Comparative Biology of Tetranychus urticae Koch (Acari: Tetranychidae) on Three Solanaceous Plants and the Predator Amblyseius hutu (Prichard & Baker) Acari: Phytoseiidae) as a Potential Biological Control Agent for Tetranychus urticae

Abstract

The two-spotted spider mite Tetranychus urticae Koch is an emerging pest of solanaceous crops worldwide. Herbivore life history parameters are useful tools for evaluating resistance or susceptibility of host plants to pests. Under laboratory conditions (27±1.0°C, 70.0±5% RH), developmental times and reproductive parameters of T. urticae were evaluated on leaves of three plants (eggplant Solanium melongena, tomato Lycopersicon esculentum, and pepperCapsicum annum). Total developmental time (egg- adult), longevity, life span and fecundity show significant differences by effect of the three plants. Eggplant was most favorite plant for T. urticae , it recorded shorter life cycle ( 9.66 & 8.52 days for female and male), longest longevity ( 9.90 & 6.50 days for female and male), longest life span (19.56 & 15.02 days for female and male) and richened fecundity (75.72 eggs /female). While pepper was the lowest favorable plant for T. urticae because the pepper leaves when offered as a food for T. urticae longest life cycle (11.99 days for female), shortest longevity and life span (5.12 & 17.11 days for female respectively) and reduced fecundity (19.66 eggs /female). Also Predatory mite Amblyseius hutu (Prichard & Baker) was reared on adult stages of two-spotted spider mite, T. urticae at 27±1.0 °C, 70.0±5 % RH and 16:8 L: D to evaluate the developmental period, fecundity rate and predatory potential of A. hutu after feeding different prey densities of T. urticae. There were three treatment with ratio two, four and six predator for Each experiment with 60 eggs and ten newly emerged T. urticae females. A. hutu female when fed on adult stages of T. urticae completed the developmental period in 4.90 days, while longevity and life span lasted 9.80 and 14.20 days respectively and fecundity reached 9.80 per female. Total of T. urticae females and eggs consumed throughout the whole experiment by 2, 4 and 6 individuals predator of A. hutu under laboratory conditions were 0.34, 0.75 and 3.00 prey females and, 6.00, 9.00 and 12.27 prey eggs for treatments 3, 4 and 6 individuals predator respectively. The time taken by the different treatment of A. hutu to drive the total spider mite populations to zero was significantly different among the treatments, while the treatment three (6 individuals predator) had the shortest extinction time for spider mite (6 days).Whenoverall daily changes in spider mite populations studied was found that, the total spider mite population started to increase rapidly until the eighth day, and then it decreased gradually to the end of the experiment.