| Effects of gamma irradiation on the reproduction biology of European corn borer Ostrinia nubilalis Hübner (Lep: Pyralidae) |
| Paper ID : 1189-3IICE (R1) |
| Authors: |
|
Shiva - Osouli *1, Maryam Atapour2, Mehrdad Ahmadi3 1Nuclear Science and Technology Research Institute, Nuclear Agriculture Research School, Karaj, Iran 2Assistant Professor of Entomology Institute of Agriculture Iranian Research Organization for Science and Technology (IROST) PO Box 33535111 Tehran, Iran 3Nuclear Science and Technology Research Institute |
| Abstract: |
| European corn borer Ostrinia nubilalis Hübner is one of the polyphagous insects which causes damage on more than 200 plant species. In this study the applicability of using sterile insect technique (SIT) and F1 sterility (when parents irradiated by sub-sterilising doses) was evaluated. F1 sterility has many advantages over the sterile male technique, including higher competitiveness and the requirement of lower radiation doses to achieve the same results. Therefore the effect of sub-sterilizing dose of 150 Gy on competitiveness ability of F1 progeny from irradiated male parents was calculated and this value was compared to parental generation ability when irradiated with sterilizing dose of 350 Gy. For this purpose, mating competitiveness value (CV) of the irradiated and F1 males was evaluated in different ratios of 1:1:1, 2:1:1, 5:1:1 and 9:1:1 (irradiated male: un-irradiated male: un-irradiated female, respectively) and compared with 0:1:1 and 1:0:1 as controls. The mean number of eggs per female was 177.00, 182.93, 187.67, 185.40 and 141.33 at the mentioned ratios respectively, when pupae were irradiated at 350 Gy, in comparison with 210.53 and 141.33 at 0:1:1 and 1:0:1 in controls. Mean percentage of egg hatch was measured as 77.25, 62. 97, 39.04 and 13.59 at different ratios at the same dose and 91.42% and 5.71% in controls, respectively. Fecundity was calculated as 61.07, 60.80, 50.27 and 28.27 eggs per female at the mentioned ratios of F1 progeny from irradiated male parents at 150 Gy compared to 202.20 and 22.87 in controls, respectively. The proportion of egg hatch was 37.66, 32.68, 19.36 and 9.67% of total eggs laid by females when mated with the same ratios of F1 Males, respectively. The percentage of hatchability of eggs decreased with increasing irradiation and F1 male ratio. The competitiveness value was calculated based on the data of hatched eggs proportion using the fried's formula at these ratios. Fried’s CV ranged from 0.78 to 1.47 for F1 generation and from 0.2 to 1.10 for parental generation. Values between 0.2 and 0.4 are normal for sterile laboratory males. It is concluded that the male moths emerging from pupae irradiated with the mentioned doses were as competitive as the untreated ones in terms of mating, and the calculated competitiveness value of the irradiated males in both generations was within the acceptable range. However, the higher CV for F1 generation indicates higher competitiveness ability of F1 generation compared to Parental generation. |
| Keywords: |
| Mating Competitiveness value, Gamma Irradiation, Ostrinia nubilalis, Sub-sterilising Dose, Sterilising Dose, Sterile Insect Technique |
| Status : Paper Accepted (Poster Presentation) |
