Development of resistance was estimated in open and polyhouse populations of thrips and mites on rose, whitefly on gerbera; thrips on chilli for some of the commonly used pesticides. It was found that all the pests have developed considerable degree of resistance to insecticides tested, though the level of resistance varied. Polyhouse populations of thrips, Scirtothrips dorsalis were found to have developed 4.15 folds resistance to imidacloprid whereas mites, Tetranychus urticae have developed 4.2 folds resistance to Abamectin.
On Rose, Synergistic action of various aromatic oils tested at 0.1 % in combination with half the recommended dose of acephate (0.5 g/l) against thrips, Scirtothrips dorsalis showed, highest synergistic action (26.93 % additional mortality) with diphenyl oxide.
Studies for the management of insecticide resistant thrips, mites and whiteflies etc under Polyhouse conditions were carried out. Pongamia oil and annona oil (both at 0.1 %) showed significant synergistic action in combination with the dicofol.
Pongamia oil 0.2 % with Deltamethrin 1 ml/l showed high synergistic activity in controlling whitefly on gerbera (98.33 % mortality).
Estimation of resistance in Aphis craccivora against dimethoate in different field collected Populations revealed development of highest resistance to dimethoate in A. craccivora in Devanahalli population, followed by in Hoskote population and Thurbanahalli population.
1. Sridhar, V. and Jhansi Rani, B. 2012. Bio-efficacy of Clofentezine 50 % SC against two spotted spider mite, Tetranychus urticae Koch on Rose cv. First red in Polyhouse. Pest Management in Horticultural Ecosystems 17 (2): 127 -131.
2. Sridhar, V. and Jhansi Rani, B. 2010. Synergistic effect of neem and pongaima oils on the bioefficacy of deltamethrin against diamondback moth, Plutella xylostella (L.) (Lepidoptera: Yponomeutidae) on Cabbage. Pest Management in Horticultural Ecosystems 16 (2) : 168-173.