Insecticidal, Oviposition Deterrent and Antifeedant Property of Certain Plant Extracts against Pulse Beetle, Callosobruchus chinensis Linn. (Coleoptera: Bruchidae)

The bruchid Callosobruchus chinensis (L.) is one of the major store grain pest of pulses capable of attacking wide range of legumes viz., green gram, black gram, chick pea and pigeon pea and causes 50 per cent damage during storage within 3 to 4 months. The infestation starts in the field, but heavy damage is done in storage. Hence, the current study was aimed to evaluate the insecticidal, oviposition deterrent and antifeedant activity of certain plant extracts against pulse beetle, C. chinensis under storage condition.

The aquous extracts (10%) of Vitex negundo, Pongamia glabra, Cassia angustifolia and Calotropis gigantea were evaluated against the pulse beetle, Callosobruchus chinensis Linn. were carried out at the Department of Agricultural Entomology, Imayam Institute of Agriculture and Technology, Thuraiyur during 2019–20. The commercial product Azadirachtin was kept as a check and the mortality rate was assessed every 24 Hours after treatment (HAT) for three days.

The mortality rate after 72HAT was 85.8–87.5% with V. negundo, followed by C. angustifolia (73.33–80.00%) and P. glabra (70.0–75.0%). Azadirachtin gave 100% mortality of the beetle. The oviposition deterrence percentage for pulse beetle, C. chinensis was found to be highest in Calotropis gigantea (37.66–68.16%) followed by Pongamia glabra (30.91–41.50) and Vitex negundo (7.58 46.75) per cent, respectively. The antifeedant activity for pulse beetle was found to be very high when treated with Azadirachtin where there was no food consumption. This was followed by V. negundo (0.1 g) and C. angustifolia (0.2 g).