SOME INSECT PESTS IN THE WEST INDIES. 



55 



preYentive, but had proved a failure. Gas lime applied to the earth 

 near the tree was effectual for a time, but on losing its offensive odour 

 became useless. The system of grease-banding, in use in this country 

 and elsewhere, was recommended for the pest, and as both tar and 

 grease were available it was suggested that this might be used as a 

 substitute for the proprietary article manufactured for such purposes. 

 The result has not yet been communicated to me, and I am still in 

 doubt as to whether such a compound will retain its viscosity for a 

 sufficiently long period in the tropics, and thus act as a barrier to 

 the inroads of the ants. This preparation should be applied to a strip 

 of grease-proof paper to prevent direct contact with the bark of the 

 tree. 



Larv.^ of a Wood-Boring Beetle Injuring the Cacao Tree. 



The larva of a longicorn beetle was found tunnelling the bark and 

 wood of cacao trees in the Chapelton district. Its occurrence was 

 extremely local, and so far as one could gather was, fortunately, not 

 of a serious nature. All the examples discovered had confined their 

 attacks to the lower portions of the stems or main branches and always 

 tenanted a spot which showed evident signs of either previous injury 

 or decay. The subject requires further investigation, though it is 

 doubtful whether the insect can, for the present at least, be looked upon 

 as a serious pest. 



As a means of prevention, tar should be applied to the ends of all 

 freshly cut branches or other wounds produced by pruning or by 

 other means, as a precautionary measure against the attacks of this 

 insect. 



Girdler-Weevil of THE Orange and Cacao {Prej)odes vittatus). 



A pest of a much more serious nature than the larva of the longi- 

 corn beetle already referred to, is a brilliantly coloured weevil (fig. 35) 

 belonging to the Ehynchophorus section of the Coleoptera. The larva 

 of this handsome insect is a very serious pest to both the orange 

 and cacao, and its methods of attack are very striking and distinctly 

 characteristic. The grubs occur, invariably, just below the surface of 

 the ground, and at a point usually immediately above the junction 

 of the roots with the main stem of the tree; and they eat away every 

 portion of the bark, right through the cambium layer, often completely 

 girdling the stem. Every trace of the bark may be removed for a 

 distance of two inches so that a complete broad ring or girdle is 

 formed (fig. 36) resulting in the ultimate death of the tree. Cacao 

 trees thus attacked sometimes throw out adventitious roots just above 

 the girdle, and in such cases the tree may survive for a time, but it 

 rarely, I believe, recovers. 



The complete life-eycle of this pest has not yet been fully traced 

 out, but Mr. E. J. WoRTLEY has been successful in rearing the beetles 

 from larvae taken from the roots of orange trees. The grub or larva 



