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Research article - Peer-reviewed, 2021

Thermal performance under constant temperatures can accurately predict insect development times across naturally variable microclimates

von Schmalensee, Loke; Hulda Gunnarsdottir, Katrin; Naslund, Joacim; Gotthard, Karl; Lehmann, Philipp


External conditions can drive biological rates in ectotherms by directly influencing body temperatures. While estimating the temperature dependence of performance traits such as growth and development rate is feasible under controlled laboratory settings, predictions in nature are difficult. One major challenge lies in translating performance under constant conditions to fluctuating environments. Using the butterfly Pieris napi as model system, we show that development rate, an important fitness trait, can be accurately predicted in the field using models parameterized under constant laboratory temperatures. Additionally, using a factorial design, we show that accurate predictions can be made across microhabitats but critically hinge on adequate consideration of non-linearity in reaction norms, spatial heterogeneity in microclimate and temporal variation in temperature. Our empirical results are also supported by a comparison of published and simulated data. Conclusively, our combined results suggest that, discounting direct effects of temperature, insect development rates are generally unaffected by thermal fluctuations.


degree‐days; development rate; fluctuations; insect; Jensen's inequality; microclimate; predictions; rate summation; temperature; thermal performance

Published in

Ecology Letters
2021, volume: 24, number: 8, pages: 1633-1645
Publisher: WILEY

Authors' information

von Schmalensee, Loke
Stockholm University
Hulda Gunnarsdottir, Katrin
Stockholm University
Swedish University of Agricultural Sciences, Department of Aquatic Resources
Gotthard, Karl
Stockholm University
Lehmann, Philipp
Stockholm University

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