The external larval morphology of aquatic and terrestrial Luciolinae fireflies (Coleoptera: Lampyridae)

The external morphology of aquatic, semiaquatic and terrestrial lucioline larvae was investigated in order to provide an overview of what traits constitute the extremely ecologically diverse Luciolinae (Coleoptera: Lampyridae). The aquatic species, Aquatica ficta (Olivier), A. leii (Fu et Ballantyne), A. hydrophila (Jeng et al.), A. lateralis (Motschulsky), A. wuhana Fu et Ballantyne, Luciola cruciata Motschulsky and L. owadai Satô et Kimura cannot swim, but instead crawl on the substrate. They have soft bodies, lateral abdominal tracheal gills and glands on eversible structures that secrete repellent substances. The back-swimming species, Luciola substriata Gorham and L. aquatilis Thancharoen, which inhabit the surface of ponds, have hardened exoskeletons, and lack gills and eversible glands. Unlike the crawling species, the backswimmershave sense organs along the ventral surface of the apical maxillary and labial palpomeres, and are metapneustic in their later instars. The larval morphology of the aquatic species is contrasted with Pygoluciola qingyu Fu et Ballantyne, whose larvae are semiaquatic and lack gills, and with the terrestrial larvae of Asymmetricata circumdata (Motsch.) (newly associated here) and Pteroptyx valida Olivier. Keys to genera of the larval Luciolinae, to species in the genus Aquatica, and to larval types based on habitat are provided. An overview of current knowledge of the lucioline larval biology and taxonomy is given. Larval morphology provides a means to better understand the specialization of trophic behaviour in aquatic and terrestrial habitats. Discussion covers use of larval characters in phylogenetic analyses, and attempts to determinehabitat and mode of life preferences from morphological considerations.