16 research outputs found
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
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
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
Frequentadoras (es) de feiras orgânicas: Relações de consumo e de gênero em territórios brasileiros
One of the marketing channels for organic products in large cities are organic and agroecological fairs, whose expansion has allowed greater accessibility for the population to healthy foods. There seems to be an increase in the search for and consumption of organic products by the Brazilian population. This panorama can be evaluated as a resource for health and food security. Considering this scenario, the objective of the present study was to identify who are the goers of organic fairs, in addition to analyzing whether they identify women as participants in the process of producing the food that is sold in these spaces. Through a structured questionnaire, answered online by 185 people from different states of the country, it was possible to characterize the target population. In this study, 84.4% of respondents identified themselves as female. People with a graduate degree and monthly income between medium and high are those who visit organic fairs more frequently. They are interested in buying healthy food, and in purchasing fresh products, sold in short circuits, in addition to being motivated to support environmental care and sustainability. Only a portion of 32.7% of respondents identifies the role of women in production and marketing in the context of agroecology. It is concluded, therefore, that a discourse that does not make visible the role of women, still prevails in society, even if their participation in agroecological production is wide.
Um dos canais de comercialização dos produtos orgânicos nas grandes cidades são as feiras orgânicas e agroecológicas, cuja expansão tem permitido maior acessibilidade da população a alimentos saudáveis. Parece haver um incremento pela busca e consumo de produtos orgânicos pela população brasileira. Este panorama pode ser avaliado como um recurso para a saúde e segurança alimentar. Considerando tal cenário, o objetivo do presente estudo foi identificar quem são os frequentadores de feiras orgânicas, além de analisar se identificam as mulheres como participantes no processo da produção dos alimentos que são comercializados nestes espaços. Através de um questionário estruturado, respondido de forma on-line por 185 pessoas de diferentes estados do país, foi possível caracterizar a população alvo. Na amostra deste estudo, 84,4% dos respondentes identificaram-se com o gênero feminino. As pessoas com pós-graduação e renda mensal entre média e alta são as que visitam as feiras orgânicas com maior frequência. Elas estão interessadas na compra de alimentos saudáveis, e em adquirir produtos frescos, comercializados em circuitos curtos, além de estarem motivadas em apoiar o cuidado e a sustentabilidade ambiental. Apenas uma parcela de 32,7% dos respondentes identifica o papel das mulheres na produção e comercialização no contexto da agroecologia. Conclui-se, assim, que ainda prevalece na sociedade um discurso que não visibiliza o papel das mulheres, mesmo que sua participação na produção agroecológica seja ampla
Negative impacts of dominance on bee communities: Does the influence of invasive honey bees differ from native bees?
Invasive species can reach high abundances and dominate native environments. One of the most impressive examples of ecological invasions is the spread of the African subspecies of the honey bee throughout the Americas, starting from its introduction in a single locality in Brazil. The invasive honey bee is expected to more negatively impact bee community abundance and diversity than native dominant species, but this has not been tested previously. We developed a comprehensive and systematic bee sampling scheme, using a protocol deploying 11,520 pan traps across regions and crops for three years in Brazil. We found that invasive honey bees are now the single most dominant bee species. Such dominance has not only negative consequences for abundance and species richness of native bees but also for overall bee abundance (i.e., strong “numerical” effects of honey bees). Contrary to expectations, honey bees did not have stronger negative impacts than other native bees achieving similar levels of dominance (i.e., lack of negative “identity” effects of honey bees). These effects were markedly consistent across crop species, seasons and years, and were independent from land-use effects. Dominance could be a proxy of bee community degradation and more generally of the severity of ecological invasions.info:eu-repo/semantics/publishedVersio
