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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]

Xylocopa nigrocincta Smith, 1854, and Xylocopa suspecta Moure & Camargo, 1988, are two nominal species within the subgenus Neoxylocopa and have a sympatric geographic distribution in South America. While X. nigrocincta is recognized by the presence of reddish metasomatic bands, X. suspecta is entirely black. Although morphologically distinct in terms of metasomal band colour, other morphological characters suggest that both species could be the same evolutionary entity and therefore synonymous. The aim of this research was to review both nigrocincta and suspecta morphotypes using an integrative approach (morphological and molecular) to evaluate if they are truly two different evolutionary lineages. Females of both species were obtained from field collections and museums, representing a large part of their morphotype distribution. Additional diagnostic characters of the external morphology were investigated, such as metasomal band colour, metasomal punctuation, wing colours, and apical regions of the basitibial plate. Mitochondrial gene sequences (COI and CytB) were used for phylogenetic reconstructions. Our results showed that both nigrocincta and suspecta morphotypes are undistinguished based on morphology, although the metasomal band colour, together with the geographic distribution, revealed the presence of three distinct morphogroups, including an intermediate one with a variable number of reddish bands. Nonetheless, the three morphogroups are not supported by molecular data and therefore represent intra-specific variations. In conclusion, our results do not support the hypothesis that the two nominal species are distinct evolutionary lineages, and we propose a synonym between X. nigrocincta and X. suspecta. [ABSTRACT FROM AUTHOR]

Canola has a long period of flowering in the winter season and this, associated with the lack of other flowers and the use of insecticides to control insect pests, means it may have a great impact on bee populations, such as Apis mellifera L. (Hymenoptera: Apidae). In this context, the use of insecticides with lower residuals and less harmful effects to bees is fundamental. Thus, the objective of the current work was to evaluate, in a laboratory bioassay, the residual toxicity and effect of imidacloprid, beta-cyfluthrin, and a mixture of both, when applied on canola in the field, on Africanized A. mellifera workers. Three commercial products were applied, formulated with imidacloprid, beta-cyfluthrin, and beta-cyfluthrin + imidacloprid. Each plot received one of the three treatments, in the concentration recommended by the manufacturer, at intervals between 14 and 0 days prior to conducting the bioassays. On the day of the bioassay, the bees were exposed to the plant material containing the treatments for a period of two hours, and were transferred to PVC cages, containing food and water. Mortality assessments were then performed at pre-established intervals until a 96 h post-exposure. Residuals on canola leaves of all tested products caused a significant reduction of honeybee worker longevity, which was less accentuated when the interval after treatment application increased. Safer pest management strategies are needed to ensure the preservation of bees. [ABSTRACT FROM AUTHOR]

Due to recent changes in regulation, acetamiprid has become the only neonicotinoid that can be applied without restrictions and in open field cultivations in the EU from 2021. We provide an overview of the current knowledge on the effects of this insecticide on bumblebees and assessed whether available empirical evidence supports the claim that acetamiprid poses negligible risk to these pollinators. We found that there is limited data on the lethal and sublethal effects of this pesticide on bumblebees. While risk assessment results suggest that field-realistic concentrations of acetamiprid have minor acute and chronic toxicity, detrimental sublethal effects, including reduced reproductive output, have been observed when bumblebees were exposed to high doses of this insecticide. We propose that further research on the topic is warranted as the more extensive application of acetamiprid may lead to such high concentrations in the field. [ABSTRACT FROM AUTHOR]

We present an analysis of the structure of Fejes Tóth cells in the natural combs of the Chinese bee, Apis cerana cerana (Hymenoptera: Apidae), and the Italian bee, Apis mellifera ligustica (Hymenoptera: Apidae). The proportion of Fejes Tóth cells in the natural combs built by bee colonies was determined. Molds of Fejes Tóth cells and three-rhombus cells were used to measure various structural parameters, such as the diameter and depth of Fejes Tóth cells and three-rhombus cells. Both Chinese bees and Italian bees built an average of no more than 18% Fejes Tóth cells on natural combs. The dihedral angle of the two hexagonal planes at the bottom of the Fejes Tóth cells was significantly less than 120°. No significant differences in the diameter and depth of Fejes Tóth cells and three-rhombus cells were observed. The results of this study clarified the structural characteristics of Fejes Tóth cells in natural combs. These data will aid the manufacture of Fejes Tóth wax comb foundations specifically and the growth of the beekeeping industry more generally. [ABSTRACT FROM AUTHOR]

