Biology of Euseius yousefi (Acari: Phytoseiidae) Life Tables and Feeding Behaviour on Different Diets

Abstract

Effects on development, survivorship and reproduction of Euseius yousefi Zaher and El-Borolossy were studied in the laboratory using four different diets: the tetranychid mite Tetranychus urticae koch, the eriophyid mite Eriophyes dioscoridis Soliman and Abou-Awad, date palm pollen Phoenix dactylifera (L.) and sweet corn Zea mays L. pollen. The total development time ranged between 6.25 and 7.27 days for the adult female on animal diets and date palm pollen. In contrast, sweet corn pollen prolonged the developmental time and a higher nymphal mortality occurred. A total of 63.8, 50.5 and 57.6 eggs per female were obtained when eriophyid and tetranychid mites as well as date palm pollen, were provided, respectively. A diet of T. urticae provided the shortest generation time (T) and female longevity as well as the highest intrinsic rate of natural increase (rm = 0.294). A diet of E. dioscoridis resulted greatest female longevity and mean total fecundity which resulted in the highest net reproductive rate (Ro) value, intrinsic rate of increase (rm = 0.231) and finite rate of increase (e r m = 1.260) per day for E. yousefi. A diet of date palm pollen showed a close values of (T), (rm), (e r m) and total eggs per female with a diet of eriophyid mite. The sex ratio of E. yousefi was strongly female biased (♀/total ranged 0.73-0.82). Sweet corn pollen was the least favorable food source, with shortest adult longevity and without reproductive activity.