title: Detrimental effects of electron beam irradiation on the cowpea bruchid Callosobruchus maculatus.
abstract: BACKGROUND
  Electron beam (eBeam) irradiation technology is an environmentally friendly, chemical-free alternative for disinfesting insect pests of stored grains. The underlying hypothesis is that specific doses of eBeam will have defined detrimental effects on the different life stages. We evaluated the effects of eBeam exposure in a range of doses (0.03-0.12 kGy) on the development of the cowpea bruchid (Callosobruchus maculatus) at various stages of its life cycle.
  
  
  RESULTS
  Differential radiosensitivity was detected during egg development. Early and intermediate stages of eggs never hatched after exposure to a dose of 0.03 kGy, whereas a substantial portion of black-headed (i.e. late) eggs survived irradiation even at 0.12 kGy. However, further development of the hatched larvae was inhibited. Although midgut protein digestion remained intact, irradiated larvae (0.06 kGy or higher) failed to develop into normal living adults; rather, they died as pupae or abnormally eclosed adults, suggesting a detrimental effect of eBeam on metamorphosis. Emerged irradiated pupae had shorter longevity and were unable to produce any eggs at 0.06 kGy or higher. At this dose range, eggs laid by irradiated adults were not viable. eBeam treatment shortened adult longevity in a dose-dependent manner. Reciprocal crosses indicated that females were more sensitive to eBeam exposure than their male counterparts. Dissection of the female reproductive system revealed that eBeam treatment prevented formation of oocytes.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, Huazhong Agricultural University, Wuhan, Hubei, China.|Department of Entomology, Texas A&M University, College Station, TX, USA.|Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, TX, USA.
authors.forename: Wen
authors.initials: W
authors.lastname: Sang
authors.affiliation: National Center for Electron Beam Research, Texas A&M University, College Station, TX, USA.
authors.forename: Mickey
authors.initials: M
authors.lastname: Speakmon
authors.affiliation: Department of Statistics, Texas A&M University, College Station, TX, USA.
authors.forename: Lan
authors.initials: L
authors.lastname: Zhou
authors.affiliation: Department of Entomology, Texas A&M University, College Station, TX, USA.|Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, TX, USA.
authors.forename: Yu
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, Huazhong Agricultural University, Wuhan, Hubei, China.
authors.forename: Chaoliang
authors.initials: C
authors.lastname: Lei
authors.affiliation: National Center for Electron Beam Research, Texas A&M University, College Station, TX, USA.
authors.forename: Suresh D
authors.initials: SD
authors.lastname: Pillai
authors.affiliation: Department of Entomology, Texas A&M University, College Station, TX, USA.|Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, TX, USA.
authors.forename: Keyan
authors.initials: K
authors.lastname: Zhu-Salzman
mesh_terms: D000818:Animals; D001517:Coleoptera / Q000254:growth & development / Q000378:metabolism / Q000502:physiology / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D004583:Electrons; D005260:Female; D007300:Insect Control / Q000379:methods*; D019476:Insect Proteins / Q000378:metabolism; D007814:Larva / Q000528:radiation effects; D008297:Male; D008675:Metamorphosis, Biological / Q000528:radiation effects; D009865:Oocytes / Q000528:radiation effects; D059748:Proteolysis / Q000528:radiation effects; D012098:Reproduction / Q000528:radiation effects
chemical_list: D019476:Insect Proteins
keywords: Callosobruchus maculatus; electron beam; emergence; irradiation; longevity; reproductive system