Southern distributional limits of Meliponini bees (Hymenoptera, Apidae) in the Neotropics: taxonomic notes and distribution of Plebeia droryana and P. emerinoides in Argentina.

The southern distribution of stingless bees in the Neotropics reaches the province of Buenos Aires, Argentina, up to 34°51' S in latitude, where two species of Plebeia are found on the west margin of the Río de La Plata: P. emerinoides (Silvestri), and P. droryana (Friese). In this area some relicts of gallery forest occur and the climate is moderated by the large water mass of the river. The taxonomy of both species is discussed. Diagnoses, updated distribution, and illustrations of some morphological features are given for both species.

Nosema ceranae in South American Native Stingless Bees and Social Wasp.

Besides the incipient research effort, the role of parasites as drivers of the reduction affecting pollinator populations is mostly unknown. Given the worldwide extension of the beekeeping practice and the diversity of pathogens affecting Apis mellifera populations, honey bee colonies are a certain source of parasite dispersion to other species. Here, we communicate the detection of the microsporidium Nosema ceranae, a relatively new parasite of honey bees, in stingless bees (Meliponini) and the social wasp Polybia scutellaris (Vespidae) samples from Argentina and Brazil by means of duplex PCR. Beyond the geographic location of the nests, N. ceranae was detected in seven from the eight Meliponini species analyzed, while Nosema apis, another common parasite of A. mellifera, was absent in all samples tested. Further research is necessary to determine if the presence of the parasite is also associated with established infection in host tissues. The obtained information enriches the current knowledge about pathologies that can infect or, at least, be vectored by native wild pollinators from South America.

Description of two new cases of gynandromorphism in Paratrigona Schwarz and Augochlora Smith (Hymenoptera: Apidae and Halictidae).

Two new records of gynandromorphism in bees are described and illustrated for Paratrigona glabella and Augochlora amphitrite. The specimens show a mixture of male and female features, complete in Augochlora and on head and mesosoma in Paratrigona. Including the specimen described herein, gynandromorphs are now known for a total of three species in Meliponini bees and three species in Augochlorini bees.

Large carpenter bees in Argentina: systematics and notes on the biology of Xylocopa subgenus Neoxylocopa (Hymenoptera: Apidae).

A systematic revision of the species of the genus Xylocopa subgenus Neoxylocopa in Argentina is provided. Seven species are included: X. atamisquensis Lucia & Abrahamovich, X. augusti Lepeletier, X. eximia Pérez, X. frontalis (Olivier), X. mendozana Enderlein, X. nigrocincta Smith and X. tacanensis Moure. The males of X. eximia and X. nigrocincta are described for the first time. Xylocopa jujuyensis Brèthes is a new junior synonym of X. nigrocincta. Photographs, occurrence maps, and identification keys for the species are presented. Information on the nest architecture and substratum preference are also given.

The identity of the enigmatic genus Stenocolletes Schrottky (Hymenoptera: Tiphiidae).

The identity of Stenocolletes Schrottky and its single species, Stenocolletespictus Schrottky, has remained a mystery since their description in 1909. Stenocolletes was originally placed in the bee family Colletidae but no known American colletid matches the original description. The type of S. pictus is likely lost as are large portions of Schrottky's collection. Herein, we describe and designate as neotype a historic specimen that closely matches Schrottky's description and place it in the current classification. Stenocolletes pictus is conspecific with the South American thiipid wasp Calchaquila albinervis (Brèthes, 1913). Both generic and specific names are new synonymous of Stenocolletes and pictus, respectively (new ju- nior synonym). Stenocolletes pictus is also recorded for the first time from C6rdoba, Argentina.

A gynandromorph of Xylocopa nigrocincta Smith (Hymenoptera: Apidae).

We describe a mixed gynandromorph of Xylocopa (Neoxylocopa) nigrocincta from a single specimen from Argentina. The specimen presents bilateral asymmetry, with the right half of its head displaying male characters and the left half displaying female characters; the mesosoma presents male characters mostly in the right half of the prothorax, pronotal lobe and distal half of the fore tibia and in the pubescence of tarsus; the rest of the mesosoma and the metasoma display female features.

A gynandromorph of Xylocopa nigrocincta Smith (Hymenoptera: Apidae) / Un ginandromorfo de Xylocopa nigrocincta Smith (Hymenoptera: Apidae)

We describe a mixed gynandromorph of Xylocopa (Neoxylocopa) nigrocincta from a single specimen from Argentina. The specimen presents bilateral asymmetry, with the right half of its head displaying male characters and the left half displaying female characters; the mesosoma presents male characters mostly in the right half of the prothorax, pronotal lobe and distal half of the fore tibia and in the pubescence of tarsus; the rest of the mesosoma and the metasoma display female features

Se describe un ginandromorfo mixto de Xylocopa (Neoxylocopa) nigrocincta de un ejemplar de Argentina. El ginandromorfo tiene asimetría bilateral en la cabeza, con su mitad derecha con caracteres del macho y su mitad izquierda con caracteres de la hembra. El mesosoma presenta algunas características de macho en la mitad anterior derecha (protorax, lóbulo pronotal, mitad posterior de la protibia y pubescencia del tarso), el resto de meso y metasoma con caracteres de la hembra.