The stingless bee Partamona helleri (Meliponini) is distributed across the Atlantic rainforest biome in Brazil. Cytogenetic studies on P. helleri have shown a conserved diploid number and the presence of several B chromosome types. Our goal was to investigate the intraspecific karyotypic variation among 21 colonies of P. helleri from 14 different localities across four Brazilian states, using classical and molecular cytogenetics, as well as image cytometry (ICM). All populations had 2n = 34 and up to 5B chromosomes, which showed inter- and intra-population variation in number and size. C-banding evidenced the centromeric/pericentromeric heterochromatin and the partially heterochromatic B chromosomes. GA(15) microsatellite hybridized in the euchromatic arm of the A chromosomes and did not mark the B chromosomes, whereas TTAGG(6) corresponded to the telomeric sequence of the A and B chromosomes. The 18S rDNA and CMA3+ sites varied among the colonies, indicating the karyotype variability of the species. The ICM demonstrated an increase in nuclear genome size regarding the presence of B chromosomes. We highlighted the importance of population studies in species with a wide range of distributions, and how the B chromosomes contribute to the intra- and inter-population variability of P. helleri. [ABSTRACT FROM AUTHOR]

Molecular cytogenetic reveal details of fine chromosomal structure that are useful in studies of chromosomal diversification, genome organization, and evolution. However, these techniques have rarely been used to describe population-level variations in the tribe Meliponini. In the present study, we compared the karyotype, number, and localization of rDNA clusters and the distribution of a repetitive DNA sequence in the genome of T. spinipes from nine locations. Although karyotypes with 2n = 34 were found in all cases, five different karyotypic formulae were detected. The heterochromatin was preferentially associated with centromeric regions. The microsatellite probe (GA)15 signals were localized mainly in the euchromatic regions of all chromosomes in most of the analyzed populations. The 18S rDNA clusters were present in four chromosomal pairs, except for the population from Palotina, which showed only two rDNA clusters. Analyses revealed a karyotypic variation in T. spinipes along the geographic distribution, proving that cytogenetic variations were not detected when scattered colonies were analyzed. [ABSTRACT FROM AUTHOR]

Stingless bees (Meliponini) form a large monophyletic group with a pantropical distribution. Southern China is on the northern border of this distribution in Asia, and previous studies have recorded a single species in Taiwan and twelve species in Yunnan. In this study, by extensive sampling from both natural nests and the nests of bee keepers in Yunnan, we identified seven stingless bee species from four genera. Species with distinctive characters that were recorded in Xishuangbanna previously but not found during this study may be rare in this region, including Homotrigona lutea and Geniotrigona thoracica. A new key, information on nesting biology, and a snapshot of the current status of meliponiculture in Yunnan are provided. Morphological characters of males of Tetragonula laeviceps, Tetragonilla collina, and Lisotrigona carpenteri are shown, including their genitalia characters. Results of multivariate morphometrics based on twelve characters support the taxonomic classification. For further studies, wider sampling, including tropical and subtropical regions of Fujian, Guangxi, Guangdong, Yunnan, Tibet, Hainan, and Taiwan, is needed to assess the full diversity of Chinese stingless bees. [ABSTRACT FROM AUTHOR]

Mating is an important process in bumblebees that could affect queen diapause survival and offspring reproduction. Both queens and males could influence mating failure. Here, we used the indigenous bumblebee Bombus lantschouensis to evaluate the mating interactions of males and gynes. The effects of kin recognition and males and gynes from multiple colonies on mating latency, mating duration, and the mating success rate were investigated. The results showed that gynes mated with related males had a longer mating latency than those mated with unrelated males (42.88 ± 3.8 min and 24.15 ± 2.5 min, respectively, P < 0.05) and that the mating success rate was significantly higher in unrelated groups than in related groups (49.29 ± 4.1% and 36.74 ± 2.6%, respectively, P < 0.05). However, no preference for related or unrelated males was observed in the mixed mating groups (mating success rate 30.63 ± 3.1% and 30.73 ± 2.4%, respectively, P > 0.05). Interestingly, the occurrence of males from multiple sources significantly increased the mating success rate (one colony 39.1 ± 4.2% to four colonies 60.05 ± 5.7%, P < 0.05). Nonetheless, an increase in the number of gyne sources had no effect on the mating success rate (one colony 39.50 ± 4.9% to four colonies 43.52 ± 5.7%, P > 0.05). Mating latency was significantly more influenced by males and gynes from multiple colonies than by kin relationship, male number, and gyne number (P < 0.05). In conclusion, there is no evidence that the bumblebee B. lantschouensis can recognize kin relationships before mating. The presence of males and gynes from multiple colonies can influence mating latency. Moreover, males from multiple colonies can significantly enhance mating success, which has implications for bumblebee ecological conservation and artificial mass rearing. [ABSTRACT FROM AUTHOR]

