Evolution of andrenine bees reveals a long and complex history of faunal interchanges through the Americas during the Mesozoic and Cenozoic.

Bees are presumed to have arisen in the early to mid-Cretaceous coincident with the fragmentation of the southern continents and concurrently with the early diversification of the flowering plants. Here, we apply DNA sequences from multiple genes to recover a dated phylogeny and historical biogeographic of andrenine bees, a large group of 3000 species mainly distributed in arid areas of North America, South America, and the Palearctic region. Our results corroborate the monophyly of Andreninae and points toward a South America origin for the group during the Late Cretaceous. Overall, we provide strong evidence of amphitropical distributional pattern currently observed in the American continent as result of faunal interchange in at least three historical periods, much prior to the Panama Isthmus closure. The Palearctic diversity is shown to have arisen from North America during the Eocene and Miocene, and the Afrotropical lineages likely originated from the Palearctic region in the Miocene when the Sahara Desert was mostly vegetated. The incursions from South to North America and then onto the Old World are chronological congruent with periods when open-vegetation habitats were available for trans-continental dispersal and at the times when aridification and temperature decline offered favorable circumstances for bee diversification.

Additions to the bee Brazilian fauna: first record of Anthrenoides, Callonychium and Psaenythia (Hymenoptera, Apoidea) in the state of Piauí.

The bee genera Callonychium Brèthes, Psaenythia Gerstaecker and Anthrenoides Ducke are newly recorded in Piauí State, northeastern Brazil. The species reported here are Callonychium brasilience (Ducke, 1907) and Psaenythia variabilis Ducke, 1908, and an as yet unidentified species of Anthrenoides. Images and all known distributional records of these species are also provided. The new occurrences reported herein expand the distribution range of the species to the Caatinga biome.

Taxonomy of the bee species Anthrenoides nigrinasis (Vachal, 1909) n. comb.: redescription of the type, description of the female, and new distribution records (Hymenoptera: Apoidea).

Protandrenini includes approximately 420 species of short-tongued bees, which are exclusively distributed in the Americas (Michener 2007; Moure et al. 2007; Ascher Pickering 2017). Members of this tribe are mostly found in xeric and temperate areas in South America, and their diversity is still greatly underestimated. In fact, a major challenge to the systematics of Protandrenini is the outstanding number of species unplaced in genera or awaiting formal description (Ruz Chiappa 2004; Ramos Melo 2006; Michener 2007; Moure et al. 2007; Ramos Rozen 2014). In addition to several taxa currently considered of uncertain position within the tribe, many South American genera are in need of taxonomic revision, such as Rhophitulus Ducke, Anthrenoides Ducke, and Psaenythia Gerstaecker (Silveira et al. 2002; Michener 2007; Ramos Melo 2010; Moure et al. 2007).

Three new genera of Protandrenini bees from South America (Hymenoptera, Apidae, Andreninae)

ABSTRACT Three new genera of Protandrenini bees from South America are described. Luisanthrena new genus is proposed to include L. ruzae, new species (from Ecuador) and L. vargasllosai (Gonzalez & Alvarado, 2019), new combination (from Peru). The new genus Cisanthrena includes only the unusual species Cisanthrena perforata n. sp. from forested areas of the Andes in Peru. In addition, Austellurgus new genus is proposed to accommodate A. avulsus (Ramos & Melo, 2006), new combination (southeastern Brazil).

Three new bee species of Rhophitulus Ducke (Hymenoptera, Apidae, Protandrenini) from Argentina and Brazil.

This work describes three newly discovered species of Rhophitulus Ducke, 1907: R. labiosus n. sp. from Minas Gerais (Brazil), R. mimus n. sp. from Salta (Argentina), and R. xenopalpus n. sp. from Catamarca and Tucumán (Argentina). Photographs of the holotype of Rhophitulus steinbachi (Friese, 1916) are provided, and modifications in the morphology of a female of R. xenopalpus n. sp. when parasitized by Strepsiptera are recorded for the first time for the genus.