Larval chaetotaxy and morphometry of Oosternum costatum (Coleoptera: Hydrophilidae) including a discussion of larval characters with phylogenetic relevance
Archangelsky Miguel
Acta Entomologica Musei Nationalis Pragae 58(2): 499-511, 2018
Published online: 14th November 2018
Published in print: 31st December 2018
Views: 1332
Abstract: The primary and secondary chaetotaxy of the head capsule and head appendages of
the first and third larval instars of Oosternum costatum (LeConte, 1855)
(Coleoptera: Hydrophilidae: Sphaeridiinae, Megasternini) are described for the
first time. Morphometric characters derived from the head capsule and mouthparts
are included, together with detailed illustrations of all characters. The
morphology and chaetotaxy of these larvae is compared to that of other larvae of
the tribe Megasternini, confirming that chaetotaxy is a useful source of
characters for phylogenetic analyses. Comparative notes with Sphaeridium
Fabricius, 1775 (Sphaeridiini) are also included.
Key words: Coleoptera, Hydrophilidae, Sphaeridiinae, Megasternini, Oosternum, water scavenger beetles, larva, head, chaetotaxy, morphology, phylogeny