i83 



topped, or belted. The damage .>o done can be measured in the pro- 

 portion of leaf tissue cut off; in severe cases it amounts to a set back 

 of one year. Rarely does the insect directly kill the tree; but we do 

 not know how often. In Malaya it is certainly common to ascribe to 

 lightning the work of the Rhinoceros beetle.'^ 



The beetle must be attracted to the trees by some chemical sub- 

 stance ; and it has been suggested that this is to be found in the odour 

 of the sap, but Friederichs experimented with palm toddy fermented 

 and fresh, and did not take a single beetle thereby. The observation 

 is curious, for it is known that attacked trees may become favourite 

 trees and one boring is followed by another. However, as Friederichs 

 found that the sex odour of the beetles is attractive, we perhaps find 

 an explanation for the repeated attentions of the beetles to one tree 

 in the attraction of a beetle for more individuals of the other sex 

 than one, and the surplus insects being unwelcome in the mating 

 burrow, excavate one of their own in the same tree top. 



The beetles of course find some attraction in the decayed 

 material which they seek for egg-laying. Friederichs combining 

 the attraction of rotten cocoa husks with the smell of a large number 

 of imprisoned beetles of both sexes, and placing a light over the cage 

 caught in eight nights ten females and twelve males which were 

 attracted. The catch seems small, and as he remarks hardly worth 

 making. 



It is certainly no odour of the flowers, which attracts the beetles, 

 for long before flowering they are attacked ; and a writer in the Tropi- 

 cal Agriculturist (Beven, on p. Ill of N.S. vol. xxiv.. May, 1905) says 

 that the king coconut is particularly liable to attack in the alternate 

 years between flowering. 



The beetles mate in the holes that they make, but rarely lay 

 eggs in them. The eggs are deposited in decayed vegetation 

 wherever that may be ; and it is possible that the undoubted cases of 

 egg-laying within the burrow have been induced by some decay 

 within it. Perhaps the burrower has struck an old hole with decay 

 in its sides ; but events which take place in the tops of palms'are rather 

 hidden from the eye of man. Let it suffice to say that undoubt- 

 edly the female rhinoceros beetle does sometimes lay eggs within 

 the burrows, and that then destruction of the tree follows. The 

 writer knows well that the very first signs of decay in a felled palm 

 top are signals for the appearance of young larvee from eggs there 

 deposited. 



Into the holes penetrate the Palm-weevils to lay eggs, and in 

 giving them access to the soft tissues is the unpardonable crime of 

 the Rhinoceros beetle. 



*Cf Koningsberger, J. C, Mededcelingen van 'Slands Plantentuin, xxii. (1898) p. 42. 



