2.1. House flies
The house flies were collected from a poultry house using sweep- ing net and were transferred to the laboratory where they were reared at 27 °C and 50 ± 5% RH with a 12:12 light:dark photo- period. Adults were maintained in cages (40 · 40 · 40 cm3) cov- ered by gauze. Adult flies were provided access to food, consisting of a 1:1 ration of powdered milk and granulated sugar, and water with replenished every 24–48 h. Larval medium com- prised of 55 g wheat bran, 3 g date extract and 2 g dried alfalfa suspended in 140 mL water. One cup (250 mL) of this medium was left in each cage for oviposition by adults and subsequent development of larvae. The food was replaced every 24–48 h.