Efficacy of Piper betle Leaf extracts against sweet potato weevil Cylas formicarius (F.)

The sweet potato weevil Cylas formicarius (F.) is the most destructive pest of sweet potato. Insecticides used against this pest are highly toxic and hence undesirable. Deploying plant extracts is an ecofriendly alternative. In the present study, the crude leaf extracts of Piper betle L. were evaluated for their efficacy against the adults of C. formicarius at concentrations of 0.625, 1.25, 2.50, 5, 10 and 20 ppm through petri dish bioassay method. Adult mortality was calculated 24, 48 and 72 hr after exposure. Results indicate that the ethyl acetate extract of P. betle gave the maximum mortality; their LD₅₀ and LD₉₀ values were 11.78 and 17.13, 8.68 and 12.81, 6.14 and 10.94 ppm after 24, 48 and 72 hr, respectively.