Síntese de feromônios de lepidópteros usados no controle de pragas agrícolas

Abstract

Grain production worldwide tends to keep growing in the next years, but arable is limited. In this context, Brazil invests in technological development to assure productivity meets the demand. Nevertheless, rising numbers of pests threaten crops, from family farms to large landowners. Damage caused by insects lead to losses of billions annually and chemical pesticides are yet the most common tool of control, despite the problems regarding environment contamination and human health issues, due to their cumulative effect. Integrated Pest Management (IPM) prioritizes using less aggressive and more specific molecules, causing less environment impact. Pheromones appear as safe and efficient alternatives to monitor and control these pest insects. Present work aims to synthetize (Z)-7-heptadecene, to evaluate its attractant activity towards Opsiphanes invirae, (Z)-9-tetradecenal, minor pheromone of Helicoverpa armigena, (Z)-9-tetradecenyl acetate and (Z)-9-dodecenyl, sex pheromones of fall armyworm, Spodoptera frugiperda, besides the intermediates of (Z,E)-7,11-hexadecadienyl acetate, major component of the sex pheromones of Pectinophora gossypiella and Sitotroga cerealella. Furthermore, we propose an ,-diol bromination method, using microwave energy. Data indicate that (Z)-7-heptadecene is the sex pheromone of Opsiphanes invirae. (Z)-9-tetradecenal, when added to H. armigera pheromone blend, did not significantly increase the number of males captured during the first trials. The components of the pheromone blend of S. frugiperda were prepared for posterior field trials, as well as the intermediates P. gossypiella and S. cerealella sex pheromone. A fast run and high yield method was proposed to obtain bromo alcohols from ,-diol, through reactions applying microwaves as energy source.