Bee surveys bring valuable information regarding species distribution, phenology, and their interactions with host plants, and thus are important to bee conservation, especially in the present scenario of drastic declines reported worldwide. The Brazilian bee fauna has been surveyed intensively since the late 1960s, but the state-of-the-art of this research topic has not been explored in detail. Our main goal is to analyze the scientific literature through a systematic review of Brazilian bee surveys, describing (i) spatial sampling gaps; (ii) preferred sampling frequency and methods; (iii) species identification and vouchering practices; (iv) gender participation; and (v) how the studies are distributed among scientific journals. Our review includes 213 published studies, of which half targeted the entire bee fauna (Apoidea: Apidae sensu lato) while the other half targeted the orchid bees (Euglossini). Sampling sites are predominant in eastern Brazil, particularly within the Atlantic Forest. Hand netting bees for 1 year long was the most frequent sampling protocol to capture bees. Taxonomic identification and voucher deposition practices were mentioned in most of the papers. Men and women published almost the same number of papers, but women were less frequent as lead or senior authors and appeared less as prolific researchers. Most papers were published in a few Brazilian journals. We highlight that surveys in understudied areas are needed, especially in Amazon. Monitoring bees in previously surveyed locations is also encouraged to investigate temporal changes in bee assemblages, such as population declines, impacts of land-use changes, and effects of climate change. [ABSTRACT FROM AUTHOR]

We analyzed the port interceptions of the red dwarf honeybee, Apis (Micrapis) florea and undetermined species of Apis from regions where the A. florea is present. We also provide information on the potential distribution of this species globally and for the USA by using two climatic suitability models: Plant Hardiness Zones and Maxent. The results show several significant interceptions at US ports of entry in the last 10 years, including complete colonies associated with sea containers. In addition, the climatic models showed suitable areas in warmer regions of the world, and Southern and Western USA. Finally, we provide some additional notes for the diagnosis of the females and males of A. florea, including some novel characters from the gonangulum and the sting blades, both parts of the complex sting apparatus of the workers. [ABSTRACT FROM AUTHOR]

Bumblebees are important pollinators for many wild plants and crops. To explore gene expression characteristics in depth, stable reference genes will be essential across different developmental stages. In this context, we evaluated the stability of eight common reference genes at ten developmental stages in the bumblebee Bombus terrestris (B. terrestris) with four algorithms and two rank approaches. The results showed that all the primers for the reference genes exhibited high specificity, linear correlation (R2-value 0.9917~0.9978) and a good PCR amplification efficiency (E-value 95.4~108.6%). The combined use of RPL13 and RP49 was suggested to be the most suitable reference genes. Our candidate reference genes will help to improve the precision of the detection of gene expression at different developmental stages of bumblebee species. [ABSTRACT FROM AUTHOR]

Coordination in honeybees is heavily dependent on their chemoreception system, in which odorant-binding proteins are very important. A previous study based on the antennal transcriptome of Apis cerana cerana revealed that OBP15 was significantly up-regulated at 25-day-old. To further unravel and clarify its functional role, we first cloned and characterized AcerOBP15 from the antennae of worker bees. Sequence and phylogenetic analysis showed that AcerOBP15 belongs to the Minus-C OBPs family. AcerOBP15 was primarily expressed in forager antennae and legs. A fluorescent binding assay showed that AcerOBP15 had strong binding affinity to most floral volatiles, a restricted number of bee pheromone components and non-volatile compounds, among which the highest is myrcene. Based on RNAi and EAG assays, AcerOBP15 may be required for myrcene recognition. Taken together, we suggest that AcerOBP15 plays a dual role in olfactory and gustatory reception when foraging. Our study lays a theoretical foundation for further studies regarding the mechanism of chemoreception in A. cerana cerana. [ABSTRACT FROM AUTHOR]

The bee diversity (Apidae) estimative ranges from 18,000 to 20,000 species worldwide. Together, they show an impressive diversity in morphological, ecological, and behavioral traits, and there is still much to be understood about their taxonomy and systematics. Their chromosome count variability and genome biology are also astonishing. To date, around 200 bee species have already been karyotyped, with chromosome numbers varying from n = 3 to n = 28, and nuclear haploid genome sizes are available for approximately 70 species with a variation of 1C = 0.19 pg to 1C = 1.38 pg. The Bee Chromosome database was created (www.bees.ufop.br) to summarize the Apidae cytogenetic knowledge by assembling all the cytogenetic information published on bees. Considering the importance of cytogenetic studies for taxonomy, phylogeny, genetics, systematics, conservation, and evolution, the main goal of this database is to outline the advances in the field of bee cytogenetics over the last century. [ABSTRACT FROM AUTHOR]

