Abundance of Non-Target Predators in Genetically Modified Corn

Abstract

Genetically modified corn (maize) Zea mays (Poaceae) expressing Bacillus thuringiensis (Bt) Berliner (Bacillaceae) toxins is a controversial issue due to the risk they could pose to predators as non-target organisms. Thus it is important to evaluate that risk before Bt corn is released for commercial planting in Mexico. The effect of genetically modified corn hybrid Agrisure® VipteraTM 3111 on the abundance of non-target predators Orius insidiosus Say (Hemiptera: Anthocoridae), Coleomegilla maculata (De Geer) (Coleoptera: Coccinellidae), and Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae) was evaluated at Oso Viejo and El Camalote in Culiacan, Sinaloa, and compared with its non-genetically modified isoline with and without insecticide treatment in a randomized complete block design with 3 treatments and 4 replicates. Complete plant visual samplings were performed to determine predator abundance, frequency, and population fluctuation using the Kruskal-Wallis non-parametric statistical test. A total of 5,228 predators were collected in all hybrids in both localities: 2,431 at Oso Viejo and 2,797 at El Camalote with 2 peaks before and after pollination. In both locations, each predator population had a similar fluctuation in all hybrids. Although no statistical difference was found among treatments, in all cases, Agrisure® VipteraTM 3111 had higher abundance than the isolines with and without insecticide treatment. Results show that Agrisure® VipteraTM 3111 does not have a negative effect on predator abundance of O. insidiosus, C. maculata, and C. carnea.