Biological Studies on the Predatory Mite, Euseius Metwallyi ( Acari : Gamasida: Phytoseiidae)

• Abdel -Aziz E . Basha
• Plant Protection Department , Faculty of Agriculture ,
• Zagazig University, Egypt .
• The Third International Conference onIPM Role in Integrated Crop management and Impacts on Environment and Agricultural Products. 26-29 November 2005, Giza, Egypt.

Abstract

Biology of the predatory mite Euseius metwallyi was investigated in the laboratory at 26±3 °C and 74± 4% R.H. to clarify its response to three different food substances i.e. immature stages of the two-spotted spider mite, Tetranychus urticae, nymphs of Gynaikothrips ficorum and pollen of date palm , Phoenix dactylifera . It was found that the tested food substances significantly influenced the development and reproduction of E .metwallyi. Feeding on immature stages of T. urticae significantly accelerated period of female and male immature stages (5.37 and 4.57 days , respectively ). Adult female longevity , fecundity and daily oviposition rate were greater when the predator was fed on immature stages of T. urticae (17.66 days , 37.50 and 2.50 eggs, respectively ) and nymphs of G. ficorum (15.54 days , 27.50 and 2.30 eggs , respectively ) . On the other hand , the shortest longevity (14.83 days ), the lowest fecundity (20.05 eggs ) and the least daily oviposition rate (1.60 eggs ) were recorded when the predator was reared on pollen of P. dactylifera. Trials on predation showed that , female fed on greater number of prey individuals than male . During oviposition period , female consumed 87 and 82 % of the total prey individuals devoured during its longevity, when fed on immature stages of T . urticae and nymph of G . ficorum, respectively . The daily prey consumption and oviposition rates of the predator female were measured when provided with four different densities of T . urticae immature stages .