Toxicity of Powders from Fruit Peels of Three Citrus Plants and Leaves of Yellow Sage(lantana Camara) to Callosobruchus Maculatus Affecting Cowpea Seeds and Storage

ABSTRACTThis study evaluated the effect of powders from fruit peels of three citrus plants: lemon (Citrus limon), lime(Citrus aurantiifolia), grape (Citrus paradisi) and the leaves of wild or yellow sage plant (Lantana camara)against the bean beetle Callosobruchus maculatus (Fabricius) infesting cowpea seeds in storage. Replicatedtreatments and untreated controls were laid out in completely randomized design (CRD). In one experiment, theeffect and best rate of application of each botanical material on mortality of C. maculatus adults was determined.In the second experiment, adult emergence and best rate of application of each botanical material on freshly laidC. maculatus eggs was determined and the number of F1 adults that emerged from treated seeds and non-treatedcontrols were counted. Numbers of holed cowpea seeds and percentage weight loss from seeds after F1 adults’emergence were also recorded. Results from the experiments generally showed that within a relatively shortperiod of time and remarkably low powder application rates that were not more than 2% the weight of protectedseeds, two of the botanicals tested: lime (C. aurantiifolia) and lemon (C. limon) fruit peels powders were highlyovicidal to eggs and toxic to adults of C. maculatus, causing 100% kill of the C. maculatus adults and preventedadult emergence from C. maculatus eggs. Finally, Treatments with the lowest number of holed cowpea seeds andadult emergence from the infected seeds also exhibited the lowest percentage weight loss from the seeds and vice versa