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To provide definitions and a conceptual framework for single position surgery (SPS) applied to circumferential fusion of the lumbar spine.Narrative literature review and experts' opinion.Two major limitations of lateral lumbar interbody fusion (LLIF) have been (a) a perceived need to reposition the patient to the prone position for posterior fixation, and (b) the lack of a robust solution for fusion at the L5/S1 level. Recently, two strategies for performing single-position circumferential lumbar spinal fusion have been described. The combination of anterior lumbar interbody fusion (ALIF) in the lateral decubitus position (LALIF), LLIF and percutaneous pedicle screw fixation (pPSF) in the lateral decubitus position is known as lateral single-position surgery (LSPS). Prone LLIF (PLLIF) involves transpsoas LLIF done in the prone position that is more familiar for surgeons to then implant pedicle screw fixation. This can be referred to as prone single-position surgery (PSPS). In this review, we describe the evolution of and rationale for single-position spinal surgery. Pertinent studies validating LSPS and PSPS are reviewed and future questions regarding the future of these techniques are posed. Lastly, we present an algorithm for single-position surgery that describes the utility of LALIF, LLIF and PLLIF in the treatment of patients requiring AP lumbar fusions.Single position surgery in circumferential fusion of the lumbar spine includes posterior fixation in association with any of the following: lateral position LLIF, prone position LLIF, lateral position ALIF, and their combination (lateral position LLIF+ALIF). Preliminary studies have validated these methods.

ResumoA cirurgia da coluna continua a expandir seus horizontes para cuidar dos pacientes incapacitados com dor e deformidades. Desde a última década, nosso conhecimento sobre o alinhamento espinal, do crânio à pelve, aumentou consideravelmente. Portanto, faz-se necessária a expansão de tal conhecimento para o ortopedista geral, para que possamos proporcionar melhores cuidados para essa população.O alinhamento espinal global é um conceito crítico no entendimento do impacto ocasionado pela condição patológica (doença degenerativa, trauma, deformidade) e mesmo do seu tratamento, como na instrumentação e artrodese da coluna. O tratamento de qualquer doença na coluna deve incluir o entendimento da complexidade do alinhamento espinopélvico.A princípio, todos os parâmetros parecem puramente matemáticos e pouco aplicáveis à realidade do leitor mais desatento. Mas, aos poucos, fica claro que, como tudo em ortopedia, a biomecânica faz parte essencial do conhecimento do sistema musculoesquelético, tornando mais claras as lógicas da fisiologia do movimento.O conhecimento dos conceitos de alinhamento sagital e dos parâmetros espinopélvicos proporcionam uma melhor compreensão dos esqueletos axial e apendicular, além de um melhor entendimento dos processos fisiológicos e adaptativos da coluna frente ao processo degenerativo crescente que ocorre ao longo da vida.

Stingless bees are the most species-rich group of eusocial bees and show great diversity in behaviour, ecology, nest architecture, colony size, and worker morphology. How this variation relates to varying selection pressures and constraints is not well understood. Variation can be caused by selection acting on behavioural or morphological traits, both alone and in correlation across traits. Here we tested whether behavioural and morphological traits important for foraging and defence are linked to nest-entrance architecture, an extended phenotype relevant to both foraging and nest defence. Using 23 species we investigated whether eye size, nest entrance size, landing behaviour and foraging method show cross-species correlations. A phylogenetically-controlled comparative analysis revealed that species with relatively smaller eyes build relatively larger entrances, which in turn are associated with faster landing approaches and fewer landing errors by foragers, both of which could reduce predation risk. Concerning foraging, mass-recruiting species have c. 10-times larger entrance holes than species with a solitary foraging strategy. Larger entrances could help species with mass recruitment to rapidly increase forager traffic or mount a strong defensive response when under attack. Our results show that studying correlations among different traits helps understand phenotypic diversity in species rich groups. Made available in DSpace on 2022-10-27T12:08:50Z (GMT). No. of bitstreams: 1 Menezes-Correlated-expression-2022.pdf: 2883875 bytes, checksum: 41ff09618033b9c5ba2f56494fe42a64 (MD5) Previous issue date: 2022

