Geographical sexual size dimorphism in an ant‐eating spider, Zodarion rubidum (Araneae: Zodariidae)

Within‐species variation in body size of males and females of an ant‐eating spider Zodarion rubidum was studied by analysing 15 populations across Europe. The relationship between the body size of both sexes was allometric with female‐biased sexual size dimorphism. Body size of males did not change with latitude or temperature, while that of females changed significantly with temperature. Larger females were found in regions with higher temperature which is presumably a result of an optimal climate: higher temperature and longer season provide higher prey availability which accelerates the growth rate of females, leading to a larger body size. As female size varied more than male size, a sexual size dimorphism cline was observed in Z. rubidum. Larger sexual size dimorphism was found in warmer regions. These results thus suggest that environmental conditions (temperature) influence intraspecific variation in sexual size dimorphism in Z. rubidum. [ABSTRACT FROM AUTHOR]