CropPol: a dynamic, open and global database on crop pollination
Seventy five percent of the world's food crops benefit from insect pollination. Hence, there has been increased interest in how global change drivers impact this critical ecosystem service. Because standardized data on crop pollination are rarely available, we are limited in our capacity to understand the variation in pollination benefits to crop yield, as well as to anticipate changes in this service, develop predictions, and inform management actions. Here, we present CropPol, a dynamic, open and global database on crop pollination. It contains measurements recorded from 202 crop studies, covering 3,394 field observations, 2,552 yield measurements (i.e. berry weight, number of fruits and kg per hectare, among others), and 47,752 insect records from 48 commercial crops distributed around the globe. CropPol comprises 32 of the 87 leading global crops and commodities that are pollinator dependent. Malus domestica is the most represented crop (32 studies), followed by Brassica napus (22 studies), Vaccinium corymbosum (13 studies), and Citrullus lanatus (12 studies). The most abundant pollinator guilds recorded are honey bees (34.22% counts), bumblebees (19.19%), flies other than Syrphidae and Bombyliidae (13.18%), other wild bees (13.13%), beetles (10.97%), Syrphidae (4.87%), and Bombyliidae (0.05%). Locations comprise 34 countries distributed among Europe (76 studies), Northern America (60), Latin America and the Caribbean (29), Asia (20), Oceania (10), and Africa (7). Sampling spans three decades and is concentrated on 2001-05 (21 studies), 2006-10 (40), 2011-15 (88), and 2016-20 (50). This is the most comprehensive open global data set on measurements of crop flower visitors, crop pollinators and pollination to date, and we encourage researchers to add more datasets to this database in the future. This data set is released for non-commercial use only. Credits should be given to this paper (i.e., proper citation), and the products generated with this database should be shared under the same license terms (CC BY-NC-SA). This article is protected by copyright. All rights reserved
Canola pollinators : perspectives for sustainable use of insects, yield and climatic changes
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Previous issue date: 2017-03-20Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPESThe current loss of biodiversity has negative consequences for the environment and impacts
several pollination ecossystem services, from which human society benefits directly or
indirectly. Among the main pollinators bees, wasps, coleopterans, flies and butterflies stand
out. Bees pollinate more than 90% of 107 worldwide crops and other insects might contribute
with 20-50% of pollination. Studies about canola (Brassica napus L. cultivar ?ole?fera?) point
out that insect visitation promotes an increase of 12 to 47% in grain productivity. Faced with
this, the present work aimed to know the bee, wasp and coleopteran diversity in the canola
agroecossystem and identify potential pollinators of the crop. Furthermore, it was evaluated
how the landscape and the pollinators influence in the productivity of canola, as well as the
habitat suitability for the pollinator species in the face of climatic change in future scenarios
(2050). Insects were collected with pan traps in eight fields of B. napus (Hyola 420 and Hyola
61) in the towns of Esmeralda, Estrela and Guarani das Miss?es, RS, Brazil. For the
development of the habitat suitability maps it was used the occurrence records of species in
databases and of the canola fields in the towns informed by the crop promoters. Among the
wasps the social species Brachygastra lecheguana and Protonectarina sylveirae and the
solitary species Campsomeris spp. stand out as potential pollinators. The most representative
families of coleopterans were Melyridae, Curculionidae, Nitidulidae, Chrysomelidae and
Scarabaeidae, and the most abundant species, which is is polliniferous, with a pubescent body
and dense bristles, to which the pollen grains adhere and are transported, thus probably it is a
pollinator of canola and surrounding flowers. The productivity of canola was positively
influenced by the diversity of social and solitary bees, and the distance from the forest fragment
affected the composition of bee guilds present inside the canola fields. It was observed that the
semi-natural areas presented a positive correlation with the social native bee species richness.
