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1.
Nat Commun ; 12(1): 1690, 2021 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-33727549

RESUMO

Artificial light at night has rapidly spread around the globe over the last decades. Evidence is increasing that it has adverse effects on the behavior, physiology, and survival of animals and plants with consequences for species interactions and ecosystem functioning. For example, artificial light at night disrupts plant-pollinator interactions at night and this can have consequences for the plant reproductive output. By experimentally illuminating natural plant-pollinator communities during the night using commercial street-lamps we tested whether light at night can also change interactions of a plant-pollinator community during daytime. Here we show that artificial light at night can alter diurnal plant-pollinator interactions, but the direction of the change depends on the plant species. We conclude that the effect of artificial light at night on plant-pollinator interactions is not limited to the night, but can also propagate to the daytime with so far unknown consequences for the pollinator community and the diurnal pollination function and services they provide.


Assuntos
Ritmo Circadiano/efeitos da radiação , Plantas/efeitos da radiação , Polinização/efeitos da radiação , Animais , Insetos/fisiologia
2.
Zhongguo Zhong Yao Za Zhi ; 46(5): 1079-1083, 2021 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-33787100

RESUMO

The study is aimed to investigate the reproductive biology characteristics of Polygonatum cyrtonema, especially including phenology, flower bud differentiation, flowering timing, floral traits, pollen vigor and stigma receptivity. The results showed that P. cyrtonema forms inflorescence before the leaves spread. In the wild, P. cyrtonema is mainly pollinated by insects such as bumblebees, with a seed setting rate of 65.12%. The seed setting rate of indoor single plant isolation or self-pollination enclosed by parchment paper bag is 0, indicating that it is self-incompatible. In Lin'an city, seedlings begin to emerge from mid-March to early April(the temperature is higher than 7.5 ℃), buds begin to emerge from the end of March to mid-April, and then undergo the full bloom stage from mid-to-late April, and the final flowering stage from the end of April to mid-May. The whole flowering period lasts 36 to 45 days. There are obvious differences in the phenology of different provenances. The flowers come into bloom from the base to the top along the aboveground main axis, which usually contain 4-22 inflorescences with(2-) 4-10(-21) flowers per inflorescence. The flowering pe-riod for a single plant is 26-38 days. The single flower lasts about 20-25 days from budding to opening and withers 2 days after pollination, and then the ovary will gradually expand. If unpollinated, it will continue to bloom for 3-5 days and then wither. Flower development period is significantly related to pollen vigor and stigma remittance. The pollen viability is the highest when the flower is fully opened with anthers gathering on the stigma, and the receptivity is the strongest when the stigma protrudes out of the perianth and secretes mucus. The fruits and seeds ripen in October, and proper shading can ensure the smooth development and maturity of the seeds. This study provides a basis for the hybrid breeding and seed production of P. cyrtonema.


Assuntos
Polygonatum , Flores , Melhoramento Vegetal , Polinização , Reprodução
3.
Nat Commun ; 12(1): 1937, 2021 03 29.
Artigo em Inglês | MEDLINE | ID: mdl-33782399

RESUMO

137Cs is a long-lived (30-year radioactive half-life) fission product dispersed globally by mid-20th century atmospheric nuclear weapons testing. Here we show that vegetation thousands of kilometers from testing sites continues to cycle 137Cs because it mimics potassium, and consequently, bees magnify this radionuclide in honey. There were no atmospheric weapons tests in the eastern United States, but most honey here has detectable 137Cs at >0.03 Bq kg-1, and in the southeastern U.S., activities can be >500 times higher. By measuring honey, we show regional patterns in the biogeochemical cycling of 137Cs and conclude that plants and animals receive disproportionally high exposure to ionizing radiation from 137Cs in low potassium soils. In several cases, the presence of 137Cs more than doubled the ionizing radiation from gamma and x-rays in the honey, indicating that despite its radioactive half-life, the environmental legacy of regional 137Cs pollution can persist for more than six decades.