Objective We sought to compare the outcomes of single-position (SP) circumferential lumbar interbody fusion in lateral decubitus versus dual-position (DP) fusion. Methods A systematic literature review was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines in PubMed, Web of Science, and Scopus databases to identify comparative studies reporting the outcomes of SP lumbar interbody fusion versus DP. For risk of bias assessment, the ROBINS-I (risk of bias in nonrandomized studies of interventions) tool was used. Results Four comparative studies were included from an initial search of 3780 papers. All 4 studies were retrospective cohort studies comparing outcomes of SP versus DP LLIF. A total of 349 patients were operated using SP versus 254 using DP. All studies involved reported operating time, estimated blood loss, length of stay, change in segmental lordosis, and complications. From a general perspective, baseline variables were similar in both groups in all the studies and all reported a significant decrease in operative time and length of stays with SP. Conclusions Literature comparing SP versus lateral-then-prone lumbar fusion shows a tendency toward shorter operating time and hospital stays in SP lumbar fusion while maintaining similar perioperative outcomes.

Background Two-dimensional fluoroscopy-guided percutaneous pedicle screw placement is currently the most widely applied instrumentation for minimally invasive treatment of spinal injuries requiring stabilization. Although this technique has advantages over open instrumentation, it also presents new challenges and specific complications. The objective of this study was to provide recommendations developed from the experience of several spinal surgeons at different minimally invasive spine surgery reference centers to solve specific problems and prevent complications during the learning curve of this technique. Methods An AO Spine Latin America minimally invasive spine surgery study group analyzed the most frequent complications and challenges occurring during the placement of >14,000 two-dimensional fluoroscopy–guided percutaneous pedicle screws at different centers over 15 years. Twenty tips considered most relevant to performing this technique, excluding problems directly related to specific brands of instruments, were presented. Results The 20 tips included the following: (1) positioning; (2) clean and painless; (3) fewer x-rays; (4) check the clock; (5) beveled tip; (6) transverse-rib-pedicle; (7) double Jamshidi; (8) hammer the Kirschner wire; (9) bent tip; (10) too loose, too tight; (11) new trajectory; (12) manual control; (13) start over; (14) Kirschner wire first; (15) adhesive drape control; (16) bend the rod; (17) lower rods; (18) freehand inner; (19) posterior fusion; (20) revision. Conclusions Implementation of these tips might improve performance of this technique and reduce the complications related to percutaneous pedicle screw placement.

Stingless bees (Meliponini) are a monophyletic group of eusocial insects inhabiting tropical and subtropical regions. These insects represent the most abundant and diversified group of corbiculate bees. Meliponini mostly rely on fermentation by symbiont microbes to preserve honey and transform pollen in stored food. Bee nests harbor diverse microbiota that includes bacteria, yeasts, filamentous fungi, and viruses. These microorganisms may interact with the bees through symbiotic relationships, or they may act as food for the insects, or produce biomolecules that aid in the biotransformation of bee products, such as honey and bee bread. Certain microbial species can also produce antimicrobial compounds that inhibit opportunistic bee pathogens.

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.

Propolis has a great diversity in its composition due to numerous factors; therefore, each study is an important contribution to the knoFwledge of its composition and biological action. The objective of this study was to determine the chemical profile and biological activity of propolis produced by Scaptotrigona depilis.Extracts with 70% ethanol (EPE70) and with cereal alcohol (CAPE) were elaborated, and then characterized using UHPLC-ESI(+)-MS/MS. Volatile compounds were extracted and then characterized using gas chromatography mass spectrometry (GC-MS). In addition, antimicrobial activities were verified against resistant strains.The volatile compounds of propolis predominantly consist of sesquiterpenes. Using the exploratory metabolomic approach, compounds of different classes were putatively identified in the ethanolic extracts, of which the most representative were terpenes, and some of the sesquiterpenes identified among the volatiles were also detected. The extracts were shown to be active against Escherichia coli and Staphylococcus aureus bacteria with a minimum inhibitory concentration (MIC) of 0.5 and 1.0 mg mLThe molecular network approach proved to be determining the chemical profile of S. depilis propolis rapidly and accurately, and led to the identification of lipophilic compounds. The identification of compounds using GC-MS and UHPLC-ESI(+)-MS/MS is complementary and useful for the characterization of propolis.

