Pest Management Science (2009) 65, 313-322

Emmanouil Roditakis, Maria Grispou, Evangelia Morou, Jon Bent Kristoffersen, Nikos Roditakis, Ralf Nauen, John Vontas and Anastasia Tsagkarakou (2009)
Current status of insecticide resistance in Q biotype Bemisia tabaci populations from Crete
Pest Management Science 65 (3), 313-322
Abstract: BACKGROUND: A major problem of crop protection in Crete, Greece, is the control of Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae) with chemical insecticides owing to the rapid development of resistance. The aim of this study was to investigate the establishment of resistance and the underlying mechanisms to major insecticide classes with classical bioassays and known biochemical resistance markers.
RESULTS: During a 2005-2007 survey, 53 Q biotype populations were collected. Application history records showed extensive use of neonicotinoids, organophosphates, carbamates and pyrethroids. High resistance levels were identified in the majority of populations (>80%) for imidacloprid (RF: 38-1958×) and alpha-cypermethrin (RF: 30-600×). Low resistance levels (RF < 12) were observed for pirimiphos-methyl. A strong correlation between resistance to imidacloprid and the number of applications with neonicotinoids was observed. Significant correlations were observed between COE and P450-dependent monoxygenase activity with resistance to alpha-cypermethrin and imidacloprid respectively. A propoxur-based AChE diagnostic test indicated that iAChE was widespread in most populations. Resistance levels for alpha-cypermethrin were increased when compared with a previous survey (2002-2003). Differentiation of LC₅₀ values between localities was observed for imidacloprid only.
CONCLUSION: Bemisia tabaci resistance evolved differently in each of the three insecticides studied. Imidacloprid resistance seems less established and less persistent than alpha-cypermethrin resistance. The low resistance levels for pirimiphos-methyl suggest absence of cross-resistance with other organophosphates or carbamates used.
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Link to article at publishers website
Database assignments for author(s): Emmanouil Roditakis, John Vontas, Ralf Nauen, Anastasia Tsagkarakou

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.
	Bemisia tabaci biotype MED		Greece