Temperature dependent life parameters and predatory potential of a stigmaeid mite, Agistemus buntex, Chaudhri against two spotted spider mite, Tetranychus urticae, Dufour

Abstract

Studies were conducted to evaluate the life history parameters and predatory potential of a stigmaeid mite Agistemus buntex Chaudhri against Tetranychus urticae Dufour at three constant temperatures viz., 20, 25 and 30°C. At 25°C, egg, larvae, protonymph, deutonymph and egg to adult stages were completed in 7.36, 3.00 2.44, 2.34 and 15.14 days, respectively for male, and 8.48, 3.98, 3.69, 3.52 and 19.67 days, respectively for the female. The development time was longer at other two temperatures. Daily fecundity, total fecundity and sex ratio was much greater at 25°C compared to 20 and 30°C. The lower development threshold was found to be 6.65 and 8.35°C for A. buntex female and male, respectively. Degree day requirements (DD) for A. buntex were 346.02 DD for female and 250 DD for the male. The intrinsic rate of natural increase (rm) of A. buntex was recorded as 0.11 at 25°C. Finite rate of increase (λ) values for A. buntex were found to be 1.07, 1.12 and 1.11 at 20, 25 and 30°C respectively. From obtained results, it can be concluded that A. buntex can become a strong candidate for biological control of T. urticae in Pakistan and elsewhere along-with other control strategies. The findings will serve as baseline information to better understand the biology of the pest, which can be utilized in an effective management program.