TURKIYE ENTOMOLOJI DERGISI-TURKISH JOURNAL OF ENTOMOLOGY, vol.42, no.4, pp.241-251, 2018 (SCI-Expanded)
Frankliniella occidentalis (Pergande, 1895) (Thysanoptera: Thripidae) is a serious agricultural pest worldwide. Spinosad is used against many major pest species in Turkey, including F. occidentalis. However, resistance to spinosad was detected in F. occidentalis population collected from a greenhouse-grown peppers in Kumluca, Antalya, Turkey in 2015. This population (Antalya-2015) had been exposed to intensive, long-term spinosad application in this greenhouse. Cross resistance to acrinathrin and formetanate in the Antalya-2015 population was investigated and the stability of its resistance to spinosad was monitored over 1 year. LC values of susceptible and Antalya-2015 populations were determined using a leaf-dip bioassay and resistance ratios calculated. The resistance ratio of the Antalya-2015 population to spinosad was extremely high (up to 235-fold) and showed a 15-fold cross resistance to acrinathrin. Cross resistance to formetanate was not detected. In addition, spinetoram and spinosad were tested on the Antalya-2015 population using the recommended rates; mortalities were 88 and 38%, respectively. In the assay for stability of resistance to spinosad, mortality in Antalya-2015 population did not significantly change even after the population had been maintained in an insecticide-free environment for 1 year. Thus, resistance to spinosad in the Antalya-2015 population was stable.