Phylogeny of water scavenger beetles (Coleoptera: Hydrophilidae) based on the study of traditional morphology and the sensory system of larvae

RODRIGUEZ, GEORGINA; URCOLA, JUAN I.; ARCHANGELSKY, MIGUEL; TORRES, PATRICIA L. M.

Conferencia; Immature Beetles Meeting 2021; 2021

Larvae of water scavenger beetles (Coleoptera: Hydrophilidae) are adapted to a wide variety of aquatic habitats, and this diversity is reflected by both morphology and the sensory system. The study of Hydrophilidae larvae has proven to be a source of reliable characters at different taxonomic levels. However, most of these analyses focus on small groups such as subfamilies or tribes (e.g. ARCHANGELSKY, 2004, 2008; ARCHANGELSKY et al., 2020; MINOSHIMA et al., 2013). Here we assessed the higher-level relationships of water scavenger beetles based on larval characters. With this purpose, a phylogenetic analyses of 329 characters (179 derived from sensory system, 150 morphological, 7 ecological) score for 103 taxa was performed. The resulting data matrix was analyzed using parsimony under implied weights (K=20). The Hydrophilidae family was recovered as monophyletic with high statistical support, which is consistent with molecular and morphological evidence. Subfamilies or tribe relationships usually showed weak support, except for a few well supported clades such as Acidocerinae and Enochrinae, Hydrophilini, Hydrobiusini, Megasternini, and some groups of genera. The tribe Laccobini was non-monophiletic. The Paracymus and Tormus genera of the Paracymus-group were found nest within Chaetarthriini tribe with low support, and Tritonus was recovered as a sister group to Hydrobiusini with relatively high support. The phylogeny of the family was difficult to reconstruct due to the combined effect of convergent evolution and the amount of derived character states given the selective pressure of the environment. These two conditions affect clade relationships especially at subfamily and tribe level. However, many characters derived from the external sensory system or from traditional morphology have proven to be useful in defining the relationships between certain groups.