Made available in DSpace on 2020-12-12T01:57:45Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-03-01 National Council for Scientific Research Federal Agency for Scientific Organizations Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Chromoblastomycosis is a neglected disease characterized by cutaneous, subcutaneous or disseminated lesions. It is considered an occupational infectious disease that affects mostly rural workers exposed to contaminated soil and vegetal matter. Lesions mostly arise after a traumatic inoculation of herpotrichiellaceous fungi from the Chaetothyriales order. However, the environmental niche of the agents of the disease remains obscure. Its association with insects has been predicted in a few studies. Therefore, the present work aimed to analyze if social insects, specifically ants, bees, and termites, provide a suitable habitat for the fungi concerned. The mineral oil flotation method was used to isolate the microorganisms. Nine isolates were recovered and phylogenetic analysis identified two strains as potential agents of chromoblastomycosis, i.e., Fonsecaea pedrosoi CMRP 3076, obtained from a termite nest (n = 1) and Rhinocladiella similis CMRP 3079 from an ant exoskeleton (n = 1). In addition, we also identified Fonsecaea brasiliensis CMRP 3445 from termites (n = 1), Exophiala xenobiotica CMRP 3077 from ant exoskeleton (n = 1), Cyphellophoraceae CMRP 3103 from bees (n = 1), Cladosporium sp. CMRP 3119 from bees (n = 1), Hawksworthiomyces sp. CMRP 3102 from termites (n = 1), and Cryptendoxyla sp. from termites (n = 2). The environmental isolate of F. pedrosoi CMRP 3076 was tested in two animal models, Tenebrio molitor and Wistar rat, for its pathogenic potential with fungal retention in T. molitor tissue. In the Wistar rat, the cells resembling muriform cells were observed 30 d after inoculation. Graduate Program in Microbiology Parasitology and Pathology Federal University of Paraná University Center Campo Real Federal University of Paraná Graduate Program in Pharmacology UFPR Medical Department Federal University of Maranhão Embrapa Amazônia Oriental CPATU Westerdijk Fungal Biodiversity Institute Department of Biochemistry and Microbiology Institute of Biological Sciences UNESP-São Paulo State University Division of Microbial Resources CPQBA University of Campinas Center of Expertise in Mycology of Radboud University Medical Center Canisius Wilhelmina Hospital Department of Biochemistry and Microbiology Institute of Biological Sciences UNESP-São Paulo State University CNPq: 312811/2018–7 CAPES: Brazil CAPES: Finance Code 001, Brasilia

To describe a comprehensive setting of the different alternatives for performing a single position fusion surgery based on the opinion of leading surgeons in the field.Between April and May of 2021, a specifically designed two round survey was distributed by mail to a group of leaders in the field of Single Position Surgery (SPS). The questionnaire included a variety of domains which were focused on highlighting tips and recommendations regarding improving the efficiency of the performance of SPS. This includes operation room setting, positioning, use of technology, approach, retractors specific details, intraoperative neuromonitoring and tips for inserting percutaneous pedicle screws in the lateral position. It asked questions focused on Lateral Single Position Surgery (LSPS), Lateral ALIF (LA) and Prone Lateral Surgery (PLS). Strong agreement was defined as an agreement of more than 80% of surgeons for each specific question. The number of surgeries performed in SPS by each surgeon was used as an indirect element to aid in exhibiting the expertise of the surgeons being surveyed.Twenty-four surgeons completed both rounds of the questionnaire. Moderate or strong agreement was found for more than 50% of the items. A definition for Single Position Surgery and a step-by-step recommendation workflow was built to create a better understanding of surgeons who are starting the learning curve in this technique.A recommendation of the setting for performing single position fusion surgery procedure (LSPS, LA and PLS) was developed based on a survey of leaders in the field.

12052 Background: Older cancer patients in developing countries face considerable challenges in obtaining access to specialized medical attention, often due to a lack of human resources and healthcare infrastructure. This study sought to explore the benefit of a remote, validated geriatric assessment (GA) program for older patients starting chemotherapy in Brazil. Methods: Older adults (65+ years) beginning a new chemotherapy treatment regimen in Brazil were recruited. Through telehealth, patients were assessed with GA before starting chemotherapy treatment for any type of solid cancer and at a follow-up visit (3 months after enrollment). GA results were discussed by a multidisciplinary team (e.g., geriatrician, psychologist, nutritionist) and recommendations were determined. Outcome measures included chemo toxicity scores (CARG, scale 0-19), physical symptoms (FACT-G, scale 0-108) and activities of daily living (IADL, scale 0-5 for men and 0-8 for women, or scale 0-1 for IADL ratio). Descriptive statistics were generated, and paired t-tests were used to evaluate the change in these measures over time. Results: A total of 51 older patients from 5 different Brazilian states (Amazonas, Distrito Federal, Espirito Santo, Pernambuco and Rio Grande do Sul) have been enrolled to date. The mean distance from a patients’ home to their place of cancer treatment was 21 miles (range: 3-101 miles). Participants had a mean age of 76.5 years (SD = 7.6) and were predominantly female (57%), white (57%), married (61%), and had a high school degree or more (65%). Patients were mostly diagnosed with gastrointestinal (39%) or gynecological (20%) cancers; 55% of patients were diagnosed with a stage IV disease. The majority of patients (80%) were referred to appropriate remote services based on the GA; including geriatricians (41%), nutritionists (39%) and/or psychologist (16%). At the time of abstract submission, data from 34 complete cases were available for longitudinal analysis, in which we observed a decrease in chemo toxicity scores (M1= 6.65, M2= 5.88, p = 0.035) and an improvement in FACTG (M1= 92.94, M2= 98.53, p < 0.001). The improvement in IADL ratio was not significant (M1= 0.79, M2= 0.85, p = 0.069). Conclusions: This novel, ongoing study is, to our knowledge, the first to implement a remote GA program in Brazil. Our preliminary findings suggest that a remote GA program, with appropriate referrals to specialists, may increase the reach of supportive services and improve cancer care in developing countries.

