Leopoldo J. Alvarez

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.

Nesting biology and associated insect enemies of the exotic leaf cutter bee Megachile (Eutricharaea) concinna (Hymenoptera: Megachilidae) in Argentina

The nesting biology of the exotic bee Megachile (Eutricharaea) concinna Smith, 1879 and its negative interactions with other insects were studied. Trap nests made of wood were located in an urban environment in Buenos Aires province, Argentina, and surveyed during 26 months. The lifecycle and the structure of the nest of M. concinna are described. We also report six interactions between this bee and native and exotic parasitoids and cleptoparasites. The species Baryscapus megachilidis is recorded here for the first time in Argentina.

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.

First record of Melaloncha (Diptera: Phoridae) parasitoid associated with Bombus (Apidae: Bombini) in Argentina

Fil: Lucia, Mariano. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Division Entomologia; Argentina. Consejo Nacional de Investigaciones Cientificas y Tecnicas; Argentina

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.

Occurrence of the exotic leafcutter bee Megachile (Eutricharaea) concinna (Hymenoptera: Megachilidae) in southern South America. An accidental introduction?

Summary Here we report for the first time the presence of the exotic leafcutter bee Megachile (Eutricharaea) concinna in South America, based on specimens collected in the northeast part of Buenos Aires province, Argentina. We believe that M. concinna accidentally entered the country probably together with the introduction of M. rotundata to different regions of the country for commercial purposes since the 1970s. A diagnosis, illustrations, flowers records, and nesting data are given.

Description of the male, new geographical record, and biological notes on the small resin bee Hypanthidioides (Ctenanthidium) bifasciata (Urban, 1993) (Hymenoptera: Megachilidae)

Abstract. We describe and figure the previously unknown male of Hypanthidioides (Ctenanthidium) bifasciata (Urban, 1993) based on specimens reared from a trap nest along with a female. This species, originally known only from the type specimen collected in Colonia, Uruguay, is also newly recorded from Buenos Aires, Argentina. We provide for the first time information on the nest structure and, based on the analysis of pollen grains from brood cells, record five host plant species belonging to the families Apiaceae, Asteraceae, Brassicaceae, and Fabaceae. Most pollen grains belong to an undetermined species of the genus Melilotus L. (Fabaceae).

Detection of honey bee viruses in Argentinian stingless bees (Hymenoptera: Apidae)

The Meliponini is a eusocial group of bees tropically distributed. In Argentina, 37 species have been recorded, mostly in Misiones province. They use a great variety of sites to build their nests including tree hollows, cavities formed in rocks, human constructions or underground spaces. Numerous natural enemies are associated with stingless bees, including viruses. Until now, some viruses present in honey bees and related to the colony collapse disorder (CCD), have been found in several wild bees around the world. Here, we have studied the presence of honey bee viruses in stingless bees from different locations of Misiones province, Argentina. On this research, 73 samples of ten workers belonging to 12 species of stingless bees and feral honey bees, have been analyzed. Our results confirm the presence of three viruses: ABPV, IAPV and DWV Type A in four species of stingless bees and feral honey bees. More studies are required to establish if ABPV, IAPV and DWV are natural pathogens of stingless bees that have been spilled over to honey bees, or were transmitted by Apis mellifera to stingless bees.

First record of the parasitoid Melittobia hawaiiensis (Hymenoptera: Eulophidae) associated with Emphorini bees (Hymenoptera: Apidae)

Melittobia hawaiiensis Perkins (Hymenoptera: Eulophidae), a common gregarious ectoparasitoid of aculeate Hymenoptera and other orders of insects, is reported for the first time as a parasitoid of Melitoma segmentaria (Fabricius) (Hymenoptera: Apidae) in Buenos Aires, Argentina.