1. Agrisure® Viptera TM 3111 GM corn hybrid and its respective isoline provided by Syngenta Agro S.A. de C.V.- Mexico were used. Research was carried out at El Camalote, Culiacan, Sinaloa; Mex., using an complete randomized block design with three treatments and four replicates. Treatments consisted of Agrisure® Viptera TM 3111, its conventional hybrid with two insecticide treatments using emamectin benzoate to control Spodoptera frugiperda during the crop cycle and the same hybrid without chemical control. Visual inspections were preformed every other week, taking 10 plants at random and checking them for the pest to determine the population abundance, frequency and fluctuation. The number of individuals (abundance) of Chaetocnema pulicaria evaluated in each material was analyzed by non-parametric statistic using the Kruskal-Wallis test in order to observe changes in the insect population. Different corn hybrids have been genetically modified (GM) by the insertion of genes that express the ∂-endotoxin of Bacillus thuringiensis (Bt) (Bruck et al. 2006), in which the plant expresses the protein with insecticidal activity against Lepidoptera and some Coleoptera insects (Silva, 2005). In Mexico, GM corn planting is not authorized for commercial purposes; however, Bt maize planting was permitted experimentally under biosafety conditions to test their pest control effectiveness. The objective of this research was to evaluate the effect of a GM corn hybrid Agrisure® Viptera TM 3111 with the Cry1Ab and Vip3Aa20 toxins of Bacillus thuringiensis (Bt) which provides resistance to Lepidoptera and mCry3A to Coleoptera, over abundance of the corn flea beetle Chaetocnema pulicaria, in Sinaloa, Mex. GENETICALLY MODIFIED CORN EFFECT OVER Chaetocnema pulicaria (COLEOPTERA: CHRYSOMELIDAE) AS A NON-TARGET PEST Agustín Hernández-Juárez &, Luis. A. Aguirre-Uribe*, Mariano Flores-Dávila, Gustavo A. Frías-Treviño, Ernesto Cerna-Chávez, Jerónimo Landeros-Flores. Departamento de Parasitología. Universidad Autónoma Agraria Antonio Narro. Calzada Antonio Narro # 1923, Buenavista, Saltillo; Coahuila, México. & PhD student, chinoahj14@hotmail.com, *luisaguirreu@yahoo.com.mx INTRODUCTIONMATERIALS AND METHODS RESULTS AND DISCUSSION Bruck, J. D., Lopez, M. D., Lewis L. C., Prasifka J. R. and R. D. Gunnarson. 2006. Effects of Transgenic Bacillus thuringiensis Corn and Permethrin on Nontarget Arthropods. J. Agric. Urban Entomol. 23(3): 111-124. Daly, T. and G. D. Buntin. 2005. Effect of Bacillus thuringiensis Transgenic Corn for Lepidopteran Control on Nontarget Arthropods. Environ. Entomol. 34(5):1292-1301. Dively, G. P. and R. Rose. 2002. Effects of Bt transgenic and conventional insecticide control on the non-target natural enemy Community in sweet corn. 1st International Symposium on Biological Control of Arthropods. Forest Health Technology Enterprise Team. United States. 265-274 p. Silva, C. C. A. 2005. Maíz Genéticamente Modificado. AGRO-BIO. Bogotá, Colombia. 60 pp. LITERATURE CITED Table 1. Abundance of Chaetocnema pulicaria in genetically modified corn Agrisure® Viptera TM 3111 and conventional hybrid in El Camalote, Culiacan, Sinaloa, Mex. Hybrid Abundance Population mean 1 Agrisure® Viptera TM 3111 397 79.4 Conventional hybrid +i 188 37.6 Conventional 299 59.8 Fig.1. Population fluctuation of Chaetocnema Pulicaria in genetically modified corn Agrisure® Viptera TM 3111 and conventional hybrid in El Camalote, Culiacan, Sinaloa, Mex. +i=insecticide; 1 P= 0.932, df=2 Results show that the GM corn expressing the Bt toxin does not have a negative effect on the abundance or changes in population density of C. pulicaria. Dively and Rose (2002) found greater abundance of flea beetle and no adverse effects were observed with Bt corn and mentioned that insecticide control has a negative impact on non-target secondary pests. Daly and Buntin (2005), studied populations of non-target arthropods in Bt corn and found no differences among them indicating that secondary pests such as C. pulicaria presented greater abundance in Bt corn and suggested that they are not adversely affected concluding that GM corn does not present adverse effects over non-target populations in corn. A 100% frequency was found throughout the growing season in the three hybrids evaluated (Fig. 1); population density did not differ among evaluated hybrids (Table 1), although is observed that the GM hybrid had a higher density and abundance than its conventional hybrids. Agrisure® Viptera TM 3111 showed the highest number of C. pulicaria, probably due to a greater availability of food resources. Conventional hybrid with insecticide treatment had the lowest population density with respect to Agrisure® Viptera TM 3111 and the conventional hybrid without insect control, suggesting that chemical control with emamectin benzoate affected the abundance of corn flea beetle, while the same hybrid without insect control, showed a decrease in population density, which was influenced by leaf damage caused by fall armyworm in this hybrid, leading to a reduced availability of food for corn flea beetle.