THE RELATIVE ACTIVITY AND FUNCTIONAL RESPONSE OF PHYTOSEIULUS PERSIMILIS (ACARINA: PHYTOSEIIDAE) AND TETRANYCHUS URTICAE (ACARINA: TETRANYCHIDAE): THE EFFECT OF TEMPERATURE

Abstract

The activity of the predacious mite Phytoseiulus persimilis Athias-Henriot was greater oh a glass substrate than on a bean leaf substrate. Temperature did not affect its relative activity on the two substrates. The phytophagous mite Tetranychus urticae Koch was inactive on the bean leaf substrate. It was active on the glass substrate and its activity varied with temperature. The functional response of P. persimilis and T. urticae was examined at four temperatures (15°, 20°, 25°, 30 °C). Each functional response to increasing temperature rose curvilinearly to a plateau. From Holling’s disk equation, rate of successful search increased and handling time decreased.