PARA RUBBER. 15] 



for most of them provision their nests with Aphides taken from 

 some other plant. Specimens of a small Longicorn beetle, said to 

 be responsible for the death of young Eevea trees, have been 

 received from Southern India. The insect proves to be Pterolophia 

 annulata, Chevr.. a species that occurs in Ceylon also. I have no 

 records of injury done by this insect to Para rubber in this country, 

 but I have bred out a specimen from the diseased bark of a Ceara 

 rubber tree. My correspondent from India reports that the beetles 

 girdle the stems ; the upper parts of the trees dying back down to 

 the injured area. This girdling habit is common to many species of 

 Longicorn beetles. The object of the manoeuvre is believed to be to 

 check the sap and induce the degree of decay best suited to the 

 nourishment of the grubs of the beetle ; the eggs having first been 

 inserted in the back above the point of injury. If this pest should 

 become common, it might cause serious damage on rubber plant- 

 ations. In case of any occurrence of the pest the stems of all 

 the trees should be carefully searched. The adult beetles will 

 probably be found clinging to the bark of the trees, when they 

 can be easily captured and destroyed." 



Root Diseasi us. 



Fungi. — A root disease due to a fungus has already been men- 

 tioned as occurring in the St raits and Ceylon in association with white 

 ants, but probably preceding them. Petch has shown that the 

 Ceylon fungus can spread underground on roots of grasses, &c. and 

 that it is a species of Polyporus (Fomes semitostus). The hyphae are 

 described as occurring on the first six inches of the trunks as well as 

 the roots. Any trees so affected should be isolated by digging a 

 deep trench round them about a foot wide, as in the case of the root 

 disease in tea. and. if possible, the diseased specimens should be 

 uprooted and burnt. 



The Fomes fungus, affecting the roots of rubber plants in the 

 Straits, is described as follows in the Agricultural Bulletin of the 

 Straits and F. M. S. for May, 1904 :— 



" The fruiting part of Fomes semitostus is a broad, fiat, rounded 

 plate often very irregular in form, usually reniform -1 to G inches 

 across, and of an orange-red colour beneath, paler above, where it is 

 marked with rings and fine striae : beneath can be seen with a lens 

 the honeycomb-like structure of the hymeneal surface. The texture 

 of the fungus is tough, and it possesses a strong mushroom-like 

 scent. 



'•This fungus is very common on decaying stumps of all kind.-: of 

 trees and is, properly speaking, a dead wood feeder, but like a number 

 of allied species attacks also living tree-. 



As adisease fungus I would class this as contagious, as opposed to 

 an infectious fungus, as it appears to spread from root to root in the 

 ground without being dangerously dispersed through its spores. 



