The diseases and pests of the rubber tree . oss of 150 pounds of dryrubber per month ; and he instances one case in which over37,000 slugs were collected in a period of three weeks. In young Rubber these slugs have caused great damageby an entirely different method of feeding. They cUmb upthe stems during the night and eat off the terminal buds then develop, and these are in turn bitten off,until the plants assume the appearances shown in Fig 38,which is a photograph, nearly natural size, of the lead-ing shoots of three plants after repeated attacks. On theshoot in the centre the apex
The diseases and pests of the rubber tree . oss of 150 pounds of dryrubber per month ; and he instances one case in which over37,000 slugs were collected in a period of three weeks. In young Rubber these slugs have caused great damageby an entirely different method of feeding. They cUmb upthe stems during the night and eat off the terminal buds then develop, and these are in turn bitten off,until the plants assume the appearances shown in Fig 38,which is a photograph, nearly natural size, of the lead-ing shoots of three plants after repeated attacks. On theshoot in the centre the apex is clubbed and consists of anumber of arrested shoots, while lower down the stem theleaves have disappeared, and side-shoots, some of themsimilarly clubbed, have developed, though the stem was stiUgreen. The apices of the other two are similar, but each stemhas developed several side-shoots ; the tops of these side- vm PESTS 247 shoots have also been attacked, and on one of them buds haveappeared lower down and are giving rise to Fia. 38.—^The eSeot of slugs. Under normal conditions each of the leaders photographedwould be a straight green stem, growing only at the apex ; 248 THE RUBBER TREE but in each case the apex has been converted into a clusterof short shoots, most of which have not been permitted todevelop further, while on those which have temporarilyescaped injury and grown for a short distance the sameprocess is being repeated. This may be continued until theplant dies. In any case the damage is serious, as the develop-ment of the plants is arrested, and they may be so distortedas to be worthless. These slugs feed chiefly at night. Hence they are notgenerally observed in the act, and the injury may be attri-buted to insects. During the day-time they may be foundunder dead leaves, etc., round the trees, or on the undersideof living leaves on the tree itself. In Ceylon they were foundclimbing the stems in the evening. Plants which hadbranched were not sever
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