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1.
Ecotoxicol Environ Saf ; 207: 111268, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32916533

RESUMO

Foraging is essential for honey bee colony fitness and is enhanced by the waggle dance, a recruitment behavior in which bees can communicate food location and quality. We tested if the consumption of nectar (sucrose solution) with a field-realistic concentration of 4 ppm flupyradifurone (FPF) could alter foraging behavior and recruitment dancing in Apis mellifera. Foragers were repelled by FPF. They visited the FPF feeder less often and spent less time imbibing sucrose solution (2.5 M, 65% w/w) with FPF. As a result, bees feeding on the FPF treatment consumed 16% less nectar. However, FPF did not affect dancing: there were no effects on unloading wait time, the number of dance bouts per nest visit, or the number of dance circuits performed per dance bout. FPF could therefore deter bees from foraging on contaminated nectar. However, the willingness of bees to recruit nestmates for nectar with FPF is concerning. Recruitment can rapidly amplify the number of foragers and could overcome the decrease in consumption of FPF-contaminated nectar, resulting in a net inflow of pesticide to the colony. FPF also significantly altered the expression of 116 genes, some of which may be relevant for the olfactory learning deficits induced by FPF and the toxicity of FPF.


Assuntos
4-Butirolactona/análogos & derivados , Abelhas/fisiologia , Inseticidas/toxicidade , Néctar de Plantas , Piridinas/toxicidade , 4-Butirolactona/toxicidade , Animais , Abelhas/efeitos dos fármacos , Comportamento Alimentar , Alimentos , Sacarose
2.
Chemosphere ; 262: 127735, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32777610

RESUMO

Despite the restriction of the use of neonicotinoids in the EU, including thiamethoxam and clothianidin, the debate over their risk on honey bees has not been fully settled. This study presents results of a three-year study working with 180 honey bee colonies in ten replicates. Colonies were sorted into three treatments (60 colonies per treatment) exposed to sunflower blooms grown from seeds treated with thiamethoxam, clothianidin and a non-treated control. Each colony was assessed at six moments: one before to exposition to sunflower, two during the exposition (short-time risk), two after exposition (medium-time risk) and one after wintering (long-time risk). The health and development of the colonies were assessed by monitoring adult bee population, brood development, status of the queen, food reserves and survival. No significant difference among treatments when raw data was considered. However, when evolution from initial status of the colony was evaluated, a significant difference was observed from the first week of exposure to sunflower blooms. In this period, the number of adult bees and the amount of brood were slightly lower in the bee hives exposed to neonicotinoids, although such differences disappeared in subsequent evaluations. The concentration of residues in samples of beebread and adult bees was at the level of ng·g-1. Magnitude of the effect of the treatment factor on the variability of colony health and development related parameters was low. The most important factor was the hive, followed by the replicate and year, and to a lesser extent the initial strength of the colonies.


Assuntos
Abelhas/efeitos dos fármacos , Guanidinas/toxicidade , Helianthus , Inseticidas/toxicidade , Neonicotinoides/toxicidade , Sementes/efeitos dos fármacos , Tiametoxam/toxicidade , Tiazóis/toxicidade , Animais , Abelhas/fisiologia , Ecotoxicologia/métodos , Flores , Guanidinas/análise , Helianthus/efeitos dos fármacos , Inseticidas/análise , Neonicotinoides/análise , Resíduos de Praguicidas/análise , Polinização , Própole/análise , Sementes/química , Espanha , Tiametoxam/análise , Tiazóis/análise
3.
PLoS One ; 15(12): e0241393, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33370277