Males can control female reproduction using genital plugs to impede access by rivals. In social bees, ants, and wasps, plugging may involve traumatic mating, with females being harmed. In stingless bees, chances are that plugs may promote ovarian activan, and are thought to ensure single mating?a general tendency among the social Hymenoptera. However, understanding on relationships between mating plugs, traumatic mating, and mating systems in stingless bees remains limited. To address this, we (1) compared mated queens of 7 Neotropical species to understand the patterns of copulatory marks in females and (2) compared pre- and post-mating genitalia of males and females in Melipona fasciculata to depict plug functional morphology. Data revealed an unprecedented consequence of mating in stingless bees: the characteristic marks left by mating plugs on female abdomens and the inferences that can be made from them. To our surprise, in 1 species M. fasciculata we found that queens retain the plug long after mating, and may carry it for the rest of their lives. All the other 6 species retained the plug for only a short period. Remated queens were only found in M. seminigra, whose multiple copulatory marks match previous findings of polyandry in this species. Our study shows that queens can remate, and suggests that male genital morphology may determine in part the time persistence of plugs. We conclude that traumatic mating plugs do not fully prevent remating in stingless bees and that mating systems are not uniform in this group. Nonetheless, exceptional cases of facultative polyandry in social insects?for example, when mating plugs fail?may confirm a general tendency for single mating in close link with efficient mating plugs. Made available in DSpace on 2022-03-12T02:25:33Z (GMT). No. of bitstreams: 1 Menezes-Queens-remate-2021.pdf: 832682 bytes, checksum: 5f2af29141433e0774e54690deb690bb (MD5) Previous issue date: 2021

Predicting outcomes of land use change on biodiversity and ecosystem services remains a key priority for ecologists, but may be particularly challenging in diverse tropical ecosystems. Trait-based approaches are a key tool to meet this challenge. Such approaches seek functional mechanisms underpinning species’ responses to environmental disturbance and contributions to ecosystem services. Here, we use a functional trait approach to study effects of land use change on stingless bee communities and on pollination services to acai palm (Euterpe oleracea, Arecaceae) in the eastern Brazilian Amazon. We compared traits of stingless bees visiting acai inflorescences across a land use intensity gradient (low to high forest cover) to determine: (1) the role of traits in bee species’ responses to deforestation; (2) how deforestation affects functional composition of bee communities; and (3) whether bee traits better explain variation in acai fruit production than species diversity metrics. We found that bee species’ responses to deforestation were non-random and predicted by body size, with small-sized bees more susceptible to forest loss, and changes in functional diversity of bee communities were important for pollination services. However, not all changes in functional diversity were associated with forest loss. Together, these results suggest that: (1) large tracts of minimally disturbed tropical rainforest are vital for the conservation of diverse stingless bee communities; (2) efficient pollination is contingent on bee species not only having divergent trait values (functional dispersion), but also traits’ relative abundance in communities (functional evenness); and (3) high functional diversity in stingless bee communities buffers acai pollination services to loss of sensitive species. Thus, conservation strategies must focus on protecting wider biodiversity, not just ecosystem services, to guarantee conservation of native eusocial bee taxa. Doing so will safeguard crop pollination services, the pollination of native plant communities, and the long-term resilience of Amazon forest ecosystems.

