Individual study: Trials on control of the cocoa pod borer Conopomorpha cramerella (Snellen) in Sabah by regular complete harvesting
Wood B.J., Fee C.G., Cheong S.S. & Foh C.C. (1992) Trials on control of the cocoa pod borer Conopomorpha cramerella (Snellen) in Sabah by regular complete harvesting. Tropical Pest Management, 38, 271-278
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Use pesticides only when pests or crop damage reach threshold levels
A trial in 1985-1988 in Sabah, Malaysia (Wood et al. 1992) found that lindane applications, made when monitoring confirmed that cocoa pod borers Conopomorpha cramerella were present, did not stop infestations from continuing to increase in January-June 1986. In 1987-1988, cocoa Theobroma cacao pod infestation was similar when insecticide applications were determined using either low or high pod infestation thresholds. At peak levels in 1987 and 1988, 74% and 21% of pods were infested in the low-threshold plot, respectively, versus 84% and 17% in the high-threshold plot. In January-June 1986 cocoa pod borer moths were monitored using pheromone traps and lindane was applied seven times in response to positive catches. In 1987-1988, thresholds were set using an index of pod infestation that quantified the percentage of infested pods at four severity levels. An experimental field was divided into two plots which were assigned different thresholds (index values of 5 and 30) for applying insecticide. Low-threshold plots received more cypermethrin applications than high-thresholds plots (22 vs. seven applications in 1987, two vs. zero applications in 1988). Pod infestation was assessed for each threshold treatment using 200-400 pods taken from 3-4 randomly selected heaps of harvested crop. Effects on natural enemies were not presented.