We analysed the daily high-resolution gridded dataset of surface temperature (E-OBS version 14.0; http://ensembles-eu.metoffice.com) provided by the ENSEMBLES project in the period from 1 January 1950 to 31 August 2016  under the assumption that larvae do not survive longer than three days at 0 °C or lower temperatures (see Results - The effect of temperature on the cumulative larval and pupal mortality and development). These specific conditions have occurred on average from 1 to 6 events per year during the above mentioned period in Germany, with an increase to the south-east (Fig. 4).Fig. 4Average number of frost events with three days or longer at 0 °C or lower temperatures per year (1950–2016) in Germany. The temperature threshold was experimentally assessed and is valid for the larval stage, i.e. larvae do not survive such frost events