Bioefficacy of plant extracts on ovicidal and oviposition deterrent against sugarcane stalk borer Chilo auricilius Dudgeon (Lepidoptera: Crambidae)

Abstract

Sugarcane is a long-duration crop of 10-12 months and therefore is liable to be attacked by several insect pests. The present study aimed at assessing the ovicidal, oviposition, and larvicidal potential of two medicinal indigenous plants. Bioefficacy of Nerium indicum Mill. and Murrya koenigii L. spreng leaves extracts were tested against Chilo auricilius D. sugarcane stalk borer. The plant extracts prepared by sequential extraction method using a different solvent like, petroleum, chloroform, methanol, distilled water, and acetone at different concentrations were used. Ovipositional behavior of adult moths and the hatching percentage of the eggs were recorded using the choice method for each fraction of the plant extract. The chloroform extract of N. indicum 2.66% eggs/female and chloroform/petroleum ether extracts of M. koenigii 9.33% eggs/female were found to be effective, and reduced oviposition as compared to other extracts. At 20% concentration, petroleum ether and distilled water extracts of N. indicum 52.00 and petroleum ether extract of M. koenigii gave the lowest larval survival (74.00,72.00 and 70.00%) after 24, 48, and 72 h of exposures, respectively. However, petroleum ether extract of N. indicum at 8, 10, and 20% concentration survival of three days old eggs were registered at 60, 58, and 56%, whereas petroleum ether extract of M. koenigii at similar concentration recorded 77, 47, and 72% survival.