Detrimental effects of electron beam irradiation on the cowpea bruchid Callosobruchus maculatus

Abstract

eBeam irradiation has very defined effects on cowpea bruchid development and reproduction. A dose of 0.06 kGy could successfully impede cowpea burchid population expansion. This information can be exploited for post-harvest insect control of stored grains.

Assessment irradiation effects on different development stages of Callosobruchus maculatus and on chemical, physical and microbiological quality of cowpea seeds

“…Tilton (1974) reported that the dose 500 Gy would virtually control all stored product pests by preventing their reproduction or adult emergence instead of providing acute mortality which would require much higher doses. Sang et al (2015) found that irradiation of C. maculatus adults to 2 kGy (2000 Gy) resulted in ∼50% acute mortality. They added that until 1000 Gy (1 kGy) they did not start to observe immediate deaths.…”

Parental hypoxic exposure influences performance of offspring in Callosobruchus maculatus

“…To obtain age‐synchronized bruchid cultures, adults (∼300, 1–4 days old) were introduced into a plastic cup containing approximately 150 cowpea seeds and were allowed to lay eggs for 2 h. Infested seeds obtained this way generally carried 5–10 eggs on each. Since cowpea bruchids feed and develop inside the seeds, precise larval and pupal developmental stages were determined as described previously: time periods required from egg laying to first, second, third, fourth instar larval and pupal stages are 156–180, 222–246, 288–312, 366–420 and 498–552 h, respectively. Hatched larvae burrow into the seeds, causing egg color change from clear to cream white.…”

Hypoxic environment protects cowpea bruchid (Callosobruchus maculatus) from electron beam irradiation damage

“…Infested cowpea seeds in culture flasks were placed on a high‐density polyethylene (HDPE) cassette and irradiated at doses of 30, 50 and 100 Gy, respectively. These doses were selected to best reflect the protective effect of hypoxia based on previous eBeam dose response analysis . Each eBeam irradiation treatment was accompanied by an alanine dosimeter placed among cowpea seeds to be irradiated to verify the absorbed irradiation dose by a Bruker eScan spectrometer (Bruker, Billerica, MA, USA).…”

“…For Indian meal moth ( Plodia interpunctella ), 350 Gy γ‐ray can suppress egg hatch and larval development, but higher doses are needed to inhibit pupae and adults . Studies with cowpea bruchids ( Callosobruchus maculatus ) show that 30 Gy eBeam irradiation causes 90% mortality of fourth larvae and a dose of 60 Gy or higher is lethal to all larval stages . Although pupae are more tolerant, individuals that survived irradiation at pupal stage display smaller and more fragile ovaries in adults.…”

“…Although pupae are more tolerant, individuals that survived irradiation at pupal stage display smaller and more fragile ovaries in adults. Irradiated adults or adults derived from irradiated pupae are either infertile or produce eggs that do not hatch …”