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

Absence of Leishmaniinae and Nosematidae in stingless bees

Bee pollination is an indispensable component of global food production and plays a crucial role in sustainable agriculture. The worldwide decline of bee populations, including wild pollinators, poses a threat to this system. However, most studies to date are situated in temperate regions where Apini and Bombini are very abundant pollinators. Tropical and subtropical regions where stingless bees (Apidae: Meliponini) are generally very common, are often overlooked. These bees also face pressure due to deforestation and agricultural intensification as well as the growing use and spread of exotic pollinators as Apis mellifera and Bombus species. The loss or decline of this important bee tribe would have a large impact on their provided ecosystem services, in both wild and agricultural landscapes. The importance of pollinator diseases, which can contribute to decline, has not been investigated so far in this bee tribe. Here we report on the first large pathogen screening of Meliponini species in southern Brazil. Remarkably we observed that there was an absence of Leishmaniinae and Nosematidae, and a very low occurrence of Apicystis bombi. Our data on disease prevalence in both understudied areas and species, can greatly improve our knowledge on the distribution of pathogens among bee species

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

Age polyethism in Plebeia emerina (Friese) (Hymenoptera: Apidae) colonies related to propolis handling

Stingless bees collect plant resins and make it into propolis, although they have a wider range of use for this material than do honey bees (Apis spp.). Plebeia spp. workers employ propolis mixed with wax (cerumen) for constructing and sealing nest structures, while they use viscous (sticky) propolis for defense by applying it onto their enemies. Isolated viscous propolis deposits are permanently maintained at the interior of their colonies, as also seen in other Meliponini species. Newly-emerged Plebeia emerina (Friese) workers were observed stuck to and unable to escape these viscous propolis stores. We examined the division of labor involved in propolis manipulation, by observing marked bees of known age in four colonies of P. emerina from southern Brazil. Activities on brood combs, the nest involucrum and food pots were observed from the first day of life of the marked bees. However, work on viscous propolis deposits did not begin until the 13th day of age and continued until the 56th day (maximum lifespan in our sample). Although worker bees begin to manipulate cerumen early, they seem to be unable to handle viscous propolis till they become older

Abelhas associadas à cultura da canola em Passo Fundo, Rio Grande do Sul, Brasil: Bees associated with canola crops in Passo Fundo, Rio Grande do Sul state, Brazil

A cultura da canola é visitada por uma diversidade de polinizadores, principalmente abelhas, durante sua floração. Embora estudos tenham registrado a ocorrência de espécies de abelhas na cultura, novos levantamentos podem ampliar a lista desses polinizadores associados com a canola. Por isso, este trabalho teve por objetivo conhecer as abelhas associadas à cultura da canola no município de Passo Fundo, estado do Rio Grande do Sul, Brasil. Foram realizadas seis amostragens, com rede entomológica, em julho de 2015, numa área experimental da Embrapa Trigo, Passo Fundo-RS, cultivada com canola, Brassica napus L. var. oleifera, híbrido Hyola 433. Foram coletadas 1.064 abelhas, destacando-se como as mais abundantes Trigona spinipes (71,05%) e Apis mellifera (25,10%). Além disso, também foram amostrados exemplares de Bombus pauloensis, Plebeia droryana, Tetragonisca fiebrigi, Augochlora spp., Augochloropsis sp., Ceratina spp., Dialictus spp., Exomalopsis spp. e Neocorynura spp. De acordo com os resultados obtidos, a canola é visitada por numerosas espécies de abelhas. Portanto, o manejo da cultura deve evitar impactos negativos sobre esses polinizadores, seja almejando o aumento da produtividade de grãos, como a conservação da diversidade de abelhas

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

Record of Ataenius Picinus Harold, 1868 (Coleoptera: Scarabaeidae: Aphodiinae) associated with exposed carcasses in southern Brazil

Ataenius picinus Harold, 1868 is a scarab beetle, which is distributed worldwide. Individuals of this species have been found associated with animal feces, soil samples, leaf litter and decaying fruit, as some cases on carcasses. In this study, we propose the extension of trophic niche of this species based on observations of alternative scavenging resources. Individuals were collected from the carcasses of domestic pigs in southern Brazil. We collected 126 individuals, which represented 68 % of beetles collected during the total decomposition period (14 days). The observed abundance was higher in the decay stage and thus, given this preference, this species may be useful for estimating the maximum postmortem interval, based on the chronology of species arrival at the resource. © 2016, Sociedad Venezolana de Entomología.Ataenius picinus Harold, 1868 is a scarab beetle, which is distributed worldwide. Individuals of this species have been found associated with animal feces, soil samples, leaf litter and decaying fruit, as some cases on carcasses. In this study, we propose3164853CAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORSEM INFORMAÇÃOThe authors are thankful to CAPES for granting scholarships, to Dr. Luciano de Azevedo Moura for facilitating the primary identification of beetles, to FEPAGRO for providing the experimental site, and reviewers for valuable suggestion

Análise de resíduos de agrotóxicos em amostras de mel de Apis mellifera obtidas a partir de floradas de canola de municípios do Rio Grande do Sul, Brasil: Analysis of pesticide residues in honey samples of Apis mellifera obtained from canola blooms from municipalities in Rio Grande do Sul state, Brazil

A canola, durante o ciclo de cultivo, pode ser infestada e danificada por diversas pragas (insetos, fungos e plantas daninhas). Visando reduzir a incidência e os danos provocados por esses agentes bióticos, os agricultores realizam aplicações de inseticidas, fungicidas e herbicidas nas lavouras. O uso destes produtos químicos reduz a incidência e os danos provocados pelas pragas, mas também pode contaminar as flores que são visitadas pelas abelhas durante a floração da cultura e, com isso, pode resultar na contaminação do mel por resíduos de agrotóxicos. Diante da escassez de estudos sobre avaliação de pesticidas em mel de canola no Brasil, este trabalho teve por objetivo verificar se o mel produzido por Apis mellifera, a partir de floradas de canola de municípios do Rio Grande do Sul, apresentava resíduos de agrotóxicos. Para isto, 26 amostras de mel, obtidas a partir de floradas de canola, de nove municípios do RS, foram analisadas por cromatografia líquida/espectrometria de massas sequencial (LC-MS/MS) e por cromatografia a gás/espectrometria de massas sequencial (GC-MS/MS), totalizando 305 princípios ativos rastreados. Das 26 amostras de mel analisadas, em dez não foram detectados agrotóxicos, em nove amostras foram detectados três princípios ativos [2,4-D (ácido 2,4-diclorofenoxacético), epoxiconazol e imidacloprido] em concentração abaixo do limite de quantificação do método utilizado (10 µg/kg), em uma amostra detectou-se o inseticida deltametrina, também abaixo do limite de quantificação do método, e em 11 amostras foi detectado o fungicida carbendazim, em concentrações quantificadas pelo método que variaram entre 10 µg/kg e 100 µg/kg. Contudo, mesmo o princípio ativo carbendazim, em todas as amostras nas quais foi quantificado, ficou em concentrações abaixo do limite permitido pela legislação brasileira para mel, estabelecido em 1000 µg/kg. Portanto, de acordo com os resultados das amostras analisadas, o mel foi considerado seguro para consumo, considerando os limites de resíduos de agrotóxicos estabelecidos pela legislação brasileira