Contact and fumigant toxicity of five pesticidal plants against Callosobruchus maculatus (Coleoptera: Chrysomelidae) in stored cowpea (Vigna unguiculata).
Resource type
Journal article
Date published
December 2015
Abstract
Insecticidal activities of five pesticidal plant species, , (Syn: ) , , and , which have been reported to control storage pests, were evaluated as leaf powders against (Fabricius 1775) in stored cowpea. Their efficacy was compared with the commercial pesticide Actellic dust (pirimiphos-methyl) at the recommended concentration (50 g/90 kg), and with untreated cowpea seeds as a negative control. The plant powders were applied at concentrations of 0.01, 0.1, 1 and 3 g/10 g of cowpea seeds in 250 ml plastic containers (to measure contact toxicity), or 0.005, 0.05, 0.5 and 5 g tied in small muslin cloth bags and hung in 500 ml plastic bottles containing 10 g of cowpea seeds (to measure fumigant toxicity). Mortality of adults, oviposition deterrence, adult emergence, and percent seed damage were recorded. Complete protection of seeds and inhibition of adult emergence were achieved in Actellic dust-treated seeds; contact toxicity using leaf powders of at all concentrations, at concentrations of 0.1, 1 and 3 g and at concentrations of 1 and 3 g; and fumigant toxicity using . at concentrations of 0.5 and 5 g and . at a concentration of 5 g. Head space analysis of . and . identified ascaridole and camphor, respectively, as components that could be responsible for the bioactivity of these plant species. These plants may, therefore, serve as effective but less harmful biopesticide alternatives to Actellic. Conversely, . and . were not effective, indicating that they should not be promoted for controlling bruchids in cowpea.
Journal title
International Journal of Tropical Insect Science
Volume
35
Issue
4
Publisher
Springer Science and Business Media LLC
Place of publication
Berlin/Heidelberg, Germany
ISSN
1742-7584
eISSN
1742-7592
Official URL
Rights statement
In Copyright
Collection
Philip Stevenson