Biological control trials on the cocoa [Theobroma cacao] pod borer in the Philippines.
1986
Nagaraja H. | Reyes T.M. | Vanialingam T.
Acrocercops cramerella Snellen (Lepidoptera, Gracillariidae) was a serious pest of cacao. The larva bored into the young pod rendering the beans unsuitable for marketing. The pest which was endemic to Southeast Asia was now a threat to cacao industry. A biological control programmeusing an indigenous oligophagous egg parasite, Trichogrammatoidea sp. Estate, Davao del Sur, Philippines. This parasite was bred on eggs of the rice moth Corcyra cephalonica Stn. (Lep., Pyralidae). Exploratory trials in the field confirmed that the number of adult females released was positively correlated to the rate of parasitism. The dispersal distance from release points were found to extend up to 9 meters beyond. Mass release was organised from February, 1983 and the rate of release varied between 7,125 adults per hectare per week to 104,410 per hectare per week in January, 1984 and thus over 30,000,000 parasites were released in 12 months. The pod damage by the borer in the released area decreased steadily from 43.3% at the commencement of the release to about 10% at the end of one year. The number of entry holes showed a steady decrease from about 57 to 8. A similar trend was also observed in the reduction of exit holes.
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