Predatory Efficacy of <i>Phytoseiulus persimilis</i> Athias-Henriot (Acari: Phytoseiidae) on the Two Spotted Spider Mite <i>Tetranychus urticae</i> Koch (Acari: Tetranychidae)
The relative abundance Tetranychus urticae and Phytoseiulus persimilis as well as voracity of the predator were conducted on potted eggplants. After six weeks of release of ten female T. urticae in control plants, the highest mite population reached at 184.21 / leaf, against 67.92 and 107.48 / leaf in plants which received two predators after 1st and 3rd week respectively. After nine weeks the number of mite / leaf reduced to 13.21 and 23.97 / leaf after 1st and 3rd week of introduction of the predator, the control population was 81.32. Adult P. persimilis as single predator fed 8.2, 15.4 and 20.6 T. urticae eggs after 24, 48 and 72 h respectively. Again a single predator when tested separately fed 5.4, 10.8 and 14.6 T. urticae larvae after 24, 48 and 72 h respectively. A single adult predator fed on 3.6, 7.0 and 12.0 adult T. urticae after the same durations. When varying number (10, 20, 30, 40 and 50) of prey (larvae or adults) were provided to a single predator it fed 5.0, 6.6, 6.8, 9.0 and 9.4 larvae against 3.2, 3.2, 3.4, 3.6 and 3.6 adults respectively.
Key words: Predation, spider mite, eggplant, voracity, release. Â
J. bio-sci. 15: 127-132, 2007