Assuntos
Radioisótopos de Césio/metabolismo , Mel/análise , Plantas/metabolismo , Poluentes Radioativos do Solo/metabolismo , Solo/química , Animais , Abelhas/química , Abelhas/fisiologia , Radioisótopos de Césio/química , História do Século XX , História do Século XXI , Armas Nucleares/história , Plantas/química , Polinização/fisiologia , Poluentes Radioativos do Solo/química , Análise Espaço-Temporal , Estados Unidos
4.
Sci Total Environ ; 768: 144899, 2021 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-33736351

RESUMO

Tropical plant species are vulnerable to climate change and global warming. Since flowering is a critical factor for plant reproduction and seed-set, warming and elevated atmospheric carbon dioxide concentrations (eCO2) are crucial climate change factors that can affect plant reproductive dynamics and flowering related events in the tropics. Using a combined free-air CO2 enrichment and a free-air temperature-controlled enhancement system, we investigate how warming (+2 °C above ambient, eT) and elevated [CO2] (~600 ppm, eCO2) affect the phenological pattern, plant-insect interactions, and outcrossing rates in the tropical legume forage species Stylosanthes capitata Vogel (Fabaceae). In comparison to the control, a significantly greater number of flowers (NF) per plot (+62%) were observed in eT. Furthermore, in warmed plots flowers began opening approximately 1 h earlier (~09:05), with a canopy temperature of ~23 °C, than the control (~09:59) and eCO2 (~09:55) treatments. Flower closure occurred about 3 h later in eT (~11:57) and control (~13:13), with a canopy temperature of ~27 °C. These changes in flower phenology increased the availability of floral resources and attractiveness for pollinators such as Apis mellifera L. and visitors such as Paratrigona lineata L., with significant interactions between eT treatments and insect visitation per hour/day, especially between 09:00-10:40. In comparison to the control, the additive effects of combined eCO2 + eT enhanced the NF by 137%, while the number of A. mellifera floral visits per plot/week increased by 83% during the period of greatest flower production. Although we found no significant effect of treatments on mating system parameters, the overall mean multilocus outcrossing rate (tm = 0.53 ± 0.03) did confirm that S. capitata has a mixed mating system. The effects of elevated [CO2] and warming on plant-pollinator relationships observed here may have important implications for seed production of tropical forage species in future climate scenarios.


Assuntos
Dióxido de Carbono , Reprodução , Animais , Abelhas , Mudança Climática , Flores , Insetos , Polinização
5.
An Acad Bras Cienc ; 93(2): e20190431, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33656049

RESUMO

Oil Tea (Camellia oleifera) is an important woody edible oil plant in China. Oil Tea suffers from low rate of fruit set during production, which is related to poor pollination and fertilization. Pollen vigor is directly related to pollination and fertilization. Using the interspecific hybrid Y3 (C. grijsii × C. oleifera) as plant material, we studied the effects of sucrose, H3BO3, MgSO4, and IAA on pollen germination using an orthogonal design to determine the best culture medium. Results indicated that pollen germination rates were significantly affected by medium components and ranged from 29.13% to 56.84%. Pollen tube length was the longest in the T5 medium surpassing the control group by 489.36 µm. MgSO4 turned out to be the most important germination medium component having great effect on the pollen germination rate. The optimal culture medium to promote pollen tube growth of Oil Tea Y3 was: 1% agar, 150 g·L-1 sucrose, 0.15 g·L-1 H3BO3, 0.07 g·L-1 MgSO4, and 0.01 g·L-1 IAA. The results of this paper may provide information for foliar application of Mg and IAA, which can improve pollen tube growth of Oil Tea in practice.


Assuntos
Pólen , Polinização , China , Meios de Cultura , Germinação , Chá
6.
Ecotoxicol Environ Saf ; 214: 112105, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33690003

