Toxicity and joint action of some plant extracts against Culex pipiens larvae.J. _ Arab Biol

In this study, the larvicidal activity and bioefficacy of two different extracts (acetone and hexane) of Artemisia herbalba, Lavandula multifida, Peganum harmala and Ruta chalepensis against the 3rd instar larvae of Culex pipiens was performed under laboratory evaluation. The toxicity values of acetone extracts based on Lc50 values may be arranged in a descending order as follows: R. chalepensis > P. harmala > A. herbalba> L. multifida. On the contrary, hexane extracts may be arranged as follows: L. multifida > A. herbalba > P. harmala > R. chalepensis. The data also revealed significant decrease in growth index in treated individuals ranged (2.00 - 8.90) when compared to control (11.25). The sublethal concentrations of the acetone extracts induced sterility in the progeny of C. pipiens mosquitoes ranged 61(R. chalepensis) -73% (A. herbalba) whereas, hexane extracts induced sterility ranged 55 (A. herbalba) - 64% (R. chalpensis). There are no negative effects on the hatchability of eggs.