Acaricide resistance in field collected two-spotted spider mite, Tetranychus urticae from Okra in Punjab

Bioassay studies were conducted in the laboratory to determine the effect of four acaricides on different field collected populations of two-spotted spider mite, Tetranychus urticae Koch, from okra. There were statistical differences in susceptibility to different acraicides (propargite, spiromesifen, fenpyroximate and fenazaquin) in different regions (Abohar, Malerkotla, Ludhiana) of Punjab. The population with a resistance ratio of more than 60 with respect to an acaricide was considered as resistant population to the acaricide. Among all the acaricides, low to higher levels of resistance (0–27, 550 fold) was observed in mites to tested acaricides in Punjab. The highest resistance ratio (27,550 fold) was found in Malerkotla population for fenazaquin as compared to Ludhiana populations, while Ludhiana populations had more resistance ratio (11,720 fold) for spiromesifen as compared to the other populations. In case of propargite, highest resistance ratio was 3,725fold in Ludhiana population.