446 



[December, 1012. 



COCONUT PALM INSECTS IN TRINIDAD. 



BEETLES AND CATERPILLARS. 



The West Indian Bulletin has a paper on the above subject by 

 Mr. F. W. Urieh, Entomologist to the Board of Agriculture, Trinidad. 

 Mr. Urich states that on the whole the coconut palm is fairly free from any 

 serious insect pest ; occasionally attacks are isolated and sporadic ; many 

 of the insects appear to follow fungus disease or attack trees growing 

 under unfavourable soil conditions ; others again are well kept in check 

 by natural enemies and only increase when these enemies are prevented 

 from doing their work. 



Beetles Boring in the Stem 



The palm weevil (Rhynchophorus palmarum) has always been credited 

 with being most destructive to coconuts, but with few exceptions is 

 generally a secondary pest. The female beetle appears to be attracted 

 by the acetic fermentation which takes place in diseased trees ; further, 

 in most cases it has been observed to select only trees injured by cuts, 

 cracks or abrasions for ovipositing. Young trees up to four and five 

 years of age are those mostly attacked. Full-grown trees are not touched. 

 Mr. Dolly of Myaro, a most careful observer, states Mr. Urich has pointed 

 out that when young trees are growing in old cultivation the falling 

 fronds of the tall trees sometimes damage the tender leaves of the small 

 ones and so open the way to a beetle attack. Ihe part of the stem selected 

 is generally the soft tissue near the top and at the bases of the fronds , 

 the larvae sometimes eat into the petiole of the leaf when it is fairly 

 young. 



The remedies employed have been preventive and consist in tarring 

 wounds. If the growing point is attacked, and as long as the bud is not 

 damaged, the larvae are cut out and the wound dressed with tar. 



The Bearded Weevil. 



The bearded weevil (Rhina barbirostris) has different habits from 

 the preceding species, inasmuch as it attacks full or half-grown trees- 

 It confines its attack only to the stem. The damage is done by the larvae 

 which bore regular galleries in the hardest part of the stem. Like the palm 

 weevil, the bearded weevil is attracted by fermentation and it is signi- 

 ficant that trees suffering from bud rot are attacked at the top and those 

 affected by root disease at the base of the stem. The female beetle is 

 not attracted by wounds but when she lays eggs she gnaws a little 

 depression in the hard bark of the stem. The methods of control adopted 

 have been preventive and consist in tarring the stem of the trees that 

 have been scorched- A mixture of white lime, to which is added 5 lb. 

 of arsenate of lead to every 50 gallons of solution, is also used. Ambrosia 

 beetles (Xyleborus perforans) and allied species attack trees under the 

 same conditions as the bearded weevil. 



There is quite a number of caterpillars, Coccidss and Aleyrodidaa 

 to be found on coconut leaves, but with one or two exceptions none of 

 them do any damage as they are either not numerous or are kept in 

 check by natural enemies, 



