Porcar M, García-Robles I, Domínguez-Escribà L, Latorre A
Institut Cavanilles de Biodiversitat i Biologia Evolutiva, Universitat de València, Apartado Postal 22085, 46071 València, Spain.
Bull Entomol Res. 2010 Jun;100(3):297-302. doi: 10.1017/S0007485309990290. Epub 2009 Sep 28.
Traditional approaches to studying the effects of genetically modified (GM) crops on beneficial insects involve either field assays, comparing insect population levels between control and GM crops or tritrophic bioassays with contaminated insects - usually larvae or eggs of Lepidoptera - as preys. Here, we report the results of a bioassay using an artificial diet, suitable for predatory Coleoptera, to supply Bacillus thuringiensis (Bt) solubilized Cry1Ab and Cry3Aa as well as trypsin-activated Cry1Ab to Atheta coriaria and Cryptolaemus montrouzieri adults and young larvae of Adalia bipunctata. Water, solubilization buffer and trypsin-treated solubilization buffer were used as controls. In total, 1600 insects were assayed. Assays showed a relatively low mortality rate in the controls, ranging from as low as 7% after 15 days (C. montrouzieri) to about 15-20% after five days (A. bipunctata) or 15 days (A. coriaria). For all three predators, there were no statistical differences between the mortality recorded in any of the treatment groups and the corresponding controls. These results indicate a lack of short- (A. bipunctata) and long-term (A. coriaria and C. montrouzieri) mortality associated with oral ingestion of Cry1Ab and Cry3Aa at the high dose tested (50 microg ml-1). We discuss the relevance of these findings for the ecology of beneficial Coleoptera and compatibility with Bt and GM Bt crops.
研究转基因作物对有益昆虫影响的传统方法包括田间试验，即比较对照作物和转基因作物之间的昆虫种群水平，或者进行三营养生物测定，以受污染的昆虫（通常是鳞翅目幼虫或卵）作为猎物。在此，我们报告了一项生物测定的结果，该测定使用适合捕食性鞘翅目的人工饲料，向伪瓢虫和孟氏隐唇瓢虫成虫以及二斑叶螨幼虫提供苏云金芽孢杆菌（Bt）溶解的Cry1Ab和Cry3Aa以及胰蛋白酶激活的Cry1Ab。用水、溶解缓冲液和经胰蛋白酶处理的溶解缓冲液作为对照。总共对1600只昆虫进行了测定。测定结果显示，对照组的死亡率相对较低，从15天后低至7%（孟氏隐唇瓢虫）到5天后约15 - 20%（二斑叶螨）或15天后（伪瓢虫）不等。对于所有三种捕食者，任何处理组记录的死亡率与相应对照组之间均无统计学差异。这些结果表明，在测试的高剂量（50微克/毫升）下，口服Cry1Ab和Cry3Aa与短期（二斑叶螨）和长期（伪瓢虫和孟氏隐唇瓢虫）死亡率无关。我们讨论了这些发现对有益鞘翅目生态学的相关性以及与Bt和转基因Bt作物的兼容性。
