Impact of Electron Beam Irradiation on the Developmental Stages of Callosobruchus maculatus (Coleoptera: Bruchidae) and Bactrocera zonata (Diptera: Tephritidae)

Abstract

An eco-friendly electron beam irradiation (EBI) technology was used to assess the effect of EBI on the different development stages of Callosobruchus maculatus (F.) and Bactrocera zonata (Saunders). No adults emerged after 3-d-old eggs of C. maculatus were irradiated with 304.8 Gy of EBI, and no adults emerged from the F1 generation of larvae and pupae irradiated with 103.6 Gy. The adult stage of C. maculatus was the most tolerant of EBI, with a high dose (414.3 Gy) irradiation of the adult stage resulting in complete prevention of the F1 generation adult emergence. Large-scale tests confirmed that 414.3 Gy was an effective dose for the phytosanitary and security treatment for C. maculatus. An EBI dose of 414.3 Gy prevented B. zonata egg hatching. EBI doses of 304.8, 414.3, and 653.5 Gy prevented the development of first, second, and third larval instars to pupation, respectively. Using the criterion of adult emergence from the F1 generation, targeting the third larval stage, considered the most tolerant stage to EBI, a dose of 304.8 Gy was effective for quarantine and security treatment of B. zonata.