Winter survival in caterpillars of Cydia pomonella exposed to semi-natural conditions.

aLaboratory-reared caterpillars were used for this experiment. They were gradually cold-acclimated prior to transfer outdoors on 3 October 2010. Groups (i) and (ii) remained outdoors for the whole winter. Groups (iii–v) were moved back to the laboratory on 5 January 2011 and exposed to simulated winter conditions in incubators (under constant darkness). All groups were moved to constant 25°C on 10 March 2011 to check their survival (pupation). See text for more details.