author(s)
Prabhu S, Priyadharshini Pachiappan, Thangamalar A and Veeravel R

abstract
An experiment was conducted to study the effect of dust formulation of milkweed plant (Calotropis gigantea R. Br.) plant parts Viz., leaf, flower, stem, root and whole plant against Helicoverpa armigera (Hubner) (Noctuidae : Lepidoptera). The insecticidal action of dust formulation of C. gigantea plant parts were applied on II, III instar stages of H. armigera larvae with concentrations of 2, 4, 6, 8 and 10 percent. Among the different plant parts, the leaf dust @ 10 percent proved its superiority over other plant parts dust by recording 86.66 percent of mortality followed by eight percent (60.00%), six percent (53.33%), four percent (43.33%) and two percent (33.33%) mortality respectively in second instar larvae of H. armigera. Leaf dust at 10 percent recorded maximum mortality rate of 83.33 percent whereas eight, six, four and two percent recorded mortality of 76.66, 46.66, 40.00 and 26.66 percent respectively in third instar larvae. Hence, the present study revealed that leaves from C. gigantea R. Br have insecticidal properties and could be an alternative candidate for chemical pesticides.