Neha Srivastava, Rashmi Morey and Abhay Khandagle
Abstract
Culex quinquefasciatus (C. quinquefasciatus) is found in tropical and warm temperate regionsand can transmitseveral viral diseases like Elephantiasis or Filariasis, West Nile fever, St. Louis encephalitis, and Japaneseencephalitis causes millions of deaths every year. Long term use of synthetic pesticides to control mosquitoes,has led to the emergence of insecticide resistant vector, ecological imbalance, and harm to mammals, watercontamination, toxicity to non-target organisms and residual effects. Therefore, plant based products arebeing searched and evaluated all over the world as an alternative control. The present study evaluated theefficacy of essential oil of Tagetes erecta (T. erecta) and Cymbopogon nardus (C. nardus) as a larvicidal, ovicidal,ovipositional deterrency and adulticidal agent against C. quinquefasciatus. Various bioassays against theIVthinstar larvae, eggs and adults of C. quinquefasciatus were carried out. Five different concentrations of10, 20, 40, 80,160, 320, 640 ppm was prepared for T. erecta whereas 20, 40, 80,160,320, 640, 1280 ppmconcentrations were prepared for C. nardus essential oil to get LC50. Mortality data was calculated by Logprobitmethod of Finney using SPSS 16 (SPSS 2010) following Abbott method. The GCMS analysis of theessential oil of T. erecta and C.narduswas also conducted to estimate the presence of bioactive compunds inthe essential oils. The essential oil of T. erectaand C.nardus, showed LC50 at 42.02 ppm and 160.29 ppmrespectively after 24 hours. Whereas LC50 after 48 hrs is recorded at 39.25 ppm in T. erectaand 94.39 ppm inC. nardus against C. quinquefasciatus. At 40 ppm, T.erecta showed ovicidal activity with 40.99%, ovipositionalactivity with 57.80% and adulticidal activity with 88.00%. On the other hand, C. nardus at 160.29 ppmexhibited ovicidal activity with 77.63%, ovipositional activity with 73.33% and adulticidalactivity with73.6%. Many active phytochemicals was also found in the essential oil of T. erecta and C. nardus. It is concludedthat the essential oil of both T. erecta and C. nardus are very effective mosquitocidal agent against C.quinquefasciatus. However T. erectashows more effective results in comparision to C. nardus.