RUBBER 627 



Mcechotypa verrucicollis. This beetle has the reputation 

 of damaging the stems of young Hevea trees by gnawing 

 off the bark. A number of the living beetles were sub- 

 mitted to me, together with an example of their work. 

 The injured stems showed irregular patches of the (still 

 green) bark destroyed, in some cases completely ringing 

 the tree. It was noticeable, however, that no latex had 

 exuded from the wounds, and examination of the roots dis- 

 closed the presence of a fungus (Botryodiplodia elastica). 

 The probability, therefore, was that the injured plants 

 were diseased and had ceased to produce latex before the 

 advent of the beetles. To put the matter to the test, I 

 confined 'some of the beetles in a cage, together with a 

 healthy young Hevea tree. I watched one individual 

 climb up the stem and fix its jaws in the tender bark. 

 The first puncture resulted in a bead of latex which 

 adhered to the mouth-parts of the beetle, and evidently 

 proved very distasteful to it. The insect immediately 

 abandoned the attack and moved off, doing its best to 

 remove the sticky fluid. Other individuals made similar 

 attempts to feed, but were promptly repelled in the same 

 way, nor could they be induced to repeat the experiment. 

 After a week's confinement without other food they still 

 refus-ed to touch the living bark; but when supplied with 

 fresh branches of Cassia, they speedily stripped them. 

 My successor, Mr. Rutherford, on the other hand, in a 

 recently issued report, expresses himself as convinced by 

 experiment that these beetles are able to consume healthy 

 Hevea bark with impunity, but that they prefer withered 

 bark. 



A smaller beetle Niphona sp. (near parallels) has 

 been accused of similar injury. 



In the Federated Malay States two small Longicorns 

 Epepeotus luscus and Clytanthus annularis have been 

 included amongst rubber pests on somewhat slender 

 evidence. The former is reported as having been " once 

 found in the trunk of a Para tree," while the latter " once 

 oviposited on Para seedlings." Clytanthus annularis is a 

 well-known borer in bamboos, and it is improbable that 

 a bamboo insect would attack such a totally different plant 

 as Hevea. 



