The unity of characters: ecological and morphological specialisation in larvae of Hawaiian platynine Carabidae (Coleoptera)

Life history information and first instar egg bursters are compared for lar vae of 25 species across the monophyletic radiation of Hawaiian Platynini ( Coleoptera : Carabidae). The plesiotypic larval duration is approximately f ive weeks, with derived extension of the larval period having evolved durin g phylogenetic diversification of the radiation. This extension in larval d uration is associated with vestigialisation of the metathoracic flight wing s. Egg size is larger in those brachypterous species with slower developing larvae, reflecting pervasive ecological specialisation of these taxa in th e isolated, favourable, and temporally stable habitats of Hawaiian montane forests. First instar egg bursters are also compared across these taxa, wit h evolution of a keel-like egg burster congruently defining a clade also ch aracterised by longer larval duration and larger egg size. A functional lin kage between egg burster configuration and egg size is rejected by lack of any association between egg size and egg burster type in the related genus Calathus. Such rejection does not reduce the value of the egg burster for p hylogenetic inference. The ability to assess taxa for both life history tra its and egg burster configuration argues for similar treatment of all such characters, both ecological and morphological, when estimating phylogeny.