RESUMO

Eusocial Apis mellifera colonies depend on queen longevity and brood viability to survive, as the queen is the sole reproductive individual and the maturing brood replenishes the shorter-lived worker bees. Production of many crops rely on both pesticides and bee pollination to improve crop quantity and quality, yet sublethal impacts of this pesticide exposure is often poorly understood. We investigated the resiliency of queens and their brood after one month of sublethal exposure to field relevant doses of pesticides that mimic exposure during commercial pollination contracts. We exposed full size colonies to pollen contaminated with field-relevant doses of the fungicides (chlorothalonil and propicanizole), insecticides (chlorypyrifos and fenpropathrin) or both, noting a significant reduction in pollen consumption in colonies exposed to fungicides compared to control. While we found no difference in the total amount of pollen collected per colony, a higher proportion of pollen to non-pollen foragers was detected in all pesticide exposed colonies. After ceasing treatments, we measured brood development, discovering a significant increase in brood loss and/or cannibalism across all pesticide exposed groups. Sublethal pesticide exposure in general was linked to reduced production of replacement workers and a change in protein acquisition (pollen vs. non-pollen foraging). Fungicide exposure also resulted in increased loss of the reproductive queen.


Assuntos
Abelhas/efeitos dos fármacos , Clorpirifos/toxicidade , Fungicidas Industriais/toxicidade , Inseticidas/toxicidade , Nitrilos/toxicidade , Pólen , Piretrinas/toxicidade , Triazóis/toxicidade , Animais , Abelhas/fisiologia , Feminino , Polinização , Reprodução/efeitos dos fármacos
7.
Ecol Lett ; 24(4): 668-675, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33524201

RESUMO

Pollinator declines in agricultural landscapes are driven by multiple stressors, but potential interactions of these remain poorly studied. Using a highly replicated semi-field study with 56 mesocosms of varying wild plant diversity (2-16 species) and oilseed rape treated with a neonicotinoid, we tested the interacting effects of resource diversity and insecticides on reproduction of a solitary wild bee. Compared to mesocosms with oilseed rape monocultures, availability of resources from wild plants complementing oilseed rape doubled brood cell production. In addition, bee reproduction increased due to plant diversity and identity effects. Exposure to neonicotinoid-treated oilseed rape reduced bee larval to adult development by 69%, but only in mesocosms with oilseed rape monocultures. Availability of complementary flower resources can thus offset negative effects of neonicotinoid-treated oilseed rape on wild bee reproduction. Policy should encourage the implementation of diverse floral resources mitigating negative effects of crop monocultures and insecticides, thereby sustaining solitary bee populations in agricultural landscapes.


Assuntos
Inseticidas , Animais , Abelhas , Produtos Agrícolas , Inseticidas/toxicidade , Neonicotinoides , Polinização , Reprodução
8.
Am J Bot ; 108(2): 216-235, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33576061

RESUMO

With more than 200 species, the genus Agave is one of the most interesting and complex groups of plants in the world, considering for instance its great diversity and adaptations. The adaptations include the production of a single, massive inflorescence (the largest among plants) where after growing for many years, sometimes more than 30, the rosette dies shortly afterward, and the remarkable coevolution with their main pollinators, nectarivorous bats, in particular of the genus Leptonycteris. The physiological adaptations of Agave species include a photosynthetic metabolism that allows efficient use of water and a large degree of succulence, helping to store water and resources for their massive flowering event. Ecologically, the agaves are keystone species on which numerous animal species depend for their subsistence due to the large amounts of pollen and nectar they produce, that support many pollinators, including bats, perching birds, hummingbirds, moths, and bees. Moreover, in many regions of Mexico and in the southwestern United States, agaves are dominant species. We describe the contributions of H. S. Gentry to the understanding of agaves and review recent advances on the study of the ecology and evolution of the genus. We analyze the present and inferred past distribution patterns of different species in the genus, describing differences in their climatic niche and adaptations to dry conditions. We interpret these patterns using molecular clock data and phylogenetic analyses and information of their coevolving pollinators and from phylogeographic, morphological, and ecological studies and discuss the prospects for their future conservation and management.


