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The limited availability of antivirals for new highly pathogenic strains of virus has become a serious public health. Therefore, news products against these pathogens has become an urgent necessity. Among the multiple sources for news antibiotics and antivirals, insect exudates or their products has become an increasingly frequent option. Insects emerged 350 million years ago and have showed a high adaptability and resistance to the most varied biomes. Their survival for so long, in such different environments, is an indication that they have a very efficient protection against environmental infections, despite not having a developed immune system like mammals. Since the ancient civilizations, the products obtained from the bee have been of great pharmacological importance, being used as antimicrobial, anti-inflammatory, antitumor and several other functions. Investigations of biological activity of propolis have been carried out, mainly in the species Apis mellifera, and its product have showed activity against some important viruses. However, for the Meliponini species, known as stingless bees, there are few studies, either on their chemical composition or on their biological activities. The importance of studying these bees is because they come from regions with native forests, and therefore with many species of plants not yet studied, in addition to which they are regions still free of pesticides, which guarantees a greater fidelity of the obtained data. Previous studies by our group with crude hydroalcoholic extract of propolis demonstrated an intense antiviral activity against Herpes, influenza, and rubella viruses. In this work, we chose to use aqueous extracts, which eliminates the presence of other compounds besides those originally present in propolis, in addition to extracting substances different from those obtained in alcoholic extracts. Therefore, this study aimed to identify, isolate and characterize compounds with antiviral effects from aqueous propolis extracts from Scaptotrigona aff postica, in emerging viruses such as zicavirus, chikungunya, and mayaro virus. The evaluation of the antiviral activity of the crude and purified material was performed by reducing infectious foci in VERO cell cultures. The results obtained with crude propolis, indicate a high reduction of zica virus (64×) and mayaro (128×) when was used 10% v/v of propolis. The reduction of chikungunya virus was of 256 fold, even when was used 5% v/v of propolis. The chemical characterization of the compounds present in the extracts was performed by high-pressure liquid chromatography. Through the purification of propolis by HPLC and mass spectrometry, it was possible to identify and isolate a peak with antiviral activity. This substance showed activity against all viruses tested. When purified fraction was used, the reduction observed was of 16 fold for zicavirus, 32 fold for mayaro virus and 512 fold for chikungunya virus. Likewise, it was observed that the antiviral response was concentration dependent, being more intense when propolis was added 2 h after the viral infection. Now we are carrying out the chemical characterization of the purified compounds that showed antiviral action. [ABSTRACT FROM AUTHOR]

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]

Orchid bees (Hymenoptera: Apidae) are exclusively Neotropical insects that occur naturally from Mexico to Argentina. Eufriesea species are the least studied among the five genera because they are often univoltine and active for a few months. Eufriesea brasilianorum is seldom collected and is one of the least-known species. We analyzed the data for this rare and threatened species using Maxent and an ensemble of models to determine distribution hypotheses for E. brasilianorum in Brazil. A small area of high suitability was found in eastern Brazil, including Atlantic Forest remnants. More studies must be developed to validate our predictions for E. brasilianorum. Future validation of the predictions obtained for E. brasilianorum will allow further discussion to list E. brasilianorum as a threatened species in the most recent National Action Plan for Conservation of Pollinator Insects Threatened by Extinction. [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]

Stingless bees are a unique resource to Afrotropical ecosystems where they pollinate crops and natural vegetation, and produce honey which has medicinal powers. Studies on African stingless bees are limited partly due to difficulties in identifying them in the field. This study aimed to explore the use of nest characteristics as a simplified technique to discriminate Tanzanian stingless bee species. A total of 49 nests belonging to eight stingless bee species were studied in 15 locations. Qualitative and quantitative data on nesting sites, nest cavities, and architecture of nest entrances, brood rearing area and food storage area were collected and analyzed by comparison of means, hierarchical clustering and principal component analysis (PCA). We found that, differences in nest characteristics among stingless bee species reflected adaptations which enhanced various functions including insulation, ventilation, defense and survival. Four of the studied species were clearly separated on the dendrogram generated by Gower's distance and PCA plot based on quantitative data of nest architecture. Qualitative data assisted the distinction of two other species which had similar nest architecture. The findings of this study suggest that nest characteristics can facilitate identification of stingless bee species in the field. We propose the development of taxonomic tools based on key nest characteristics to provide a practical and user-friendly approach which even personnel who lack scientific expertise can use to discriminate stingless bee species. Such tools would contribute to the advancement of stingless bee management, research and extension services. [ABSTRACT FROM AUTHOR]

