F₁ sterility and its application to control Ephestia spp. in date warehouses in Iraq

A modification of sterile insect technique (SIT) called partial sterility/inherited sterility or F₁ sterility is suggested for controlling stored product insect pest belonging to Lepidoptera order such as Ephestia spp. This modification showed longer population suppression with a low number of released insects. The percentage of egg hatch of Ephestia cautella, Ephestia figulilella and Ephestia calidella males and females irradiated as pupae at age 5-6 days with either 0.25 or with 0.35 kGy and the produced adults were mated either together or to the opposite sex were as follows: E. cautella/0.0, 13.9 and 19.9% for the dose 0.25kGy and 0.0,7.6 and 13.4% for the dose 0.35 kGy in comparison with the 96.9% for the control group; E. figulilella/2.7, 7.3 and 21.7% for the dose 0.25 kGy and 0.0, 10.4 and 12.3% for the dose 0.35 kGy in comparison with the 82.9% for the control group; E. calidella/3.0, 8.9 and 20.0% for the dose0.25 kGy and 0.0, 15.0 and 13.0% for the dose 0.35 kGy in comparison with the 94.9% for the control group. Presented results representing the following mating for the above three species: irradiated male × irradiated female; irradiated female × un-irradiated male and un-irradiated female × irradiated male in comparison with the control group (un-irradiated female × un-irradiated male). We observed very interesting results because it showed that the percentage of egg hatch of F₁ progeny of the above three species produced from the above mentioned crosses and mated either together or with un-irradiated opposite sex caused reduction in the egg hatch to an average ranged between 0.0 and 5.2% and most of the progeny produced were malformed. In conclusion these results are very important as we mentioned above because it may reduce the number of released insect in the warehouses through generation.