EFFECT OF DRIED PLANT POWDER IN THE MEXICAN BEAN WEEVIL (Zabrotes subfasciatus Boheman) AND ITS DAMAGE TO STORED LIMA BEAN (Phaseolus lunatus L.

Abstract

Background. Plant powders are ecological agents for pest management in grains stored by small-scale farmers. Objective. This study was conducted to evaluate the effects of plant powders of leaves of basil (Ocimum basilicum), spearmint (Mentha spicata), wormseed (Chenopodium ambrosioides) and rue (Ruta graveolens) on the mortality, repellency and infestation of Zabrotes subfasciatus in stored grains of Phaseolus lunatus. Methodology. The plant powders were applied at concentration of 1% (weight/weight) to grain samples stored in plastic containers and subsequently the grains were infested with Z. subfasciatus adults. Results. The powder of C. ambrosioides caused 96% and 100% mortality in Z. subfaciatus adults at 2 and 4 days after exposure, respectively. The powder of C. ambrosioides caused a decrease in oviposition and progeny production.  The powder of C. ambrosioides completely prevented the damage to the grain. Plant powders of the other species had minimal repellent effects. Implication. Plant powders represent a feasible alternative to manage pest insects of stored grain. Conclusion. The powder of C. ambrosioides prevents damage by Z. subfasciatus in stored grains of P. lunatus.