Resistance to spinosad in the western flower thrips, Frankliniella occidentalis (Pergande), in greenhouses of south-eastern Spain

• Published in: Pest management science 2007-07, Vol.63 (7), p.682-687
• Main Authors: Bielza, P, Quinto, V, Contreras, J, Torné, M, Martín, A, Espinosa, P.J
• Format: Article
• Language: English
• Subjects: Animals; application rate; Biological and medical sciences; Capsicum annuum; Control; crop production; cross-resistance; Drug Combinations; Frankliniella occidentalis; Fundamental and applied biological sciences. Psychology; greenhouse production; Greenhouses; insect control; insect pests; Insecta - physiology; insecticide resistance; Insecticide Resistance - physiology; Insecticides; Macrolides; peaches; Phytopathology. Animal pests. Plant and forest protection; plant pests; Protozoa. Invertebrates; Prunus persica; Resistance to control; Spain; spinosad; Strain; sweet peppers; synergism; Thysanoptera
• ISSN: 1526-498X; 1526-4998
• DOI: 10.1002/ps.1388

Susceptibility to spinosad of western flower thrips (WFT), Frankliniella occidentalis (Pergande), from south-eastern Spain was determined. LC50 values of the field populations without previous exposure to spinosad collected in Murcia in 2001 and 2002 ranged from 0.005 to 0.077 mg L-1. The populations collected in Almeria in 2003 in greenhouses were resistant to spinosad (LC50 > 54 mg L-1) compared with the authors' highly susceptible laboratory strain. The highly sensitive laboratory strain leads to very high resistance ratios for the field populations (>13 500), but these ratios do not necessarily mean resistance problems and control failures (spinosad field rate 90-120 mg L-1). The populations collected in Murcia from some greenhouses in 2004 were also resistant to spinosad (RF > 3682). Spinosad overuse, with more than ten applications per crop, produced these resistant populations in some greenhouses. Spinosad showed no cross-resistance to acrinathrin, formetanate or methiocarb in laboratory strains selected for resistance towards each insecticide. Correlation analysis indicated no cross-resistance among spinosad and the other three insecticides in 13 field populations and in nine laboratory strains. The synergists piperonyl butoxide (PBO), S,S,S-tributyl phosphorotrithioate (DEF) and diethyl maleate (DEM) did not enhance the toxicity of spinosad to the resistant strains, indicating that metabolic-mediated detoxification was not responsible for the spinosad resistance. These findings suggest that rotation with spinosad may be an effective resistance management strategy.