Predator-Prey Interaction between Amblyseius longispinosus (Evans) (Acari:Phytoseiidae) and Tetranychus macfarlanei Baker and Pritchard (Acari:Tetranychidae)

Interaction between the phytoseiid predator, Amblyseius longispinosus (Evans) and the red spider mite, Tetranychus macfarlanei Baker and Pritchard on cotton at ratios of 1:5, 1:10, 1:20 and 1:30 indicated that irrespective of prey ratios, the predator consumed sufficient numbers to counter the increasing prey population. The prey elimination was slightly prolonged at 1:10, 1:20 and 1:30 ratios whereas in case of 1:40 and 1:50 ratios, the prey population was not suppressed on potted cotton plants kept under green house condition, even after fifth week. The curves obtained by the functional and numerical responses between prey egg density and prey eggs destroyed and number of eggs laid by the predator, reached a plateau and the shape of the curves in both the responses is curvilinear.