Genetic control of colour polymorphism in spittlebugs (Philaenus spumarius) differs between isolated populations

Abstract

Species that have extensive geographic ranges but limited gene flow may have evolved different genetic backgrounds in widely separated populations. The spittiebug Philaenus spumarius is highly polymorphic for dorsal coiour/pattern throughout its extensive northern temperate range. In Scandinavian populations, the eight meianic morphs are wholly or substantially restricted to the females and are dominant to typical in females but recessive in males. In a survey of 548 populations in England and Wales, the same morphs are regularly expressed amongst males and meianic frequencies in the two sexes approach equality, suggesting a different mode of genetic control. Laboratory breeding experiments using British stock demonstrate the dominance of meianics to typical in males as well as females. It is suggested that this difference in inheritance for the same polymorphic trait is due to different dominance modifiers in populations from the two regions. © The Genetical Society of Great Britain.