Reclassifying the genera within the Exophthalmus genus complex
The New World tribe Eustylini Lacordaire, 1863, pertains to the broad-nosed weevils (Entiminae) and currently comprises 23 genera. Members of Eustylini include agriculturally important species, e.g., Diaprepes abbreviatus (Linnaeus, 1758), an introduced citrus pest in the continental U.S. Franz (2012) published the first phylogeny of Eustylini based on morphological characters. Eustylini were recovered as polyphyletic and re-circumscribed to include several genera previously placed in other tribes. As a result, all but two of the sampled eustyline genera formed a monophyletic clade. The Exophthalmus genus complex is positioned within that clade and contains eight sampled genera, the largest (with 95 species) being Exophthalmus Schoenherr, 1823.
The 2012 analysis uncovered systematic problems that motivate the current study. Exophthalmus remains polyphyletic, with its species separated into at least three clades. Thus Exophthalmus needs to be redelimited and its current members reassigned to phylogenetically appropriate generic membership. The clade of continentals species also contains Rhinospathe Chevrolat, 1878, and Chauliopleurus Champion, 1911, warranting generic synonymy. Tropirhinus Schoenherr, 1823, Tetrabothynus Labram & Imhoff, 1852, Compsoricus Franz, 2012, and part of Exophthalmus exhibit ambiguous boundaries. These groups need to be either re-circumscribed or synonymized.
The current project builds upon Franz (2012) by using a molecular phylogeny to corroborate generic delimitation, expanding taxonomic sampling, and utilizing previously undocumented morphological characters.
Undergraduate student researchers, Joseph Hunter and Richard Thomas, are involved in aspects of morphological dissections and documentation in this project.
A poster based on initial results was presented at the 2015 Annual Meeting of the Entomological Society of America (see below).
The 2012 analysis uncovered systematic problems that motivate the current study. Exophthalmus remains polyphyletic, with its species separated into at least three clades. Thus Exophthalmus needs to be redelimited and its current members reassigned to phylogenetically appropriate generic membership. The clade of continentals species also contains Rhinospathe Chevrolat, 1878, and Chauliopleurus Champion, 1911, warranting generic synonymy. Tropirhinus Schoenherr, 1823, Tetrabothynus Labram & Imhoff, 1852, Compsoricus Franz, 2012, and part of Exophthalmus exhibit ambiguous boundaries. These groups need to be either re-circumscribed or synonymized.
The current project builds upon Franz (2012) by using a molecular phylogeny to corroborate generic delimitation, expanding taxonomic sampling, and utilizing previously undocumented morphological characters.
Undergraduate student researchers, Joseph Hunter and Richard Thomas, are involved in aspects of morphological dissections and documentation in this project.
A poster based on initial results was presented at the 2015 Annual Meeting of the Entomological Society of America (see below).