In vitro rearing of stingless bee queens and their acceptance rate into colonies

International audienceAbstractThe in vitro rearing of queen bees can improve the management and conservation of pollinator insects. Here, we have developed an in vitro queen-rearing protocol for Plebeia droryana (Apidae, Meliponini). Firstly, we evaluated the amount of food offered naturally to P. droryana queen larvae. After, we grafted P. droryana larvae onto acrylic plates which were kept in constant darkness at 25 °C and different relative humidity along larval development. We also compared intertegular distance of P. droryana queens reared in vitro and naturally. We then tested whether queens reared in vitro would be accepted into new colonies with older and/ or callow workers. We found that P. droryana larvae developed into queens if fed with 66 μL of larval food. The survival rate of P. droryana queens was > 75 %. The queens reared in vitro are similar in size to naturally produced ones. Finally, colonies only containing callow workers are more likely to accept queens reared in vitro. This queen-rearing technique may improve beekeeping practices in the Neotropical Region

Influence of Wild Bee Diversity on Canola Crop Yields

The foraging range of bees determines the spatial scale over which each species can provide pollination services. In agricultural ecosystems, productivity is related not only to the taxonomic diversity of bees per se, but also to the location of their nesting sites, which reflects on their flying range. Within this context, the present study sought to assess how wild bee assemblages affect the yield of Brassica napus at three different distances (25 m, 175 m, 325 m) from forest remnants in Southern Brazil. Bees were sampled by means of pan traps and findings were analyzed using the Shannon diversity index and generalized linear models. We identified 11 species of native bees, both solitary and social, as well as the exotic species Apis mellifera, which was most abundant. Our findings show that canola crop yield were positively influenced by the diversity of bee species. This demonstrates that native bees, not only A. mellifera, can contribute significantly to the productivity of canola crops. In addition, we found that bee body size is significantly associated with flight distance traveled within the canola fields, and demonstrated a relationship with nesting sites. Thus, we hypothesize that canola yields are associated with the presence of wild bee species, both social and solitary, and that maintenance of these pollinators is directly dependent on practices adopted in rural areas, whether within plantation fields per se or in forest remnants used as nesting sites by wild bees

Diapause in Stingless Bees (Hymenoptera: Apidae)

Extreme environmental conditions may negatively affect development animals which present behavior strategies in order survivor them. Insects present a wide range of adaptive behaviors that have allowed them to successfully respond to adverse climatic conditions by temporarily interrupting some of their activities or development. One of these behaviors is diapause. It is a gradual and progressive interruption in development or ontogeny of any organism in some phase of their lifecycle in order to survivor unfavorable environmental conditions that occur cyclically. The objective of this review is to give an overview of the current knowledge about diapause in stingless bees and future perspectives of study. It focuses on Plebeia Schwarz species because this behavior has been observed mainly in these bees. In this group of bees there is a stop in the provisioning and oviposition process in autumn/winter, called reproductive diapause. Besides the stop in brood rearing, other behaviors, as for example foraging, are modified. The mechanisms that induce the reproductive diapause are still unclear, but the evidence points out to the temperature and photoperiodism as the main drivers of this behavior

Uncovering untapped potentials: diversifying business may yield profitable earnings, yet it remains an overlooked strategy among beekeepers: Descobrindo potenciais inexplorados: diversificar negócios apícolas pode gerar lucros, ainda que continue sendo uma estratégia negligenciada pelos apicultores

Beekeeping is a rewarding business that offers numerous opportunities beyond just honey production. While most beekeepers are solely focused on honey production, this approach can be limiting due to the fluctuation of weather and market conditions. Therefore, it is essential to diversify your business by exploring other honey bee products and services. Our research investigated the beekeeping practices of 100 beekeepers from seven regions in southern Brazil to identify the most common practices and potential opportunities for diversification. Our study focused on ten major beekeeping practices, including products or services as honey, queen rearing, swarm, propolis, pollen, beeswax, royal jelly, sanitary control activity, digital technology enthusiasm, and migratory beekeeping. We used a semi-structured questionnaire consisting of 86 questions that were analysed with generalized Procrustes analysis and clustered heatmap. Overall, we found that honey production, digital technology enthusiasm, and migratory beekeeping are the most common beekeeping practices among beekeepers, regionally. Conversely, the exploitation of beeswax, pollen, swarm, and royal jelly production were relatively rare, creating opportunities for beekeepers looking to diversify their earnings and reduce competition. Additionally, our research revealed that certain regions have adopted specific beekeeping practices better than others, which suggests that there are possibilities for improvement and growth in the beekeeping industry. Finally, our research demonstrates the potential for beekeepers to diversify their business beyond just honey production. By exploring other honey bee products and services, beekeepers can reduce the impact of market limitations caused by weather and market fluctuations, ultimately creating a more resilient and profitable business