Stingless bees (Apidae, Meliponini) are a group of highly eusocial bees with pantropic distribution. The variety of life styles among the approximately 600 species and their frequent specialization on a specific habitat type render them a promising group to study how environmental pressures shaped specific traits during evolution. The present review aimed at identifying potential ecological drivers of bee cognition. Some interesting trends emerged from the scarce literature existing on this topic. A species' investment in particular neural substrates (sensory periphery, centers of information processing and integration) is associated with its foraging and anti-predator strategies. Innate preferences are tuned to often very specific needs, including defense against nest robbers, obligatory cleptobiosis, or foraging under dim-light conditions. These sensory biases, however, can be molded through experience and learning. In addition to associations between particular features of a food source and its quality, bees evaluate feeding sites based on previous experience with signals and cues that indicate potential competition. Moreover, inexperienced foragers learn specific characteristics of an exploited resource, like its scent or profitability, through recruitment signals produced by active food collectors. However, the cognitive abilities of bees, which are key to efficient food collection, are threatened by anthropogenic stressors. Sublethal doses of agrochemicals, in particular, have been shown to provoke cell death of higher brain centers, therewith reducing learning skills of the exposed individuals. Important questions for future studies are whether and to what extent different levels of cognitive plasticity found among stingless bees may attenuate the impact of human stressors. [ABSTRACT FROM AUTHOR]

The current ecological crisis stemming from the loss of biodiversity and associated ecosystem services, highlights the urgency of documenting diversity and distribution. Bees are a classical example of an ecologically and economically important group, due to their high diversity and varied ecosystem services, especially pollination. Here, two common biodiversity indices, namely species richness and phylogenetic diversity, are evaluated geographically to determine the best approach for selecting areas of conservation priority. The model organisms used in this study are the North American species belonging to the bee genus Diadasia (Apidae). Based on the results obtained by analyzing distributional records and a molecular phylogeny, we can see that species richness and phylogenetic diversity are closely linked, although phylogenetic diversity provides a more detailed assessment of the spatial distribution of diversity. Therefore, while either one of these commonly used indices are valid as far as selecting areas of conservation priority, we recommend, if possible, to include genetic information in biodiversity and conservation studies. [ABSTRACT FROM AUTHOR]

Stingless bee honey is an important component of African ethno-medicine, used to treat a variety of health conditions. However, there is scanty information on the therapeutic properties of honeys produced by Afrotropical stingless bees. This study investigated the antimicrobial properties of honeys produced by six species of stingless bees from different vegetation zones of Tanzania. Antimicrobial activity was assessed against standard cultures of Staphylococcus aureus, Bacillus subtilis, Salmonella typhi and Candida albicans by agar well diffusion and broth microdilution methods. Mean inhibition zones ranged from 7.0 – 26.3 mm for gram-positive bacteria, 6.9 – 26.9 mm for gram-negative bacteria and 17.0 – 30.9 mm for Fungi. On the other hand, geometric means of the minimum inhibitory concentrations ranged from 0.1 – 10% v/v for gram-positive bacteria, 0.1 – 20% v/v for gram-negative bacteria and 0.1 – 1.3% v/v for Fungi. Some honey samples exhibited stronger antibacterial activity compared to the standard antibiotic, ciprofloxacin (25 µg/mL). C. albicans displayed the highest sensitivity to stingless bee honey despite being resistant to fluconazole and terbinafine (25 µg/mL). The strongest antimicrobial effect was exhibited by honey samples produced by Dactylurina schmidti. Antimicrobial activity of stingless bee honey was largely influenced by the amount of phytochemicals. To the best of our knowledge, this is the first study that investigates antimicrobial activity of honeys produced by a number of Afrotropical stingless bee species. Our findings validate the use of stingless bee honey in traditional medicine and advocate for its potential for clinical management of complex wounds, candidiasis and drug resistant pathogenic microorganisms. [ABSTRACT FROM AUTHOR]

The Western honeybee (Apis mellifera) plays a crucial role in pollinating natural ecosystems and crops. They support global food production, maintenance of biodiversity, and generation of income from hive by-products. In modern agriculture, frequent use of chemicals, such as herbicides, exposes bees directly to their toxicity. Whereas the noxious effects of commonly used herbicides on honeybees have become an emerging concern worldwide, their toxicity on the African subspecies Apis mellifera scutellata Lepeletier is unknown. In this study, we exposed A. m. scutellata to field concentrations of both paraquat and glyphosate and determined their effects on bee food consumption and survival rates. We found that the mortality rates of bees upon herbicide ingestion were concentration dependent. Lethal doses of paraquat and glyphosate were 10.8 and 229.5 µg/bee, respectively. Our findings suggest that the African honeybee is susceptible to paraquat and tolerant to glyphosate than its European counterpart. This study provides a baseline to help in regulating herbicide use and/or establishing their safe concentrations to protect biodiversity, particularly the beneficial pollinator insects such as bees. [ABSTRACT FROM AUTHOR]

Urbanization is considered one of the major threats to biodiversity worldwide, with a special concern for native species decline, including wild bees. Through the increase of impervious surfaces, urbanization diminishes, fragments, and warms city environments, significantly reducing nesting and foraging resources for bees. Understanding the response of wildlife to urbanization in terms of reproduction, foraging efficiency, and offspring provisioning is important to species conservation in the face of continued urban development. In this study, we investigated how different levels of urbanization affect individual foraging effort, survival, brood productivity, and fitness in Ceratina calcarata. Our findings show that low urbanization levels favour larger-bodied adults, but foraging efforts (determined by wing wear) were higher at moderate disturbance levels. Larger-bodied mothers produced more numerous offspring (clutch size), mainly in medium disturbance sites. Likewise, larger-bodied mothers produced a larger-bodied offspring at low urbanization levels. Our results indicate that wild bees benefit from low and medium levels of urbanization indicated by maternal and offspring fitness in terms of body size and the number of brood, respectively. This suggests significant effects of urbanization on the fitness and stability of wild bee populations. This study provides novel insights into the impact of urban land use and highlights the importance of conserving and providing green spaces for pollinators. [ABSTRACT FROM AUTHOR]