RESUMO

Bee pollen is a natural product that has valuable nutritional and medicinal characteristics and has recently garnered increasing attention in the food industry due to its nutritive value. Here, we harvested pollen loads from the Al-Ahsa oasis in eastern Saudi Arabia during spring, summer, autumn, and winter in 2018/2019 to compare the nutritional value of bee pollen protein with the amino acid requirements of honeybees and adult humans. Based on the nutritional value of bee pollen protein, the optimal season for harvesting bee pollen was determined. The composition of the bee pollen showed the highest contents of crude protein, total amino acids, leucine, glutamic acid, valine, isoleucine, threonine, and glycine in samples collected in spring. The highest contents of lysine, phenylalanine, threonine, tryptophan, arginine, tyrosine, and cysteine were observed in samples collected in winter. The highest contents of histidine, methionine, and serine were in samples collected in autumn. Moreover, the highest levels of aspartic acid, proline, and alanine were in samples collected in summer. Leucine, valine, lysine, histidine, threonine, and phenylalanine (except in autumn bee pollen) contents in pollen from all four seasons were above the requirements of honeybees. Leucine, valine, histidine, isoleucine (except in autumn bee pollen), lysine (except in spring and summer bee pollen), and threonine (except in winter and spring bee pollen) in all tested samples were above the requirements of adult humans. In comparison with the minimal amino acid requirements of adult humans and honeybees, the 1st limiting amino acid in bee pollen collected during the different seasons was methionine. Bee pollen collected during spring (March-May) and winter (December-February) can be considered a nutritive food source for adult humans and honeybees.


Assuntos
Abelhas , Pólen/química , Adulto , Aminoácidos/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Abelhas/crescimento & desenvolvimento , Abelhas/fisiologia , Dieta , Humanos , Necessidades Nutricionais , Valor Nutritivo , Proteínas de Vegetais Comestíveis/análise , Arábia Saudita , Estações do Ano
4.
PLoS One ; 15(12): e0237484, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33332351

RESUMO

Livestock grazing and non-native plant species affect rangeland habitats globally. These factors may have important effects on ecosystem services including pollination, yet, interactions between pollinators, grazing, and invasive plants are poorly understood. To address this, we tested the hypothesis that cattle grazing and site colonization by cheatgrass (Bromus tectorum) impact bee foraging and nesting habitats, and the biodiversity of wild bee communities, in a shortgrass prairie system. Bee nesting habitats (litter and wood cover) were marginally improved in non-grazed sites with low cheatgrass cover, though foraging habitat (floral cover and richness, bare soil) did not differ among cattle-grazed sites or non-grazed sites with low or high cheatgrass cover. However, floral cover was a good predictor of bee abundance and functional dispersion. Mean bee abundance, richness, diversity and functional diversity were significantly lower in cattle-grazed habitats than in non-grazed habitats. Differences in bee diversity among habitats were pronounced early in the growing season (May) but by late-season (August) these differences eroded as Melissodes spp. and Bombus spp. became more abundant at study sites. Fourth-corner analysis revealed that sites with high floral cover tended to support large, social, polylectic bees; sites with high grass cover tended to support oligolectic solitary bees. Both cattle-grazed sites and sites with high cheatgrass cover were associated with lower abundances of above-ground nesting bees but higher abundance of below-ground nesters than non-grazed sites with low cheatgrass cover. We conclude that high cheatgrass cover is not associated with reduced bee biodiversity or abundance, but cattle grazing was negatively associated with bee abundances and altered species composition. Although floral cover is an important predictor of bee assemblages, this was not impacted by cattle grazing and our study suggests that cattle likely impact bee communities through effects other than those mediated by forbs, including soil disturbance or nest destruction. Efforts aimed at pollinator conservation in prairie habitats should focus on managing cattle impacts early in the growing season to benefit sensitive bee species.


Assuntos
Abelhas/fisiologia , Gado/fisiologia , Polinização/fisiologia , Animais , Biodiversidade , Bromus/fisiologia , Bovinos , Ecossistema , Flores/fisiologia , Pradaria , Plantas , Estações do Ano
5.
PLoS One ; 15(12): e0242668, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33296376

