2.4. Screening of fungal isolates virulence
An aqueous suspension of each fungal strain was prepared and the concentration was adjusted to 108 conidia mL 1, in sterile distilled water. For testing the virulence of the fungi on the larval stage of M. domestica, groups of 25 larvae were immersed in conidial suspension for 10 s and were then placed on damp filter paper kept in a white disposable plastic container (100 mL vol- ume). Containers were sealed with lids. The control larvae were dipped in 0.01% Tween-80 solution. Each treatment was repli- cated three times. Each group of larvae was transferred after 24 h to the container with 70 g of larval medium. The tops of the dishes were covered with gauze and incubated at 27 °C with photoperiod 12:12 (light:dark). Emerged adults were recorded as the rate of survival and subsequently the rate of mortality was calculated.
For testing the effect of fungal isolates on adults, 3–4 day adults were anesthetized with CO2 and batches of 25 were dipped in a suspension containing 108 conidia mL 1 for 10 s and then placed on a piece of filter paper in small cages (20 · 20 · 20 cm). They were provided with sugar and powdered milk as solid medium and water. Cages were kept at 27 °C with photoperiod 12:12 (light:dark). The control flies were treated with 0.01% solution of Tween-80. All treatments were replicated three times. Mortality was recorded for 7 days at 24 h intervals.