Weed Control Strategies for Restoration of the Atlantic Forest in the State of Rio de Janeiro - Brazil

The objective was to evaluate the best weed control strategy, for the formation of forest stands in Atlantic Forest, Brazil, aiming at restoration in an area dominated by Urochloa decumbes, evaluating the biological indicators and costs. It also sought to verify the magnitude of response of mechanical control compared to treatment without intervention, for similar sites where the experiment was installed and conducted. The treatments were: T1 - mechanical (mowing and crowning); T2 - chemical (application of glyphosate syrup); T3 - mechanical cultural (weeding, seeding and cultivation of Cajanus cajan and Canavalia ensiformes); T4 - chemical cultural (application of glyphosate, seeding and cultivation of legumes); T5 - absolute control (no intervention after planting). Activities and evaluations were carried out up to 30 months after planting the seedlings of the five species used. It was observed that in all treatments the survival of the plants reached values higher than 80%, at 6 and 18 months after planting. It was found that, on average, the tree plants in T2, T3, and T4 showed significantly higher growth than those in T1 and T5, which did not differ. The control with glyphosate is indicated for areas with predominance of Urochloa sp. Strategy control with glyphosate and cultivation of herbaceous legumes has potential use and needs adjustments to reduce costs. Also, that the control with mowing and crowning is not indicated due to the high cost and not favoring the growth of the planted trees, because it did not show significant differences in relation to the controls.O objetivo foi avaliar a melhor estratégia de controle de plantas daninhas, para a formação de povoamentos florestais na Mata Atlântica, Brasil, visando a restauração em área dominada por Urochloa decumbes, avaliando os indicadores biológicos e custos. Também buscou verificar a magnitude da resposta do controle mecânico em relação ao tratamento sem intervenção, para locais semelhantes onde o experimento foi instalado e conduzido. Os tratamentos foram: T1 - mecânico (roçada e coroamento); T2 - químico (aplicação de xarope de glifosato); T3 - cultura mecanizada (capina, semeadura e cultivo de Cajanus cajan e Canavalia ensiformes); T4 - cultura química (aplicação de glifosato, semeadura e cultivo de leguminosas); T5 - controle absoluto (sem intervenção após o plantio). As atividades e avaliações foram realizadas até 30 meses após o plantio das mudas das cinco espécies utilizadas. Observou-se que em todos os tratamentos a sobrevivência das plantas atingiu valores superiores a 80%, aos 6 e 18 meses após o plantio. Verificou-se que, em média, as plantas arbóreas em T2, T3 e T4 apresentaram crescimento significativamente maior do que as de T1 e T5, que não diferiram. O controle com glifosato é indicado para áreas com predominância de Urochloa sp. Estratégia de controle com glifosato e cultivo de leguminosas herbáceas tem potencial de uso e necessita de ajustes para redução de custos. Também, que o controle com roçada e copa não é indicado devido ao alto custo e não favorecer o crescimento das árvores plantadas, pois não apresentou diferenças significativas em relação às testemunhas.The objective was to evaluate the best weed control strategy, for the formation of forest stands in Atlantic Forest, Brazil, aiming at restoration in an area dominated by Urochloa decumbes, evaluating the biological indicators and costs. It also sought to verify the magnitude of response of mechanical control compared to treatment without intervention, for similar sites where the experiment was installed and conducted. The treatments were: T1 - mechanical (mowing and crowning); T2 - chemical (application of glyphosate syrup); T3 - mechanical cultural (weeding, seeding and cultivation of Cajanus cajan and Canavalia ensiformes); T4 - chemical cultural (application of glyphosate, seeding and cultivation of legumes); T5 - absolute control (no intervention after planting). Activities and evaluations were carried out up to 30 months after planting the seedlings of the five species used. It was observed that in all treatments the survival of the plants reached values higher than 80%, at 6 and 18 months after planting. It was found that, on average, the tree plants in T2, T3, and T4 showed significantly higher growth than those in T1 and T5, which did not differ. The control with glyphosate is indicated for areas with predominance of Urochloa sp. Strategy control with glyphosate and cultivation of herbaceous legumes has potential use and needs adjustments to reduce costs. Also, that the control with mowing and crowning is not indicated due to the high cost and not favoring the growth of the planted trees, because it did not show significant differences in relation to the controls

