The evaluation on control potential using X-ray to irradiate adult Spodoptera frugiperda (Lepidoptera: Noctuidae)

The sterile insect technique (SIT), involving the rearing of larvae for pupation followed by irradiating pupae, is employed for environmentally friendly invasive pest management. Despite its effectiveness, the cost of pupae production poses challenges for small farmers in developing countries. Alternatively, utilizing insect trapping techniques can capture abundant adult insects in their natural habitats, but application potential of adult SIT approach remains unclear.

We used the invasive pest Spodoptera frugiperda (Lepidoptera: Noctuidae) to assess the effectiveness of X-ray irradiated moths on their sterility rates, mating competitiveness, flight ability, and larval control efficiency in the field. Our findings revealed that optimal X-ray doses for 1-, 3-, and 5-day-old adult S. frugiperda were 154, 173, and 180 Gy, respectively. These doses rendered males more than 80.0% infertile and females nearly completely infertile. Significantly, the flight ability of sterilized males remained unaffected by sub-sterilizing doses of irradiation. Furthermore, in a release ratio of 16:1:1 (irradiated males-unirradiated males-unirradiated females), irradiated males exhibited the highest mating competitiveness (0.79). In the field-cage experiments, the corrected leaf protection rate and the corrected population decline rate in the 16:1:1 release plot were 60.50% and 74.21%, respectively.

These findings suggest that radiation-induced sterility in adult S. frugiperda holds promise for practical applications, offering a conceptual framework and novel approaches for advancing radiation-based pest control technology. © 2024 Society of Chemical Industry.