We conducted several tests on the stingless bee Melipona quadrifasciata aiming to determine the impact of the glue used for applying radio frequency identification (RFID) tags on this bee species. The study was organized in three experimental sets, in which we evaluated the effects of a synthetic glue, a natural glue (shellac), and the effects of the bee manipulation alone (control group). We performed (i) an in vitro experiment (bioassay), in which we tested five different experimental treatments in triplicate: chip plus synthetic glue, chip plus shellac, synthetic glue, shellac, and control, totaling 150 bees (n = 30 per treatment); (ii) field experiments, in which we tested the RFID tracking system composed of RFID tags, reading units, antennas, and circuit boards; and (iii) the morphological and histochemical analyses of the flight muscles of bees collected from each experimental treatment (n = 5 per treatment) at 48 h after the beginning of bioassay. Use of the natural glue, as opposed to the synthetic glue, promoted an increase of the bees' longevity while inhibiting detrimental impacts on their foraging activities, as observed by both the bioassay and field experiments. We found negative responses to the synthetic glue treatment combined with the electronic tags, showing that the natural glue induces less morphological damage to the flight muscles of tagged stingless bees. [ABSTRACT FROM AUTHOR]

In solitary bees, monandry is common in several species. Post-copulation strategies exerted by males to prevent females from mating with other males are known and vary between species. We studied a population of Epicharis dejeanii(Centridini) analyzing the reproductive aspects. The average mating time and the behavior of the couples were observed. Males performed synchronized movements of the legs and antennae in addition to vibrations that generated a loud sound. The females remained static, starting movements with their legs to finish the mating after approximately 50 s. During the mating, the females' sting was kept exposed. The males inserted the aedeagus into the female's genital opening but kept out the genitalia. The male's post-copulatory behavior seems to be performed simultaneously during mating. [ABSTRACT FROM AUTHOR]

Vitellogenin (Vg) plays a vital role in the reproduction of oviparous species, as the precursor of the major egg storage protein. In bees, most of the studies of this protein rely on honey bees (Apis mellifera), and very little is known in solitary species. The solitary bees Centris tarsata and C. analis were chosen to characterize vg cDNA and better understand its expression. The Vg-deduced amino acid sequences from these bees have typical Vg features found in other hymenopterans. Besides its main site of synthesis, the fat body, transcripts of vg were also observed in ovaries. Males also showed expression of vg, although in lower levels compared with females. During development, vg expression was observed in late larvae, pupae, and female adults. The highest amounts of vg transcripts were observed in egg-laying females. Expression of vg increased rapidly in a few hours after female adult emergence, which indicates that its gene expression does not depend on mating to be triggered. [ABSTRACT FROM AUTHOR]

Products made by bees are well-known for their beneficial properties and nutritional value. This association has been proven by scientific studies that describe their composition and biological activities. The aim of this study is to portray the state of the art on research regarding stingless bee honey. The search for standards that guide the trade of these products is still portrayed as a future perspective, since there are significant differences in relation to honey from Apis mellifera and it often requires additional treatments. [ABSTRACT FROM AUTHOR]

Partamona is a genus of stingless bee composed of 33 neotropical species that occur from Mexico to Brazil. The scarcity of cytogenetic studies on Partamona limits the use of this indispensable information for the recognition of species. In this study, a comparative cytogenetic analysis of three Partamona species of controversial taxonomy was carried out. Partamona ailyae, Partamona sooretamae, and Partamona aff. helleri showed the chromosome numbers, 2n = 34 and n = 17. However, differences were found in the karyotypic formula of 2K = 22M + 12SM in P. ailyae, 2K = 20M + 14SM in P. sooretamae, and 2K = 28M + 6SM in P. aff. helleri. CMA3/DAPI staining revealed heterogeneity in the composition of heterochromatin, and differences in the number of CMA3+ signals among the species, ranging from 10 in P. ailyae to 18 in both P. sooretamae and P. aff. helleri. Two rDNA sites were found in both P. ailyae and P. sooretamae, whereas six sites were found in P. aff. helleri. Moreover, chromosomal heteromorphism was found in P. aff. helleri, resulting from a reciprocal translocation of a NOR region between pairs 1 and 5. Although chromosome number was the same, the karyotypes were diverse due to variations in the content and distribution of constitutive heterochromatin as well as the number and location of 18S rDNA regions. These variations are useful to the cytotaxonomic distinction of the species. [ABSTRACT FROM AUTHOR]

