Circadian clocks are internal endogenous oscillators present in most organisms. They govern daily physiological and behavioral cycles. It is known for a long time that the clock system can function on longer time scales as well, controlling photoperiodical changes. These changes occur when the day length gets shorter (or longer) and allow the organisms to predict the beginning of a new season.
I am going to elucidate the role played by the circadian clock in the induction of photoperiodical changes in aphids. These insects drastically alter their reproductive behavior from asexual to sexual in autumn (when days become shorter). They also anticipate the cold season by adopting characteristic survival strategies until spring, when favorable conditions return. Starting from the characterization of the circadian clock, I will investigate the circadian behavior as well as the spatiotemporal expression of the neuronal clock.
Aphids have prominent agricultural relevance since they are the main insect crop pests in temperate regions. Understanding their circadian and photoperiodical biology might turn out to be essential to control their growth.