Simulated winter warming negatively impacts survival of Antarctica's only endemic insect

Abstract

1. Antarctic winters are challenging for terrestrial invertebrates, and species that live there have specialised adaptations to conserve energy and protect against cold injury in the winter. However, rapidly occurring climate change in these regions will increase the unpredictability of winter conditions, and there is currently a dearth of knowledge on how the highly adapted invertebrates of Antarctica will respond to changes in winter temperatures.2. We evaluated the response of larvae of the Antarctic midge, Belgica antarctica, to simulated winters at three ecologically relevant mean temperature scenarios: warm (−1°C), normal (−3°C) and cold (−5°C). Within each scenario, larvae were placed into three distinct habitat types in which they are commonly observed (decaying organic matter, living moss, and Prasiola crispa algae). Following the simulated overwintering period, a range of physiological outcomes were measured, namely survival, locomotor activity, tissue damage, energy store levels and molecular stress responses.3. Survival, energy stores and locomotor activity were significantly lower following the Warm overwintering environment than at lower temperatures, but tissue damage and heat shock protein expression (a proxy for protein damage) did not significantly differ between the three temperatures. Survival was also significantly lower in larvae overwintered in Prasiola crispa algae, although the underlying mechanism is unclear. Heat shock proteins were expressed least in larvae overwintering in living moss, suggesting it is less stressful to overwinter in this substrate, perhaps due to a more defined structure affording less direct contact with ice. 4. Our results demonstrate that a realistic 2°C increase in winter microhabitat temperature reduces survival and causes energy deficits that have implications for subsequent development and reproduction. While our Warm winter scenario was close to

The Impact of Climate on the Energetics of Overwintering Paper Wasp Gynes (Polistes dominula and Polistes gallicus)

“…Metabolic measurement is an appropriate tool to assess a species' vulnerability to climate warming, and the energy supply (amount of energy stores) is essential in this context. As the microhabitats investigated in this study were obviously not buffered from the impact of ambient temperature, we simulated the energetic costs under future climate conditions with the simple assumption of a 1 to 3 • C elevated ambient air temperature during overwintering (Figure 6) (see also [50]). Our calculations suggest that the energetic costs will increase in a similar course in all species: up to about 36% additional costs in P. gallicus IT, 41% in P. dominula IT, and 45% in P. dominula AT under a 3 • C increase scenario.…”

Survival and nutritional requirements for overwintering Drosophila suzukii (Diptera: Drosophilidae) in Kentucky

“…As a result, energy drain is a significant risk associated with winter warming (Williams et al 2015). Indeed, some insects have lower survival and energy reserves during warmer winters (Williams et al 2015, Potts et al 2020, Devlin et al 2022, González-Tokman et al 2020). For D. suzukii, the impact of warm winters is complicated, because while days above 10 °C are necessary for foraging, as indicated by increased trap catches (Leach et al 2019a), in lab conditions, when the average temperature is above 5 °C, frequent warming periods are detrimental to survival (Stockton and Loeb 2021).…”

A chromosome map of Belgica antarctica Jacobs (Diptera: Chironomidae) from Antarctica, including chromosome variability

“…Of particular interest are its possible responses to climate change, as has been occurring in the Antarctic Peninsula region in recent decades (Turner et al 2014, Convey & Peck 2019, Bargagli 2020). However, to date, few studies of either B. antarctica or Antarctic microarthropods more generally have directly addressed climate change (Devlin et al 2022, Matheson & McGaughran 2023). Belgica antarctica 's karyotype was briefly described 60 years ago on the basis of the salivary gland chromosomes (Martin 1962).…”