Hemoglobins are mainly functional in the transport and storage of O2, and are present in aerobic, lung respiratory metazoans. Based on recent studies, it has been determined that globin-like proteins are also found in invertebrate groups which have tracheal respiratory systems. Thus, it has been claimed that the globin molecules may have housekeeping functions beyond their known functions. In this study, the presence of a hemoglobin gene was investigated in a natural pollinator, Bombus terrestris. Bombus terrestris (Hymenoptera: Apidae: Bombinae) is an ecologically and economically important species, it has a wide distribution in high and low altitude habitats, can live in different localities in terms of altitude and temperature. The expression of globin gene was determined using real time qPCR and RACE system, and confirmed by SRA data. The potential globin ORF sequence was 516 bp nucleotide and 171 bp amino acid long. This data was deposited in the GenBank database under accession number OP312897. On the other hand, expression profiles were investigated in different hypoxic conditions at different developmental stages (larva, pupae and adult) and in different tissue types (abdomen, thorax, head and legs). It was determined that the globin gene is transcribed in all developmental stages, but only in abdomen; and that globin expression decreases with decreasing amount of oxygen. [ABSTRACT FROM AUTHOR]

The conservation of terrestrial ecosystems depends largely on the preservation of pollinators, mainly bees. Stingless bees are among the main pollinators of native plants and crops in tropical regions, where they can be exposed to agrochemicals while foraging on contaminated flowers. In the present study, we investigated the effects on stingless bees of both a commonly used insecticide and herbicide in Brazil. Plebeia lucii Moure, 2004 (Apidae: Meliponini) foragers were orally chronically exposed to food contaminated with different concentrations of commercial formulations of the insecticide acephate or the herbicide glyphosate. Bee mortality increased with increasing agrochemical concentrations. Depending on its concentration, the acephate-based formulation reduced the lifespan and impaired the flight ability of bees. The glyphosate-based formulation was toxic only under unrealistic concentrations. Our results demonstrate that realistic concentrations of acephate-based insecticides harm the survival and alter the mobility of stingless bees. The ingestion of glyphosate-based herbicides was safe for forager bees under realistic concentrations. [ABSTRACT FROM AUTHOR]

Neonicotinoids harm especially bumblebees and other species in agricultural areas all over the world. The toxic effect of thiamethoxam from the neonicotinoid group has been little studied especially on bees. This research aimed to evaluate the effects of thiamethoxam on the immune system cells of Bombus terrestris workers. Different ratios of 1/1000, 1/100 and 1/10 of the recommended maximum application dose of thiamethoxam formed the experimental groups. Ten foraging workers were used for each dose and control groups. Contamination was ensured by spraying the prepared suspensions at different ratios to the bees for 20 s at a pressure of 1 atm. The effects of thiamethoxam on the structures of immune system cells of bumblebees and the amount of these cells were investigated after 48 h of exposure. In general, anomalies such as vacuolization, cell membrane irregularities and cell shape changes were detected in prohemocyte, plasmatocyte, granulocyte, spherulocyte and oenocytoid in each dose group. Hemocyte area measurements in all groups were examined comparatively between groups. In general, granulocyte and plasmatocyte sizes were decreased, while spherulocyte and oenocytoid were increased. It was also determined that there was a significant decrease in the amount of hemocytes in the 1 mm3 hemolymph as dose increased. The results of the study revealed that sublethal doses of thiamethoxam negatively affected hemocytes and their amounts of B. terrestris workers. [ABSTRACT FROM AUTHOR]

Acarapis woodi (Rennie 1921) (Acari: Tarsonemidae) is one of the mites that settles in the respiratory system of honeybees (Apis mellifera L. (Hymenoptera, Apidae)) and distributed throughout the world. It causes significant economic losses on honey production. In Türkiye, studies on the existence of A. woodi are very limited and so far, no studies on the molecular diagnosis and phylogenetic of it have been reported in Türkiye. This study was conducted to investigate the prevalence of A. woodi in Türkiye, especially in areas where beekeeping is intense. Diagnosis of A. woodi was performed using both microscopic and molecular methods using specific PCR primers. Adult honeybee samples were collected from 1.193 hives in 40 provinces of Türkiye between 2018 and 2019. Based on identification studies, the presence of A. woodi was detected in a total of 3 hives (0.5%) in 2018 and 4 hives (0.7%) in 2019. This is the first report for determination of A. woodi in Türkiye. [ABSTRACT FROM AUTHOR]

