Repellent and toxic activities of fumes of some plant materials against Culex mosquito
Mosquito coils (bars), formulated from three plant leaves, namely; Acalypha torta, Carica papaya and Calotropis gigantica, and seeds of Peganum harmala, were tested as repellents or toxicants against laboratory reared Culex sp. adult mosquitoes when burnt as an incense. None of the plants showed toxic activity, as knockdown was less than 5% in all cases. Slight repellency was observed with Acalypha sp. (0.21) and P. harmala (0.19), as these showed significant difference (P < 0.05) from values recorded for the control, i.e. bars without plant material.