The Brazilian stingless bee Scaptotrigona depilis requires the brood cells-associated fungus Zygosaccharomyces sp. as steroid source for metamorphosis. Besides the presence of Zygosaccharomyces sp., other fungi inhabit S. depilis brood cells, but their biological functions are unknown. Here we show that Candida sp. and Monascus ruber, isolated from cerumen of S. depilis brood provisions, interact with Zygosaccharomyces sp. and modulate its growth. Candida sp. produces volatile organic compounds (VOCs) that stimulate Zygosacchromyces sp. development. Monascus ruber inhibits Zygosacchromyces sp. growth by producing lovastatin, which blocks steroid biosynthesis. We also observed that in co-cultures M. ruber inhibits Candida sp. through the production of monascin. The modulation of Zygosaccharomyces sp. growth by brood cell-associated fungi suggests their involvement in S. depilis larval development. This tripartite fungal community opens new perspectives in the research of microbial interactions with bees. Made available in DSpace on 2019-11-26T18:13:46Z (GMT). No. of bitstreams: 1 MenezesMicrobialCommunities2019.pdf: 1605731 bytes, checksum: eac5cfd1729fbd12538d1a0a22b5e1cf (MD5) Previous issue date: 2019

In this study, we investigated the chemical compositions and antioxidant and antimicrobial activities of propolis produced by the stingless bee Frieseomelitta longipes and the honeybee Apis mellifera collected from colonies in North Brazil. In terms of volatile composition, both mono- and sesquiterpenes were detected in the propolis of F. longipes while only sesquiterpenes were detected in that of A. mellifera. Out of 50 volatiles identified in all samples, 26 were found exclusively in F. longipes propolis and 8 were found exclusively in A. mellifera propolis. The chemical profiles of the propolis extracts were determined by atmospheric pressure chemical ionization-mass spectrometry and liquid chromatography-electrospray ionization-tandem mass spectrometry allowed to identify several prenylated benzophenones. A. mellifera extracts exhibited major antioxidant activity as assessed by the 2,2-diphenyl-1-picrylhydrazyl method and all extracts exhibited antioxidant activity as assessed by the β-carotene/linoleic acid method. The ethanolic extracts of the propolis showed promisor activity against all tested microorganisms. Made available in DSpace on 2019-02-15T23:42:42Z (GMT). No. of bitstreams: 1 01004042qn41050485.pdf: 673911 bytes, checksum: 0fa612807ad27c5b53f14b66e2607183 (MD5) Previous issue date: 2019-02-14

Here we describe the life histories of adult males of the the Amazonian stingless bee Melipona flavolineata Friese, commonly known as ?uruçu amarela?. Males reach sexual maturity inside nests, presenting seminal vesicles full of sperm cells and becoming able to fl y at a mean age of 10 and 15 days, respectively. They aggregate twice in their lives, once before leaving the nest, and another at external congregation sites, by using their capacity to reach congregation sites dependent on morphological attributes, such as large eyes and elongated thorax. Furthermore, we describe three atypical phenomena for Meliponini males: M. fl avolineata males have dimorphic color pattern; they lose their genital capsules, even when they fail to copulate; and penisless (sterile) males can stay alive for up to two days. The life history strategies of Meliponini males have only just started to be told and provide many interesting questions for future studies. Made available in DSpace on 2019-02-13T23:44:43Z (GMT). No. of bitstreams: 1 Veigaetal2018.pdf: 743710 bytes, checksum: 9ce0ef38bcbab43cc44bce53cdd1e81a (MD5) Previous issue date: 2019-02-13

Understanding the functional roles of different pollinator species is crucial to the development of sustainable farming practices in pollinator-dependent crops. However, this can be challenging for crop plants in tropical regions with hyper-diverse pollinator communities. Here, we assess pollen loads of different insect visitors to inflorescences of acai palm (Euterpe oleracea), the most important native crop in the Amazon estuary region. Flower-visiting insects were collected from pistillate (female) inflorescences at eight sites, including four managed floodplain forests and four plantations. Pollinator Importance Value Index (PIVI) and Relative Importance (RI) scores were calculated for common visitor taxa (≥ 10 individuals) using sum visit frequencies and median pollen loads. Pollen load analyses revealed that over seventy insect taxa, including bees, flies, beetles, wasps and ants, were effective vectors of E. oleracea pollen. Native bees, including both solitary and eusocial taxa, were the most efficient pollen vectors, with median pollen loads at least eight times higher than those of the next best insect group (flies). Insect pollen loads were at their highest between 0800 and 1300 hours, and four insect taxa had RI scores > 0.05, including two meliponine bees belonging to the Trigona genus (Trigona branneri Cockerell and Trigona pallens Fabricius) and two halictid bee genera (Augochloropsis and Dialictus). Our results suggest that native bees play an important role in acai pollination and should be the primary focus of pollinator management in acai production systems.