Since its foundation, Apidologie has steadily gained recognition as a journal that reports results from high-quality scientific research on the biology of bees, and this means Apidae in general, not only on its most prominent species, the Western honey bee, Apis mellifera. All started 50 years ago in a conversation between two eminent scientists, Jean Louveaux, director of one of INRA's bee research unit in Bures-sur-Yvette and editor of the French Annales de l'Abeille, and Friedrich Ruttner, director of the Bee Research Institute in Oberursel and editor of the German Zeitschrift für Bienenforschung, where they discussed the possibility of merging these two journals to create an international bee research journal. Here, we take Apidologie's 50th anniversary as an opportunity to provide our readers with background information on the journal's history, especially on the persons and their contributions along this journey. [ABSTRACT FROM AUTHOR]

Bees are key regulators in the maintenance of global biodiversity and food security. Overwhelming evidence has shown elevated colony losses for honey bees and a decrease in the abundance of other pollinators. Insecticides of the neonicotinoid type have been associated with these losses, but few studies have explored how residual exposure doses affect the queen's energy metabolism. Here, we studied how a residual dose of neonicotinoid (imidacloprid), combined with reproductive status (virgin and inseminated) affects honey bee queen's metabolism. We conducted the same experiment in two geographical locations (Chile and Colombia) and found a strong reduction of standard metabolic rate (SMR) in insecticide-treated queens (Chilean queen bees 11.3% reduction in watt output; Colombian queen bees 11.7% reduction in watt output). No effects were found when comparing reproductive condition on SMR. We will highlight the possible consequences of a weak honey bee queen's performance on colony stability. [ABSTRACT FROM AUTHOR]

For bees to reach isolated islands, they need to be able to cross large water barriers. However, functional traits such as nesting behavior, flight range, and body size can limit their dispersal. In this study, the bee faunas of seven different islands or island groups (Anholt, Canary Islands, Fiji Islands, Hawaiian Islands, Madeira, Malta, and Sri Lanka) were analyzed by comparing them to the mainland bee fauna. Nesting strategy and body size for each species were recorded. The relative distribution of traits among the island species were then compared to traits of the mainland species. We found that among islands located furthest from mainland, the proportion of wood nesting bees are higher than for those located closer to mainland, suggesting that wood nesting bees are more capable of island dispersal, most likely due to the associated rafting ability or the ease of being passively transported over water. The body size among the immigrated island species were shown to be commonly of moderate size, while a majority of mainland species were of small size, indicating that moderate sized bees—with longer flight range—were the more likely island migrators. The methods used could be useful for future studies of ecological influences on body size, as well as how other biological traits are adapted for migrant conditions, potentially serving as predictors in regards to climate change, dispersal ability, and control of invasive species. [ABSTRACT FROM AUTHOR]

We measured abundance, diversity, and richness of Euglossa bees (Euglossini, Apidae) in lowland semi-deciduous forest in Darién National Park, Panamá, during the wet and dry seasons in the canopy and understory for five consecutive years (2013 to 2017) using McPhail traps baited with eucalyptus oil. We found a precipitous decline in abundance and richness throughout the 5 years of our study. Alpha diversity also declined throughout the study. Abundance, species richness and alpha diversity were significantly higher in the dry than in the wet season. There were no significant differences in the diversity, richness, or abundance between the canopy and understory. Our data contrast sharply with previous long-term studies of euglossine bees which showed stable populations. [ABSTRACT FROM AUTHOR]

The sampling of orchid bees across different biomes provides an excellent opportunity to analyze morphological variability in this group. We examined the morphological variation of populations of Eulaema nigrita in the context of the determination of geographic origin. It also evaluated population variability of this group in different landscapes from two important biomes, Atlantic Forest, Brazilian Savanna, and the transition zone between them. These analyses were achieved by documenting the pattern of morphological differentiation using geometric morphometric analysis of the wings of 256 individuals, sampled from nine locations, from four different physiognomies. Results indicated that individuals from the Atlantic Forest physiognomies are larger than the ones from the Savanna. The clusterization of individuals was based on landscape features of the sampling areas. The results indicate little or even a complete absence of population structure. Overall, site-specific population differentiation is not strongly supported by wing traits, reinforcing the statement consistent with the broader pattern that orchid bees have a high migratory capacity. However, the subtle differentiation may indicate the existence of locally adapted traits kept by female philopatry or phenotypic plasticity triggered by environmental factors yet to be studied. [ABSTRACT FROM AUTHOR]