Regarding the category of landscape named ?Forest?, it was observed that there is a negative
correlation in the 1000 meters radius with the subsocial or solitary bee abundance, possibly
explained by their nesting habit, which is mainly underground, which means that it is not
exclusively dependent of forest to build their nests. Accordingly, in the ?Agriculture? category,
the agricultural landscape in the 1000 meters radius was positively correlated to the abundance
of the same guild, fact attributed to the nesting inside canola fields. In view of the different
degrees of heterogeneity of the landscape in canola crops, it can be observed that the
composition of insects in the canola agroecossystem responds to the ecological and historical
factors of each region, being related to the quality of the habitat and food resources for the
species. The areas of habitat suitability for canola show a high potential for future crop
expansion, however, for this to happen, strategies such as the use of cultivars that have greater
tolerance to climatic variables should be established, because they affect plant phenology. In
addition, it is suggested to use efforts to introduce the crops in places that are suitable in the
future scenario. Furthermore, when comparing the habitat suitability only for canola and then in
overlapping with the stingless bee species, we can observe that the appropriate areas increase
significantly, reinforcing that for the expansion of the crop, conservation measures of natural
and semi-natural habitats for providing food and nesting resources for pollinators are needed.A perda atual da biodiversidade tem consequ?ncias negativas para o meio ambiente e impacta
diversos servi?os ecossist?micos de poliniza??o, dos quais a sociedade humana se beneficia
direta ou indiretamente. Entre os principais polinizadores destacam-se as abelhas, vespas,
cole?pteros, moscas e borboletas. Sabe-se que as abelhas polinizam mais de 90% de 107
culturas globais e que outros insetos podem contribuir com 25-50% na poliniza??o. Estudos
sobre canola (Brassica napus L. variedade ole?fera) apontam que a visita de insetos promove o
aumento da produtividade dos gr?os de 12 a 47%. Diante disto, o presente trabalho objetivou
conhecer a diversidade de abelhas, vespas e cole?pteros em agroecossistema de canola e
identificar potenciais polinizadores da cultura. Al?m disso, foi avaliado como a paisagem e os
polinizadores influenciam na produtividade de canola, bem como as ?reas de adequabilidade de
habitat para esp?cies polinizadoras frente ?s mudan?as clim?ticas em cen?rios futuros (2050).
Os insetos foram coletados com o uso de pan traps em oito lavouras de B. napus (Hyola 420 e
Hyola 61) nos munic?pios de Esmeralda, Estrela e Guarani das Miss?es, RS, Brasil. Para
desenvolvimento dos mapas de adequabilidade de habitat utilizou-se registros de ocorr?ncias
das esp?cies em bases de dados e dos munic?pios com lavouras de canola fornecidos por
fomentadoras da cultura. Dentre as vespas destacam-se as esp?cies sociais Brachygastra
lecheguana e Protonectarina sylveirae e as esp?cies solit?rias Campsomeris spp.,
Eucyrtothynnus spp. e Tiphia spp. como potenciais polinizadores. As fam?lias mais
representativas de cole?pteros foram Melyridae, Curculionidae, Nitidulidae, Chrysomelidae e
Scarabaeidae, sendo que a esp?cie mais abundante, Astylus variegatus, que ? polin?faga, com
corpo pubescente e densas cerdas, aos quais os gr?os de p?len se aderem e s?o transportados,
portanto, provavelmente ? polinizador da canola e de flores do entorno. A produtividade de
canola foi positivamente influenciada pela diversidade de abelhas, sociais e solit?rias, e a
dist?ncia do remanescente florestal afetou a composi??o das guildas de abelhas presentes no
interior da lavoura. Foi observado que as ?reas seminaturais tiveram correla??o positiva com a
riqueza de abelhas sociais nativas. J? na categoria de paisagem denominada ?Mata?, pode-se
observar que h? correla??o negativa no raio de 1000 metros com a abund?ncia de abelhas
subsociais ou solit?rias, possivelmente atribu?do ao h?bito de nidifica??o destas, que ?
