Current status of acaricide resistance in two spotted spider mite, Tetranychus urticae koch and its underlying mechanism

Two-spotted spider mite (TSSM), Tetranychus urticae Koch (Acari: Tetranychidae) is a serious limiting factor in sustainable production of many crops including vegetables, fruits and ornamentals in protected and open field conditions across the globe. Presently, acaricides are the only option to manage this mite pest. In conventional crop management systems, development of resistance necessitates further applications of acaricides, increasing the use of chemicals and the cost of production of a particular crop; thus becoming a cause of concern to the scientific community. T. urticae is the most notorious species in terms of the total number of pesticides to which its populations have become resistant and is reported to have impaired field control efficacy of all established chemical groups of acaricides, including the organophosphates, carbamates, pyrethroids, chlorinated hydrocarbons, mitochondrial electron transport inhibitors (METI) and other acaricides with novel modes of action. Detoxifying enzymes and resistant genes play major roles in imparting resistance. The paper reviews the acaricide resistance status and the underlying mechanisms of various classes of acaricides against T. urticae.