Séminaire de Scott HAYWARD (University of Birmingham)


Le vendredi 10 novembre 2017 à 10h00, salle Bernard AUVRAY, bâtiment 15, Campus de Beaulieu, UR1

Le vendredi 10 novembre 2017 à 10h00, salle Bernard AUVRAY, bâtiment 15, Campus de Beaulieu, UR1

Is Winter coming? How climate warming disrupts the diapause response

Résumé :
At temperate latitudes a specialized state of dormancy, termed diapause, is used as an overwintering strategy by virtually all insects. Photoperiod is the dominant environmental cue programming diapause, with the short days of late summer and early autumn signalling the advent of winter. This means diapause induction often occurs well in advance of adverse conditions and sometimes even in the generation preceding the actual diapausing stage.  Temperature also plays an important role influencing the decision to enter diapause, as well as affecting many key diapause characteristics such as duration and stress tolerance.  Thus, climate warming potentially poses a significant problem, as it could decouple the relationship between photoperiodic and temperature cues resulting in ambiguous signals about when winter is coming.  Here I discuss how the trans-generational programming of diapause can be disrupted by elevated temperatures as well as the downstream effects on cold stress physiology and winter survival.  We identified that differences of just 5°C during the adult sensitive stage in Calliphora vicina dramatically alter the diapause characteristics of their progeny, and the capacity of these 3rd instar larvae to survive winter. We also investigated how different autumn and winter microclimates alter patterns of diapause termination and spring emergence – leaving individuals susceptible to extreme spring cold events. The talk concludes by discussing how this has important implications for several insect species, including key ecosystem service providers such as pollinators.

Contact : Scott HAYWARD