Espécies de Omophoita Chevrolat, 1836 e Alagoasa Bechyné, 1955 (Coleoptera, Chrysomelidae, Galerucinae, Alticini) do sul do Brasil: taxonomia e filogenia

Abstract

Omophoita Chevrolat, 1836 is a genus representative of the neotropical coleopterofauna, often sampled in diversity works and that forms a mimetic complex, and often sympatric, with Alagoasa Bechyné 1955. Many species of these genera were described based on insufficient characters for their delimitation, such as color and pattern of smears in elytra. Such taxa often appear in survey works only as a genus due to their difficult identification, as the group has great similarity of external characters, while the lack of identification results in a gap in its real geographic distribution. In this context, the main objective of this work was to present updated morphological descriptions, including new information from male and female genitalia to Omophoita recorded for southern Brazil, as well as to perform a cladistic analysis of available specimens to better delimit synapomorphies of these groups and facilitate identification futures with a dichotomous key. Specimens previously identified by specialists from national and international collections were used. The morphology analyzes were carried out from the dissection and observation of the specimens externally, with the aid of a stereomicroscope and photographic records carried out with self-assembly equipment. Nine species of Omophoita were registered in southern Brazil, with an update in the morphological description of: O. communis (Bechyné 1959), O. equestris (Fabricius 1787), O. latitarsis (Bechyné 1955), O. magniguttis (Bechyné 1955), O. octoguttata (Fabricius 1775), O. personata (Illiger 1807), and O. sexnotata (Harold, 1876). We also recorded 22 species of Alagoasa from southern Brazil, with an update in the morphological description of: A. areata (Germar 1824), A. decemguttata (Fabricius, 1801), A. libentina (Germar, 1824), A. plaumanni Bechyné, 1955 and A. scissa (Germar, 1824). A cladistic analysis of Omophoita species, using novel characters of external and internal morphology was performed. An extensive survey of morphological characters generated a data matrix with 127 characters. The genus Omophoita, as well as the genera chosen to compare Alagoasa and Asphaerina Bechyné, 1963, were recovered as monophyletic. This morphological analysis also allowed the construction of a dichotomous identification key for the studied Omophoita and Alagoasa species. Synapomorphies and homologies relevant to each group are presented, data from male and female genitalia, used for the first time in this type of analysis, were significant for the definition of internal lineages. Our work presents the first efforts to elucidate the biodiversity of these groups in the Neotropical region using morphological data, which we still plan to complement with molecular sequencing.