Body Size of the Monomorphic AntLasius niger: Young Colonies along a Metal Pollution Gradient

摘要

Metal pollution may cause the decrease in the individual body size. In ants, themorphological diversity within and between colonies may be much higher than thatconsidered before, even in monomorphic ants. In this study we measured the body size,expressed as head width, ofLasius nigerworkers collected from 44 young colonies in theirergonomic stage along a well-known gradient exhibiting chronic metal pollution. Wecalculated statistics describing the body size distribution curve, namely, average, median, datarange, skewness, and kurtosis. None of these statistics correlated with the pollution level. Contrary to our previous study performed on mature colonies, workers from young coloniesdo not display pollution-related morphological changes. The results stress the importance ofdevelopmental stage of colony on diversifying body size of the worker cast, in monomorphicants living in metal-polluted areas.