Banca de DEFESA: ANDERSON SILVA DE CARVALHO

ACTION OF HYDROLATE FROM CAATINGA SPECIES ON MORTALITY AND BEHAVIOR OF Sitophilus zeamais, PEST OF STORED GRAIN

Botanical insecticides, corn weevil, mortality, repellency.

The main pest that affects stored corn is Sitophilus zeamais, causing significant losses in production. The most used method to control this pest is the use of synthetic insecticides, which brings a series of factors that harm the health of man and the environment, with that the application of botanical insecticides has gained worldwide emphasis. Therefore, this work aims to evaluate the chemical composition of the hydrosol of 04 caatinga species and its insecticidal and repellent effect in the control of S. zeamais. Leaves of the species, Engl brasiliensis, Senna sp, M. peruiferum Lf and C. argyrophyllus Kunth were collected and submitted to the hydrodistillation process. The chemical characterization of the hydrolates was performed in a gas chromatograph coupled to a mass spectrometer. The fumigating effect of the hydrolates was carried out in fumigation chambers with a capacity of 0.5L, where 10 unsexed S. zeamais adults were confined in 20g of corn. The ingestion and contact mortality test was carried out in Petri dishes (90 × 15 mm) containing 20g of dry and clean corn kernels and 10 unsexed S. zeamais adults. The repellent effect of hydrolates was performed using acrylic arenas, containing 20g of untreated corn and treated with 4 concentrations of hydrolates (100, 200, 300 and 400µL/L of air). 10 adult insects of S. zeamais were placed in the center of the arena and after 48h the repellency index was determined by the formula IR=2T/(T + C). None of the hydrolates showed insecticidal action against S. zeamais, with no significant mortality in the tests carried out. All hydrolates were repellent in at least one of the concentrations, with S. brasiliensis Engl. and Senna sp. Repellent action at a concentration of 200µL, M. peruiferum Lf repellent at a concentration of 300 µL and C. argyrophyllus Kunth repellent with the use of 100 µL of the hydrolate. zeamais, however they can be used in the behavioral management of this insect.