RESUMO

Honey bees (genus Apis) are well known for the impressive suite of nest defenses they have evolved to protect their abundant stockpiles of food and the large colonies they sustain. In Asia, honey bees have evolved under tremendous predatory pressure from social wasps in the genus Vespa, the most formidable of which are the giant hornets that attack colonies in groups, kill adult defenders, and prey on brood. We document for the first time an extraordinary collective defense used by Apis cerana against the giant hornet Vespa soror. In response to attack by V. soror, A. cerana workers foraged for and applied spots of animal feces around their nest entrances. Fecal spotting increased after colonies were exposed either to naturally occurring attacks or to chemicals that scout hornets use to target colonies for mass attack. Spotting continued for days after attacks ceased and occurred in response to V. soror, which frequently landed at and chewed on entrances to breach nests, but not Vespa velutina, a smaller hornet that rarely landed at entrances. Moderate to heavy fecal spotting suppressed attempts by V. soror to penetrate nests by lowering the incidence of multiple-hornet attacks and substantially reducing the likelihood of them approaching and chewing on entrances. We argue that A. cerana forages for animal feces because it has properties that repel this deadly predator from nest entrances, providing the first report of tool use by honey bees and the first evidence that they forage for solids that are not derived from plants. Our study describes a remarkable weapon in the already sophisticated portfolio of defenses that honey bees have evolved in response to the predatory threats they face. It also highlights the strong selective pressure honey bees will encounter if giant hornets, recently detected in western North America, become established.


Assuntos
Abelhas/fisiologia , Fezes , Comportamento Predatório/fisiologia , Vespas/fisiologia , Animais , Especificidade da Espécie
6.
J Insect Sci ; 20(6)2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-33232488

RESUMO

The health of insect pollinators, particularly the honey bee, Apis mellifera (Linnaeus, 1758), is a major concern for agriculture and ecosystem health. In response to mounting evidence supporting the detrimental effects of neonicotinoid pesticides on pollinators, a novel 'bee safe' butenolide compound, flupyradifurone (FPF) has been registered for use in agricultural use. Although FPF is not a neonicotinoid, like neonicotinoids, it is an excitotoxic nicotinic acetylcholine receptor agonist. In addition, A. mellifera faces threats from pathogens, such as the microsporidian endoparasite, Nosema ceranae (Fries et al. 1996). We therefore sought 1) to increase our understanding of the potential effects of FPF on honey bees by focusing on a crucial behavior, the ability to learn and remember an odor associated with a food reward, and 2) to test for a potential synergistic effect on such learning by exposure to FPF and infection with N. ceranae. We found little evidence that FPF significantly alters learning and memory at short-term field-realistic doses. However, at high doses and at chronic, field-realistic exposure, FPF did reduce learning and memory in an olfactory conditioning task. Infection with N. ceranae also reduced learning, but there was no synergy (no significant interaction) between N. ceranae and exposure to FPF. These results suggest the importance of continued studies on the chronic effects of FPF.


Assuntos
4-Butirolactona/análogos & derivados , Abelhas/efeitos dos fármacos , Agentes de Controle Biológico/efeitos adversos , Inseticidas/efeitos adversos , Nosema/química , Piridinas/efeitos adversos , Olfato/efeitos dos fármacos , 4-Butirolactona/efeitos adversos , Animais , Abelhas/fisiologia , Aprendizagem
7.
J Insect Sci ; 20(5)2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-33021636

RESUMO

Pollinators provide a key ecosystem service vital for the survival and stability of the biosphere. Identifying factors influencing the plant-pollinator mutualism and pollinator management is necessary for maintaining a healthy ecosystem. Since healthy beehives require substantial amounts of carbohydrates (nectar) and protein (pollen) from forage plants such as clover, we must assess how resources offered by plants change under limited water conditions in order to fully understand how drought modifies the pollination mutualism. Here we document how reduced water availability leads to decreased nectar quality and quantity and decreased protein quality of pollen. Furthermore, we provide conclusive evidence that these lower quality resources lead to decreased survival and productivity in both developing honey bees (Hymenoptera: Apidae) and bumble bees (Hymenoptera: Apidae). The results emphasize the importance of the nutritional effects of reduced water on bees when predicting shifts of pollination mutualisms under climate change.


Assuntos
Abelhas/fisiologia , Polinização/fisiologia , Abastecimento de Água , Animais , Secas , Ecossistema , Eficiência , Comportamento Alimentar , Medicago/química , Néctar de Plantas/química , Plantas/química , Pólen/química , Análise de Sobrevida
8.
Toxicon ; 187: 279-284, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33035564

RESUMO

A survey on 5115 beekeepers and 121 patients treated with bee venom by an apitherapy clinic in the Hubei province, the epicenter of COVID-19 in China, reported that none of the beekeepers developed symptoms associated with COVID-19, the new and devastating pandemic. The hypothesis that immunity to bee venom could have a preventive effect was expressed and the authors of the Chinese survey suggested that the next step should be animal experiments on monkeys. We believed that before starting such studies, a second independent survey should verify the findings and define the hypothesis more clearly. Thus we asked all German beekeepers to complete an assessment form which would summarize their experiences with COVID-19. In contrast to the Chinese study we found that two beekeepers had died from a SARS-CoV-2 infection and forty-five were affected. The reaction to bee stings (none; mild swelling; severe swelling) correlated with the perceived severity of the SARS-CoV-2-infection-associated symptoms - exhaustion and sore throat. Beekeepers comorbidity correlated with problems with breathing at rest, fever, and diarrhea. Our results did not confirm the findings of the Chinese study. However, since the antiviral effects of bee venom have been found in several studies, we cannot exclude that there could be a direct preventive or alleviating effect when bee venom is administered during the infection.


Assuntos
Venenos de Abelha/toxicidade , Abelhas/fisiologia , Betacoronavirus/imunologia , Infecções por Coronavirus/imunologia , Mordeduras e Picadas de Insetos , Exposição Ocupacional/efeitos adversos , Pneumonia Viral/imunologia , Adulto , Idoso , Criação de Animais Domésticos , Animais , Feminino , Alemanha , Humanos , Masculino , Pessoa de Meia-Idade , Pandemias , Fatores de Risco
9.
J Insect Sci ; 20(5)2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-33098431

RESUMO

The abdominal intersegmental structures allow insects, such as honey bees, dragonflies, butterflies, and drosophilae, to complete diverse behavioral movements. In order to reveal how the complex abdominal movements of these insects are produced, we use the honey bee (Apis mellifera L.) as a typical insect to study the relationship between intersegmental structures and abdominal motions. Microstructure observational experiments are performed by using the stereoscope and the scanning electron microscope. We find that a parallel mechanism, composed of abdominal cuticle and muscles between the adjacent segments, produces the complex and diverse movements of the honey bee abdomen. These properties regulate multiple behavioral activities such as waggle dance and flight attitude adjustment. The experimental results demonstrate that it is the joint efforts of the muscles and membranes that connected the adjacent cuticles together. The honey bee abdomen can be waggled, expanded, contracted, and flexed with the actions of the muscles. From the view point of mechanics, a parallel mechanism is evolved from the intersegmental connection structures of the honey bee abdomen. Here, we conduct a kinematic analysis of the parallel mechanism to simulate the intersegmental abdominal motions.


Assuntos
Abelhas/fisiologia , Abdome , Animais , Fenômenos Biomecânicos , Movimento
10.
Proc Biol Sci ; 287(1936): 20201950, 2020 10 14.
Artigo em Inglês | MEDLINE | ID: mdl-33049176

RESUMO

Honeybees can be directed to profitable food sources by following waggle dances performed by other bees. Followers can often choose between using this social information or relying on memories about food sources they have visited in the past, so-called private information. While the circumstances that favour the use of either social or private information have received considerable attention, still little is known about the neurophysiological basis of information use. We hypothesized that octopamine and dopamine, two biogenic amines with important functions in reward signalling and learning, affect dance use in honeybees. We orally administered octopamine and dopamine when bees collected food at artificial feeders and tested if this affected interest in dance information about a new food source. We predicted that octopamine reduces interest in dances and strengthens private information use via an increase in the perceived value of the previously exploited resource. Since dopamine has been shown to lower reward perception, we expected it to act in the opposite direction. Octopamine-treated foragers indeed followed 32% fewer dances than control bees and increased the use of private information. Conversely, dopamine-treated bees followed dances 15% longer than control bees, but surprisingly did not use social information more. Overall, our results suggest that biogenic amine signalling affects interactions among dancers and dance followers and, thus, information flow about high-quality food sources.


