Role of pod shape, color and spatial distribution on egg distribution and egg parasitism of the cocoa pod borer,Conopomorpha cramerella (Snellen) (Lepidoptera: Gracillariidae)

I. Azhar and G. E. Long

Abstract

The effects of several characteristics of cocoa pods (shape, color, height and location within tree) on the survival and mortality of healthy eggs of the cocoa pod borer (CPB),Conopomorpha cramerella  (Snellen), and of eggs parasitized byTrichogrammatoidea bactrae fumata  Nagaraja (TBF) were investigated in a mixed cocoa hybrid block at the Cocoa Research Station, Tawau, Sabah, Malaysia. CPB eggs on susceptible pods at different heights within the tree were counted weekly until the pods ripened; their survival and mortality were then recorded. At the same time, the survival and mortality of TBF-parasitized eggs on these pods were monitored and recorded. Pods from different locations within the tree were sampled on another set of selected trees and the numbers of CPB eggs per pod were recorded. More pods occurred in the middle portion of the canopy, and fewer in the top level of canopy and on the main chupon below the jorquette. Neither pods of specific shape, color, nor specific heights were preferentially selected for oviposition by the CPB. More pods and more eggs per pod were recorded on fan branches than on the main chupon. Survival and mortality of non-parasitized CPB eggs and of eggs parasitized by TBF were not significantly affected by pod height, shape and color. Results suggest that egg sampling is more readily carried out on pods in the middle of the canopy. TBF should be released within the canopy, where more pods are located. Planting of cocoa clones with a particular pod shape or color is unlikely to affect the infestation level.

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