author(s)
M Visnupriya and N Muthukrishnan

abstract
Pot culture experiments were conducted in the Insectary of AC & RI, Madurai in order to assess the persistent toxicity of spinetoram against H. armigera and S. litura on tomato fruits and leaves respectively. Insecticidal solutions were prepared by dissolving spinetoram 12 SC 0.6 ml, 0.75 ml and 0.9 ml, indoxacarb 14.5 SC 1.04 ml, novaluron 10 EC 1.5 ml and quinalphos 25 EC 2.0 ml in one liter of water which were equivalent to the field doses. Insecticide solutions treated tomato fruits and leaves were put in a container and released 20 numbers of H. armigera and S. litura respectively in each container. Observations on larval mortality were recorded from each treatment at 24 h intervals and calculate persistence toxicity. More than 50 per cent mortality of H. armigera larva was observed in spinetoram 12 SC at 45 and 54 g a.i./ha and indoxacarb 14.5 SC at 75 g a.i/ha upto 11 DAT where as that was upto 7 DAT for spinetoram 12 SC 36 g a.i/ha and novaluron 10 EC at 75 g a.i/ha. Spinetoram 12 SC was applied at 54 g a.i./ha, cent per cent mortality of third instar of S. litura larvae was observed at 1 DAT and 3 DAT, 90.87 at 5 DAT and there was no mortality after 21 DAT. The ORE of the insecticides based on PTI values was spinetoram 54 g a.i./ha > spinetoram 45 g a.i./ha > indoxacarb > novaluron > spinetoram 36 g a.i./ha > quinalphos.