predominantemente subterr?neo, isto ?, n?o dependem exclusivamente de florestas para
construir seus ninhos. Em conson?ncia, na categoria de ?Agricultura?, a paisagem agr?cola no
raio de 1000 metros foi correlacionada positivamente com a abund?ncia da mesma guilda, fato
atribu?do a nidifica??o no interior das lavouras. Diante de diferentes graus de heterogeneidade
da paisagem nas lavouras de canola pode-se observar que a composi??o de insetos no
agroecossistema da canola responde aos fatores ecol?gicos e hist?ricos de cada regi?o,
relacionando-se com a qualidade do habitat e recursos alimentares para as esp?cies. As ?reas de
adequabilidade de habitat para canola mostram um elevado potencial para expans?o da cultura
no futuro, contudo para que isto aconte?a deve-se estabelecer estrat?gias como a utiliza??o de
cultivares que tenham maior toler?ncia ?s vari?veis clim?ticas, visto que estas afetam a
fenologia das plantas. Em acr?scimo, sugere-se empregar esfor?os para introdu??o da cultura
em lugares que s?o adequados no cen?rio futuro. Al?m disso, ao compararmos a adequabilidade
de habitat somente para canola e depois em sobreposi??o com as esp?cies de abelhas sem
ferr?o, podemos observar que as ?reas adequadas aumentam expressivamente, refor?ando que
para expans?o da cultura necessita-se medidas de conserva??o de habitats naturais e
seminaturais para fornecer recursos alimentares e de nidifica??o para os polinizadores
Assembleia de abelhas e efeito da dist?ncia de remanescentes florestais na produ??o de gr?os e no valor econ?mico de Brassica napus (Hyola 420) no sul do Brasil
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Previous issue date: 2013-03-11The pollination service is fundamental to the maintenance of biodiversity, human feeding and production of biofuels. This service is threatened by the need of increasing grain production, which enlarge seeding areas causing the degradation of vegetation and biodiversity loss. Thus, in certain crops the narrow dependence of pollinators is related to the quality of adjacent habitats. Studies point out that there is a decline of pollinators with the increase of the distance to forest fragments, promoting a decrease in productivity. Brassica napus, commonly known as canola, fits this scenario. Therefore, the present work aimed to characterize the assemblage of bees in three classes of habitats and analyze the effect of the distances from forest fragments in the grain production and economic value of Brassica napus (Hyola 420) in southern Brazil. The study was conducted in four agricultural areas with canola, in the town of Esmeralda, RS. The diversity of bees was sampled using pan traps in three classes of habitats: (1) canola field in bloom; (2) forest fragment; and (3) ruderal vegetation. In order to evaluate the production of grains by free visitation of insects at 25 m, 175 m and 325 m from the edge of the forest fragments 11 to 18 plants were harvested in the canola fields. For productivity analysis, the plants were harvested in plots of 225 m2 and extrapolated to one hectare. With the projected incomes it was calculated the total economic loss/field using the difference between the most profitable plot (25 m) and the least profitable one (325 m). It was collected 886 bees belonging to 87 species. Among the families collected, Apidae was the most abundant with 441 individuals, being 254 of the Apis mel?fera species, followed by Halictidae, Andrenidae, Colletidae and Megachilidae. In the three classes of habitats sampled the greatest number of individuals was collected in the ruderal vegetation (50%) followed by the canola field in bloom (47%) and the forest fragment (3%). Eight species were registered in the three classes of habitats, being four of them of native social bees. Besides, it was observed that the species exclusive to determine habitat class were rare, that is, represented by one or few individuals. Eight species were exclusive to the interior of the canola fields, 51 to the ruderal vegetation and six to the forest fragment. Most rare species exibits subsocial or social behavior, small size and inhabit open ?reas. It was observed a significant decrease in the mean number of seeds per silique along the