DISEASES AND PESTS 63 



this treatment. As a diseased tree is certain to die if not 

 treated, there can be no error in naming it ; bnt to try this 

 method with healthy trees in the expectation of warding off 

 infection is not advisable, because (1) there is no evidence that 

 the treatment would succeed, and (2) there is the certainty 

 that the tree would be seriously injured in a way that would 

 make it more susceptible to infection. 



My own experience with fire in healthy tree makes 

 me very sceptical as to the advisability of attempting 

 to save trees by this method, especially in any place 

 infested by Rhynchophorus. The most favourable of all 

 the reports on the result of flaming, showing a possible 

 saving of 31 out of 144 trees, has already been noted. 

 The red beetle is not, indeed, as dangerous a pest as the 

 bud rot ; but the difference is not great enough to 

 make it worth while to apparently save less than one- 

 quarter of the trees from the one pest at the cost of 

 making them subject to the other. 



Altogether there are two conclusions which can 

 certainly be drawn at this time with confidence that 

 they will permanently hold good : 



First : The best way of fighting these diseases is 

 by destroying the sources of infection. 



Second : Attempts to save infected trees are at 

 best a waste of time and effort. Even if some trees are 

 saved, it is at a cost for the whole work of more than 

 those saved are worth. When unsuccessful these 

 attempts lose time and preserve sources of infection. 

 If I had stopped to test the efficiency of remedial 

 measures, as I was urged to do by some of the coco-nut 

 planters of La Laguna, I would not merely have delayed 

 checking the bud rot, but at the same time would in- 

 evitably have lost the confidence of the people to an 

 extent which would have made such success as was 

 achieved impossible. 



INSECT ENEMIES 



Oryctes rhinoceros. — This is one of the two 

 decidedly most important insect enemies of the coco- 