Nectar and pollen are the basic food resources of stingless bees. The current advance of meliponiculture led to the search for supplementary feeding. Despite little is known about native bee supplementation, several alternative foods have been tested as protein substitutes, with soy being one of the most commonly used. In this study, we compared the effect of a semiartificial soy-based diet versus a natural diet on the longevity of adult worker of Melipona flavolineata Friese and Scaptotrigona aff. postica (Latreille). A total of 200 workers of each species (40 from each colony) were used, of which 100 comprised the control group (consumed honey and pollen) and 100 the experimental group (honey and a semiartificial food based on soybean extract). The workers were divided into groups of 20 individuals confined in MDF boxes not completely enclosed, without a queen, and kept in BOD incubators. Dead bees were counted and removed daily. Kaplan-Meier survival curves were plotted for each species. We found greater longevity in workers who consumed only natural pollen (71 days for M. flavolineata , 78 days for S. aff. postica, in average) compared to those consuming the soy-based diet (62 days for M. flavolineata , 61 days for S. aff. postica, in average). Workers of M. flavolineata that consumed pollen lived nine days more (21.8%) than those fed on the soy-based diet, while S. aff. postica workers lived seven days more (12.7%). As longevity was only slightly reduced, we can recommend a soy-based diet for stingless bees during dearth periods or for supplemental feeding of newly formed colonies.

The study of the feeding of bees is important because periods of flowering shortages reduce the availability of food, jeopardising their survival and limiting the production of their colonies. Previous studies on artificial protein feeding have not reported the chemical composition of the artificial feed, its effect on the colony nor the characterisation of the food. Thus, the present research aimed to study an artificial proteic feed for Melipona flavolineata. We investigated its chemical composition and the effect of natural fermentation on its quality. We also investigated its effects on colony and individual health. The artificial food presented a chemical composition different from natural pollen. It was richer in carbohydrates and lipids than natural pollen, but it was poorer in protein than natural pollen. Nevertheless, the difference between the artificial food and natural pollen did not affect the survival or size of immature individuals, with only adult longevity being affected, albeit not drastically. Decreased amounts of sugar and the addition of ingredients with higher protein content are recommended for future formulations. A diet based on soy extract showed satisfactory results as a food substitute for pollen. Based on these results, diet ingredients can be adjusted to obtain a better-quality food. Artificial diets can be used during scarcity periods or in areas with low availability of natural food sources. However, it is important to emphasize that artificial diets will never fully replace natural food sources. Beekeepers should also improve the environment with plants that provide pollen continuously.

The differentiation of workers into morphological castes represents an important evolutionary innovation that is thought to improve division of labor in insect societies. Given the potential benefits of task-related worker differentiation, it is puzzling that physical worker castes, such as soldiers, are extremely rare in social bees and absent in wasps. Following the recent discovery of soldiers in a stingless bee, we studied the occurrence of worker differentiation in 28 stingless bee species from Brazil and found that several species have specialized soldiers for colony defence. Our results reveal that worker differentiation evolved repeatedly during the last ~ 25 million years and coincided with the emergence of parasitic robber bees, a major threat to many stingless bee species. Furthermore, our data suggest that these robbers are a driving force behind the evolution of worker differentiation as targets of robber bees are four times more likely to have nest guards of increased size than non-targets. These findings reveal unexpected diversity in the social organization of stingless bees., Although common in ants and termites, worker differentiation into physical castes is rare in social bees and unknown in wasps. Here, Grüter and colleagues find a guard caste in ten species of stingless bees and show that the evolution of the guard caste is associated with parasitization by robber bees.

