Cassidinae

Abstract: Background The great diversity of the “Phytophaga” (weevils, longhorn beetles and leaf beetles) has been attributed to their co-radiation with the angiosperms based on matching age estimates for both groups, but phylogenetic information and molecular clock calibrations remain insufficient for this conclusion. Methodology A phylogenetic analysis of the leaf beetles (Chrysomelidae) was conducted based on three partial ribosomal gene markers (mitochondrial rrnL, nuclear small and large subunit rRNA) including over 3000 bp for 167 taxa representing most major chrysomelid lineages and outgroups. Molecular clock calibrations and confidence intervals were based on paleontological data from the oldest (K-T boundary) leaf beetle fossil, ancient feeding traces ascribed to hispoid Cassidinae, and the vicariant split of Nearctic and Palearctic members of the Timarchini. Principal Findings The origin of the Chrysomelidae was dated to 73–79 Mya (confidence interval 63–86 Mya), and most subfamilies were post-Cretaceous, consistent with the ages of all confirmed body fossils. Two major monocot feeding chrysomelid lineages formed widely separated clades, demonstrating independent colonization of this ancient (early Cretaceous) angiosperm lineage. Conclusions Previous calibrations proposing a much older origin of Chrysomelidae were not supported. Therefore, chrysomelid beetles likely radiated long after the origin of their host lineages and their diversification was driven by repeated radiaton on a pre-existing diverse resource, rather than ancient host associations.

Abstract: The natural history of Acentroptera basilica Guerin-Meneville, 1844 and A. cf. tessellata Baly, 1958 (Cassidinae: Sceloenoplini) associated with Aechmea aquilega Salisb. and Vriesea sp. (Bromeliaceae), respectively, is registered. Adults of both species are leaf scrapers, although larvae are leaf-miners. The immature stages of both species of Acentroptera are described and illustrated for the first time. The male and the female genitalia of A. basilica and new records for both species are also included.

Abstract: Immature stages of Stolas aenea and S. nudicollis are described based on specimens collected in Rio de Janeiro, Brazil. Descriptions including chaetotaxy, illustrations and photographs (including SEM images) are given for eggs, first and last instar stages. New host plant records are presented for both species. This is the first detailed description for any species in the genus Stolas. Morphological comparisons with other Mesomphaliini species are provided.