edge-interior gradient in all fields, except in the field four. Thus, the forest fragments presented an importante role in the grain yield, and, consequently in the profit, allowing to infer that there is a loss in the grain productivity along the gradiente, which can be altered in at most 2760 kg/ha, which is equivalent to R 350 thousand. Considering that the sampled fauna in the different agricultural environments is distinct and that most species of bees are potential pollinators agents of canola, it is suggested the maintenance of ruderal and forest areas nearby canola fields. This practice can provide resources to the permanence of pollinators in the area, so that they can perform the pollination service raising the grain productivity and the economic value associated to this.O servi?o de poliniza??o ? fundamental para a manuten??o da biodiversidade, alimenta??o humana e produ??o de biocombust?veis. Esse servi?o ? amea?ado pela necessidade de aumento da produ??o de gr?os, a qual amplia ?reas de semeadura provocando a degrada??o da vegeta??o e perda da biodiversidade. Assim, em certas culturas a estreita depend?ncia de polinizadores est? relacionada ? qualidade dos habitats adjacentes. Estudos apontam que h? decl?nio de polinizadores conforme aumenta a dist?ncia de remanescentes florestais, promovendo um decr?scimo na produtividade. Brassica napus, popularmente conhecida como canola, se enquadra nesse cen?rio. Dessa maneira, o presente trabalho objetivou caracterizar a assembleia de abelhas em tr?s classes de habitats e analisar o efeito de dist?ncias de remanescentes florestais na produ??o de gr?os e no valor econ?mico de Brassica napus (Hyola 420) no Sul do Brasil. O estudo foi conduzido em quatro ?reas agr?colas com canola, no munic?pio de Esmeralda, RS. A diversidade de abelhas foi amostrada com uso de pan traps em tr?s classes de habitats: (1) lavoura de canola em flora??o; (2) remanescente florestal e (3) vegeta??o campestre. A fim de avaliar a produ??o de gr?os com livre visita??o de insetos a 25 m, 175 m e 325 m da borda de remanescentes florestais foram colhidas nas lavouras de canola 11 a 18 plantas. Para an?lise de produtividade, as plantas foram colhidas em parcelas de 225 m2 e extrapoladas para um hectare. Com os rendimentos projetados calculou-se o preju?zo total/lavoura pela diferen?a entre a parcela mais lucrativa (25 m) e a menos lucrativa (325 m). Foram coletadas 886 abelhas pertencentes a 87 esp?cies. Dentre as fam?lias coletadas, Apidae foi a mais abundante com 441 indiv?duos, sendo 254 da esp?cie Apis mellifera, seguida de Halictidae, Andrenidae, Colletidae e Megachilidae. Nas tr?s classes de habitats amostradas o maior n?mero de indiv?duos foi coletado na vegeta??o campestre (50%) seguido do interior da lavoura de canola em flora??o (47%) e do remanescente florestal (3%). Oito esp?cies foram registradas nas tr?s classes de habitats, sendo quatro destas de abelhas sociais nativas. Al?m disso, foi observado que as esp?cies exclusivas ? determinada classe de habitat foram raras, ou seja, representadas por um ou poucos indiv?duos. Oito esp?cies foram exclusivas do interior da lavoura de canola, 51 da vegeta??o campestre e seis do remanescente florestal. A maioria das esp?cies raras exibe comportamento subsocial ou solit?rio, tamanho reduzido e habita locais abertos. Observou-se um decr?scimo significativo na m?dia de sementes por s?liqua ao longo do gradiente borda-interior em todas as lavouras, exceto na lavoura quatro. Dessa forma, os remanescentes florestais apresentaram um importante papel no rendimento dos gr?os, e, consequentemente no lucro, permitindo inferir que h? perda na produtividade ao longo do gradiente, podendo se alterar em at? 2760 kg/ha, o equivalente a R 350 mil reais. Considerando-se que a fauna amostrada nos diferentes ambientes agr?colas ? distinta e que a maioria das esp?cies de abelhas se apresenta como potencial agente polinizador para canola sugere-se a manuten??o de habitats campestres e florestais nas proximidades das lavouras de canola. Essa pr?tica pode fornecer subs?dios para a perman?ncia dos polinizadores na ?rea, para que esses efetuem o servi?o de poliniza??o elevando a produ??o de gr?os e o valor econ?mico associado a esse