Heatwave-induced demographic variation across populations is decoupled from thermal tolerance in a widespread ant
Abstract
Extreme heat events are increasing under climate change, yet their effects on social insect population dynamics remain poorly understood, particularly at early stages of colony development. We experimentally exposed colonies of the black garden ant (Lasius niger) from three European populations to a short-term heatwave (30°C for 4 days) to assess how acute thermal stress influences colony demography, functional traits, and thermal tolerance. Heat exposure accelerated egg production and brood development, with the strongest response observed in the northernmost population, indicating population-dependent plasticity in developmental timing. However, heat events experienced as larvae reduced thermal resistance in newly emerged workers independently of body size, revealing a trade-off between accelerated growth and physiological performance. These findings demonstrate that sublethal heat events can simultaneously enhance colony growth and compromise worker thermal performance, with population-dependent variation in developmental sensitivity that is cryptic under benign conditions. Our results highlight the importance of integrating demographic and physiological responses across populations and life stages when assessing insect vulnerability to climate extremes.
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BibTeX
@article{tyczynski2026heatwaveinduced,
title = {{Heatwave-induced demographic variation across populations is decoupled from thermal tolerance in a widespread ant}},
author = {Tania Tyczynski and Romain Libbrecht and Irene Villalta},
journal = {Journal of Thermal Biology},
year = {2026},
month = nov,
doi = {10.1016/j.jtherbio.2026.104614},
url = {https://hal.science/hal-05856755v1},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Heatwave-induced demographic variation across populations is decoupled from thermal tolerance in a widespread ant
AU - Tania Tyczynski
AU - Romain Libbrecht
AU - Irene Villalta
PY - 2026
DA - 2026/11/02
JO - Journal of Thermal Biology
DO - 10.1016/j.jtherbio.2026.104614
UR - https://hal.science/hal-05856755v1
AB - Extreme heat events are increasing under climate change, yet their effects on social insect population dynamics remain poorly understood, particularly at early stages of colony development. We experimentally exposed colonies of the black garden ant (Lasius niger) from three European populations to a short-term heatwave (30°C for 4 days) to assess how acute thermal stress influences colony demography, functional traits, and thermal tolerance. Heat exposure accelerated egg production and brood development, with the strongest response observed in the northernmost population, indicating population-dependent plasticity in developmental timing. However, heat events experienced as larvae reduced thermal resistance in newly emerged workers independently of body size, revealing a trade-off between accelerated growth and physiological performance. These findings demonstrate that sublethal heat events can simultaneously enhance colony growth and compromise worker thermal performance, with population-dependent variation in developmental sensitivity that is cryptic under benign conditions. Our results highlight the importance of integrating demographic and physiological responses across populations and life stages when assessing insect vulnerability to climate extremes.
SN - 0306-4565
SN - 1879-0992
ER -