Data from: Young male mating success is associated with sperm number but not with male sex pheromone titres

Background: Intraspecific communication is of crucial importance
throughout the animal kingdom and may involve a combination of visual,
gustatory, olfactory and acoustic cues. Variation in male sex pheromone
amount and composition may convey important information to female
conspecifics, for instance on species identity or age. However, whether
increased male pheromone titres are associated with fitness benefits for
the female, thus indicating a role as an honest signal, is under debate.
Results: Against this background, we tested in the butterfly Bicyclus
anynana (1) whether young males being successful or unsuccessful in
gaining a mating differed in sex pheromone titres and (2) for associations
between male pheromone titres and spermatophore mass, eupyrene sperm
number, and a variety of female and offspring life-history traits.
Successful and unsuccessful males did not differ in pheromone titres,
however eupyrene sperm number was much higher in successful males.
Pheromone titres were not associated with any fitness-related female or
offspring trait measured in our study, though correlation analyses yielded
evidence for trade-offs among specific traits. Patterns did not differ
among control and olfaction-blocked females. Conclusion: Therefore, we
suggest that in young B. anynana pheromone titres do not indicate male
quality.