Figure 3.

Emergence of male and female O. bicornis under temperature cycles with ramping temperature adjustment. Circular 24 h plot of emergence phases of male (blue dots) and female bees (red dots) (1 min time resolution). Bees emerged during several days under daily temperature cycles with slowly adjusting temperature conditions (hour ZT 0–6: temperature ramp from 10 °C to 20 °C; hour ZT 6–12: 20 °C; hour ZT 12–18: temperature ramp from 20 °C to 10 °C; hour ZT 18–24: 10 °C). We found no difference in distribution of male and female emergence phases (Watson U² test: p > 0.05). The best-suited emergence temperature seems to be approximately 20 °C for both sexes (red and blue arrows indicate the mean emergence phase averaged over all days for female and male bees).