Figure 1. Light:dark cycles and temperature conditions in the environmental chamber and sample collection points.

The grey area (scale on left Y-axis) shows seasonal changes in the day length and the lines (scale on the right Y-axis) respective changes in temperature during the day (dashed line), dawn/dusk in spring (thicker dashed line) and the night (solid line). The light:dark cycles and the dates indicate when the females were transferred into the chamber and when the different age ND (non-diapause) and D (diapause) females were collected. In addition to the microarray strain (175OJ8, D. montana), two additional D. montana strains and three D. littoralis and D. ezoana strains were collected for detecting the onset of reproductive diapause, and for qPCR (samples 150D and 150 ND) and CCRT experiments (samples 250D and 250ND).