Distinct timing systems operate the locomotor activity rhythm and the photoperiodic response in the parasitic jewel wasp, Nasonia vitripennis

Photoperiodism, the ability to respond to the length of the day or night, allows most temperate organisms to adapt their life cycles to seasonal changes. Although the molecular machinery of the circadian clock in photoperiodism has been extensively studied, the relationship between clocks regulating daily behavioural rhythms and the photoperiodic response remains debated. This study simultaneously assessed the daily activity rhythm and photoperiodic response in the parasitic jewel wasp, Nasonia vitripennis, under symmetrical skeleton photoperiods: PPs16 (LDLD 1:14:1:8 h) and PPs10 (LDLD 1:8:1:14 h). Under PPs16, all females showed long-day locomotor activity profiles, with some exhibiting long-day photoperiodic responses and others exhibiting short-day responses. Under PPs10, both long- and short-day photoperiodic responses were observed, regardless of their short-day locomotor activity profiles. These findings suggest that the timing system regulating the daily activity rhythm is separate from that controlling the photoperiodic response in N. vitripennis.