Although the importance of bees as the pollinators responsible for maintaining gene flow for many native and cultivated plants in ecosystems around the world is recognized, much of their biodiversity and behavior remains to be discovered. Stingless bees are considered key pollinators for several plant species in tropical and subtropical ecosystems and they also provide pollination services for economically important agricultural crops. Many countries are using the honey bee (Apis mellifera Linnaeus, 1758, Hymenoptera: Apidae) as a surrogate to evaluate the risk of pesticides to all species of bees. However, there is uncertainty regarding the extent to which honey bees can serve as surrogates for non-Apis bee species in the risk assessment for pesticides. This paper provides a short overview of the life history traits relevant in risk assessment of stingless bees. It summarizes what is known about stingless bee exposure to pesticides compared to that of honey bees and presents criteria for potential candidate species from Brazil for use in pesticide risk assessment in tropical environments. This paper also identifies gaps in knowledge of bee biology and pesticide exposure routes not covered by the current honey bee exposure assessment paradigm. Based on these gaps, research is needed on life history traits, estimates of nectar and pollen consumption, mud, resin, and water collection and available protocols to adequately assess toxic effects of pesticides to stingless bees. This review is part of a series of papers on the risk of exposure of non-Apis bees to pesticides.

The larval stage of the stingless bee Scaptotrigona depilis must consume a specific brood cell fungus in order to continue development. Here we show that this fungus is a member of the genus Zygosaccharomyces and provides essential steroid precursors to the developing bee. Insect pupation requires ecdysteroid hormones, and as insects cannot synthesize sterols de novo, they must obtain steroids in their diet. Larval in vitro culturing assays demonstrated that consuming ergosterol recapitulates the developmental effects on S. depilis as ingestion of Zygosaccharomyces sp. cells. Thus, we determined the molecular underpinning of this intimate mutualistic symbiosis. Phylogenetic analyses showed that similar cases of bee-Zygosaccharomyces symbiosis may exist. This unprecedented case of bee-fungus symbiosis driven by steroid requirement brings new perspectives regarding pollinator-microbiota interaction and preservation.

Spine surgeons are exposed to high amounts of radiation from fluoroscopic procedures during their lifetime. In this study, we evaluated spine surgeons' knowledge of and attitude regarding radiation exposure during spine surgery.We developed a questionnaire including questions about surgeons' characteristics and knowledge of and attitude regarding radiation exposure during spine surgery. A survey was performed with the members of AOSpine Latin America. The main variables studied were specialty, years of experience, surgeon's position during fluoroscopy, and practices to reduce the patient's and surgeon's radiation exposure during surgery. The results were analyzed and compared among different specialties, levels of experience, and countries of origin.The questionnaire was answered by 371 members of AOSpine Latin America from different countries. The sample was mostly from orthopedic surgeons (57.1%) and surgeons in practice for longer than 10 years (54.2%). Thyroid lead protection was used by 64.2% of the spine surgeons, lead glasses by 20.2%, and lead gloves by 7%. A dosimeter badge was never or only rarely used by 75.7%. The correct answer for surgeon position during lateral lumbar fluoroscopy was reported by only one-third of the surgeons. The reported rate of thyroid protector use was higher in surgeons from Brazil and Colombia compared with surgeons from Mexico and Argentina (P 0.001), whereas the use of pulsed-mode fluoroscopy was higher in Mexico and Argentina compared with Brazil and Colombia (P0.0001).Future efforts toward implementing educational programs in Latin America focused on safety strategies are needed to minimize intraoperative radiation exposure.

Different microorganisms are present in pot-pollen and participate in bee bread preparation. During fermentation, vitamins, antimicrobial compounds, and enzymes can be secreted. Spoilage of bee bread is avoided by the low pH of pot-pollen, caused by lactic and acetic acid fermentation and alcoholic fermentation, and by the presence of natural products with antibiotic properties produced by resident microbiota of stored bee pollen. Interactions among microorganisms living in pot-pollen can control and optimize the microbiota, after resistant microorganisms survive in the adverse conditions created by fermentation. Evidence suggests that the symbiotic relationship between bees and pot-pollen microorganisms is stable and that an inoculum can be added by bees to ferment freshly collected and deposited pollen. The quality of pollen selected to prepare bee artificial diets and the addition of fermented pollen as an inoculum to ferment the material augment food in periods of scarcity. Additionally, propagation of plants with different blooming periods, and flowers with abundant pollen, may aid meliponiculture.

