The New World oil‐collecting bees Centris and Epicharis (Hymenoptera, Apidae): molecular phylogeny and biogeographic history

Abstract

Martins A.C., Melo G. A.R. (2016). The New World oil-collecting bees Centris and Epicharis (Hymenoptera, Apidae): molecular phylogeny and biogeographic history. -Zoologica Scripta, 45, 22-33. We present a first comprehensive time-calibrated phylogeny for two Neotropical genera of bees, Centris and Epicharis, whose females collect floral oil together with pollen for larval provisioning, and that traditionally have been grouped in the tribe Centridini. Our analyses rely on a matrix of 167 taxa and 4228 aligned nucleotides for the subfamily Apinae, with denser sample of Centris and Epicharis. Centris and Epicharis are strongly supported monophyletic groups, but Centridini is paraphyletic in relation to the corbiculate bees. The inner phylogenetic relationships of Epicharis agree with the current taxonomic classification. In Centris, three main clades were recovered, namely the Centris, Trachina and Melacentris groups. Inner relationships in Centris suggest the reinstatement of some subgenera and proposition of new ones. Early diversification of Centris and Epicharis took place at the tropical regions of South America. Epicharis and the Melacentris group in Centris mostly diversified in that region, expanding over Central America and tropical North America only recently in the last 3 My. The groups Trachina and Centris present a complex biogeographic history, with expansions to the Nearctic region, the Antilles, and temperate regions of South America in the late Oligocene and Miocene.

Dynamic microbiome evolution in social bees

“…The host taxa relationships presented here (Figs. 4 and 5) were obtained by joining the results of multigene phylogenies within Apis ( 104 ), Bombus ( 105 , 106 ), and the Meliponini ( 90 ), together in a supertree based on their most highly supported relations with each other and with the outgroups ( 94 , 103 , 107 ). For bee species that were not included in these previous studies, placement was based on that of their respective genera.…”

Palaeocene origin of the Neotropical lineage of cleptoparasitic bees Ericrocidini‐Rhathymini (Hymenoptera, Apidae)

“…As expected, this lineage arose after the origin of their hosts, Centris and Epicharis . The Epicharis line diverged from Centris + corbiculate bees in the Cretaceous, at circa 90 Ma (Martins et al ., ; Martins & Melo, ), much earlier than the differentiation of the ancestral lineage of their parasites. Rhathymini showed an almost coincidental origin to their host's crown, 25 Ma (the crown age of Epicharis is estimated to be 31–28 Ma) (Martins et al ., ; Martins & Melo, ).…”

“…We constrained the root age according to previous estimates for the divergence between Anthophorini and the cleptoclade (Martins & Melo, ) applying a normal distribution prior with mean of 100 Ma and SD of 5 (Fig. ).…”

“…Morphological data also have suggested a close relationship between the cleptoparasitic Ericrocidini and Rhathymini and their hosts, Centris and Epicharis (traditionally placed in a single tribe, Centridini, but see Martins & Melo ), supported by several potential synapomorphies (Snelling & Brooks, ). Other phylogenetic analyses based on morphology (Roig‐Alsina & Michener, ; Straka & Bogusch, ) and molecules (Cardinal et al ., ) did not support such a close relationship.…”

“…Alternatively morphological phylogenies have pointed to a sister relationship between Ericrocidini and Melectini (Roig‐Alsina & Michener, ) or Ericrocidini and Isepeolini (Straka & Bogusch, ). All recent molecular studies contradict both hypotheses and support a sister relationship between Ericrocidini and Rhathymini, which are nested inside the large cleptoclade, forming the ericrocidine line together with Protepeolini, Isepeolini and Osirini (Cardinal et al ., ; Cardinal & Danforth, ; Litman et al ., ), while Centris and Epicharis are closely related to the corbiculate bees (Martins et al ., ; Martins & Melo, ).…”