Assuntos
Abelhas/fisiologia , Dopamina/metabolismo , Octopamina/metabolismo , Comunicação Animal , Animais , Comportamento Social
11.
PLoS One ; 15(10): e0239742, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33021997

RESUMO

The yellow-legged hornet, Vespa velutina nigrithorax (Hymenoptera: Vespidae, Lepeletier 1836), is native to Southeast Asia and has been unintentionally introduced in France. The species is spreading in many areas of the world. The European Union has classified V. velutina as a species of concern because the hornet significantly affects beekeeping activities, mostly by preying honeybees (Apis mellifera) at beehive entrances. No current control method is simultaneously eco-friendly and effective. Here, we aimed to develop a greener technique for destroying V. velutina nests, inspired by a defense behavior used by the eastern honeybee (Apis cerana), the "heat ball". In the laboratory, we tested how V. velutina of different sexes, castes, and developmental stages responded to different heat exposure systems employing a range of temperature levels. Overall, the time of death decreased as temperature increased. Hornets died faster when the temperature was gradually increased than when it was instantaneously increased; larvae seemed to be more thermally tolerant. The most promising and potential technique for quickly destroying hornet nests may be steam injection, as the humid airflow system killed all hornets within 13 seconds, and therefore could be a good candidate for a green nest control method.


Assuntos
Controle de Insetos/métodos , Espécies Introduzidas , Termotolerância/fisiologia , Vespas/fisiologia , Animais , Abelhas/fisiologia , Feminino , França , Temperatura Alta , Larva/fisiologia , Masculino , Temperatura
12.
Sci Rep ; 10(1): 16400, 2020 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-33009441

RESUMO

Landscape-scale bark beetle outbreaks alter forest structure with direct and indirect effects on plants and animals in forest ecosystems. Using alpine spruce forest and a native bee community as a study system, we tested how tree mortality from bark beetles impacts bee foraging habitats and populations. Bees were collected across the growing season (early-, middle-, and late-season) for two years using passive trapping methods, and collections were used to analyze patterns in species abundances and diversity. Three important findings emerged: (1) forest stands that were post-outbreak had 62% higher floral density and 68% more floral species during peak bloom, respectively, than non-affected stands; (2) bee captures were highest early-season (June) and were not strongly affected by bark beetle outbreak; however, mean number of bee species and Shannon-Weiner diversity were significantly higher in post-outbreak stands and this effect was pronounced early in the growing season. Corresponding analysis of ß-diversity indicated higher accumulation of bee biodiversity in post-outbreak stands and a turnover in the ratio of Bombus: Osmia; (3) bee captures were linked to variation in foraging habitat, but number of bee species and diversity were more strongly predicted by forest structure. Our results provide evidence of increased alpine bee biodiversity in post-outbreak stands and increased availability of floral resources. We conclude that large-scale disturbance from bark beetle outbreaks may drive shifts in pollinator community composition through cascading effects on floral resources, mediated via mortality of overstory trees.


Assuntos
Abelhas/crescimento & desenvolvimento , Abelhas/fisiologia , Besouros/crescimento & desenvolvimento , Besouros/fisiologia , Animais , Biodiversidade , Conservação dos Recursos Naturais/métodos , Surtos de Doenças , Ecossistema , Flores/fisiologia , Florestas , Casca de Planta , Polinização/fisiologia , Estações do Ano , Árvores/fisiologia
13.
PLoS One ; 15(10): e0231120, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33095783

RESUMO

Mutualistic plant-pollinator interactions are critical for the functioning of both non-managed and agricultural systems. Mathematical models of plant-pollinator interactions can help understand key determinants in pollination success. However, most previous models have not addressed pollinator behavior and plant biology combined. Information generated from such a model can inform optimal design of crop orchards and effective utilization of managed pollinators like western honey bees (Apis mellifera), and help generate hypotheses about the effects of management practices and cultivar selection. We expect that the number of honey bees per flower and male to female flower ratio will influence fruit yield. To test the relative importance of these effects, both singly and simultaneously, we utilized a delay differential equation model combined with Latin hypercube sampling for sensitivity analysis. Empirical data obtained from historical records and collected in kiwifruit (Actinidia chinensis) orchards in New Zealand were used to parameterize the model. We found that, at realistic bee densities, the optimal orchard had 65-75% female flowers, and the most benefit was gained from the first 6-8 bees/1000 flowers, with diminishing returns thereafter. While bee density significantly impacted fruit production, plant-based parameters-flower density and male:female flower ratio-were the most influential. The predictive model provides strategies for improving crop management, such as choosing cultivars which have their peak bloom on the same day, increasing the number of flowers with approximately 70% female flowers in the orchard, and placing enough hives to maintain more than 6 bees per 1000 flowers to optimize yield.


