Toxicity of plant species on Callosobruchus maculatus(Coleoptera: Bruchidae)

Abstract

In order to find ways that are less toxic to the environment and human health, the use of plant species has emerged as an efficient alternative in the control of stored grain pests. The carouscho,Callosobruchus maculatus(F.),is one of the main pests of the storage of cowpea (Vigna unguiculataL.). The objective of this study was to evaluate the toxicity of plant species of Caesalpinia pyramidalis, Curcuma longaL., Origanum vulgare L. and Xylopia aromaticaon C. maculatusmortality. The experimental units were composed of Petri dishes (9.0 x 1.5 cm), with the bottom covered by filter paper containing 0.5g of each vegetable powder for 20g of cowpea beans. Lethal times were estimated for 10, 30, 50, 70 and 90% of insect adults. Four replicates were used. Mortality was observed in all species in the first 6 hours of contact with the extracts, with higher expression for C. longus. After 24 hours of exposure, more than 60% of accumulated mortality was contacted for all species. The interval between 19 and 25 hours was sufficient to cause mortality of 60% of the population according to the plant species, and to cause 90% of mortality, it was necessary between 72 and 90 hours of exposure to the different species. Saffron caused 50% of accumulated mortality with 18h 36 'of exposure, being the most efficient species in the control of adults of C. maculatus, demonstrating the capacity of this species for the development of insecticidal products