title: Effects of Bacillus thuringiensis toxin Cry1Ac and Beauveria bassiana on Asiatic corn borer (Lepidoptera: Crambidae).
abstract: In this study, interactions between Cry1Ac, a toxic crystal protein produced by Bacillus thuringiensis (Berliner), and Beauveria bassiana on the mortality and survival of Ostrinia furnacalis was evaluated in the laboratory. The results showed that Cry1Ac is toxic to O. furnacalis. Not only were larval growth and development delayed, but pupation, pupal weight and adult emergency also decreased when larvae were fed on artificial diet containing purified Cry1Ac toxin. When third instars O. furnacalis were exposed to combination of B. bassiana (1.8x10(5), 1.8x10(6) or 1.8x10(7) conidia ml(-1)) and Cry1Ac, (0.2 or 0.8 microg g(-1)), the effect on mortality was additive, however, the combinations of sublethal concentrations showed antagonism between Cry1Ac (3.2 or 13 microg g(-1)) and B. bassiana (1.8x10(5) or 1.8x10(6) conidia ml(-1)). When neonates were reared on sublethal concentrations of Cry1AC until the third instar, and survivors exposed B. bassiana conidial suspension, such treatments showed additive effect on mortality of O. furnacalis except for the combination of Cry1Ac (0.2 microg g(-1)) and B. bassiana (1.8x10(6) conidia ml(-1)) that showed antagonism.
authors.affiliation: Department of Entomology, College of Agronomy and Biotechnology, China Agricultural University, Beijing 100094, China.
authors.forename: Xiao-Mu
authors.initials: XM
authors.lastname: Ma
authors.forename: Xiao-Xia
authors.initials: XX
authors.lastname: Liu
authors.forename: Xia
authors.initials: X
authors.lastname: Ning
authors.forename: Bo
authors.initials: B
authors.lastname: Zhang
authors.forename: Fei
authors.initials: F
authors.lastname: Han
authors.forename: Xiu-Min
authors.initials: XM
authors.lastname: Guan
authors.forename: Yun-Feng
authors.initials: YF
authors.lastname: Tan
authors.forename: Qing-Wen
authors.initials: QW
authors.lastname: Zhang
mesh_terms: D000818:Animals; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000633:toxicity*; D052982:Beauveria; D004731:Endotoxins / Q000633:toxicity*; D006460:Hemolysin Proteins / Q000633:toxicity*; D007814:Larva / Q000254:growth & development / Q000382:microbiology; D007915:Lepidoptera / Q000254:growth & development / Q000382:microbiology*; D010572:Pest Control, Biological / Q000379:methods*
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D004731:Endotoxins; D006460:Hemolysin Proteins; C030956:insecticidal crystal protein, Bacillus Thuringiensis