Insecticide activity of plant extracts of the northeastern Brazilian flora for the control of Sitophilus Zeamais [Mots, 1885] AND Sitotroga Cerealela [Olivier, 1819]

Abstract

One of the typical crops of the semiarid tropic is the maize Zea mays L., a rustic plant cultivated in the Brazilian northeastern semiarid region mainly by small farmers. It is one of the sources of protein and carbohydrates and an economic alternative for job creation, especially for rural populations. Among the factors limiting its cultivation are pests, among which weevil and Angoumois grain moth. This work aims to evaluate the insecticide activity of plant extracts obtained from medicinal plants of the Brazilian northeastern flora for the control of Angoumois grain moth and weevil under laboratory conditions. The methodology consisted in the production of plant powders, which were mixed with 99.8% alcohol, and then macerated and filtered. Using a rotary evaporator and applying a water bath, it was possible to separate the alcohol from the filtered solution, resulting in a creamy paste, which is the extract itself, later used in tests with insects. Preliminary tests were applied at the concentrations of 0% [control] to 100% ml of extracts. Extracts with a mortality rate ³50% were analyzed by bioassays and four replicates, each consisting of a lot of five insects. The experimental design was completely randomized.