150 PARA RUBBER. 



The curious knobs and irregular surfaces on the trunks of Para 

 rubber trees are not due to parasitic fungi ; they are wounds which 

 have been made either by falling branches or by carelessness 

 in tapping operations. Of course, they may serve as lodging areas 

 for the spores of fungi or undesirable insects. 



Insect pests. — Ridley has reported the existence of a borer which 

 may attack the wood of Para trees, and identified it as belonging 

 to the genus Platypus. 



Ants* attack the incised areas six eet from the ground, and in 

 some cases construct earthworks up to a height of 30 to 40 feet and 

 enter the tree at some weak point or wound area. The white ant — 

 Termes gestroi — is reported to be one of the most troublesome pests 

 in the Federated Malay States. Arden, when dealing with the loss 

 of Para rubber trees in the Straits, points out that there may be 

 some association between the ravages of the white ants and the 

 fungus of the roots of Para rubber. Similar relationships have been 

 suspected in Ceylon, f where the taproot had probably been eaten 

 by white ants and the dead roots were covered with a network of 

 white fungus hyphae. " The fungus attacked the sound wood and 

 bark, and that the injury was due to this was supported by the 

 receipt from another locality of a young plant which had been killed 

 by apparently the same fungus. In this case there were no side 

 roots ; the plant therefore died after the taproot had been per- 

 meated by the fungus, and as this was indicated by the withering 

 f its leaves, it was uprooted before the white ants discovered it." 



Green states that he has repeatedly received specimens of dead 

 branches and stems of Hevea brasiliensis , perf orated by a Bostrichid 

 beetle (Xylopertha mutilata. Wek.), but he believes that in every 

 case the beetle has effected its entrance after the death of the parts. 



Slugs % (Limax sps.) have also been reported as attacking the stem 

 and eating the remains of the latex left in the wounds after tapping. 

 " Living specimens of the slugs received at Peradeniya wer? fed with 

 fresh latex. Its presence was almost immediately scented out by 

 them. One of them drank for about ten minutes." Hand-picking 

 or the use of quick-1 me should be effective. 



Mr E. E. Green has the following notes regarding pests which are 

 associated with the stems, in the Tropical Agriculturist, February, 

 1906 :— 



" The cut ends of young Hevea stumps are frequently tunnelled 

 by various small species of bees and wasps. But these insects are 

 not responsible for the dying back. The pith of any dead stem 

 would be utilized in a similar manner. 



' ' When a Hevea plant is stumped it usually dies back to the node, 

 and it is in such dried ends that the tiny wasps construct their nests. 

 They cannot be regarded as pests, but more properly as friends, 



* Stanley Arden, Annual Report, 1902. 



t T. Petch, Mycological Notes, Tropical Agriculturist, October, 1905. 

 % E. E. Green, Entomological Notes, Tropical Agriculturist, Septem- 

 ber, 1905. 



