Influence of Biotic and Abiotic Factors on Tritrophic Relations of Mulberry, Mealy Bug, Maconellicoccus Hirsutus (Green) and its Entomophages

The biotic and the abiotic factors influencing the tritrophic relations between the mulberry, the mealy bug and its entomophages were studied to enhance the efficacy of integrated pest management technique against the pest. The biotic and the abiotic factors heavily influenced the tritrophic relations. The temperature showed positive correlation with the mealy bug infestation and its population while the relative humidity, rainfall and rainy days showed a negative correlation. The seasonal activity of the entomophages coincided with the activity of the mealy bugs. The entomophages population is significantly positively correlated with temperature and negatively correlated with rainfall, rainy days and humidity. The major biotic factors affecting the relations are the presence of four types of ants. The average number of mealy bug population was comparatively higher in ant attended colonies (61.22) than unattended ones (49.22). The population of predatory fauna decreased significantly (1.0) on ants association compared to the mealy bug infested shoots free from the ants (4.78) which indicates the deterring potentiality of the attendant ants on predators. Results revealed that the abiotic factors should be considered before the release of bio control agents, the movement of ants should be restricted and generalized predator should be encouraged.