insect 

 protrude from its burrow, giving the latter a ragged appearance. 

 During the daytime the beetles are freqtiently encountered in very 

 old holes, into which they evidently have gone for the purpose of 

 hiding." Mr. Banks has figured a standing tree in which nearly 

 the whole interior from the top to within half a yard of the ground 

 has been hollowed out and from which nearly a hundred larvse 

 were taken. 



This unfortunate taste for the cocoanut tree is probably an 

 acquired one, for the larvte are also found in a variety of other 

 situations and appear to have a remarkable power of adapting 

 themselves to circumstances. They will flourish in rotten wood, 

 decaying leaves, sawdust, manure heaps, etc., and in one case 

 70,000 grubs are said to have been taken upon one estate from 

 the ground itself, the soil being a very rich vegetable mould. The 

 ground was flooded in order to destroy them (Agric. Bull. Straits 



