Laboratory Investigation on the Effect of Some Plant Extracts on the Development of Culex quinquefasciatus

الملخص

Ethanol and acetone extracts of four species of plants (Allium tuberosum, Apium leptophylum, Carica papaya and Cymbopogon citratus) were tested in respect of their influence on the development of pre-imaginal stages of mosquito (Culex quinquifasciatus) in concentration 100, 10 and 1mg/L. Eight experiments, four replications were conducted in each case. For each replication, 25 first stage larvae were placed in each dish of experiment and control. The developments of larvae were followed daily till the completion of cycle. All concentrations of ethanol and some of acetone extracts of A.tuberosum were significantly prolonged the time of the growth beside increase mortality of larvae in acetone extract of concentration 100mg/L during development. A. leptophyllum in ethanol and acetone extracts of concentrations 100mg/L, the developmental period of the pupal stage and in acetone extract of 10mg/L from L4 to pupa were significantly lengthened. Also, the same vegetable in both extracts produce mortality during this experiment. The two extract of C. papaya in 100mg/L and the extracts of C. citratus in 100 and 10 mg/l were prolonged time of the development and causing high mortality, out of 100/100 and 77(100) in ethanol and acetone extracts of C. papaya respectively but only acetone extract of C. citratus lead to high mortality of larvae 25/100 in 100mg/L. The differences in obtained responses necessitate the adoption of deeper research to isolate the active principle of such plants for potential use in mosquito control program