Abstract
Supercooling points (SCPs) of females and nymphs of the western flower thrips, Frankliniella occidentalis, were not different between populations reared under 16L-8D photoregime at 25°C and 8L-16D at 15°C. The period of 100% lethal time of yellow-colored females collected on 9 October 2001 from an unheated plastic film greenhouse was 336 hrs at-5°C, and those of dark-colored females collected on 23-28 November 2000 were 672 hrs at-5°C and 168 hrs at-10°C. The results indicate that the cold tolerance of these populations is stronger than that of populations reared at constant temperature.
