10 



from the picking of discoloured pods as ripe. When pickers 

 have learned to distinguish between ripe pods and unripe ones 

 which are discoloured by thrips' attacks, there is but little appa- 

 rent loss from this cause. 



Lefroy stated (West Indian Bulletin, Vol. II. p. 183) that the cocoa 

 thrips is found on leaves and pods of cocoa and on leaves of 

 cashew, guava, and Liberian coffee in Grenada, and on cocoa in 

 St. Vincent, St. Lucia and Dominica. It is also found on cocoa 

 in Guadeloupe, and I found it on wild guava and cotton in St. 

 Lucia. As an additional note of interest, it may be mentioned 

 that I have found both winged and wingless forms of adult 

 female thrips. So far as I have seen, the males are always 

 winged, and of a lighter colour than the females. 



TREATMENT. 



The treatment of thrips naturally falls under two heads , the 

 application of insecticides for the direct control of the insects, 

 and cultural methods for the improvement of the general health 

 and vigour of the cocoa trees. 



So far as thrips' attacks are recorded, these are always much 

 more severe when they occur under certain conditions. In sea- 

 sons of extreme drought and in localities where for any reason 

 the health of the cocoa trees is impaired, thrips' attacks are liable 

 to be experienced, while in seasons of favourable rainfall, and in 

 cocoa orchards where all matters of good cultivation, such as 

 draining, forking, pruning, and manuring receive careful atten- 

 tion, thrips are rarely prevalent. 



From this it will be at once concluded that the matter of first 

 importance is the health of the trees, and in the case of an 

 outbreak of thrips, careful attention should be given to these 

 points. 



Rainfall conditions cannot be controlled, but by thorough atten- 

 tion to cultural practices, a condition of the trees and of the soil 

 can be maintained which will make them much less susceptible to 

 the effects of continued drought, on the one hand, and of exces- 

 sive rainfall on the other. 



Another operation that should be included under cultural methods 

 consists in the destruction of all wild and useless trees growing 

 in the vicinity of cocoa cultivations, which are likely to be in- 

 fested by the cocoa thrips. The plants on which this insect is 

 known to occur are, cashew, guava, Liberian coffee, and wild 

 cotton. If any of these occur as valuable plants, it might pay to 

 treat them for the destruction of thrips in the same way that the 

 cocoa trees are treated. 



If it becomes necessary to spray cocoa for the better control of 

 thrips, one of the washes given herewith might be used. 



On account of the extremely uneven and rugged character of 

 the ground in many cocoa orchards, spraying could be performed 

 only with difficulty, and since careful attention to cultural details 