Assuntos
Agave , Animais , Abelhas , Ecologia , México , Filogenia , Polinização , Sudoeste dos Estados Unidos
9.
Ecotoxicol Environ Saf ; 212: 112015, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33561775

RESUMO

Osmia excavata is an important pollinator in commercial fruit orchards. Little information has been published about ecotoxicity to O. excavata, especially the larvae. To clarify the risk of commonly used insecticides with different modes of action to the larvae of O. excavata, six insecticides (clothianidin, acetamiprid, sulfoxaflor, lambda-cyhalothrin, chlorfenapyr and abamectin) were selected for evaluation of their acute lethal toxicity and sublethal effects. Clothianidin and abamectin were the two most toxic insecticides to the larvae of O. excavata with LD50 values of 0.007 (0.006-0.008) and 0.0004 (0.0003-0.0006) µg active ingredient (a.i.) bee-1, respectively. And their ecological risks were high according to the hazard quotient values (HQ > 2500). Sulfoxaflor was identified as the only safe insecticide for O. excavata (HQ < 50) under field conditions. Sublethal toxicity tests showed that larval weight was significantly decreased by ingesting food treated with clothianidin, lambda-cyhalothrin and abamectin (less than the maximum field registered concentrations on fruit trees) due to interference with consumption per larva and reduction of the efficiency of conversion of ingested food. Additionally, above three insecticides significantly prolonged larval developmental duration before cocooning and decreased eclosion rate. Overall, there results suggested that clothianidin and abamectin should not be applied, especially during the flowering phase, the application frequency of lambda-cyhalothrin should be minimized for the purpose of conserving O. excavata. Our results provided important evidences for selecting appropriate insecticides for use in fruit orchards.


Assuntos
Abelhas/efeitos dos fármacos , Inseticidas/toxicidade , Larva/efeitos dos fármacos , Animais , Abelhas/crescimento & desenvolvimento , Produtos Agrícolas/crescimento & desenvolvimento , Relação Dose-Resposta a Droga , Ecotoxicologia , Guanidinas/toxicidade , Dose Letal Mediana , Neonicotinoides/toxicidade , Nitrilos/toxicidade , Polinização , Piretrinas/toxicidade , Piridinas/toxicidade , Medição de Risco , Compostos de Enxofre/toxicidade , Tiazóis/toxicidade
10.
Ecotoxicol Environ Saf ; 212: 112008, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33578129

RESUMO

Pollutants can have severe detrimental effects on insects, even at sublethal doses, damaging developmental and cognitive processes involved in crucial behaviours. Agrochemicals have been identified as important causes of pollinator declines, but the impacts of other anthropogenic compounds, such as metallic trace elements in soils and waters, have received considerably less attention. Here, we exposed colonies of the European honey bee Apis mellifera to chronic field-realistic concentrations of lead in food and demonstrated that consumption of this trace element impaired bee cognition and morphological development. Honey bees exposed to the highest of these low concentrations had reduced olfactory learning performances. These honey bees also developed smaller heads, which may have constrained their cognitive functions as we show a general relationship between head size and learning performance. Our results demonstrate that lead pollutants, even at trace levels, can have dramatic effects on honey bee cognitive abilities, potentially altering key colony functions and the pollination service.


Assuntos
Abelhas/efeitos dos fármacos , Comportamento Animal/efeitos dos fármacos , Poluentes Ambientais/toxicidade , Chumbo/toxicidade , Reversão de Aprendizagem/efeitos dos fármacos , Animais , Abelhas/fisiologia , Cefalometria , Cognição/efeitos dos fármacos , Relação Dose-Resposta a Droga , Cabeça/anatomia & histologia , Polinização
11.
Oecologia ; 195(3): 751-758, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33566166

RESUMO

Temporal dynamics of plant-pollinator interactions inform the mechanisms of community assembly and stability. However, most studies on the dynamics of pollination networks do not consider plant reproductive traits thus offering poor understanding of the mechanism of how networks maintain stable structure under seasonal changes in flower community. We studied seasonal dynamics of pollination networks in a subtropical monsoon forest in China with a clear rainy season (April-September) and dry season (October-March) over 2 consecutive years. We constructed dioecy-ignored networks (combining visitations to dioecious male and female plants by ignoring the difference between dioecious and hermaphroditic plants) and dioecy-considered networks (excluding those visitations that only occurred either on dioecious male or female plants) for eight sampling sessions for each season. Although flower richness and flower abundance were higher in the rainy season than in the dry season, no pronounced seasonal difference was found in network specialization, nestedness and modularity for both networks. There were only significant differences in plant community robustness and pollinator specialization between seasons for dioecy-considered networks but not for dioecy-ignored networks. Furthermore, we found the flower abundance of dioecious and hermaphrodite plants mostly showed trade-off variation between rainy and dry seasons. Our results suggest various plant reproductive traits affect the temporal dynamics of pollination networks, which should be considered for conservation of plant-pollinator interactions in forest communities.