Orchid bees are important long-distance pollinators in Neotropical rainforests. Despite their great flight capacity, some species avoid leaving the forest and might be then more vulnerable to the negative effects of habitat fragmentation. Here, we sampled the euglossine fauna from a forest fragment in an urban zone and compared the data to two surveys conducted in the same area 28 and 20 years before. Twelve species were sampled, and the highest values of both abundance and richness were recorded in the present sampling. Species turnover was observed with the resilient species Euglossa cordata and Eulaema nigrita presenting a high increase in number over the years whereas the prevalent species in the former samplings, Euglossa pleosticta, show the highest stable populations. Conversely, the abundance of Euglossa annectans decreased until zero in the last sampling. The studied orchid bee populations had a lower stability value when compared with other euglossine long-term surveys. Our results indicate that even a small forest fragment within an urbanised landscape and subjected to different levels of anthropogenic impacts harbours a diverse euglossine fauna. It is suggested that not only the preservation and maintenance of forest fragments in urban areas but also its restoration after environmental impacts are important procedures to support species-rich wildlife. [ABSTRACT FROM AUTHOR]

Tetrapedia diversipes is an oil-collecting solitary species widely distributed in the Neotropical region. The high incidence of this species in trap nests makes it potentially a model species for ecological, genetic, evolutionary, and physiological studies. Here, we performed a population genetic study by using mitochondrial and microsatellite markers. This study aimed to investigate the genetic diversity, gene flow among populations, and offspring relatedness within the nest. The results indicated female philopatry and gene flow to be mainly mediated by males. Data on offspring relatedness suggested that nest owner replacement is common in this species. [ABSTRACT FROM AUTHOR]

It is generally accepted that temperate subspecies of honey bees can maintain stable temperatures inside their nests; however, little information is available on the cooling ability of tropical honey bees and the effect of high environmental temperatures on individuals. In this study, we registered temperatures in the brood area of strong- and medium-populated colonies of Africanized honey bees during heatwaves (maximum environmental temperature 44 °C) between April and May in the tropical Yucatán Peninsula of México. To evaluate the effect on colonies, we compared the body size of workers produced under high temperatures in the field and siblings produced at stable 34–35 °C laboratory conditions. We found that in the field, temperatures of the brood nest in both types of colony can increase above 36 °C during the hottest part of the day, especially in less strong colonies. Workers produced in the field were significantly smaller, compared to those reared in the lab at stable temperatures. This is a first study reporting body size reduction in honey bees as a consequence of possible thermoregulation disruption during heatwaves. We discuss our results considering potential effects of heat stress to Africanized honey bee colonies and tropical beekeeping. [ABSTRACT FROM AUTHOR]

Sacbrood virus (SBV) caused significant colony collapse in Korean Apis cerana. Therefore, breeding of resistant bees to counter this viral disease is urgently needed. Considering that hygienic behavior in honey bees confers colony-level resistance against brood diseases, we utilized this trait for selecting A. cerana colonies. In addition, the brood survival rate was evaluated after colonies were SBV-inoculated. Over four selective generations, dead brood removal and brood survivorship in selected colonies were higher than those in the controls, which were not selectively bred for those traits (P < 0.01, 99.3 vs. 89.9% for removal of pin-killed pupae; P < 0.01, 99.0 vs. 63.9% for removal of SBV-killed larvae; and P < 0.01, 70.0 vs. 9.2% for brood survivorship). Following SBV inoculation, selected colonies showed an increase in the number of surviving pupae and adults, whereas control colonies collapsed mostly. Our results confirm the feasibility of selecting SBV-resistant A. cerana. [ABSTRACT FROM AUTHOR]

For eusocial bees, colony defense is paramount. An uncommon strategy is the deployment of hovering guard bees, which has been previously described for only a few species of Neotropical meliponines. This report describes the use of flying guards for the Paleotropical stingless bee species Tetrigona apicalis (Smith) which is the first known species in the region to incorporate this defense strategy. The first appearance of hovering guards occurs ca. 0800, and the number of guards increases until an assemblage of ca. several to 25 guards is formed within an hour of the first appearance of a flying guard. The cloud of hovering guards remains throughout the day until dusk and has a continuous presence unless interrupted by rain. The group hovers in front of the entrance tube out to a distance of 10 to 35 cm with the guards facing the entrance tube. The length of time an individual hovering guard bee spends in flight averaged 17 min 52 s ± 18 min 2 s. The longest hovering flight was 1 h 48 min 46 s. This compares to a reported guard flight time of ca. 58 min for the Neotropical meliponine Tetragonisca angustula, the only other stingless bee species where flying guard flight times have been investigated. [ABSTRACT FROM AUTHOR]