Assuntos
Actinidia/fisiologia , Abelhas/fisiologia , Polinização , Algoritmos , Animais , Produção Agrícola , Feminino , Frutas/crescimento & desenvolvimento , Masculino , Modelos Teóricos , Nova Zelândia , Densidade Demográfica
14.
BMC Evol Biol ; 20(1): 139, 2020 10 29.
Artigo em Inglês | MEDLINE | ID: mdl-33121428

RESUMO

BACKGROUND: Honeybees have extraordinary phenotypic plasticity in their senescence rate, making them a fascinating model system for the evolution of aging. Seasonal variation in senescence and extrinsic mortality results in a tenfold increase in worker life expectancy in winter as compared to summer. To understand the evolution of this remarkable pattern of aging, we must understand how individual longevity scales up to effects on the entire colony. In addition, threats to the health of honey bees and other social insects are typically measured at the individual level. To predict the effects of environmental change on social insect populations, we must understand how individual effects impact colony performance. We develop a matrix model of colony demographics to ask how worker age-dependent and age-independent mortality affect colony fitness and how these effects differ by seasonal conditions. RESULTS: We find that there are seasonal differences in honeybee colony elasticity to both senescent and extrinsic worker mortality. Colonies are most elastic to extrinsic (age-independent) nurse and forager mortality during periods of higher extrinsic mortality and resource availability but most elastic to age-dependent mortality during periods of lower extrinsic mortality and lower resource availability. CONCLUSIONS: These results suggest that seasonal changes in the strength of selection on worker senescence partly explain the observed pattern of seasonal differences in worker aging in honey bees. More broadly, these results extend our understanding of the role of extrinsic mortality in the evolution of senescence to social animals and improve our ability to model the effects of environmental change on social insect populations of economic or conservation concern.


Assuntos
Envelhecimento , Abelhas/fisiologia , Longevidade , Estações do Ano , Animais , Modelos Biológicos
15.
Proc Biol Sci ; 287(1937): 20200980, 2020 10 28.
Artigo em Inglês | MEDLINE | ID: mdl-33109012

RESUMO

Bumblebees (Bombus spp.) are important and widespread insect pollinators, but the act of foraging on flowers can expose them to harmful pesticides and chemicals such as oxidizers and heavy metals. How these compounds directly influence bee survival and indirectly affect bee health via the gut microbiome is largely unknown. As toxicants in floral nectar and pollen take many forms, we explored the genomes of bee-associated microbes for their potential to detoxify cadmium, copper, selenate, the neonicotinoid pesticide imidacloprid, and hydrogen peroxide-which have all been identified in floral nectar and pollen. We then exposed Bombus impatiens workers to varying concentrations of these chemicals via their diet and assayed direct effects on bee survival. Using field-realistic doses, we further explored the indirect effects on bee microbiomes. We found multiple putative genes in core gut microbes that may aid in detoxifying harmful chemicals. We also found that while the chemicals are largely toxic at levels within and above field-realistic concentrations, the field-realistic concentrations-except for imidacloprid-altered the composition of the bee microbiome, potentially causing gut dysbiosis. Overall, our study shows that chemicals found in floral nectar and pollen can cause bee mortality, and likely have indirect, deleterious effects on bee health via their influence on the bee microbiome.


