Vol. 2, Issue 1, Part A (2015)

Author(s): Sweta Bhan, Lalit Mohan, Chand Narayan Srivastava

Abstract: The present study was carried out to evaluate the larvicidal efficacy of Temephos and the Petroleum ether, Hexane and Methanol extracts of Cuscuta reflexa alone and their combinations against the anopheline and culicine larvae. It describes the compatibility of synthetic insecticide, Temephos and phytoextract, C. reflexa. Different combination ratios of Temephos and petroleum ether extract of C. reflexa viz. 1:1, 1:2 and 1:4 were prepared and evaluated for their larvicidal potentiality against larvae of Anopheles stephensi and Culex quinquefasciatus. Among these combination ratios 1:1 were found to be more effective than other ratios with LC₅₀ 0.0013, 0.0010 and 0.0009 mg/L and LC₅₀ of ­­ 0.0016, 0.0014 and 0.0013 mg/L against anopheline and culicine larvae after 24, 48 and 72 hours of treatment, respectively. The co-toxicity coefficient for the 1:1 mixture were 178.57, 191.67 and 181.82 and synergistic factor 1.78, 1.92 and 1.82 at LC₅₀ after 24, 48 and 72 hrs against anopheline larvae. Against culicine larvae, the co-toxicity coefficient and synergistic factor for the 1:1 mixture were 375, 357.14 and 307.6 and 3.75, 3.57 and 3.08 respectively, at LC₅₀ after 24, 48 and 72 hours of exposure. The combination of Temephos and C. reflexa is an ideal eco-friendly and cost effective approach to combat mosquito vectors.

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