Small spermatophore size and reduced female fitness in an isolated butterfly population
1. The Glanville fritillary butterfly (Melitaea cinxia L.) has a small population (Ne ∼ 100) on the small island of Pikku Tytärsaari (PT) in the Gulf of Finland. The population has remained completely isolated for ∼100 generations, which has resulted in greatly reduced genetic variation and high genetic load (low fitness). In particular, females lay small egg clutches with a low egg‐hatching rate