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Both the identity and prevalence of parasitoid dipterans associated with bumble bees (Bombus spp.) in southern South America are little known. Between 2009 and 2017, a total of 2978 bumble bees were individually collected in 63 localities from 11 provinces of the country. After dissections, the presence of parasitoids was observed in the native bumble bees Bombus pauloensis, B. bellicosus, B. opifex, and B. brasiliensis, plus in the exotic invasive species B. terrestris. A combination of both morphological and molecular analysis based on the COI gene allowed the isolation of two species of Physocephala (Conopidae) and one of Helicobia (Sarcophagidae), expanding their host range and geographic distribution. The second instar larva of Helicobia aurescens is described. [ABSTRACT FROM AUTHOR]

A problem for understanding bumblebee biogeography is that if bumblebees dispersed from Asia through North America to South America, if they are poor at long-distance dispersal with establishment over sea, and if the land bridge between North and South America was not established until c. 3 Ma BP, then there is an apparent conflict with the divergence among currently endemic South American lineages having been dated as early as 15–17 Ma. Using the first complete phylogenetic trees for all known and accepted extant species of the groups involved, we show how this conflict could be resolved. We suggest that characterizing bumblebees as being associated generally with temperate flower-rich meadows conflates divergent habitat specializations between two early lineages, associated with northern lowland grasslands and with southern montane grasslands respectively, which may have driven divergences in behaviour and in biogeographic processes. First, for most of the lowland grassland group of bumblebees, estimated dates of divergence are consistent with dispersal to South America via the land-bridge corridor that opened at c. 3 Ma, followed by extant endemic lineages diverging in situ within South America. In contrast, for the second group that occupies montane grassland habitats (and for a few montane lineages of the 'lowland' group), we suggest that dispersal to South America at c. 3 Ma could be consistent with older divergence for currently endemic species if: (1) many of the extant South American lineages had already diverged outside the region before 3 Ma in neighbouring Mesoamerica; and (2) they had been constrained within the high mountains there, dispersing southwards into South America only once the isthmus corridor had become established; and (3) some of those ancestral montane lineages had become extirpated from Mesoamerica during subsequent warm climatic fluctuations. This interpretation re-emphasizes that biogeographic studies need to consider habitat-specific dispersal models that change through time. [ABSTRACT FROM AUTHOR]

A detailed phylogeny of bumblebees is urgently needed to understand speciation and biogeographic diversification in the Neotropical region. We sequenced autosomal and mtDNA loci from nine Brazilian bumblebee species and compiled it with the data already available to obtain highly resolved phylogenetic trees with fossil-calibrated dates. The ancestral Bombus lineage was estimated to diversify between 47.08 and 34.27 million years ago (Ma) in the Holarctic region, but largely restricted to the eastern Old World. The Neotropical region was initially colonized in the Late Miocene, where bumblebee diversification was shown to be consistent with geologic and climatic events of the Late Cenozoic. Neotropical bumblebees likely originated from Nearctic lineages, which dispersed towards South America after 29 Ma. [ABSTRACT FROM AUTHOR]

Bumble bees (Bombus spp.) are important pollinators insects involved in the maintenance of natural ecosystems and food production. Bombus pauloensis is a widely distributed species in South America, that recently began to be managed and commercialized in this region. The movement of colonies within or between countries may favor the dissemination of parasites and pathogens, putting into risk while populations of B. pauloensis and other native species. In this study, wild B. pauloensis queens and workers, and laboratory reared workers were screened for the presence of phoretic mites, internal parasites (microsporidia, protists, nematodes and parasitoids) and RNA viruses (Black queen cell virus (BQCV), Deformed wing virus (DWV), Acute paralysis virus (ABCV) and Sacbrood virus (SBV)). Bumble bee queens showed the highest number of mite species, and it was the only group where Conopidae and S. bombi were detected. In the case of microsporidia, a higher prevalence of N. ceranae was detected in field workers. Finally, the bumble bees presented the four RNA viruses studied for A. mellifera, in proportions similar to those previously reported in this species. Those results highlight the risks of spillover among the different species of pollinators. [ABSTRACT FROM AUTHOR]

Bumblebees (Hymenoptera: Apidae: genus Bombus Latreille, 1802) constitute an important group of pollinators for many wild plants and crops in north temperate regions and South America. Although knowledge of these insects has been increasing over the last decades, some geographic areas remain poorly studied and additions to the knowledge of their faunas are infrequent. Afghanistan is one example of a country that is currently underrepresented in the scientific literature despite its high species diversity. For this study, more than 420 new occurrence records were gathered for 17 bumblebee species belonging to all eight subgenera recorded in the country, including the first record of a species closely related to the B. longipennis group. Additionally, the first standardized database for Afghan bees is launched, which we hope will be enriched in the future to allow further assessments of population trends for the bumblebees of Afghanistan. Finally, the previously published species records for the country are discussed considering the most recent taxonomic revisions of the genus and key perspectives are highlighted for further work in this understudied country and neighboring regions. [ABSTRACT FROM AUTHOR]

The Neotropical bumblebee Bombus (Fervidobombus) atratus Franklin is widely distributed in South America ranging from tropical and subtropical lowlands to high altitudes in the Andes. Thermal investigations of the Neotropical bumblebee Bombus atratus at rest were performed by means of thermometry. Most social insects are diurnal foragers. When they are inside their nests during the night, they carry out some tasks such as cleaning the nest, brood care or nest thermoregulation. However, forager bees generally pause at night in a sleep-like state. A bumblebee nest was transferred to a brood chamber which was maintained at approximately constant temperature (28 ± 1 °C) to prevent the workers from building the protecting involucrum so that one could mark them at birth. To provide a temperature gradient, two chambers were installed adjacent to the brood chamber, so that the workers had the chance to choose between 3 temperatures: the first one kept at 22 ± 1 °C, the second at 19 ± 1 °C and 28 ± 1 °C. The temperatures of the chambers were recorded continuously by a four channel data logger. Three categories of tasks performed by workers were registered in this investigation: warming brood (task 1), feeding brood (task 2) and foragers (task 3). During the experiment 357 workers were born and 252 (71%) of them showed sleep-like behaviour. The total sleep time in hours according to the work done by the workers was task 1 (240.6 h) > task 3 (236.0 h) > task 2 (227.3 h). The workers who performed tasks 1 and 2 preferred to sleep at the highest temperature (28 ± 1 °C) and the forager workers at 22 ± 1 °C. [ABSTRACT FROM AUTHOR]