148 HISTORY AND CAUSE OF THE COCONUT BUD-EOT. 



either absent or present in such small numbers as to have no serious 

 effect on the transpiration, it is very clear that these insects can not 

 be considered as a primary cause of the bud-rot. Reports * have been 

 made on the serious injury and even death of coconut trees in Taliiti 

 and other South Sea islands by these scale insects. It is much to be 

 regretted that the investigator has failed to give a sufficient descrip- 

 tion of the tissues of the diseased tree to enable a comparison to be 

 made with trees affected by bud-rot. 



The claim that insects such as the palm weevil, the rliinoceros 

 beetle, and others are the cause of the bud-rot is frequently made 

 by coconut planters. The effect of such insects is purely local, and 

 even if they are present in great numbers they can have no direct 

 influence in bringing about a rotted condition of the bud. They 

 may, however, possibly play an important part in carrying the bac- 

 teria from diseased tissues to healthy ones, the organism gaining 

 entrance through the wound caused by the boring or feeding of the 

 insect. 



Not many scientific investigators have definitely ascribed the rot 

 of the heart tissue of the coconut to any particular cause. For the 

 most part they have stated what they have seen in the tissues and 

 suggested what might be the cause. In several cases, however, the 

 diseased condition of the coconut tree has been distinctly said to be 

 due to fungi. The most strildng are two late publications, those of 

 Mr. Stockdale and of Dr. Fredholm, one of wliicli has been published 

 widely, in regard to diseases in Trinidad. The work of both of these 

 investigators has already been discussed in detail in another pubUca- 

 tion,2 but it seems desirable to repeat it in this connection. 



Mr. Stockdale' s investigations showed to him two distinct types 

 of coconut disease in Trinidad. In one, which he called the "root 

 disease," the trunk showed a red discoloration toward the outside 

 for a considerable part of its length, and the decayed roots and the 

 petioles were inl'ested with a fungus. Eventually, when the vitality 

 of the tree had been reduced, the terminal bud became involved in 

 a soft rot, and the putrid mass then fell over and the tree died. Mr. 

 Stockdale found, also, what he supposed was bud-rot. In tliis dis- 

 ease the roots appeared to be healthy, the stem showed no sign of 

 the discoloration, but the bud was involved in a vile sort of bac- 

 terial rot, and eventually fell over. In the advancing margin of the 

 rot usually were only bacteria, but in a few cases there was some 

 fungous mycelium. This investigator concluded that the root 



iDoane, R. W. Notes on Aspidiotus Destructor Sig. and Its Chalcid Parasite in Tahiti. Journal of 

 Economic Entomology, vol. 1, 1908, pp. 341-342. Also Notes on Insects Afifecting the Coconut Trees in 

 the Society Islands. Journal of Economic Entomology, vol. 2, 1909, pp. 220-223. 



2 Johnston, J. R. The Serious Coconut Palm Diseases in Trinidad. Bulletin 64, Trinidad Departmenf 

 of Agriculture, 1910, pp. 25-29. 

 228 



