Experimental and Applied Acarology (1998) 22, 17-30

G.A. Herron, V.E. Edge, L.J. Wilson and J. Rophail (1998)
Organophosphate resistance in spider mites (Acari : Tetranychidae) from cotton in Australia
Experimental and Applied Acarology 22 (1), 17-30
Abstract: Tetranychus urticae Koch was resistant to all organophosphates (OPs) tested. The demeton-S-methyl resistance was extremely high (maximum resistance factor (RF) 650X), as was the dimethoate resistance (maximum RF 750X). The parathion resistance was high (maximum RF 78X), while the profenofos resistance in T. urticae remained stable from 1976 until 1988 (approximately 15X) and that of monocrotophos from 1976 until 1989 (approximately 40X) after which the resistance rose. The resistance in T. urticae peaked in the 1995 season at levels of >100X for profenofos and >40OX for monocrotophos, rendering both chemicals ineffective. Tetranychus ludeni Zacher was also resistant to all the OP chemicals tested, but at lower levels than for T urticae. The LC₅₀ values indicated that the demeton-S-methyl and monocrotophos resistance in T. ludeni was an order of magnitude less than for T urticae. The maximurn profenofos resistance levels against T. ludeni (6.5x) were approximately one-quarter those of the maximum profenofos resistance levels against T. urticae (30X). The parathion LC₅₀ values and dimethoate RFs indicate T. ludeni to be ultimately only half as resistant as T. urticae. We consider that the relative lack of tolerance to OPs exhibited by T. ludeni may have contributed to its apparent disappearance from Australian cotton. Tetranychus urticae was the dominant mite pest in Australian cotton during 1976-1995. Tetranychus ludeni reached damaging levels in the late 1970s but virtually disappeared from cotton during the 1980s.
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Link to article at publishers website
Database assignments for author(s): Grant A. Herron, Lewis J. Wilson

Research topic(s) for pests/diseases/weeds:
pesticide resistance of pest

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Tetranychus urticae	Cotton (Gossypium)
	Tetranychus ludeni	Cotton (Gossypium)