title: Bt maize fed-prey mediated effect on fitness and digestive physiology of the ground predator Poecilus cupreus L. (Coleoptera: Carabidae).
abstract: We investigated the effects of a Bt maize hybrid on fitness and digestive physiology of the ground-dwelling predator Poecilus cupreus L., as compared with the near-isogenic hybrid. A tritrophic assay revealed that there was a great decline in the detection of Cry1Ab toxin through the trophic chain, the concentration of the toxin being 945, 349 and 37 ng g(-1) of fresh weight in Bt maize leaves, Spodoptera littoralis (Boisduval) larvae and P. cupreus larvae, respectively. Moreover, the toxin was only detected in 8% of the P. cupreus adults collected from fields growing Bt maize. Developmental time of both larvae and pupae of P. cupreus was not adversely affected by the Cry1Ab toxin via fed-prey. To elucidate potential detrimental effects due to a reduction in the quality of the prey, we assessed the digestive proteolytic activities of P. cupreus adults from a laboratory culture and insects collected in commercial Bt and non-Bt maize fields. Field-collected P. cupreus adults had higher proteolytic activities than those reared in the laboratory, whereas no significant differences were found between P. cupreus adults reared on Bt and non-Bt maize fed-S. littoralis or between P. cupreus adults collected in commercial Bt and non-Bt maize fields.
authors.affiliation: Laboratorio Interacción Planta-Insecto, Departamento de Biología de Plantas, Centro de Investigaciones Biológicas, C.S.I.C., Ramiro de Maeztu, 9, 28040 Madrid, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: Alvarez-Alfageme
authors.forename: Félix
authors.initials: F
authors.lastname: Ortego
authors.forename: Pedro
authors.initials: P
authors.lastname: Castañera
mesh_terms: D000818:Animals; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000493:pharmacokinetics* / Q000633:toxicity; D001517:Coleoptera / Q000737:chemistry / Q000187:drug effects / Q000502:physiology*; D004068:Digestive System Physiological Phenomena / Q000187:drug effects*; D004731:Endotoxins / Q000493:pharmacokinetics* / Q000633:toxicity; D020387:Food Chain; D006460:Hemolysin Proteins / Q000493:pharmacokinetics* / Q000633:toxicity; D018515:Plant Leaves / Q000737:chemistry; D030821:Plants, Genetically Modified / Q000737:chemistry*; D013030:Spain; D018411:Spodoptera / Q000737:chemistry; D018709:Statistics, Nonparametric; D003313:Zea mays / Q000737:chemistry / Q000235:genetics*
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D004731:Endotoxins; D006460:Hemolysin Proteins; C030956:insecticidal crystal protein, Bacillus Thuringiensis