Bioefficacy of azadirachtin in controlling culex pipiens pipiens (diptera : culicidae)‎

الملخص EN

Azadirachtin was tested for its effects against First P Pand second instars larvae of mosquito Culex pipiens pipiens (Diptera : Culicidae), laboratory reared larvae were exposed to 0.125 ; 0.250; 0.500 and 0.750 mg / L of azadirachtin in laboratory of biology animal application, biology Department, university of Badji Mokhtar, Annaba, Algeria.

Larvicidal assays were conducted according to standard World Health Organization (WHO) .The results have been exploited according to classic statistical methods.

A linear correlation was revealed between concentration and larval mortality.

At first stage, larval mortality increased from 45.83 % at 0.125 mg / L to 94.44 % at concentration 0.750mg / L of Azadirachtin in direct effect.

The lethal concentration LCR16R, LCR50R and LCR90R in direct effect was measured as 0.056 ; 0.166 and 0.663 mg / L respectively.

Cumulate mortality increased from 54.28 % to 95.71 % at 0.125mg / L and 0.750mg / L respectively.

The LCR16R, LCR50 Rand LCR90R values for Azadirachtin were 0.040 ; 0,127 and 0.555mg / L respectively.

At second stage, larval mortality increased from 39.66 % at 0.125 mg / L to 87.66 % at concentration 0.750mg / L of azadirachtin in direct effect, the LCR16R, LCR50 Rand LCR90R values was 0.063 ; 0.190 and 0.891 mg/L respectively.

In indirect effect the mortality increased from 49.27 % to 91.54 at 0.125mg / L and 0.750mg / L respectively, the LCR16R, LCR50 Rand LCR90R values was 0.041 ; 0.141 and 0.724 mg / L respectively.

After a comparison between the two stages showed that the first stage is the most sensitive than the second stage .The results show that the azadirachtin is promising as a larvici.