Assuntos
Melhoramento Vegetal , Polinização , Animais , China , Ecossistema , Feminino , Flores , Florestas , Insetos , Masculino , Estações do Ano
12.
J Vis Exp ; (167)2021 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-33554968

RESUMO

Researchers often collect and analyze corbicular pollen from honey bees to identify the plant sources on which they forage for pollen or to estimate pesticide exposure of bees via pollen. Described herein is an effective pollen-trapping method for collecting corbicular pollen from honey bees returning to their hives. This collection method results in large quantities of corbicular pollen that can be used for research purposes. Honey bees collect pollen from many plant species, but typically visit one species during each collection trip. Therefore, each corbicular pollen pellet predominantly represents one plant species, and each pollen pellet can be described by color. This allows the sorting of samples of corbicular pollen by color to segregate plant sources. Researchers can further classify corbicular pollen by analyzing the morphology of acetolyzed pollen grains for taxonomic identification. These methods are commonly used in studies related to pollinators such as pollination efficiency, pollinator foraging dynamics, diet quality, and diversity. Detailed methodologies are presented for collecting corbicular pollen using pollen traps, sorting pollen by color, and acetolyzing pollen grains. Also presented are results pertaining to the frequency of pellet colors and taxa of corbicular pollen collected from honey bees in five different cropping systems.


Assuntos
Abelhas/fisiologia , Pólen/fisiologia , Manejo de Espécimes/métodos , Ácido Acético/química , Animais , Polinização , Coloração e Rotulagem
13.
Sci Total Environ ; 767: 144913, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33636787

RESUMO

The biodiversity of insects is threatened worldwide. Numerous studies have reported the serious decline in insects that has occurred in recent decades. The same is happening with the important group of pollinators, with an essential utility for pollination of crops. Loss of insect diversity and abundance is expected to provoke cascading effects on food webs and ecosystem services. Many authors point out that reductions in insect abundance must be attributed mainly to agricultural practices and pesticide use. On the other hand, evidence for the effects of non-thermal microwave radiation on insects has been known for at least 50 years. The review carried out in this study shows that electromagnetic radiation should be considered seriously as a complementary driver for the dramatic decline in insects, acting in synergy with agricultural intensification, pesticides, invasive species and climate change. The extent that anthropogenic electromagnetic radiation represents a significant threat to insect pollinators is unresolved and plausible. For these reasons, and taking into account the benefits they provide to nature and humankind, the precautionary principle should be applied before any new deployment (such 5G) is considered.


Assuntos
Ecossistema , Polinização , Animais , Biodiversidade , Produtos Agrícolas , Radiação Eletromagnética , Insetos
14.
Nat Commun ; 12(1): 718, 2021 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-33531484

RESUMO

Ficus (figs) and their agaonid wasp pollinators present an ecologically important mutualism that also provides a rich comparative system for studying functional co-diversification throughout its coevolutionary history (~75 million years). We obtained entire nuclear, mitochondrial, and chloroplast genomes for 15 species representing all major clades of Ficus. Multiple analyses of these genomic data suggest that hybridization events have occurred throughout Ficus evolutionary history. Furthermore, cophylogenetic reconciliation analyses detect significant incongruence among all nuclear, chloroplast, and mitochondrial-based phylogenies, none of which correspond with any published phylogenies of the associated pollinator wasps. These findings are most consistent with frequent host-switching by the pollinators, leading to fig hybridization, even between distantly related clades. Here, we suggest that these pollinator host-switches and fig hybridization events are a dominant feature of fig/wasp coevolutionary history, and by generating novel genomic combinations in the figs have likely contributed to the remarkable diversity exhibited by this mutualism.


