Rodolpho Menezes

The impact of the broad disjunction between Amazonia and the Atlantic Forest on biodiversity has been the theme of several discussions in recent decades. Here, we evaluate the effects of dependence on humid environments and the role of historical factors on the level, distribution and structuring of genetic variation in widely distributed Neotropical insects. For such, we test whether climatically stable zones (i.e. refuges) in both Amazonia and the Atlantic Forest concentrate higher genetic diversity in the social paper wasps Angiopolybia pallens and Synoeca surinama. We found that historical events have avoided the interchange of A. pallens between both rainforests at least since the Early Pliocene and that ancient colonization in north-western Amazonia and the Bahia refuge significantly predicts genetic diversity in populations of this species. Conversely, the split between the Atlantic Forest and remaining western populations of S. surinama is more recent (Plio-Pleistocene); thi...

Cuticular hydrocarbons perform multiple functions in insects such as protecting against desiccation and pathogenic infection, and signaling interactions. Evaluation of cuticular hydrocarbon (CHC) profiles of insects is commonly performed by extraction using a nonpolar solvent such as hexane. Specimens intended for CHC analysis are ideally handled by avoiding contact with solvents such as ethanol. However, insects are frequently stored in ethanol after collection, especially if intended for molecular analysis. To determine if it is possible that chemical compounds in the cuticles of specimens can withstand previous exposure to ethanol, we evaluated the efficiency of CHC extraction from specimens preserved in 95% ethanol. We extracted cuticular compounds from specimens of the social wasp Polybia paulista (Ihering) with no contact with ethanol solvents and compared them with those from specimens stored in 95% ethanol. We analyzed chemical composition from wasps and the 95% ethanol in w...

Phenotypic characters are traditionally the main information for species discrimination in taxonomic studies of invertebrates. However, the presence of interand intraspecific polymorphism makes it difficult to identify species in many groups such as Neotropical social wasps. Herein, we examined different sources of biological information such as adult morphology, male genitalia, nest architecture, and genetic data applying an integrative taxonomic approach to study pinned museum specimens belonging to the social wasp genus Pseudopolybia de Saussure, 1863. Based on multiple independent lines of evidence, we described a new Neotropical swarm-founding social wasp, Pseudopolybia cryptica sp. n. Moreover, we proposed a phylogenetic hypothesis for Pseudopolybia including this new species. Our taxonomic findings applying an integrative approach reinforce that the social wasp diversity in the Neotropics may be underestimated due to morphological similarity.

Phenotypic characters are traditionally the main information for species discrimination in taxonomic studies of invertebrates. However, the presence of inter-and intraspecific polymorphism makes it difficult to identify species in many groups such as Neotropical social wasps. Herein, we examined different sources of biological information such as adult morphology, male genitalia, nest architecture, and genetic data applying an integrative taxonomic approach to study pinned museum specimens belonging to the social wasp genus Pseudopolybia de Saussure, 1863. Based on multiple independent lines of evidence, we described a new Neotropical swarm-founding social wasp, Pseudopolybia cryptica sp. n. Moreover, we proposed a phylogenetic hypothesis for Pseudopolybia including this new species. Our taxonomic findings applying an integrative approach reinforce that the social wasp diversity in the Neotropics may be underestimated due to morphological similarity.

Evolutionary processes related to climatic changes and ecological factors, such as microhabitat affinities and food specialization, can be important contributors to phylogeographic discordance between codistributed and related species. Here, we evaluate the evolutionary histories of two cactophilic and codistributed Drosophila species (Diptera: Drosophilidae) from South America, Drosophila antonietae and Drosophila meridionalis, where they use mainly Cereus hildmaniannus (Cactoideae: Cereeae) as host, using mitochondrial DNA sequences and species distribution modeling. The diversification of both species was estimated during the Pleistocene. For both species, the distribution of suitable areas through the Last Glacial period to the present showed a similar dynamic from Andes Valley through east and through the Paraná-Paraguay river basin to the Atlantic coastline. The current distribution of D. antonietae was influenced by demographic expansion and putative migration route from nort...

