164 



rains occur is the best time to search for attacked trees as their presence 

 is then made apparent by the mud encasement. 



Mr. Kobinson in his report in T. gestroi says " the damage is 

 caused not so much by the actual death of the tree, for in many 

 cases the living tissues are perfectly sound but from a weakening of 

 the trunk and tap root added to the natural brittleness of the wood 

 rendering then unable to resist the slightest wind pressure " My 

 observations corroborate this and I have found in some cases that 

 besides wind pressure, rain will often cause diseased trees to fall, due 

 to the increased weight of the foliage. 



Age of Teee when Attacked. 



According to Mr. Robinson it is very rare for any material damage 

 to be done to para rubber before the age of 3i years. My experience 

 however has been very different and Mr. Robinson's statement may 

 I think be accounted for by the fact that when his investigations 

 were conducted comparatively little land had been taken up for the 

 purpose of planting rubber, young plantations being rare. 



On nearly 40 estates in different parts of the Peninsula which I 

 have visited during the last 18 months I find that trees are attacked 

 very commonly, and with very disastrous effects, at any age from 6 

 months upwards, sometimes the stumps before sprouting being killed. 



The time occupied by Gestroi in killing trees of 18 months is very 

 short. The roots are almost invariably the subject of attack, being 

 hollowed out from the apex to within about an inch from the surface 

 of the ground, making the tree's hold so fragile that it is remarkable 

 how they remain upright and show no signs of weakness or decay. 



Propping Fallen Trees. 



A common practice among planters is to prop up young trees 

 which have fallen through Gestroi attack. Such a procedure is un- 

 doubtedly prompted by the fear of losing 18 months growth, but it 

 must be taken into consideration that such trees are very liable to be 

 continully attacked and thus prove a source of danger to other trees. 



On one estate which I visited during 1907 trees of the age of 8-9 

 years were treated in this way, the top having been cut off to within 

 10 leet of the ground. 



Inside an area of 50 acres some 40 trees had received this treat- 

 ment and no less than 70 per cent of the trees within this area were 

 attacked by Gestroi. Without exception those trees which had been 

 propped if were riddled by Gestroi, and must I maintain have been 

 a factor aiding the mutiplication of this serious pest. 



As long as such a practice is continued any reduction in the 

 numbers of this pest cannot resonably be expected, besides which each 

 estate that becomes so infected is a dangerous neighbour. 



Native Trees Attacked. 



Several native trees suffer very considerably from the attacks of 

 Termes gestroi. Of these Kumpas (Kumpasia malaccensisj and the 

 several species of Meranti (Shorea) appear to be the favoured woods. 

 Coconut, Kapok cotton (Eriodendron) and several species of mango 

 are also frequently killed by Gestroi. 