The use to stingless bees in Tanzania is widespread, however, the traditional knowledge and practices are not well documented. This study assessed the traditional knowledge of stingless bees and their utilization in 21 Districts representing seven geographical zones of mainland Tanzania. Knowledge on stingless bees and their uses was collected using semi-structured interviews which were supplemented with field observations. Stingless bee samples from hives and natural nests were also collected for identification. We found that a total of six species of stingless bees are utilized in Tanzania namely Meliponula ferruginea (Lepeletier 1841), Meliponula togoensis (Stadelmann 1895), Meliponula beccarii (Gribodo 1879), Hypotrigona gribodoi (Magretti 1884), Plebeina armata (Magretti 1895) and Dactylurina schmidti (Stadelmann 1895). M. ferruginea was the most widespread species, found in all seven geographical zones. In many parts of the country, stingless bee honey is mainly obtained through honey hunting which employs destructive methods. Domestication of stingless bees (meliponiculture) is well established in the Northern zone where the majority of respondents domesticated stingless bees, and 74.1% of stingless bee hives were found in this region. Stingless bee honey is used primarily as medicine to treat health ailments including ulcers, respiratory infections, fire burns, wounds, asthma, broken bones, intestinal worms and reproductive problems. Generally, there is an overexploitation of natural stingless bee nests which threatens the sustainability of stingless bee populations and their natural habitats. We can build upon this knowledge to better utilize stingless bees and their products while protecting their populations and natural habitats. [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]

Large rivers are usually associated with vicariance and diversification of terrestrial species, but little is known about these effects in overlooked areas from South America, like São Francisco River (SFR). In this study we tested this hypothesis by analyzing populations of Melipona mandacaia, an endemic stingless bee from Caatinga whose distribution is associated to SFR. The influence of the river width as a natural barrier to the gene flow among populations of M. mandacaia from both margins of SFR was inferred from genetic and morphometric data. Eleven microsatellite loci were amplified and 813 anterior right wings were used for geometric morphometrics. Most of the genetic variation (96.7%) in AMOVA was found within populations with evidence of low structuring (Fst = 0.032, p < 0.05). The Bayesian model and spatial analysis corroborated the lack of conspicuous genetic differentiation among samples. In morphometric analyses, the first four canonical variables explained 80.49% of the total variation. The cross-validation between populations from left and right margins revealed that about 55.44% of colonies were classified correctly. Thus, we conclude that the SFR should not be considered a natural geographic barrier to the gene flow in M. mandacaia. Implications for insect conservation: Estimates of genetic diversity and the lack genetic structure among populations separated by a putative geographic barrier are useful to the management and conservation strategies of stingless bees, particularly in relation to the translocation of bees and colonies from one site to another. [ABSTRACT FROM AUTHOR]

The increase in agricultural productivity associated with the emergence and the extensive use of pesticides is undeniable. However, strong evidence indicates that this continuous demand is causing serious environmental impacts and bringing toxic effects to associated biota as pollinating insects. The present work aims the determination of the insecticide abamectin (ABA) and the fungicide difenoconazole (DIF) in strawberry flowers (Fragaria x ananassa DUCH.) and pollen sampled from beehives of the stingless bee Tetragonisca angustula Latreille (Hymenoptera: Apidae) located nearby strawberry fields. For analysis, QuEChERS method was optimized, and the analytical performance of those two pesticides was verified. Then, the method was applied to strawberry flowers and the pollen was sampled during three field campaigns. While abamectin was not detected, the systemic fungicide difenoconazole was determined in almost all flowers and pollen samples, demonstrating the major persistence of this pesticide in investigated matrices. The results were then discussed about the difenoconazole application rate and transport to colonies to estimate a preliminary environmental risk assessment for stingless native bees. All calculations were proceeded considering exposure rates and toxicity data from the literature, adapted from Apis mellifera studies. In this sense, the determination, application, and discussion about risk assessment figure out as an important tool to the knowledge about the preliminary risks of native bees exposed to pesticides. [ABSTRACT FROM AUTHOR]

Stingless bees are important pollinators of wild and cultivated plants, and they produce medicinal honey. However, their taxonomy and systematics are still debated and would benefit a continent-wide revision. Here, we explore the potential of wing shape in delineation and classification of Afrotropical Meliponini using geometric morphometrics. We sampled 749 specimens from nine countries of sub-Saharan Africa, belonging to the genera Meliponula (n = 8), Dactylurina (n = 2) and Plebeina (n = 1). Specimens collected from Kenya were used as standards to assess similar species collected from other eight African countries. Eleven landmarks were plotted on the right forewing of each specimen to conduct multivariate analyses and group/specimen classification. Our results show that seven out of eleven African stingless bee species were reliably discriminated using wing shape, however, there was overlap in the remaining four species, namely Meliponula cameroonensis, Meliponula ferruginea, Meliponula togoensis and Meliponula erythra. In conclusion geometric morphometrics represent a promising taxonomic tool that can be applied to identify African stingless bee species. [ABSTRACT FROM AUTHOR]

