Developmental plasticity of butterflies: A meta‐analysis of temperature effects

Temperature is a key ecological factor influencing biological processes across various levels of biological organization. At the individual level, temperature changes often impact life‐history traits. The Temperature–Size Rule predicts lower body mass at higher temperatures, whereas the Metabolic Theory of Ecology predicts faster growth rates and shorter development times with rising temperature via its effects on metabolism. Butterflies, a highly diverse group distributed worldwide, often exhibit plastic responses to differences in ambient temperature. As such, climate change may potentially impact their life history traits, population dynamics and interactions. We conducted a Bayesian multilevel meta‐regression of 71 studies published between 1960 and 2024, encompassing 673 effect sizes, to assess the impact of temperature variation on butterfly growth rate, development time and body mass across ontogenetic stages and sexes. Our meta‐analysis reveals that rising temperatures markedly accelerate growth and shorten development time in butterflies at a rate of ca. 10%/Δ°C, while body mass is comparatively only weakly affected. These temperature effects on growth and development are consistent across sexes and life stages and are largely independent of evolutionary history, suggesting a basis in fundamental biochemical constraints. These patterns highlight the potential for climate change to reshape butterfly life cycles, population dynamics and ecological interactions.