RUBBER 



always had grave doubts as to the part the termites have 

 played in the injury. The species concerned are mainly 

 fungus-feeders. They attack dead and diseased wood 

 and vegetable tissues directly such material has been 

 invaded by the mycelium of any fungus. In my experi- 

 ence, sound wood or healthy plants are seldom if ever 

 attacked by any of the three species that I have men- 

 tioned. In every case of injury to rubber plants or trees 

 that I have examined there has been indubitable evidence 

 of previous invasion by some parasitic or saprophytic 

 fungus. 



A single instance of a colony of Eutermes inanis 

 inhabiting the hollow stem of a rubber tree has come to 

 my notice. The insects were devouring the wood inside, 

 but left the living exterior parts alone. The original 

 stem of the tree had been broken off by the wind; and 

 several secondary stems had been thrown up from the 

 stump. The termites were occupying a cavity in the old 

 stem at the base of the new growth. At my recom- 

 mendation the nest was scooped out, and the cavity was 

 flooded with naphthalin dissolved in petrol. This treat- 

 ment proved successful, and the termites vacated the tree. 



The common mound-building termites (Termes rede- 

 manni and T. obscuriceps) sometimes construct galleries 

 and screens of earth over the stems of living rubber trees, 

 but this need cause no alarm if the tree is sound and 

 healthy. They merely eat off the functionless dead outer 

 bark, leaving the stem smooth and clean. As soon as 

 they have cleared away the dry outer bark the insects 

 will desert the tree of their own accord. But if their 

 presence on the stem is considered undesirable, it may 

 be prevented by sprinkling the soil around the base of 

 each tree with a mixture of refuse petroleum and water, 

 about i part of oil to 20 of water. 



The evidence against the notorious T. gestroi is 

 of a different nature. This species does not occur in 

 Ceylon, and its work has not come under my direct 

 observation; but it is a serious pest in the Federated 

 Malay States, and in Borneo, Sumatra, and Java. Mr. 

 H. C. Pratt, Government Entomologist, F.M.S., and 

 Mr. Towgood, of Kuala Selangor, have given us some 



