ROIG Sergio Alberto
Systematics and Cladistics of the genus Megalostomiswith Biogeographic considerations (Coleoptera: Cryptocephalinae)
AGRAIN, F.; ROIG JUÑENT, SERGIO
SYSTEMATIC ENTOMOLOGY (PRINT)
WILEY-BLACKWELL PUBLISHING, INC
Lugar: Londres; Año: 2011 vol. 36 p. 672 - 672
The present study includes a cladistic analysis of the subtribe Megalostomina. It is a systematic and phylogenetic study of a Neotropical group of case bearer leaf beetles, called that way because of the particular habit of their larvae, living in a portable protective case. A comparative study of the external and internal adult morphology of Clytrini was undertaken. A new set of characters is described for the subtribe Megalostomina, from the internal sac of aedeagus, which provides useful phylogenetic signal. More than 180 photographs illustrating the most important characters (74 characters and their respective states) used in the cladistic analysis are provided. The cladistic analysis of 57 terminal taxa and 95 characters was undertaken, under equal weights, and also using implied weights as a means to down-weight homoplasious characters. The main objectives of the phylogenetic analyses were two-fold: at higher level, to test monophyly and explore intergeneric relationships of the subtribe Megalostomina, and regarding the genus Megalostomis (the study group), to reconstruct the relationships among the species, while testing monophyly of the genus and its constituent subgenera as in previous classifications.After cladistic analysis, it turns out that the subgenera of Megalostomis as in previous classifications are not natural units. The 42 species recognized in the material examined in this study can be assigned to two groups, one containing mostly species of North and Central America, and a larger one made up of mostly South American species. However, they are not formally named as subgenera yet, being more prudent to wait until additional evidence supporting these clades becomes available for analysis, when performing the systematic revision of the remaining genera of Megalostomina.Furthermore, results of the cladistic analysis also support changes in the generic classification of the subtribe Megalostomina: Coleorozena Moldenke 1981, syn. nov. of Coscinoptera Lacordaire 1848; Coleothorpa Moldenke 1981, syn. nov. of Coscinoptera Lacordaire 1848; and Euryscopa (Coleoguerina) Moldenke 1981, syn. nov. of Coscinoptera Lacordaire 1848. Other taxonomic changes suggested by the results of the cladistic analysis are delayed until a major taxon sampling and additional characters become available to be analyzed in further studies.