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The generalist predator Orius albidipennis Reut. (Hem., Anthocoridae) and entomopathogenic fungus Metarhizium anisopliae (Metchnikoff) Sorokin (Ascomycota: Clavicipitaceae) are important biocontrol agents of Thrips tabaci Lindeman (Thys., Thripidae) in most greenhouses. In this study, we estimated searching time, feeding time and predation rate in O. albidipennis feeding on untreated and treated thrips larvae which had been inoculated with three concentrations of M. anisopliae V275 at four time intervals; 0, 24, 48 and 72 h after infestation. Applied concentrations were 1 )10 3 , 2)10 4 and 2 )10 5 conidia/mL which roughly correspond to the LC 25 , LC 50 and LC 75 for second instar-larvae. O. albidipennis responded to the presence of the M. anisopliae on the treated hosts by increasing the searching time and decreasing feeding time and predation rate levels. It was also able to detect and avoid treated patches.

Abstract:The entomopathogenic fungus conidia viability and sporulation may be affected by different environmental factors or by bio-pesticides and chemical products used to protect cultivated plants. In this research, we investigated the compatibility of Metarhizium anisopliae DEMI 001 isolates with three insecticides: fipronil, pyriproxyfen and hexaflumuron. The effect of fipronil, pyriproxyfen and hexaflumuron on sporulation, vegetative growth and conidial germination of the fungus was studied based on measuring the vegetative growth and sporulation. SDA medium was mixed with fipronil (10, 40 and 120 ppm), pyriproxyfen (10, 500 and 1 000 ppm), hexaflumuron (20, 50 and 120 ppm). SAD medium excluding insecticides was designated as blank. To determine the sporulation rate, spores was counted on surface area and vegetative growth was measured on the basis of colony diameter. The results showed that hexaflumuron at the concentration of 120 ppm reduced the vegetative growth to 0% showing the highest reduction effect compared to pyriproxyfen (24.59%) and fipronil (24.31%). All three insecticides reduced drastically the conidial germination at the highest concentrations (0-15%). Hexaflumuron treatment with 0% germination at all three concentrations and fipronil and pyriproxyfen with 32.36% and 9.7% germination at 200 ppm were not significantly different. Regarding the highest negative effect of hexaflumuron on germination at all three concentrations, this insecticide should not be applied together with the entomopathogenic fungus.