Fitness components of male and female winter moths (Operophtera brumata L.) (Lepidoptera, Geometridae) relative to measures of body size and asymmetry

In this article we present data from two experiments on the association bet ween individual asymmetry and fitness in the winter moth. We performed a ma te selection experiment and compared asymmetry and body size of mated and u nmated males collected in the field. Individual asymmetry was not associate d with copulation probability adult life span, or body size, even though bo dy size is a reliable indicator of larval and pupal survival, female fecund ity, adult life span, and thus expected fitness. There was only a weak posi tive effect of body size on mating success, contrary to the strong effect o f female size on male choice found in previous experiments. Both males and females were capable of repeated mating, and the number of matings was corr elated with female size, but neither with male body size nor with adult asy mmetry. Yet, females engaged in repeated matings more frequently if they we re first mated to a more asymmetrical male. This may indicate that more asy mmetrical males lose paternity due to female remating, although direct pate rnity analyses need to be carried out. In addition, repeated mating may be uncommon under field situations. In conclusion, the relationship between in dividual asymmetry and fitness seems to be at best weak in the winter moth.