Congregation sites and sleeping roost of male stingless bees (Hymenoptera: Apidae: Meliponini)

Very little is known about stingless bee reproductive biology or male behaviour. In \ud this note we provide the first observations on the male aggregations (congregation \ud sites and roosting sites) of some stingless bee species. Our observations show that \ud males of two stingless bee species can congregate on the same site. We also report \ud for the first time the substrates used by stingless bee males for resting at night, that \ud at least one species forms large sleeping roosts composed of hundreds of individuals, \ud and that sleeping roost locations are not reused on subsequent nights.The authors thank Dr. Silvia R. M. Pedro and Dr. Sidnei Mateus (Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, USP) for the identification of Plebeia droryana and and Polybia sp., respectively. Financial support received: CFS and AVN from the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); CM from the Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP, process 07–50218-1); VLIF from the PVNS scholarship from CAPES. The authors also thank the CAPES – PROAP 2010 program for field trip financial support for CFS. Authors gratefully acknowledge Rodolfo R. Jaffé (BeeLab USP) for his critical reading of the manuscript and suggestion

Catheter Related Bloodstream Infection (CR-BSI) in ICU Patients: Making the Decision to Remove or Not to Remove the Central Venous Catheter

Background Approximately 150 million central venous catheters (CVC) are used each year in the United States. Catheter-related bloodstream infections (CR-BSI) are one of the most important complications of the central venous catheters (CVCs). Our objective was to compare the in-hospital mortality when the catheter is removed or not removed in patients with CR-BSI. Methods We reviewed all episodes of CR-BSI that occurred in our intensive care unit (ICU) from January 2000 to December 2008. The standard method was defined as a patient with a CVC and at least one positive blood culture obtained from a peripheral vein and a positive semi quantitative (\u3e15 CFU) culture of a catheter segment from where the same organism was isolated. The conservative method was defined as a patient with a CVC and at least one positive blood culture obtained from a peripheral vein and one of the following: (1) differential time period of CVC culture versus peripheral culture positivity of more than 2 hours, or (2) simultaneous quantitative blood culture with 5:1 ratio (CVC versus peripheral). Results 53 CR-BSI (37 diagnosed by the standard method and 16 by the conservative method) were diagnosed during the study period. There was a no statistically significant difference in the in-hospital mortality for the standard versus the conservative method (57% vs. 75%, p = 0.208) in ICU patients. Conclusion In our study there was a no statistically significant difference between the standard and conservative methods in-hospital mortality

Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory

The Auger Engineering Radio Array (AERA) is part of the Pierre Auger Observatory and is used to detect the radio emission of cosmic-ray air showers. These observations are compared to the data of the surface detector stations of the Observatory, which provide well-calibrated information on the cosmic-ray energies and arrival directions. The response of the radio stations in the 30 to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of the incoming electric field. For the latter, the energy deposit per area is determined from the radio pulses at each observer position and is interpolated using a two-dimensional function that takes into account signal asymmetries due to interference between the geomagnetic and charge-excess emission components. The spatial integral over the signal distribution gives a direct measurement of the energy transferred from the primary cosmic ray into radio emission in the AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air shower arriving perpendicularly to the geomagnetic field. This radiation energy -- corrected for geometrical effects -- is used as a cosmic-ray energy estimator. Performing an absolute energy calibration against the surface-detector information, we observe that this radio-energy estimator scales quadratically with the cosmic-ray energy as expected for coherent emission. We find an energy resolution of the radio reconstruction of 22% for the data set and 17% for a high-quality subset containing only events with at least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO