Voltinism-associated differences in winter survival across latitudes: integrating growth, physiology, and food intake.

Species that span large latitudinal gradients face strong differences in voltinism and in winter conditions within their range. Latitudinal gradients in winter survival and especially their underlying mechanisms and association with voltinism patterns are poorly studied. We tested in the damselfly Enallagma cyathigerum whether high-latitude populations were better in dealing with the longer winters compared to central- and low-latitude populations and whether this was associated with changes in voltinism.