Stingless bees play a key role in natural environments and human economy because of their pollination services and high-value products. However, information on their nesting habitats and nest characteristics is scarce for almost all Ethiopian stingless bee species. To gain insights into the nest ecology and biology of stingless bees in the country, different habitats from 11 districts were assessed and general nest properties, such as entrance dimension, shape, entrance tunnel length, nest size, nesting substrate and internal nest architecture, were characterized. A total of 49 natural nests of two stingless bee species belonging to two genera: Meliponula and Liotrigona were found. The 47 nests of Meliponula baccarii (M. baccarii) (Gribodo) were found under the ground at an average depth of 50.50 ± 9.32 cm in three different soil types, while the two nests of Liotrigona bottegoi (L. bottegoi) were found in the cavities of Albizia shimperiana trunks at the heights of 2.8 and 3.0 m above the ground. Nest architecture and biology differed greatly between species but similar within each. Though the basic nest architecture and biology were similar within the species, they varied in size from nest to nest. The above characteristics therefore can be used for the management and conservation of the species. Finally, the data on nesting substrates, nest architecture and nest biology are of outmost importance for future designing suitable bee hives for keeping both species and also to conserve the natural nesting sites for their future utilization in pollination. [ABSTRACT FROM AUTHOR]

Apis mellifera is an important bee pollinating native and crop plants but its recent population decline has been linked to the use of pesticides, including fungicides that have been commonly classified as safe for bees. However, many pesticides, in addition to direct mortality cause sublethal effects, including damage to target selective honey bee organs. The midgut is the organ responsible for the digestion and absorption of nutrients and the detoxification of ingested substances, such as pesticides. This study evaluated the histopathological and cytotoxic changes in the midgut of A. mellifera workers caused by the pesticide azoxystrobin. The limit-test was performed, and a 100 µg a.i./bee dose was administered orally and midgut analyzed with light and transmission electron microscopies after 24 h and 48 h of pesticide exposure. The midgut of the control bees has a single layer of digestive cells, with spherical nuclei, nests of regenerative cells, and the lumen coated with the peritrophic matrix. The bees fed on azoxystrobin showed morphological changes, including intense cytoplasm vacuolization and cell fragments released into the gut lumen. The protein detection test showed greater staining intensity in the nests of regenerative cells after 24 h of exposure to azoxystrobin. The occurrence of damage to the midgut in A. mellifera exposed to azoxystrobin indicates that although this fungicide has been classified as low toxicity for bees, it has sublethal effects in the midgut, and effects in other organs should be investigated. [ABSTRACT FROM AUTHOR]

The low number of pollinating insects is the limiting factor for entomophilous plants in the north, and the situation is exacerbated by a short growing season and often unfavorable weather conditions for their life. The paper presents the results of studying the complex of pollinators of the specialized melittophilic species Veronica spicata at the northern limit of its distribution. It is shown that the structure of this complex is determined by the structural features of V. spicata flowers, the latitudinal position, and the differentiation of ecological niches of the species in the north. Unlike other parts of the range, where solitary bees play an important role in the pollination of V. spicata, this function in the north is performed by representatives of the genus Bombus Latr. (Hymenoptera, Apidae). Considering the level of species diversity and population structure, the pollinator complex of V. spicata is based on short proboscis species of bumblebees: Bombus lucorum s.l., B. jonellus, B. pratorum, B. sporadicus, and medium proboscis B. pascuorum. In accordance with the differentiation of ecological niches of V. spicata in the north, differences in the structure of the pollinator complex and foraging strategies of bumblebees were revealed. [ABSTRACT FROM AUTHOR]

Historic and contemporary data can shed light on a species' conservation status and work together to address two main goals in conservation biology: (1) identifying species under extinction risk and (2) the forces shaping this process. Museomics is the study of historical DNA acquired from museum specimens that allows researchers to answer myriad questions across many taxa. Museomics is an effective way to understand how populations have been affected by human and climate factors from a historic perspective. Here, our goal is to investigate changes in wild populations of two small carpenter bee species (Ceratina calcarata and C. dupla) across a 50-year time span. We sampled museum specimens and recent collections to determine their genetic diversity, population structure, effective population size, signatures of selection, and local adaptation. Both species displayed reduced genetic diversity and effective population size through time. We identified signatures of adaptation in both species across human-altered land use and climate change scenarios. We found signatures of selection in genes related to biochemical defense, insecticide, and thermal tolerance, which are consistent with the observed increase in agricultural land use development and rising temperatures over the past 50 years. Our findings suggest that these species are facing population inbreeding, possibly attributable to human land-use change and agrochemicals in their environment. Overall, this study highlights the use of museomics to understand species declines, threats to populations, and targets for remediation. [ABSTRACT FROM AUTHOR]

