Radiobiological studies on fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae)

Abstract The fall armyworm, Spodoptera frugiperda (JE Smith, 1797) is a notorious invasive pest causing significant economic damage to various crops. The extensive damage caused by this pest has created havoc in India and has become a nightmare for farmers. The management steps taken for controlling the pest have become futile. There are several instances depicting the failure of conventional management tactics, viz resistance against insecticides and transgenic maize lines paving the way for exploiting newer paradigms of pest management. Hence, a novel approach through the use of gamma irradiation against the pest was attempted. A dose-response trial encompassing doses from 50 to 200 Gy was employed to study the adverse effects of gamma irradiation on the biology of fall armyworm. The irradiated insects were crossed with their counterpart and the developmental profile of progeny was analysed. The obtained results were quite promising and showed a significant effect on the biology of the pest with progression of the irradiation dose. When females were exposed to irradiation and crossed with fertile counterparts, fecundity decreased with an increase in irradiation dose. A considerable increase in the egg, larval and pupal period was observed at 100 and 150 Gy. This decreased fecundity reduces the pest’s build-up in the field and the prolonged developmental period make the pest more prone to biotic and abiotic annihilation factors. Hence, the above-mentioned strategy has plausible applications in the near future and this tool can better be fitted into area-wide integrated pest management programmes.