AGRICULTURAL RESEARCH COMMUNICATION CENTRE www.arccjournals.com/www.legumeresearch.in Legume Research, 38 (2) 2015 : 260-267 Print ISSN:0250-5371 / Online ISSN:0976-0571 Field evaluation of newer insecticide molecules and botanicals against pod borers of Red gram S. Sambathkumar * , C. Durairaj, N. Ganapathy and S. Mohankumar Department of Agricultural Entomology, Tamil Nadu Agricultural University, Coimbatore- 641 003, India. Received: 30-04-2014 Accepted: 12-08-2014 DOI:10.5958/0976-0571.2015.00048.X ABSTRACT Field experiments were conducted during Kharif 2012 to evaluate the efficacy of newer insecticides and botanicals followed by Indoxacarb against pod borers infesting redgram variety CO 6. Among newer insecticides, the significant least incidence of Maruca vitrata was recorded in indoxacarb 15.8 EC @ 75 g a.i./ha (3.1 webbings/ 10 plants) and chlorantraniliprole 18.5 SC 30 g a.i./ha (3.9 webbings/ 10 plants). The minimum larval population of Helicoverpa armigera was recorded in chlorantraniliprole 18.5 SC @ 30 g a.i./ha (9.5 nos./ 10 plants) and indoxacarb 15.8 EC @ 73g a.i/ha (10.3 nos./ 10 plants). Low per cent podfly grain damage (11.7) was recorded in chlorantraniliprole 18.5 SC @ 30 g a.i./ha with the highest yield of 892.2 kg/ha in indoxacarb 15.8 EC @ 75g a.i/ha. Among botanicals and combination of botanicals and indoxacarb spray, least number of Maruca webbings, minimum Helicoverpa larval population (18.3), Helicoverpa pod damage (16.3%) were recorded in Neem soap (10g) followed by indoxacarb (0.5ml) (5.7/ 10 plants) with maximum yield of 732.9 kg/ha in Pongamia soap (10g) followed by indoxacarb (0.5ml). Key words: Botanicals, Helicoverpa armigera, Maruca vitrata, Newer insecticides, Redgram. *Corresponding author’s e-mail: sambathagritech@gmail.com, INTRODUCTION Pulses have a unique position in sustainable crop production as they provide highly nutritive food from seeds and keep the soil alive and productive from root nodules. Pigeonpea is the second important pulse crop next to chickpea, accounting for about 1.18 per cent of total pulse area and 17.00 per cent of total pulse production of the country (Kunal Shah and Anuj Agarwal, 2009). Though, India has the distinction of being the world’s largest producer of pulses, the average productivity is low because of the abiotic and biotic stresses. On an average, 2.5 to 3.0 million tonnes of pulses are lost annually due to pest problems (Rabindra et al., 2004). The major insect pests during different growth stages are thrips, whitefly, leafhopper and stemfly caused appreciable damage. But, worldwide, over 30 species of lepidoptera feed on pods and seeds of redgram (Shanower et al., 1999). Among them, Legume pod borer, Maruca vitrata Geyer, gram pod borer, Helicoverpa armigera Hubner and podfly, Melanagromyza obtusa Malloch are the major biotic constraints in increasing the production and productivity under subsistence farming conditions of redgram, irrespective of agroecological zones. The larvae of H. armigera feed on seedling foliage, flower buds, flowers, young pods and developing seeds. Infestation of M. vitrata is a highly challengeable menace, ultimately reducing the quality and quantity of the economic produce. The concealed feeding of this pest complicates control by pesticides and difficulty in penetration to feeding sites by natural enemies. According to Naresh and Jaipal Singh (1984) the pod and seed damage caused by M. testulalis was 11.56 and 6.38 per cent respectively on pigeon pea. The infested immature pods do not show external evidence of damage until the fully grown larvae chew exit holes in the pod walls. It damages seeds by making bore holes and tunnels in them. Damaged grains shrivel and insect excreta lead to development of saprophytic fungus, which further destroys the grain. Moreover, continuous focus of redgram pest management research has been on H. armigera and large scale cultivation of transgenic cotton in Tamil Nadu, pest scenario on redgram has changed to pay more attention on M. vitrata and M. obtusa also. Management of redgram pest is complicated as crop is affected by three groups of insect with different biology and variable population dynamics occurring throughout year across wider geographical areas. Sole reliance on chemical pesticides led to development of resistance and resurgence of secondary pests.