Exploring the hormetic effects of radiation on the life table parameters of Spodoptera frugiperda

Background: Spodoptera frugiperda, a global agricultural pest, can be effectively controlled through the sterile insect technique. However, exposure to low-dose radiation below the sterilization threshold may induce hormetic effects. Here, the biphasic aspects of the fertile progeny population of S. frugiperda were analyzed using an age-stage, two-sex life table after dosing male and female pupae with 10-350 Gy gamma radiation.

Results: The parental sterilizing dose for 6-day-old female and male pupae was 200 and 350 Gy, respectively. The total longevity, pre-adult survival rate, net reproduction rate, and intrinsic growth rate of the offspring population increased with decreasing radiation doses from 250 to 10 Gy. Offspring population of parents treated with low doses of 10-100 Gy showed better life table parameters compared to non-irradiated controls. Females and males fecundity irradiated with 10, 50, and 100 Gy and 10 Gy, respectively, exceeded controls, producing 2339.4, 2726.4, 2311, and 2369 eggs, as opposed to 1802.9 eggs produced by the controls. Males irradiated with 10 Gy displayed the highest intrinsic rates of increase and net reproduction rate, at 0.1709 and 682.3, respectively. Projections from the survival rate and fecundity indicated that female and male S. frugiperda populations after 10 Gy irradiation may grow considerably faster than the controls.

Conclusion: This study explores the hormetic effects of low-dose radiation on S. frugiperda through life table analysis, while providing enhancements for utilizing substerilizing gamma dose in a modified F₁ sterility technique. © 2023 Society of Chemical Industry.