Egg size variation in European Satyrine butterflies (Nymphalidae, Satyrinae)

The interspecific relationships between egg size and female size, sexual size dimorphism, latitude, preoviposition and egg-laying behaviour, was investigated in European Satyrine butterflies by controlling for taxonomic relatedness and by simple cross-species comparisons. Egg size scales positively to female size, although the relationship is not significant (but nearly so) when taxonomic effects are controlled for. Egg size is correlated with latitude. When the effects of latitude are removed, the relationship between egg and female size becomes more evident. Sexual size dimorphism is negatively correlated with egg size, but the effect disappears when adult size is controlled for. Small egg size is related to long preoviposition. No relationship between egg laying mode and egg size appears. The results are interpreted as evidence for positive scaling of egg to female size, with superimposed effects of egg size radiation. The correlation of egg size with latitude suggests that temperature, or season length, is likely to have made an important contribution to egg size selection within this geographic area.