a comprehensive assessment of the effects of bt cotton on coleomegilla maculata demonstrates no detrimental effects by cry1ac and cry2abbt棉花的影响的全面评估coleomegilla maculata cry1ac和cry2ab没有不利影响.pdfVIP

A Comprehensive Assessment of the Effects of Bt Cotton on Coleomegilla maculata Demonstrates No Detrimental Effects by Cry1Ac and Cry2Ab 1,2 ¨ 3 1 2 1 Yunhe Li , Jorg Romeis , Ping Wang , Yufa Peng , Anthony M. Shelton * 1 Department of Entomology, Cornell University/NYSAES, Geneva, New York, United States of America, 2 State Key Laboratory of Plant Disease and Insect Pests, Institute ¨ of Plant Protection, Chinese Academy of Agricultural Science, Beijing, China, 3 Agroscope Reckenholz-Tanikon Research Station ART, Zurich, Switzerland Abstract The ladybird beetle, Coleomegilla maculata (DeGeer), is a common and abundant predator in many cropping systems. Its larvae and adults are predaceous, feeding on aphids, thrips, lepidopteran larvae and plant tissues, such as pollen. Therefore, this species is exposed to insecticidal proteins expressed in insect-resistant, genetically engineered cotton expressing Cry proteins derived from Bacillus thuringiensis (Bt). A tritrophic bioassay was conduced to evaluate the potential impact of Cry2Ab- and Cry1Ac-expressing cotton on fitness parameters of C. maculata using Bt-susceptible and -resistant larvae of Trichoplusia ni as prey. Coleomegilla maculata survival, development time, adult weight and fecundity were not different when they were fed with resistant T. ni larvae reared on either Bt or control cotton. To ensure that C. maculata were not sensitive to the tested Cry toxins independent from the plant background and to add certainty to the hazard assessment, C. maculata larvae were fed artificial diet incorporated with Cry2Ab, Cry1Ac or both at .10 times higher concentrations than in cotton tissue. Artificial diet con