Fipronil has been widely used in agriculture and forestry in Brazil to control several pests. However, this insecticide may be hazardous to non-target organisms, including stingless bees, which are essential pollinators of crops and natural environments. Here, we investigated the effect of 24-h acute oral exposure to LC50 of fipronil on the Malpighian tubules of the stingless bee Partamona helleri (Friese). Insecticide exposure decreases the respiration rate of forager bees, and the Malpighian tubules are severely affected, as shown by the epithelial architecture disorganization, loss of cytoplasmic content, degradation of the brush border, and nuclear pyknosis. In addition, fipronil ingestion increases the number of Malpighian cells positive for peroxidase, LC3, cleaved caspase-3, and JNK. However, Notch and ERK1/2-positive cells decrease in the exposed bees. These changes in the signaling proteins indicate an increase in oxidative stress, autophagy and apoptosis, and impairment of cell recovery. Overall, our results demonstrate the toxicological effects of fipronil on a stingless bee, which compromises the physiology of this important pollinator. [ABSTRACT FROM AUTHOR]

Honey DNA metabarcoding provides information of floral sources of honey and foraging plant preferences of honey bees. We evaluated the floral composition of honey from two different species of honey bees, Apis cerana honey (ACH) and A. mellifera honey (AMH) in a mixed apiary located in a semi-forest environment to understand the floral preference and level of interspecific competition on floral resource. Three honey samples were collected from different hives of each species in mid-August. In total, 56 plant taxa were identified across the honey samples and among them, 38 taxonomic units were found in ACH compared with a total of 33 in AMH. The number of major plants (> 1% of reads) in honey samples was 9 and 11 in ACH and AMH respectively indicating the higher diversity of plant taxa in AMH. 23 taxonomic units were found exclusively in ACH, 18 taxonomic units were found only in AMH and 15 taxonomic units were shared between ACH and AMH indicating that 73% of the taxonomic units were present only in honey originated from one of the honeybee species. Qualitative and quantitative analyses of the shared major plants revealed the division of floral resource between these co-existing honey bee species pointing to a low level of interspecific competition between these two important pollinators. [ABSTRACT FROM AUTHOR]

We describe five new species of Tetragonula namely, Tetragonula vikrami Viraktamath, sp. n. (from Karnataka), T. sumae Viraktamath, sp. n. (from Tamil Nadu), T. ashishi Viraktamath and Jagruti, sp. n. (from Maharashtra), T. shishirae Viraktamath sp. n. (from Rajasthan) and T. shubhami Viraktamath, sp. n. (from Chhattisgarh) with associated female and male bees. These new species are distinct in having robust penis valve. Besides, T. sumae, T. ashishi, T. shishirae and T. shubhami have robust gonostylus which is lamellate, broad and apically outwardly curved finger-like structure. Tetragonula vikrami resembles T. iridipennis, however, the five new species differ from the other known species of Tetragonula in morphometry, shape, size, and structure of gonostylus, penis valve and the structure of the sternum 5 and 6. The discovery of these five new species elevates the total number of stingless bee species to 22 and the number of species in the genus Tetragonula to 17 from India. [ABSTRACT FROM AUTHOR]

Harrison's rule, that body size is positively correlated between parasites and hosts, has been reported in a range of taxa, but whether the rule is applicable to cleptoparasitic insects is poorly understood. Subfamily Nomadinae, the largest group of cleptoparasitic bees, usurp the nests of a variety of host bees. Within the subfamily, Nomada exploits the most diverse hosts, using at least ten genera from five families. Here, we reassess the phylogeny of Nomadinae, including the expanded sampling of the genus Nomada, to explore host shift fluctuations throughout their evolutionary history and test the applicability of Harrison's rule for the subfamily. Our phylogenetic results are mostly congruent with previous investigations, but we infer the tribe Hexepeolini as a sister taxon to the tribe Nomadini. Additionally, the results reveal discrepancies with the traditional classifications of Nomada. Ancestral state reconstruction of host use indicates that, early in their evolution, parasites used closer relatives, before attacking less related groups later. Lastly, we confirm Harrison's rule in Nomadinae, supporting that body size dynamics influence the host shifts of cleptoparasitic bees. [ABSTRACT FROM AUTHOR]

As a result of their industrial past, legacy cites often have elevated concentrations of soil heavy metal contamination. Metal pollution can have negative and prolonged ecosystem impacts, and bees that forage in these urban ecosystems are at risk of exposure. Legacy cities are known to support species rich bee communities, which highlights the importance of determining the impact of heavy metal contamination on wild bee health. We examined how oral exposure to concentrations of four metals found within the provisions of bees foraging within Cleveland, Ohio, USA influenced colony growth of Bombus impatiens Cresson (Hymenoptera: Apidae), a common species within legacy cities across the eastern United States. Colony weight and brood survivorship were compared among hives fed uncontaminated sucrose solution (hereafter nectar), nectar spiked with one metal (arsenic, cadmium, chromium, or lead), and nectar containing all metals, after 15 or 30 d of exposure within flight tents. Across both exposure periods, we found a significantly higher proportion of dead brood in metal exposed hives. Additionally, colonies fed all four metals had a significantly higher proportion of dead brood than those fed a single metal. Our findings illustrate that even low, environmentally relevant concentrations of metals collected by B. impatiens in legacy cities can negatively influence bee colony growth. We highlight the need to identify metal exposure routes for bees in contaminated landscapes to minimize risk and bolster conservation habitat initiative success. [ABSTRACT FROM AUTHOR]

