Abstract

                                The field experiments were conducted at Regional Research Station,Vriddhachalam, during rabi/summer season for three consecutive yearsfrom 2012 to 2015 to test the efficacy of newer molecules insecticidesagainst sucking insect pests thrips and leafhopper in groundnut. Amongthe seven newer molecule insecticides tested, imidacloprid 200SL @ 200ml ha-1 was found to be effective in reducing thrips damage (16%) followedby thiamethoxam 25WG @ 200gm ha-1 (18%) as against 33% in control.Imidacloprid 200SL and acetamiprid 20%SP@ 100 gm ha-1 registeredless incidence of leafhopper (15%) compared to control (32%). Therefore,acetamiprid 20%SP @ 100 gm ha-1, thiamethoxam 25WG @100 gm.ha-1gm/ha and imidacloprid 200SL @ 200 ml. ha-1 were found to be effectiveagainst thrips, leafhopper population and its damage. These three moleculesrealized more dry pod (2274 kg/ha-1, 2013 kg ha-1, 2100 kg ha-1) andhaulm yield (8.2 t ha-1, 7.6 t ha-1, 7.8 t ha-1) and ultimately the benefit costratio of 1:2.8; 1:2.4 and 1:2.5 respectively. However, imidacloprid 200SLand thiamethoxam 25WG 200 ml ha-1 recorded more number of predatorycoccinellids (0.51 and 0.40 plant-1), spider (0.27 and 0.24 plant-1), spideregg mass (0.10 and 0.12 plant-1). Thus, the use of imdiacloprid 200SL orthiamethoxam 25WG individually or incorporation of these chemicals in anintegrated pest management programme for sucking pests on groundnutmay prove as economically viable with less effect on natural enemies ingroundnut eco-system during rabi/summer seasons.

Key words : acetamiprid; imidacloprid; thiamethoxam; coccinellids; spiders; groundnut