Resistência de cultivares de trigo à Sitophilus zeamais (Coleoptera: Curculionidae)

Abstract

Sitophilus zeamais is one of the main stored grain pests. The resistance of populations to control and concern about residues of active ingredients in food, combined with the great post-harvest loss even with all the existing control technology, has led to the need to study new control alternatives. Cultivars of wheat (Triticum aestivum L.) appears as one of the alternatives to this problem aiming at sources of resistance. The objective of this work was to identify S. zeamais resistant wheat varieties and to identify possible resistance types related to insect and cultivar interactions. The experiment was carried out in the laboratory of Entomology of the Federal Technological University of Paraná, Campus of Pato Branco. Five wheat genotypes, TBIO Iguaçu, TBIO Mestre, 140318, 15419 and 15314 were used. The genotypes were not submitted to any phytosanitary treatment, aiming to control insects or fungi. Five replicates were used for each genotype, with 50 g of wheat for each replicate with 20 adults of unsexed S. zeamais insects. The containers were kept for ten days at a temperature of 27 ± 2 ° C and U.R of 60%. Subsequently the insects were removed, and after 30 days daily observations were initiated to follow the emergence of adults. The number of insects emerged, duration of the egg-adult cycle, loss of mass consumed of the grains. The data were statistically evaluated using the F test and the means compared by the Tukey test, with a significance level of 5%. It was verified that genotypes 15319 and TBIO Iguaçu presented greater resistance, increasing the duration of the biological cycle, reducing the number of insects emerged, while genotype 140318 presented susceptibility, having a shorter biological cycle duration, and a higher number of insects emerged.