Managed and wild pollinators often cohabit in both managed and natural ecosystems. The western honeybee, Apis mellifera, is the most widespread managed pollinator species. Due to its density and behaviour, it can potentially influence the foraging activity of wild pollinators, but the strength and direction of this effect are often context-dependent. Here, we observed plant–pollinator interactions in 51 grasslands, and we measured functional traits of both plants and pollinators. Using a multi-model inference approach, we explored the effects of honeybee abundance, temperature, plant functional diversity, and trait similarity between wild pollinators and the honeybee on the resource overlap between wild pollinators and the honeybee. Resource overlap decreased with increasing honeybee abundance only in plant communities with high functional diversity, suggesting a potential diet shift of wild pollinators in areas with a high variability of flower morphologies. Moreover, resource overlap increased with increasing trait similarity between wild pollinators and the honeybee. In particular, central-place foragers of family Apidae with proboscis length similar to the honeybee exhibited the highest resource overlap. Our results underline the importance of promoting functional diversity of plant communities to support wild pollinators in areas with a high density of honeybee hives. Moreover, greater attention should be paid to areas where pollinators possess functional traits similar to the honeybee, as they are expected to be more prone to potential competition with this species. [ABSTRACT FROM AUTHOR]

Stingless bees are important pollinators in the tropics. The tremendous variation in body size makes them an excellent group to study how miniaturization affects vision and visual behaviours. Using direct measurements and micro-CT, we reconstructed the eye structure, estimated anatomical spatial resolution and optical sensitivity of the stingless bee Tetragonula iridipennis. T. iridipennis is similar in size to the Australian stingless bee Tetragonula carbonaria and is smaller than honeybees. It has correspondingly small eyes (area = 0.56 mm2), few ommatidia (2451 ± 127), large inter-facet (3.0 ± 0.6°) and acceptance angles (2.8°). Theoretical estimates suggest that T. iridipennis has poorer spatial resolution (0.17 cycles degree−1) than honeybees, bumblebees, and T. carbonaria. Its optical sensitivity (0.08 µm2 sr), though higher than expected, is within the range of diurnal bees. This may provide them with greater contrast sensitivity, which is likely more relevant than the absolute sensitivity in this diurnal bee. Behaviourally determined detection thresholds for single targets using y-maze experiments were 11.5° for targets that provide chromatic contrast alone and 9.1° for targets providing chromatic and achromatic contrast. Further studies into microhabitat preferences and behaviour are required to understand how miniaturization influences its visual ecology. [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 interactions between plants and their pollinators are the result of convergent evolution of floral attributes reflecting pressure exerted by pollinators. Nonetheless, the strategies employed by floral visitors to collect floral resources are extremely complex, and commonly involve theft or robbery in addition to pollination. We describe here the behavioral repertory of Apis mellifera during the collection of the floral resources, and evaluated the robbing rates of A. mellifera on the buds and flowers of Pyrostegia venusta during periods of intense and sparse flowering. We recorded the behaviors exhibited by foraging bees while collecting floral resources, quantified the numbers of floral buds and flowers with perforations in their corolla tissues, and determined whether that damage reduced nectar production. The evaluations were conducted during two distinct periods: during the period of intense flowering of P. venusta, and during the period of sparse flowering. Nectar robbing was observed during 93.4% of the visits of foraging A. mellifera bees, while nectar theft was observed during only 0.7% of the visits, and pollen theft during 5.9%. The robbing of floral buds and flowers was most intense during the period of heavy flowering. Flowers that had been intensely robbed secreted significantly less nectar than those non-robbed. The unusual nectar robbing activities of A. mellifera, especially during the period of intense flowering indicates an optimization of access to larger volumes of food resources. Our results therefore point to a major limitation of nectar per floral unit during the intense flowering period of P. venusta due to the high activity of nectar robbing by A. mellifera bees. [ABSTRACT FROM AUTHOR]

Copper sulfate (CuSO4) is widely used in agriculture as a pesticide and foliar fertilizer. However, the possible environmental risks associated with CuSO4 use, particularly related to pollinating insects, have been poorly studied. In this study, we evaluated both lethal and sublethal effects of CuSO4 on the stingless bee Partamona helleri. Foragers were orally exposed to five concentrations of CuSO4 (5000, 1666.7, 554.2, 183.4, 58.4 μg mL−1), and the concentration killing 50% (LC50) was estimated. This concentration (142.95 μg mL−1) was subsequently used in behavioral, midgut morphology, and antioxidant activity analyses. Bee mortality increased with the ingestion of increasing concentrations of CuSO4. Ingestion at the estimated LC50 resulted in altered walking behavior and damage to the midgut epithelium and peritrophic matrix of bees. Furthermore, the LC50 increased the catalase or superoxide dismutase activities and levels of the lipid peroxidation biomarker malondialdehyde. Furthermore, the in situ detection of caspase-3 and LC3, proteins related to apoptosis and autophagy, respectively, revealed that these processes are intensified in the midgut of treated bees. These data show that the ingestion of CuSO4 can have considerable sublethal effects on the walking behavior and midgut of stingless bees, and therefore could pose potential risks to pollinators including native bees. [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]

