Integrated Analyses of Cuticular Hydrocarbons, Chromosome and mtDNA in the Neotropical Social Wasp Mischocyttarus consimilis Zikán (Hymenoptera, Vespidae).

In the present work, we explored multiple data from different biological levels such as cuticular hydrocarbons, chromosomal features, and mtDNA sequences in the Neotropical social wasp Mischocyttarus consimilis (J.F. Zikán). Particularly, we explored the genetic and chemical differentiation level within and between populations of this insect. Our dataset revealed shallow intraspecific differentiation in M. consimilis. The similarity among the analyzed samples can probably be due to the geographical proximity where the colonies were sampled, and we argue that Paraná River did not contribute effectively as a historical barrier to this wasp.

Neotropical Polistinae (Vespidae) and the Progression Rule Principle: the Round-Trip Hypothesis.

The progression rule principle is based on the relation between centers of origin and basal forms, and the prediction that recently colonized areas are where novelties commonly occur. Using this concept as the null hypothesis, the aim of the present study was to test whether intuitive predictions of this model are confirmed in the Neotropical paper wasps, a group fairly studied through phylogenetic frameworks. The analyses consisted of a careful review of the distribution of different wasps of the subfamily Polistinae with available phylogenies and the association of this information with colonization routes. This procedure allowed the determination of a two-step colonization process in the Neotropical region based on the progression rule principle, for which the round-trip hypothesis is proposed. The first route (east to west) is seen in a small group of Polistes. This route is rare but strengthens the arising of paper wasps in the Americas in a Gondwanan scenario. The second route (west to east) is remarkably repeated in several other lineages. Thus, the northwestern Neotropics, mainly Amazon Forest, is proposed as the major center of origins for living Neotropical Polistinae and the round-trip hypothesis may explain both earlier and later colonization routes of the paper wasps analyzed.

Genetic diversity of Angiopolybia pallens (Lepeletier) (Hymenoptera, Vespidae, Polistinae) explained by the disjunction of South American rainforests.

Angiopolybia pallens is a swarm-founding wasp that occurs in Atlantic and Amazonian rainforests, which have been isolated from each other by a large arid corridor in central Brazil since the Tertiary. In this study, we used data from polymerase chain reaction-restriction fragment length polymorphism of 16S rDNA to infer some aspects of the genetic diversity and evolutionary history of this social wasp population. Samples collected across the species range in both rainforests showed remarkable differences that separated them into two distinct haplogroups. However, some samples from isolated areas in northeastern Bahia were more related to Amazonian lineages than to southern Bahia populations. Vicariant divergenc is discussed under South American rainforests biogeographical proposals.