Assuntos
Ficus/fisiologia , Vespas/fisiologia , Animais , Evolução Biológica , Hibridização Genética , Filogenia , Polinização/fisiologia , Simbiose/fisiologia
15.
Environ Sci Pollut Res Int ; 28(14): 17573-17586, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33403629

RESUMO

Water is essential for honey bees (Apis mellifera L.), but contaminated sources of water in agricultural environments represent a risk of exposure to potentially harmful contaminants. Providing clean water to honey bees could be an efficient and cost-effective measure for beekeepers to reduce bee mortality associated with pesticides and improve the health of their colonies. The main goal of this study was to design a waterer prototype to fulfill the water requirements of honey bees and to evaluate the potential of this waterer in improving colonies' health in agricultural settings, through mitigating the possible impact of an exposure to pesticides from puddle water. We tested the preference of honey bees regarding water composition and waterer prototypes, among which honey bees showed a strong preference for salted water and a poultry-type waterer. Our waterer models were quickly adopted and intensively used through the season in both the context of honey production in field crops and pollination services in cranberry crops. However, in neither context did the use of waterers reduce worker mortality nor increase overall colony weight. Our waterers provided bees with water containing fewer pesticides and were associated with reduced risks of drowning compared to natural sources of water. Our study suggests that the use of waterers fulfills an important requirement for honey bees and represents an interesting and convenient precautionary measure for beekeepers.


Assuntos
Mel , Inseticidas , Praguicidas , Agricultura , Animais , Abelhas , Produtos Agrícolas , Inseticidas/análise , Neonicotinoides , Polinização
16.
Planta ; 253(1): 19, 2021 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-33394122

RESUMO

In flowering plants, pollen germination on the stigma and pollen tube growth in pistil tissues are critical for sexual plant reproduction, which are involved in the interactions between pollen/pollen tube and pistil tissues. GPI-anchored proteins (GPI-APs) are located on the external surface of the plasma membrane and function in various processes of sexual plant reproduction. The evidences suggest that GPI-APs participate in endosome machinery, Ca2+ oscillations, the development of the transmitting tract, the maintenance of the integrity of pollen tube, the enhancement of interactions of the receptor-like kinase (RLK) and ligand, and guidance of the growth of pollen tube, and so on. In this review, we will summarize the recent progress on the roles of GPI-APs in the interactions between pollen/pollen tube and pistil tissues during pollination, such as pollen germination on the stigma, pollen tube growth in the transmitting tract, pollen tube guidance to the ovule, and pollen tube reception in the embryo sac. We will also discuss the future outlook of GPI-APs in the interactions between pollen/pollen tube and pistil tissues.


Assuntos
Flores , Proteínas Ligadas por GPI , Proteínas de Plantas , Tubo Polínico , Flores/metabolismo , Proteínas Ligadas por GPI/metabolismo , Óvulo Vegetal/metabolismo , Proteínas de Plantas/metabolismo , Tubo Polínico/metabolismo , Polinização/fisiologia , Pesquisa/tendências
17.
Gene ; 776: 145446, 2021 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-33484761

RESUMO

Bumblebees are important pollinators that have evolved between solitary and advanced eusocial insects. Compared with advanced honeybees, workers of social bumblebee species are prone to laying eggs during the competition phase, which leads to the end of the colony. Therefore, worker reproductive behavior has become a popular research topic for exploring various biological phenomena. Here, we demonstrate a novel reproduction-related function of an immune response protein-encoding gene (Immune Responsive Protein 30, IRP30) in Bombus terrestris by employing RNA interference (RNAi) and a transgenic Drosophila melanogaster system. The results show that worker egg-laying was significantly affected by IRP30 expression levels (P < 0.01). Compared with those in the dsGFP-treated groups, the first egg-laying time was delayed by 3.7 d and the egg number was decreased by 41% in the dsIRP30-treated group. In addition, the average size of the largest oocyte and the relative mRNA expression levels of Vg (vitellogenin) were significantly reduced in the dsIRP30-treated group (P < 0.05). Cellular localization by immunofluorescence demonstrated that IRP30 has important functions in the germ cells of workers' ovarioles. Overexpression of IRP30 was confirmed to increase the reproductive capability of the transgenic D. melanogaster. In conclusion, IRP30 regulates worker egg-laying by affecting the expression of Vg, the size of the ovary and the formation of the oocyte. These findings provide essential information for understanding the mechanisms underlying worker reproductive regulation.