Even though stingless beekeeping has a great potential as a sustainable development tool, the activity remains essentially informal, technical knowledge is scarce, and management practices lack the sophistication and standardization found in apiculture. Here, we contributed to the further development of stingless beekeeping by investigating the long-term impact of management and climate on honey production and colony survival in the stingless bee Melipona subnitida Ducke (1910). We analyzed a 10-yr record of 155 M. subnitida colonies kept by a commercial honey producer of northeastern Brazil. This constitutes the longest and most accurate record available for a stingless bee. We modeled honey production in relation to time (years), age, management practices (colony division and food supplementation), and climatic factors (temperature and precipitation), and used a model selection approach to identify which factors best explained honey production. We also modeled colony mortality in relation to climatic factors. Although the amount of honey produced by each colony decreased over time, we found that the probability of producing honey increased over the years. Colony divisions decreased honey production, but did not affect honey presence, while supplementary feeding positively affected honey production. In warmer years, the probability of producing honey decreased and the amount of honey produced was lower. In years with lower precipitation, fewer colonies produced honey. In contrast, colony mortality was not affected by climatic factors, and some colonies lived up to nine years, enduring extreme climatic conditions. Our findings provide useful guidelines to improve management and honey production in stingless bees.

Artificial feeding of stingless bee colonies is widely applied in meliponiculture to maintain colonies in good conditions during periods of natural food scarcity. Traditionally, most stingless beekeepers tend to adopt the individual feeding of colonies, to avoid conflicts among colonies or competition with feral species. We trained foragers from Melipona flavolineata colonies to collective feeders containing sugar syrup, and showed they are useful for the management of this species, since they did not cause significant intra and interspecific conflicts, and thus, worker losses. Besides, most colonies from the meliponary frequented the feeder, showing that collective feeding in this species is possible and can be recommended to keep colonies in good condition during periods of natural food dearth or after honey harvesting.

The spectacular morphological variation among workers of certain ant and termite species has fascinated evolutionary biologists since Darwin. In some species, environmental triggers induce larvae to develop into different phenotypes, e.g. minor or major workers (soldiers). Recently, the first soldier subcaste was discovered in a bee, the stingless bee Tetragonisca angustula. In contrast to ants, which raise their offspring by progressively feeding larvae until the pupal stage, T. angustula nurses mass provision individual brood cells after which the bees develop from egg to young workers in sealed cells on a seemingly uniform brood comb. This prompts the question of how this bee creates a morphologically variable workforce without larvae having direct contact with nursing workers. We investigated where T. angustula raises a larger soldier subcaste on its compact brood comb. Additionally, we examined whether size differences among workers could be generated by differential distribution of food by nursing workers. We found that colonies produce c. 1–6 % of soldier-sized workers, which mainly emerge from a small central area of the comb. In this area, cells are wider and a larger number of nursing bees unload larval food here before oviposition. Cell attendance levels prior to oviposition were similar across the comb and, thus, did not explain the larger food volumes found in the centre. Our results suggest that workers determine soldier production via larval food discharges and cell-building behaviour. Nutritional differences among larvae might then induce larvae into one or the other caste developmental pathway.

The attraction of sexual partners is a vital necessity among insects, and it involves conflict of interests and complex communication systems among male and female. In this study, we investigated the developing of sexual attractiveness in virgin queens (i.e., gynes) of Melipona flavolineata, an eusocial stingless bee. We followed the development of sexual attractiveness in 64 gynes, belonging to seven age classes (0, 3, 6, 9, 15, 18 days post-emergence), and we also evaluated the effect of different social interactions (such as competition between queens and interactions with workers) on the development of attractiveness in other 60 gynes. We used the number of males that tried to mate with a focal gyne as a representative variable of its sexual attractiveness. During the essays, each gyne was individually presented to 10 sexually mature males, and during 3 min, we counted the number of males that everted their genitalia in response to the presence of a gyne. Here, we show that M. flavolineata gynes are capable to (i) maintain their sexual attractiveness for long periods through adult life, (ii) they need a minimum social interaction to trigger the development of sexual attractiveness, and (iii) that gynes express this trait only within a social context. We conclude that the effective occurrence of matings is conditional on potential social interactions that gynes experienced before taking the nuptial flight, when they are still in the nest. These findings bring insights into the factors determining reproductive success in social insects.

International audience; AbstractThe foraging success of a bee species is related to a combination of climatic factors and resource availability. Here, we analyzed how food storage by the stingless bee Scaptotrigona aff. depilis relates to the seasonal variation in floral resources availability in a tropical environment with two well-defined seasons. We found a positive relationship between the amount of food stored and resource availability, suggesting that colonies intensify food collection in the season with higher food availability (rainy season). This ensures the perennial state of stingless bee colonies during the dry season (food scarcity and lower ambient temperatures). Bees collected pollen from at least 60 plant species, but food pots were dominated by just nine plants. Additionally, S. aff depilis attempted to unevenly use the plant species for food storage in the rainy season, which indicates that the colonies maximize their food intake as soon as resources are available.