The aim of this study was to record the parasitoid species found in social wasps nests sampled in different localities in Brazil. We sampled nests of Mischocyttarus cassununga, Mischocyttarus consimilis, Mischocyttarus imitator, Polistes canadensis, Polistes cinerascens, Polistes versicolor, Angiopolybia pallens, Leipomeles spilogastra, Polybia jurinei and two indeterminate species of Mischocyttarus. Thus, we observed that nests of M. cassununga, M. imitator and Mischocyttarus (Phi) sp.1 were parasitized by Toechorychus guarapuavus (Ichneumonidae) and nests of M. consimilis, M. imitator and Mischocyttarus sp.2 were parasitized by Toechorychus fluminensis (Ichneumonidae). Nests of P. versicolor and P. cinerascens were parasitized by Elasmus polistis (Eulophidae) and nest of P. canadensis was parasitized by Simenota depressa (Trigonalidae); nest of A. pallens and L. spilogastra, was infested by Brachymeria sp.1 and Brachymeria sp.2 (Chalcididae), respectively. Nests of M. cassununga and Polybia jurinei were parasitized by Megaselia scalaris (Phoridae).

The Neotropical Region harbors high biodiversity and many studies on mammals, reptiles, amphibians and avifauna have investigated the causes for this pattern. However, there is a paucity of such studies that focus on Neotropical insect groups. Synoeca de Saussure, 1852 is a Neotropical swarm-founding social wasp genus with five described species that is broadly and conspicuously distributed throughout the Neotropics. Here, we infer the phylo- genetic relationships, diversification times, and historical biogeography of Synoeca species. We also investigate samples of the disjoint populations of S. septentrionalis that occur in both northwestern parts of South America through Central American and the Brazilian At- lantic rainforests. Our results showed that the interspecific relationships for Synoeca could be described as follows: (S. chalibea+ S. virginea) + (S. cyanea + (S. septentrionalis/S. suri- nama)). Notably, samples of S. septentrionalis and S. surinama collected in the Atlantic For- est were interrelated and may be the result of incomplete lineage sorting and/or mitochondrial introgression among them. Our Bayesian divergence dating analysis re- vealed recent Plio-Pleistocene diversification in Synoeca. Moreover, our biogeographical analysis suggested an Amazonian origin of Synoeca, with three main dispersal events sub- sequently occurring during the Plio-Pleistocene.

Chromosome number and morphology are relevant aspects of genomic organization of eukaryotes and are considered key components to comprehend evolutionary mechanisms and karyotypic differentiation. Social wasps belonging to the tribe Epiponini show complex social characteristics that make these insects interesting models for genetic and evolutionary studies. However, there is a paucity of genetic information in social wasps as a whole. Aiming to investigate the process of chromosomal evolution of the social Epiponini wasps, chromosomes of ten species of this group were analyzed using Giemsa and fluorochrome staining techniques and fluorescence in situ hybridization in two species. In this study a high variation in the chromosome number and morphology was found and the previous range of chromosome number of Epiponini was broadened from n = 8–32 to n = 5–33. We also suggest that chromosomal segments with high GC content must have had a key role in the karyotype diversification of these wasps. Moreover, based on a phylogenetic background we find evidence of a main role of chromosomal fusion in the occurrence of gradual decrease of chromosome number in Epiponini during its chromosomal evolutionary history.

The Neotropical Polistinae wasps are diverse in taxonomy, social behavior, and nesting founding characteristics. Although some species in this group have been used as models for studies on wasp’s biology, they are poorly known in terms of cytogenetics. Here we reported an intraspecific numerical-structural chromosome variation in the swarm-founding wasp Metapolybia decorata from the Brazilian Atlantic Rainforest using conventional and molecular cytogenetic techniques. The observed structural chromosome change involved a telomeric fusion that resulted in a chromosome number range of 2n = 34–36. The origin and geographic distribution of the variant chromosome forms as well as their frequency and maintenance in the studied populations are discussed. In addition, we reported a novel and geographically restricted deletion in the fused chromosomes indicating that the species is undergoing a continued process of karyotype evolution leading to fused chromosome stabilization by elimination of inactive centromeric sequences. Evidence of differences in the telomeric sequences of this wasp was also found by in situ hybridization using the motif (T2AG2)7 as probe.