واکنش تابعی دو گونه بومی Typhlodromus khosrovensis and Euseius galllicus (Acari:Phytoseiidae) بر روی Tetranychus urticae (Acari:Tetranychidae )

The two-spotted spider mite, Tetranychus urticae Koch, is one of the most economically- important pests on a wide range of crops worldwide. Predatory mites in the family of Phytoseiidae are very effective agents because of their important role in the biological control of small-bodied pests such as spider mites, thrips, and whiteflies as well as nematodes in crops. During a study on phytoseiids of Tehran city, three species, namely Typhlodromus (Anthoseius) khosrovensis, Euseius gallicus, and T. bagdasarjani are recorded from white mulberry trees in different parts of Tehran city. Since biological parameters and foraging behavior of T. bagdasarjani already had been studied. This study evaluated the efficacies of two native phytoseiid species on eggs of Tetranychus urticae. Functional response is an important factor in predator-prey dynamics and many studies on commercial phytoseiid mites in Iran have dealt with this aspect. In contrast, few studies have been conducted on native phytoseiids. The functional response of these two phytoseiid mites was determined under laboratory conditions at 27°C, 65% RH, and a photoperiod of 16 h light 8 dark. The data on functional response were analyzed in two steps. First, the type of functional response was determined by logistic regression then the handling time and attack rate coefficients were determined by Rogers’ model. Despite, the fact that T. Khosrovensis and E. gallicus were from two different categories (Type III and IV, respectively), the functional response of two predator species to eggs of T. urticae was type II. The attack rate was similar for two phytoseiids (0.0204 and 0.0213 h-1) and the lowest handling time was recorded for E.gallicus (2.3018 h). These two species potentially aid in enhancing the control of T. urticae and other pests on mulberry trees in urban spaces.