and Magazine oj the Ceylon Agricultural Society. 



183 



TERMES GESTROI AND RUBBER. 



Interesting Notes by the F.M.S. Department 

 of Agriculture. 



Mr H G Pratt, Government Entomologist, 

 F.M.S., has just issued a bulletin containing 

 " Observations on Termes gestroi, as affecting 

 the Para Rubber tree, and methods to be em- 

 ployed against its ravages." It will, of course, be 

 necessary for estate managers to read the 

 pamphlet themselves ; no mere summary could 

 give an accurate view of its valuable contents. 

 We merely indicate them. Mr Pratt points out 

 that the factors which decido the prevalence of 

 Termes gestroi on a rubber plantation are mis- 

 understood. "There is," he says, "a popular 

 impression that gestroi has reached its deserved 

 designation as a pest merely because rubber 

 (Hevea Brasilieiisis) has been planted in the 

 F.M.S. I wish to show hero that it is not the 

 product which is planted that is the main cause 

 of the encouragement of gestroi, but the inter- 

 ference with nature when large acreages are 

 felled ; it is therefore the object of the planter 

 to meet as far as lies within his power those 

 changed conditions, lake into consideration 

 the method of planting in the F.M.S. 1,0U0 

 acres of land are taken up for the purpose of 

 planting rubber. The virgin forest is felled, 

 burnt and the acreage planted. The burn may 

 have been good, then so much the better ; on 

 the other hand it may have been bad, and 

 very little of the timber is destroyed. 

 Whether the burn was good or bad a great deal 

 of the harder wood is left undestroyed. In 

 either case the land is planted, and no heed 

 whatever is taken of the mass of felled forest 

 trees which form a continued network of logs 

 lying upon the surface of the soil. 



" The sole object of the planter is to bring his 

 trees to a tappable stage as quickly as possible, 

 and at the lowest possible cost, regardless of 

 the consequences which may follow such a pro- 

 cedure. He forgets, or does not attach sufficient 

 importance to tho fact, that at least two per- 

 cent of the larger and sometimes of the smaller 

 logs and stumps, very few of which are ever 

 completely burnt away, either have gestroi in 

 them, or will harbour them in time. A freshly 

 felled piece of land is thus a perfect home for 

 this insect; every facility is present for its mul- 

 tiplication; its dissemination from stump to 

 stump, and log to log, is rendered so easy, and 

 there is a food supply sufficient for several years. 

 After having encouraged gestroi to such an ex- 

 tent, and furnished it with every means cal- 

 culated to increase its number and its distribu- 

 tion, it is not a matter for surprise that an in- 

 sect with its habits, and which has no aversion 

 to the living Para tree, does attack the rubber 

 tree3 which are planted in the midst of such an 

 infected area." 



Mr Pratt proceeds to explain the most effec- 

 tive methods of exterminating the pest and ends 

 with a warning as to the future. He says : — 



The great majority of estates in the F.M.S. 

 aro between the ages of 1-6 years, and the 

 damage that will be caused by gestroi on these 

 various estates rests entirely with their re- 

 spective managers. Those planters who take 



steps to eradicate tho insect from their young 

 clearings will be more than repaid in the future! 

 The amount of money spent in freeing the 

 estate from this pest will depend on several 

 factors, as for instance the nature of the soil, 

 the formation of the land, the age of tho clea- 

 ring, and whether the burn was good or bad, all 

 of which have direct bearing on the prevalence 

 of this insect. Once eradicated the plautor 

 need have no fear of its return as a pest, but I 

 would strongly urge the importance of taking 

 stringent methods against gestroi on these low- 

 lying, heavily-timbered soils recently opened. 

 Unless this is done on land of this character 

 probably '20 per cent, of the trees will be lost 

 in the course of 6 or 7 years. There is, however, 

 absolutely no cause for alarm even on these 

 places. As yet they are young clearings, and if 

 the managers of such estates are provided with 

 the means to rid their plantations of gestroi 

 there are no reasons why these places should 

 not be quite free from the pest in the course 

 of three years.— Straits Times, July 8. 



A NEW FUNGUS-PEST ON PARA 

 RUBBER. 



DISCOVERED IN PERAK. 

 1 have recently received from a planter in 

 Perak portions of the branches and boughs of 

 Para rubber trees destroyed by the attacks of a 

 bark fungus hitherto unknown to me. The at- 

 tack commences on the shoots which presently 

 turn black and die, and the disease continues to 

 descend to the trunk of the tree which eventually 

 perishes. On examining the bark attacked, 

 there can be seen numerous raised spots, which 

 split and show a black fungus pushing out in 

 tho crack. In some places the bark is quite 

 thickly marked with short straight cracks 

 parallel to the axis of the branch. In older parts 

 of the branch the grey bark is covered with 

 larger elevated patches, black in colour and loo- 

 king as if soot had been thrown on the tree. The 

 cambium is dead and black, the wood drv 

 and soon perishes. Examination with the mjc'. 

 roscope shows that in theso black patches aro 

 round spaces (perithecia) imbedded in a black 

 mass, (stroma) from the interior of which are 

 discharged large numbers of oval spores, mostly 

 transversely divided. The fungus evidently be 

 longs to the group of Ascomyeetes and appears to 

 me to be allied to a genus Cucurbitaria parasitic 

 on the Laburnum in Europe in much the same 

 way as this fungus attacks Hevea here. The cor- 

 respondent who sends the specimens writes : 

 " Trees with apparently the same disease are 

 dotted about theestate singly and in groups, lam 



CUTTING DOWN ALL THE DISEASED TREES TO THE 

 POINT WHERE THE LATEX EXUDES 



healthily. This cutting back appears to 

 stop the disease as the stumps shoot again 

 in about 7 days. The disease appears to be 

 a bark or leaf one as the death seems to 

 start from the tip or tips of the branches and 

 travels down the tree and if left alone in a short 

 time will completely kill it." Of one specimen he 

 writes : "The tree I send you was alive 1-2 days 

 ago and yesterday I had to cut it back 4 inches 

 from the ground to get to healthy wood. The 



