Monitoring Studies on Population Dynamics of Major Sucking Pest Complex of Cocoa, Theobroma cacao L. in Tamil Nadu

Field experiment on population dynamics of major sucking pest complex of cocoa was conducted by direct counting in farmer's holdings in Tamil Nadu during 2014–2015. The highest number of aphids was recorded during tenth standard week (178 per top three leaves per tree) and the lowest during fortyfifth standard week (99.2). Regarding mealybugs, the highest number was recorded during ninth standard week (361 per three pods per tree) and the lowest during forty-fourth standard week (135.4). The highest number of tea mosquito bugs was recorded during forty-fourth standard week (12 per three pods per tree) and the lowest during fifth standard week (0.8). Maximum temperature (T_max) (positively) and minimum temperature (T_min) (negatively) were found to be highly correlated with abundance of aphid population with the r value of 0.480 and-0.485, respectively and were found to be statistically significant at 5 per cent level. Regarding mealybugs, maximum temperature (T_max) (positively) minimum temperature (T_min) (negatively) significantly correlated with the abundance of mealybugs with the r value of 0.420 and-0.455, respectively. Relative humidity was positively correlated with the abundance of tea mosquito bugs with the r value of 0.539 and found to be statistically significant at 5% level. From the results it inferred that regarding abundance of aphids and mealybugs temperature played a major role in the growth and development, whereas, preferred stage of the host and relative humidity were played a major role in population dynamics of tea mosquito bugs.