Estudo da preferência de Scaptocoris Carvalhoi (Becker, 1967) entre cultivares de milho transgênico e não transgênico

Abstract

The area under maize is around 12 million hectares in Brazil. However, this crop has a high yield potential, it may be directly affected by the attack of several insects from planting to its storage. This study aimed to compare transgenic maize cultivars and non-GMO, based on the levels of population migration of the brown-roots bug (S. carvalhoi) nymphs in test with opportunity of choice. Three varieties of plants were established in a group of six circular container formed of PVC, symmetrically linked by an open communication with a free passage to a central circular container. The experiment was organized in a completely randomized design and consisted of three treatments and eight repetitions. Evaluation test was conducted on the 60th day after the release of nymphs, by counting insects that have migrated into the roots of different plants. It has been shown that the nymphs of 1st, 2nd, 3rd and 4th stages, respectively, 17.5; 23.33; 34.16 and 19.16% choose for some cultivar studied. It was found that 22.5; 30.0 and 0.0% of nymphs of the first stage, chose respectively Dekald 390 YG, Syngenta Impact (conventional) and Pioneer P30F53 YG. About second stage nymphs 37.5; 27.5 and 5.0%, chose respectively Dekald 390 YG, Syngenta Impact (conventional) and Pioneer P30F53 YG, and 52.5%, 35.0% and 15.0% of third instar nymphs, choose, respectively, conventional, Dekald 390 and Pioneer P30F53 YG and 27.5; 15.0 and 15.0% of nymphs of fourth stage, choose respectively Dekald 390 YG, Syngenta Impact (conventional) and Pioneer P30F53 YG. Nymphs of the first, second, third and fourth stages were concentrated in larger quantities in conventional plant varieties and Dekald YG 390, in lower concentrations in Pioneer P30F53 YG. Pioneer P30F53 YG was the cultivar with the lowest preference (IP) by the nymphs of first, second and third stages. We conclude that corn hybrid variety Pioneer F53YG demonstrates not be attractive to S. carvalhoi nymphs, with potential for use in infested areas. Hybrid Dekalb390 YG and Syngenta Impact (conventional) are attractive to brown bug of roots (S. carvalhoi), not recommended cultivation in areas infested by the insect.