Impact of travel temperature on perceived durations for a parasitoid

Animals require the capacity to estimate time in order to synchronize and optimize their behaviours. Although temperature affects most aspects of the behavioural ecology of invertebrates, few studies examined the impact of temperature on time perception. We investigated the influence of temperature on the perceived duration of travel between host patches of an egg parasitoid, Trichogramma euproctidis. We mimicked travel between host patches by isolating wasps for a 24 h period (hereafter ‘travel’) at three different temperatures (14, 24 and 34°C) and next measured a number of parameters associated to patch exploitation (patch residence time, rate of fitness gain at departure, time motionless, active exploitation time and number of hosts parasitized). Travel temperature did not influence the number of hosts parasitized per patch. However, patch residence time, active exploitation time and time motionless significantly increased with an increase of travel temperature. Warm travel temperature negatively influenced the parasitoid’s rate of fitness gain during the last 15 minutes of patch exploitation. For foraging parasitoid females, travels between host patches at warm temperatures thus appeared longer than at cool temperatures for a travel of 24 h. These results demonstrate the thermal sensitivity of time perception in parasitoids.