Insecticidal activity of extract from Datura stramonium (F.) (Solanaceae) againstCallosobruchus maculatus

Abstract: Higher plants are a rich source of novel insecticides. Plant materials with insecticidalproperties have been used traditionally for generations throughout the world. Botanicalinsecticides compared to synthetic ones may be safer for the environment, are, generally, lessexpensive, easily processed and used by farmers and small industries. However, many plantspecies, especially from tropical regions, have the potential to be used as botanical insecticide oras font of bioactive compounds. In this study, extract of powdered leaves, stems and seeds fromDatura stramonium was obtained by a rotary evaporator apparatus and was tested underlaboratory conditions for its ability to control some stored products from attack byCallosobruchus maculatus. The experiments were conducted at 27±1°C, 60±5 % R.H. and indark condition. The mortality of adults was tested at different concentrations and two exposuretimes (24 and 48h). The effect of different concentrations on egg hatching was also tested after 6days. Also sublethal effect of different concentrations was tested on oviposition rate. The resultsshowed that the mortality increased with increases in concentration and exposure time. After 12h,high increases in mortality were seen. Data probit analysis demonstrated that lethal concentrationto kill 50% of the population (LC50) was estimated as 1680 and 16058ppm, for 24 and 48h,respectively. These results suggest that extract of D. stramonium may be of high value in grainstorage against C. maculatus, especially in subsistence agriculture where the plants are locallyavailable to farmers with little resources to meet the high cost of pesticides.