Colour‐associated mating success in a polymorphic Ladybird Beetle, <i>Harmonia axyridis</i>

Abstract

1. Body size is often an important character in mating success, but has been only infrequently mentioned in regard to colour polymorphism. In this study, mating success was investigated in a colour polymorphic Ladybird Beetle, Harmonia axyridis , with reference both to colour morph and to body size. 2. In the non‐melanic males the mating individuals were significantly larger than solitary individuals, while in melanic males there was no significant difference. 3. The mating pattern was close to random mating with respect to colour morph and there was no significant deviation. 4. The results suggest both body size and colour morph affect the male mating success and males of different body size obtain mating advantage according to the colour morph. Colour polymorphism in this species is controlled by alleles on a single locus. Thus, the alleles on that locus significantly influence the effect of selection on the quantitative character.