There are two endemic subspecies of western honey bees (Apis mellifera L.) in the Republic of South Africa (RSA), A.m. capensis and A.m. scutellata. They have traditionally been identified using morphometric characteristics, but geometric morphometric data from honey bee wings are easier to collect, possibly making them a useful alternative for identifying these subspecies. We compared the accuracy of both morphometric and geometric morphometric methods using linear discriminant and classification and regression tree analyses. We found that using geometric wing shape data from both forewings and hindwings resulted in a lower classification accuracy (73.7%) than did using models derived from the full set of standard morphometric data (97% accurate) in cross-validation. Tergite color and average ovariole number were the most important features for discriminating between the two subspecies. Finally, we used Kreiger interpolation to construct maps illustrating probable distributions of A.m. capensis and A.m. scutellata in the RSA. [ABSTRACT FROM AUTHOR]

The stingless bee Melipona beecheii is extensively distributed across Mexico and Central America and the only Melipona found in the Greater Antilles. The aim of this work was to establish possible continental affinities of M. beecheii from the Antilles. We compared populations from the main island (Cuba) with two clearly separated genetic lineages of M. beecheii on mainland, namely the Yucatán peninsula (Mexico) and Costa Rica. We used morphometrics, the degree of cephalic maculation, and microsatellite variation. Results indicate a greater morphological and genetic similarity between populations from Cuba and the Yucatán peninsula with respect to those of Costa Rica. Based on our findings, we conclude that the origin of M. beecheii from Cuba is more likely the Yucatán peninsula (Mexico). We found evidence that isolation has not been large enough to result in a new genetic lineage. [ABSTRACT FROM AUTHOR]

Body size is a known predictor of foraging distance in stingless bees (Apidae: Meliponini). However, effects of seasonality on foraging distances, particularly in tropical regions, are poorly understood. Here, we use translocation ('homing') experiments, the release of marked individuals at various distances from the nest, to investigate how homing abilities of the Neotropical stingless bee, Scaptotrigona aff. postica differ across the transition between wet and dry seasons (February–August) in a heterogenous tropical landscape in the eastern Brazilian Amazon. We also determined nectar sugar concentrations of unmanipulated returning foragers to assess temporal changes in collected resource quality. Maximum and typical homing distances (i.e. distances where 90% and 50% of released bees are lost) were estimated to be 860 and 392 m, respectively, confirming that while some individuals travel long distances, most workers must remain close to nests during foraging trips. Homing distances and collected nectar sugar concentrations showed inverse temporal patterns, as homing range declined in later months (May to August), whereas nectar sugar concentrations increased over the same period. Thus, shorter homing distances in later 'dry season' months probably reflected an increased availability of floral resources compared with earlier months. Together, our findings highlight the limited spatial extent of foraging activities in S. aff. postica workers, and that bee homing distances vary with environmental conditions. These results provide useful information for both stingless bee colony management and conservation in humid tropical regions. [ABSTRACT FROM AUTHOR]

An aggregation of the oil-collecting bee Epicharis dejeanii Lepeletier was studied at Ilha das Flores, southern Brazil. Data on seasonality, types of floral resources collected, and nesting biology were registered. The nesting area occupied 120 m2 with density of up to 8 nests/m2. The tunnel entrances remained always open and surrounded by a tumulus. Adult activity lasted approximately 70 days. The females built the nest, provisioned food, and layed the egg in 4 days. The nest's architecture was very diverse, and they were between 40 and 140 cm in depth with one or two brood cells at the end of the tunnel. Diapause occurred in the postdefecating larval stage, and there was no cocoon. Immature stages and nest architecture are described and illustrated. [ABSTRACT FROM AUTHOR]

Bombus bicoloratus is an important pollinator of wild flowers in the oriental region. We confirmed a total of 451 specimens of B. bicoloratus from China based on DNA sequences from mitochondrial cytochrome oxidase subunit I (COI) barcodes. Bombus bicoloratus is distributed mainly in tropical and subtropical areas of southern China. This species exhibits a striking intraspecific colour-pattern polymorphism both in females and males. The distribution frequency of the different colour patterns is heavily skewed, with 50.9% of the workers sharing the same colour pattern that predominates in most locations. Workers from the islands of Hainan and Taiwan possess a very distinct colour pattern, and its spatial distribution is correlated with the climate factor irradiance. Bombus bicoloratus has been recorded to collect nectar and pollen from 14 plant families, indicating that this species is polylectic. This study will be helpful for recognising bumblebee species with variable colour patterns, especially B. bicoloratus, in Asia. [ABSTRACT FROM AUTHOR]