Within the citizen science project "Flowering meadows for Saxonian butterflies", more than 640 meadows are partially and at maximum three times annually mowed in order to change urban lawns into habitats for insects. In 2019, insect diversity was evaluated using the 100 sweep net technique during five visits at nine butterfly meadows (BM) and nine intensively mowed lawns (IML). The mean arthropod biomass of these five visits per site is significantly higher on BM compared to IML. All adult individuals of Apidae, Coleoptera, Heteroptera, Orthoptera, Papilionoidea as well as Asilidae and Syrphidae have been identified morphologically, revealing 260 species from all study sites. The mean number of species per visit is significantly higher on BM compared to IML. 90 species are recorded as larva and the mean number of species per visit is significantly higher on BM compared to IML. 42 species are recorded as larva as well as adult. The records of larvae provide evidence for reproduction on the meadows. Implications for insect conservation: Our results clearly demonstrate that a reduced mowing frequency together with an always partial mowing of the area support higher biomass, abundances and diversities of insects as well as reproduction of insects on urban lawns. Therefore, reduced mowing frequency together with partial mowing is recommended for urban lawns as well as meadows in the countryside and conservation areas to foster insect diversity. [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]

There has been a long standing tradition of stingless bee, Meliponula beccarii (M. beccarii), honey hunting in Ethiopian farming communities. However, attempt has not been made to domesticate and manage stingless bees for sustainable harvest of the products. Domestication trial of M. beccarii in different hives types were conducted for colony adaptation. For this purpose, a total of 33 stingless bee colonies excavated from wild nests were transferred into five UTOB, 10 rectangular box and 18 pot hives. All of the colonies transferred to UTOB and rectangular box hives were absconded within six months of their establishment, indicating a 100% failure of M. beccarii domestication in wooden box hives set above the ground. However, among 18 stingless bee colonies transferred into pot hives and placed under the ground, 16 (88.9%) were adapted and successfully domesticated. Two season honey yield was harvested from pot hived colonies using disposable syringe and the average honey yield/colony/year was 1.10 ± 0.20 L that ranges from 90 ml – 3 L/colony. Moreover, the average volume of honey/honey pot was estimated to be 6.26 ± 1.08 ml. Furthermore, the nests of M. beccarii were protected with an average of 6.87 ± 0.65 guard bees/nest. Therefore, this study demonstrated for the first time that the possibility of M. beccarii domestication using pot hives for the sustainable honey production and conservation of this native bee species in Ethiopia. Although the current results highlighted the possibility of M. beccarii domestication for sustainable honey production, more research is needed on how to manage, multiply them, on the best way of honey harvesting technique and use of these bees for pollination services. [ABSTRACT FROM AUTHOR]

Grewia flavescens Juss. is an underutilised fruit species found throughout semi-arid and sub-humid parts of the world including India. For the first time, an attempt was made to study the role of different flower visitors on fruit set of G. flavescens. We have recorded different floral visitors, activity patterns, foraging behavior and their role in fruit set. A total of 25 species of floral visitors were recorded, of which Megachilidae (48.35%) was the most abundant group followed by Apidae (27.21%), Halictidae (10.29%) and others (14.15%). Among floral visitors, the foraging rate and foraging speed of Megachile and Xylocopa were studied. They were also effective in depositing more pollen on the stigmatic surface per visit than other flower visitors. Fruit-set was higher (71.42%) in open pollinated flowers than in artificial-cross pollinated (68.33%). Whereas, artificially-selfed and pollinator excluded flowers resulted in the lowest fruit-set (22.22% and 8.95%, respectively). G. flavescens is a self-compatible species but favouring cross pollination and also exhibited delayed self pollination to ensure reproductive success in the absence of an effective pollinator. [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]

We describe Tetragonula kyrdemkulaiensis Viraktamath and Rojeet sp. n. with associated females and males from Kyrdemkulai, Meghalaya. This appears to be one of the largest species of the genus with male holotype measuring 5.20 mm in body length and 1.85 mm in head width, while female paratypes measuring 4.93 and 1.82 mm in body length and head width, respectively. Male gonostylus arises laterally and is gently clavate apically. Penis valve is robust with a characteristic shape. One nest was found in the soil at 90 cm depth with cells arranged in a cluster. We also describe Tetragonula srikantanathi Viraktamath sp. n. based on females from Salema, Tripura. Female holotype measures 3.50 mm in body length and 1.60 mm in head width, while the paratypes measure3.58 and 1.59 mm in body length and head width, respectively, with the whole orange metasoma. One nest of this species was found in mud wall cavity with unique single-cell thick layer of brood combs which has not been reported in any other Indian species of Tetragonula. Both species were compared with the images and descriptions of primary type specimens of Tetragonula species occurring in the Indo-Malayan region and were found to be distinct in morphological characters, male genitalia and nest structure. [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]