The extent shape of organisms (body size and the allometry of specific parts) is not only the base for taxonomy, but also the key functional traits for understanding the interaction between organisms and environmental conditions. The geographical variance of body size, allometry, and the underlying mechanisms are fundamental for insect biogeography, but have not been fully documented. In this paper, we compiled data on body size (body length and body width), aspect ratio (body length/body width), and distribution of ladybirds in 28 provinces in China. Meanwhile, we obtained environmental variables representing temperature and precipitation from freely available data. To explore the spatial variance and environmental correlates of body size and aspect ratio in different species groups with various trophic positions, correlation and regression analyses were performed separately on herbivorous and predaceous ladybirds. Our results show that there is evident latitudinal gradient for body size of ladybirds, i.e., body length or width increases with increasing latitude. This is consistent with Bergmann's rule. Temperature-related variables are the main drivers of geographic variance of body size, because ladybirds usually overwinter as adults, and those with larger •研究报告• 776 生 物 多 样 性 Biodiversity Science 第 23 卷