An unpredicted occurrence of the cleptoparasitic orchid bee Aglae caerulea is announced for the Pantanal wetland biome in midwest Brazil, cataloged in a gallery forest in the Serra das Araras Ecological Station, southwestern Mato Grosso. A single female was cataloged outside the polygons where surveys were recently proposed for new orchid bee inventories in the Neotropical realm. The female found in habitat preoccupied by its hostess Eulaema nigrita is presumed representative to confirm that A. caerulea occurs in sympatry with their host in this wetland. Two recent points of occurrence in the Amazon rainforest of Mato Grosso were included here to update the Aglae distribution map. Following a meticulous literature review, several previous records from tropical moist forests in Panama and spanning from the Caribbean Sea to the Cerrado in central Bolivia and Brazil were used to complete the present record points of A. caerulea in the neotropics. The results demonstrate another distributional gap in euglossines and suggest the need for additional studies to find Aglae in southern Pantanal and farther afield. [ABSTRACT FROM AUTHOR]

We examine the origin of honey bee (Apis mellifera) populations in Kangaroo Island (Australia), Norfolk Island (Australia) and the Kingdom of Tonga using a highly polymorphic mitochondrial DNA region and a panel of 37 single nucleotide polymorphisms that assigns ancestry to three evolutionary lineages: Eastern Europe, Western Europe and Africa. We also examine inbreeding coefficients and genetic variation using microsatellites and mitochondrial sequencing. The honey bees of Kangaroo Island have a high proportion of Eastern European ancestry (90.2%), consistent with claims that they are of the subspecies A. m. ligustica. The honey bees of Norfolk Island also had a majority of ancestry from Eastern Europe (73.1%) with some contribution from Western Europe (21.2%). The honey bees of Tonga are mainly of Western European (70.3%) origin with some Eastern European ancestry (27.4%). Despite the suspected severe bottlenecks experienced by these island population, inbreeding coefficients were low. [ABSTRACT FROM AUTHOR]

Green roofs, which have become mandatory on new flat-topped buildings in many cities, increase habitat connectivity for wildlife and have contributed to a boom in urban beekeeping. The ecological benefits or risks of green roofs for wild bees (bee species other than the domesticated honey bee, Apis mellifera), however, have not been comprehensively analyzed. We therefore reviewed studies on insects caught on green roofs in Asia, Europe, or North America between 1992 and early 2017 and extracted information on wild bees. The resulting species list includes 236 Apidae identified in 35 studies, with thermophilic species probably overrepresented because roofs provide warm and dry habitats. The percentage of cavity-nesting bees on roofs is higher than that on nearby ground, while the percentage of pollen specialists is lower. Data are almost completely lacking on the reproductive success of bees on green roofs, the effect of roof age on bee diversity, and the genetic or demographic benefits of increased habitat connectivity. Our list of the bee species so far reported on green roofs will help in the selection and implementation of suitable soils, nesting aids, and plantings. [ABSTRACT FROM AUTHOR]

In bees, most of the comparative studies linking the sensory system and behavior were performed in social species. Here, we describe the morphology of antennal sensilla in solitary and cleptoparasitic bees of Apinae and Nomadinae. The external and internal structure of sensilla and setae as well as their distribution in flagella were studied in detail in two different host-cleptoparasitic associations. In addition, taking into account the presence of pores, the distribution of sensilla was compared in females and males of 39 species of these subfamilies. It was found that males of non-parasitic bees showed a higher number of multiporous sensilla. Females had more uniporous and nonporous sensilla than males. Cleptoparasitic bees showed a low diversity in types of sensilla and no sexual dimorphism in number. The pattern of sensilla in males and their cleptoparasitic females was discussed in the context of their ecological roles. [ABSTRACT FROM AUTHOR]

The stock of honey bees in the northern neotropics is likely a composite of European and African lineages, but the genetic makeup of most populations in this region has remained unstudied. We analyzed the genetic composition of honey bees across temperate and tropical regions of Mexico using mitochondrial and morphometric analyses. The results showed that honey bees from Mexico are descendent almost in similar proportion from matrilines of African and European origins. However, morphometrics indicate that most colonies are the result of extensive introgressive hybridization with Africanized bees. While large-scale displacement of European honey bees seems to have occurred in the tropical regions, higher frequencies of colonies with a mixed range of African-European markers were identified in the temperate areas. Our results suggest that the outcome of the hybridization between Africanized and European honey bees in Mexico has been significantly associated with climate. [ABSTRACT FROM AUTHOR]