Insecticidal and Repellent Activity of Plant Powders on the Weevil (Sitophilus zeamais) in Stored Corn Grains in a Rural Community of Oaxaca, Mexico

The bioinsecticidal and repellent effect of four plant powders (<i>Chenopodium ambrosioides</i>, <i>Piper auritum</i>, <i>Laurus nobilis</i>, and <i>Origanum vulgare</i>) was evaluated in the control of <i>Sitophilus zeamais</i> adults in corn grains stored in the rural community of Santa María Zacatepec, Oaxaca, Mexico. Using completely randomized experimental designs, concentrations of 1%, 2%, and 3% by mass of corn grains infested with adults of <i>S. zeamais</i> were tested; the controls were corn without powder and aluminum phosphide. The analysis was performed using ANOVA with Tukey's post hoc and Student's t-tests. The highest mortality (>80%) and repellent effect (Repellent Index < 0.3) that were statistically significant were obtained with <i>C. ambrosioides</i> and <i>P. auritum</i> at 3%. Both plant species have the potential for weevil control in stored corn and represent a friendly alternative for the environment and public health in the rural community where the study was conducted.