Assuntos
Abelhas/fisiologia , Poluentes Ambientais/toxicidade , Microbioma Gastrointestinal , Animais , Abelhas/microbiologia , Comportamento Alimentar , Flores , Inseticidas , Microbiota , Neonicotinoides , Nitrocompostos , Praguicidas/toxicidade , Néctar de Plantas , Pólen , Polinização
16.
Am Nat ; 196(5): 525-540, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33064587

RESUMO

AbstractThe rapid increase in "big data" during the postgenomic era makes it crucial to appropriately measure the level of social complexity in comparative studies. We argue that commonly used qualitative classifications lump together species showing a broad range of social complexity and falsely imply that social evolution always progresses along a single linear stepwise trajectory that can be deduced from comparing extant species. To illustrate this point, we compared widely used social complexity measures in "primitively eusocial" bumble bees with "advanced eusocial" stingless bees, honey bees, and attine ants. We find that a single species can have both higher and lower levels of complexity compared with other taxa, depending on the social trait measured. We propose that measuring the complexity of individual social traits switches focus from semantic discussions and offers several directions for progress. First, quantitative social traits can be correlated with molecular, developmental, and physiological processes within and across lineages of social animals. This approach is particularly promising for identifying processes that influence or have been affected by social evolution. Second, key social complexity traits can be combined into multidimensional lineage-specific quantitative indices, enabling fine-scale comparison across species that are currently bundled within the same level of social complexity.


Assuntos
Formigas/fisiologia , Abelhas/fisiologia , Comportamento Social , Animais , Evolução Biológica
17.
PLoS One ; 15(9): e0238888, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32915879

RESUMO

The vast majority of species of velvet ants (Hymenoptera: Aculeata: Mutillidae) are ectoparasitoids of immature stages of other aculeate Hymenoptera (bees, wasps and ants). Due to their cryptic, furtive behaviour at the host nesting sites, however, even basic information on their biology, like host use diversity, is still unknown for entire subfamilies, and the known information, scattered in over two centuries of published studies, is potentially hiding tendencies to host specialization across velvet ant lineages. In this review, based on 305 host associations spanning 132 species in 49 genera and 10 main lineages (tribes/subfamilies), we explored patterns of host use in velvet ants. Overall, 15 families and 29 subfamilies of Aculeata are listed as hosts of mutillids, with a strong predominance of Apoidea (bees and apoid wasps: 19 subfamilies and 82.3% of host records). A series of bipartite networks, multivariate analyses and calculations of different indices suggested possible patterns of specialization. Host taxonomic spectrum (number of subfamilies) of velvet ants was very variable and explained by variation in the number of host records. Instead, we found a great variation of network-based host specialization degree and host taxonomic distinctness that did not depend on the number of host records. Differences in host use patterns seemed apparent across mutillid tribes/subfamilies, among genera within several tribes/subfamilies, and to lesser extent within genera. Taxonomic host use variation seemed not dependent on phylogeny. Instead, it was likely driven by the exploitation of hosts with different ecological traits (nest type, larval diet and sociality). Thus, taxonomically more generalist lineages may use hosts that essentially share the same ecological profile. Interestingly, closely related mutillid lineages often show contrasting combinations of host ecological traits, particularly sociality and larval diet, with a more common preference for ground-nesting hosts across most lineages. This review may serve as a basis to test hypotheses for host use evolution in this fascinating family of parasitoids.


Assuntos
Formigas/fisiologia , Abelhas/fisiologia , Evolução Molecular , Interações Hospedeiro-Parasita , Filogenia , Vespas/fisiologia , Animais , Formigas/classificação , Abelhas/classificação , Vespas/classificação
18.
PLoS One ; 15(9): e0232313, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32960879

