The bio-efficacy of plant extract of Parthenium was analyzed by studying the nutritional indices such as weight gain, consumption index (CI), approximate digestibility (AD), efficiency of conversion of digested food (ECD), efficiency of conversion of ingested food (ECI) in the larvae of Hyblaea puera and Eutectona machaeralis. The aqueous extract of Parthenium significantly reduced the food ingestion in the larva of H.puera when compared to control. The level of food ingestion was very low in 1% treatment whereas in other concentrations, the nutritional indices were increased. Though the food ingestion and weight gain were increased in the 5% treatment, the consumption index was lower than the control. The same plant extract in the larva of E. machaeralis increased the CI but the ECD and ECI were very less as compared to control. The heterogeneous levels of nutritional indices revealed the various responses of the H.puera and E.machaeralis.
