71 



attacked, for they lose their green colour *nd become brown. The 

 cliches for the figures were kindly lent by Dr. Morris, Commissioner 

 of the Imperial Department of Agriculture for the W. Indies. 



Young thrips. Mature thrips. 



The Entomologist of the Department, Mr. TT. Maxwell-Lefroy,!was 

 sent by Dr. Morris to investigate the injury alleged to hive been 

 caused by thrips on cocoa estates in Grenada, and h's reports are 

 published in the West Indian Bulletin, Yol. I. No. 3. 



Mr. Lefroy found that the cocoa was " suffering from damage in four 

 distinct ways:- (a) the leaves of the young trees are attacked, leading 

 to the death of badly attacked plants ; (b) the leaves of the older t^ees 

 are attacked ; (c) the young pods are attacked, and their development 

 arrested or retarded ; (d) the mature pods are attacked." 



Little damage appeared to be done by attacks on the leaves, but if 

 thrips became very abundant, their attacks might be serious. 



When half-grown pods are attacked, they, as a rule, mature, but a 

 longer period is necessary before they are fully ripe. When a sm ill 

 pod is attacked by a large number of thrips, it shrivels up ; but this 

 should not be confused with the drying up of a large number of small 

 pods which usually occurs on every tree in a natural manner. 



The most general form of attack was that in which the pods turn a 

 deep brown colour as they mature. Young thrips carry a drop of 

 brown liquid at the end of the body, which is deposited on the pods, 

 and dries up into brown flakes. These brown fl«kes are characteristic 

 of the presence of thrips, but are not the c -use of the brown colour of 

 the pod. 



The thrips is also found on cashew, guava, and Liberian coffee, 

 and the cashew loses its leavrs when badly attacked. 



So far, Mr. Lefroy states, the damage done in Grenada is slight so 

 that no remedy is necessary. But to prevent the spread of the insect, 

 lie recommends that as soon as the beans are taken from the pods, the 

 shells should be at once buried, burnt-, or scorched, or covered with 

 lime. 



If thrips increases much, the pods should be sprayel, before they 

 are ripe, with kemsine emulsion, or resin wash. 



