Toxicity of Boldo Peumus boldus Molina for Sitophilus zeamais Motschulsky and Tribolium castaneum Herbst

Abstract

The maize weevil (Sitophilus zeamais Motschulsky) and the red flour beetle (Tribolium castaneum Herbst) are two key pests of stored-grain products worldwide. The insecticidal activity of boldo (Peumus boldus Molina) powder, liquid ethanolic and hexanic extracts against S. zeamais and T. castaneum were evaluated under laboratory conditions. The evaluated variables were mortality, emergence of adult insects (F 1 ), and grain weight loss. The experimental design was completely randomized. The mortality in S. zeamais was 100% even at the lowest powder concentration (0.5% w/w), whereas emergence of F 1 adult insects was 0% and grain weight loss was ≤ 0.08%. For T. castaneum, only 8 and 16% w/w powder concentrations reached 100% mortality. The liquid ethanolic and hexanic extracts caused 100% mortality of S. zeamais, whereas only the ethanolic extract reached this value for T. castaneum. Therefore, the powder and the evaluated extracts of P. boldus were toxic for S. zeamais and T. castaneum and are promising against these and other stored-grain pests.

Antifeedant and insecticidal effects of extracts from Melia azedarach fruits and Peumus boldus leaves on Xanthogaleruca luteola larvae

“…An efficient method for the reduction of pests, and the most used since the 1940s, has been the use of synthetic insecticides (Boulogne et al, 2012;Ortiz et al, 2012). This control is feasible because it is quick, easy to apply, and initially relatively cheap (Mahajan et al, 2009).…”

Walking stability of Rhyzopertha dominica (Fabricius, 1792) (Coleoptera: Bostrichidae)

“…Rhyzopertha dominica and T. castaneum have been studied under different climatic conditions, with variations as needed (Aguiar et al, , 2010Beckel et al, 2005;Fontes and Arthur, 1994;Gonçalves et al, 2006Gonçalves et al, , 2007Moino Junior and Alves, 1997;Oliveira et al, 2003Oliveira et al, , 2006Silva et al, 2003), and care with the method of simulating the physical structure of the storage unit should be taken into consideration so that the results may express the condition closest to the actual condition (Beckel et al, 2005;Gonçalves et al, 2006Gonçalves et al, , 2007Ortiz et al, 2012;Pacheco et al, 2009).…”