Análise da eficácia de extratos vegetais no controle da praga Sitophilus spp. em grãos armazenados.

Abstract

With the increasing of population along the human evolution, man has had to eliminate countless ecsystems to increase food production, and this has been done up to today. This down of ecological balance has bought some changes on insects' behavior have been developed and used greatly to keep control on these plagues, man has realized that this came to couse harms to ecosystems where used, and chemicals have affected man as well. The aim of this work is identification of active principlesof vegetable extracts to control the plague insect Sitophilus spp. The methodology in use was cold extraction to obtain extracts and the division into polar, non-polar and waterish substances in several concentrations. The extraction aplication has been done by the "steanTmethod. The species used for extraction were croton, orange and pepper. The first part of chromatography and the analysis of phisiological proprieties were made with the tested product. Results indicated that extracts of croton and pepper presented remarkable signs of insect mortality. The orange extract used in different concentrations didn't indicate remarkable mortality and the egg eclosion was controled parcially. The wet meaning, germination and alrenght of the corn weren't changed after extract aplication in its respective treatment. The DL50 and the DL»o of croton extract were 425,8 ppm ( mg / L ) and 796.26 ppm ( mg / L ), respectively. Meanwhile, the pepper extract presened a DL5 0 of 425,8 ppm ( mg / L ) and DL?o of 796,26 ppm ( mg / L ). With tills work, we've come in to the conclusion that extracts of red pepper and croton indicate high toxin related to the alternative control of plague insect Sitophilus spp. The orange ectract. when separated and tested in shares, hasn't presented and pesticide affect. The aplication of extracts directly from corn hasn't changed its phisiological quality to the used parameters.