Phylogeny of Leptoschoinina (Coleoptera: Curculionidae), with special reference to the Neotropical genera

JACOBINA, A.C.M.; MARVALDI, A.E.; LEIVAS, F.W.T.

Congreso; XI Congreso Argentino y XII Congreso Latinoamericano de Entomología; 2022

Weevils in the subtribe Leptoschoinina (Baridinae: Madarini) have been traditionally recognized for their sub-elliptic body; rostrum compressed in the base; long antennae; male club very large, cylindrical, compact, and velvety; prosternum flat; short mesosternum, forming a continuous surface with the prosternum and metasternum; pygidium exposed, but small and sub-horizontal. Currently, Leptoschoinina is composed of 31 genera distributed in all biogeographical regions, being exclusively Neotropical: Leptoschoinella Hustache, Leptoschoinus Dejean, Loboderes Schoenherr, Loboderinus Solari & Solari, Megabaris Hustache, Microstrates Lacordaire, Palmoderes Bondar and Platyonyx Schoenherr. Phylogenetic studies of Baridinae have questioned the monophyly of Leptoschoinina, however, they were not focused on this subtribe, which needs a directed study. Our objective is to perform a phylogenetic analysis of Leptoschoinina, to test its monophyly and, particularly, to investigate the existence of a clade of Neotropical genera. The data matrix comprised 63 terminal taxa, with the ingroup represented by all Neotropical genera (34 spp.) and by three genera of Leptoschoinina with eastern Palaearctic and Afrotropical distribution (9 spp., Acythopeus Pascoe, Athesapeuta Faust and Dendrobaris Egorov), including as outgroup taxa some representatives of Madarini (Madarina and Tonesiina) and Apostasimerini (Torcina and Zygobaridina - Xystus Schoenherr as root). The matrix of morphological characters of adults is assembled in the Mesquite program, with 72 external characters of head and thorax coded so far. Preliminary phylogenetic analyses were performed using parsimony, with the software TNT 1.5. Trees were inferred using heuristic searches under equal weights as well as implied weighting (K= 3-12). After analysis using equal weights, 174 most parsimonious trees (428 steps) were obtained, and one single tree was inferred with implied weights. Under different equal and implied weighting regimes, the genus Microstrates constitutes a clade, but the subtribe is not monophyletic and a Neotropical lineage of Leptoschoinina is not recovered. Further advances in coding additional characters, like those of genitalia, will provide more evidence to support phylogenetic hypotheses about the weevils currently in Leptoschoinina.