RESUMO

Pollination services and honeybee health in general are important in the African savannahs particularly to farmers who often rely on honeybee products as a supplementary source of income. Therefore, it is imperative to understand the floral cycle, abundance and spatial distribution of melliferous plants in the African savannah landscapes. Furthermore, placement of apiaries in the landscapes could benefit from information on spatiotemporal patterns of flowering plants, by optimising honeybees' foraging behaviours, which could improve apiary productivity. This study sought to assess the suitability of simulated multispectral data for mapping melliferous (flowering) plants in the African savannahs. Bi-temporal AISA Eagle hyperspectral images, resampled to four sensors (i.e. WorldView-2, RapidEye, Spot-6 and Sentinel-2) spatial and spectral resolutions, and a 10-cm ultra-high spatial resolution aerial imagery coinciding with onset and peak flowering periods were used in this study. Ground reference data was collected at the time of imagery capture. The advanced machine learning random forest (RF) classifier was used to map the flowering plants at a landscape scale and a classification accuracy validated using 30% independent test samples. The results showed that 93.33%, 69.43%, 67.52% and 82.18% accuracies could be achieved using WorldView-2, RapidEye, Spot-6 and Sentinel-2 data sets respectively, at the peak flowering period. Our study provides a basis for the development of operational and cost-effective approaches for mapping flowering plants in an African semiarid agroecological landscape. Specifically, such mapping approaches are valuable in providing timely and reliable advisory tools for guiding the implementation of beekeeping systems at a landscape scale.


Assuntos
Criação de Abelhas/métodos , Monitoramento Ambiental/métodos , Magnoliopsida/crescimento & desenvolvimento , Animais , Abelhas/fisiologia , Conjuntos de Dados como Assunto , Pradaria , Quênia , Aprendizado de Máquina , Fotografação , Polinização
19.
PLoS One ; 15(9): e0238685, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32915824

RESUMO

Pollination may be severely affected by the decreasing size and increasing isolation of habitat patches. However, most studies that have considered the effects of these two variables on plant-pollinator interactions have been carried out in areas that have undergone anthropogenic fragmentation, and little is known about their effects in natural habitats. The Carajás National Forest and Campos Ferruginosos National Park are two protected areas in the eastern Amazon where one can find isolated ferruginous outcrops characterized by iron-rich soil and herbaceous-shrub vegetation surrounded by Amazon forest. These patches of canga provide an opportunity to analyze plant-pollinator interactions in naturally fragmented areas. Our objective was to test whether the size and isolation of naturally isolated outcrops located in Carajás affect plant-pollinator interactions by using pollination syndromes and interaction networks. We determined the pollination syndromes of 771 plant species that occurred in eleven canga patches and performed field work to analyze plant-pollinator networks in nine canga patches. The structure of the plant-pollinator networks was not affected by the size or isolation of the canga patches. Generalist species were present in all canga areas, indicating that they are important in maintaining the plant communities in isolated canga patches. The lack of significance related to the distance between canga patches suggests that the forest does not prevent pollinator movement between canga patches.


Assuntos
Abelhas/fisiologia , Fenômenos Fisiológicos Vegetais , Plantas , Animais , Ecossistema , Florestas , Polinização , Árvores
20.
Proc Natl Acad Sci U S A ; 117(41): 25923-25934, 2020 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-32989162

RESUMO

The ability of developing complex internal representations of the environment is considered a crucial antecedent to the emergence of humans' higher cognitive functions. Yet it is an open question whether there is any fundamental difference in how humans and other good visual learner species naturally encode aspects of novel visual scenes. Using the same modified visual statistical learning paradigm and multielement stimuli, we investigated how human adults and honey bees (Apis mellifera) encode spontaneously, without dedicated training, various statistical properties of novel visual scenes. We found that, similarly to humans, honey bees automatically develop a complex internal representation of their visual environment that evolves with accumulation of new evidence even without a targeted reinforcement. In particular, with more experience, they shift from being sensitive to statistics of only elemental features of the scenes to relying on co-occurrence frequencies of elements while losing their sensitivity to elemental frequencies, but they never encode automatically the predictivity of elements. In contrast, humans involuntarily develop an internal representation that includes single-element and co-occurrence statistics, as well as information about the predictivity between elements. Importantly, capturing human visual learning results requires a probabilistic chunk-learning model, whereas a simple fragment-based memory-trace model that counts occurrence summary statistics is sufficient to replicate honey bees' learning behavior. Thus, humans' sophisticated encoding of sensory stimuli that provides intrinsic sensitivity to predictive information might be one of the fundamental prerequisites of developing higher cognitive abilities.


Assuntos
Abelhas/fisiologia , Aprendizagem , Animais , Cognição , Meio Ambiente , Humanos , Memória
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