Pest Management Science (2006) 62, 419-424

Mouhoube Ako, Hans-Michael Poehling, Christian Borgemeister and Ralf Nauen (2006)
Effect of imidacloprid on the reproduction of acaricide-resistant and susceptible strains of Tetranychus urticae Koch (Acari: Tetranychidae)
Pest Management Science 62 (5), 419-424
Abstract: Occasional reports linking neonicotinoid insecticide applications to field population outbreaks of the two-spotted spider mite, Tetranychus urticae Koch, have been a topic of concern for integrated pest management (IPM) programmes, particularly in apples. In order to shed light on the factors which may contribute to the occasional field population increase of T. urticae following the application of neonicotinoid insecticides, greenhouse experiments have been set up. Four different T. urticae strains, namely GSS (acaricide-susceptible), WI (organophosphate-selected), USA (a largely uncharacterised strain) and Akita (METI (mitochondrial electron transport inhibitor) acaricide-resistant and cross-resistant to dicofol), were compared for their fecundity without insecticide treatment and for their ovipositional response to foliar and drench applications of the field-relevant dose of imidacloprid (100 mg litre^-1). Without insecticide treatment, strain GSS laid significantly more eggs (162.50 (±5.43)) than the multiple resistant strain Akita (139.90 (±5.54)) during a 16 day oviposition period. With imidacloprid treatment the highest effect was observed with GSS, with a significantly reduced number of eggs in drench (143.40 (±4.22)) and foliar (144.60 (±5.85)) applications. For strains Akita and USA, no significant differences were observed in oviposition between imidacloprid treatments and controls. The proportion of F₁ female offspring decreased significantly with drench application for GSS and WI, while no differences were observed among strains in the survival of F₁ immature stages, except for strain USA. The viability of eggs was relatively high (from 82.9 (±4.5)% for USA to 95.2 (±1.2)% for GSS) and not affected by imidacloprid treatments.
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Link to article at publishers website
Database assignments for author(s): Ralf Nauen, Christian Borgemeister, Hans-Michael Poehling

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	Apple (Malus)