Assuntos
Abelhas/genética , Abelhas/metabolismo , Reprodução/genética , Animais , Animais Geneticamente Modificados/genética , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Feminino , Expressão Gênica/genética , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Ovário/metabolismo , Oviposição , Óvulo/metabolismo , Polinização , Reprodução/fisiologia , Comportamento Sexual Animal/fisiologia , Vitelogeninas/genética
18.
Ecotoxicol Environ Saf ; 211: 111869, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33450537

RESUMO

Solitary bees are among the most important pollinators worldwide however population declines especially in croplands has been noticed. The novel pesticide sulfoxaflor is a competitive modulator of nicotinic acetylcholine receptors (nAChR) in insects. While there is evidence of a negative impact of neonicotinoids on bees of several social organization levels, our overall knowledge on the impact of sulfoxaflor on bees is poor. Here we present for the first time a study showing effects of field realistic doses of sulfoxaflor on solitary bees. Bees submitted to long term exposure of field realistic doses of sulfoxaflor (5 µg dm-3, 10 µg dm-3, 50 µg dm-3) and control were observed regarding their survival rate. Moreover, we recorded metrics related to flower visitation and flight performance. We discover that the highest field realistic dose is lethal to Osmia bicornis along five days of exposure. The effect of sulfoxaflor reduces the outcome of foraging, important features for fruit and seed production of cross-pollinated plant species. Bees exposed to pesticide visited flowers mostly walking rather than flying. Flight performance was also impaired by the pesticide.


Assuntos
Abelhas/fisiologia , Inseticidas/toxicidade , Animais , Comportamento Alimentar/efeitos dos fármacos , Flores/efeitos dos fármacos , Neonicotinoides/toxicidade , Praguicidas/toxicidade , Polinização/efeitos dos fármacos , Piridinas , Compostos de Enxofre , Taxa de Sobrevida
19.
20.
Ecotoxicol Environ Saf ; 208: 111681, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396013

RESUMO

Analysis of particulate matter originating from beef cattle feed yards on the High Plains of the United States has revealed occurrence of multiple pesticides believed to potentially impact non-Apis pollinators. Among these pesticides are those that are highly toxic to Apis mellifera (honey bees). However, little non-Apis bee species toxicity data exist; especially pertaining to beef cattle feed yard-derived pesticides. Therefore, we conducted a series of 96-h contact toxicity tests with blue orchard mason bees (Osmia lignaria) using three neonicotinoids, two pyrethroids, and two macrocyclic lactones. Neonicotinoids (thiamethoxam, imidacloprid, and clothianidin) were most toxic with LD50 values ranging from 2.88 to 26.35 ng/bee, respectively. Macrocyclic lactones (abamectin and ivermectin) were also highly toxic to O. lignaria with LD50 estimates of 5.51-32.86 ng/bee. Pyrethroids (permethrin and bifenthrin) were relatively less toxic with LD50 values greater than 33 ng/bee. Sensitivity ratios for each pesticide were calculated to relate O. lignaria LD50 values to existing honey bee toxicity data. All three neonicotinoids were more toxic to O. lignaria than A. mellifera, but pyrethroids and abamectin were relatively less toxic. Additionally, three of seven pesticides (43%) resulted in significantly different mass normalized LD50 values for male and female O. lignaria. These results indicate that non-Apis pollinators may be highly susceptible to pesticides originating from beef cattle feed yards, necessitating consideration of more stringent regulatory protections than those based on A. mellifera pesticide sensitivity.


Assuntos
Abelhas/efeitos dos fármacos , Lactonas/toxicidade , Compostos Macrocíclicos/toxicidade , Neonicotinoides/toxicidade , Praguicidas/toxicidade , Piretrinas/toxicidade , Animais , Relação Dose-Resposta a Droga , Feminino , Dose Letal Mediana , Masculino , Modelos Teóricos , Polinização/efeitos dos fármacos , Testes de Toxicidade Aguda
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