Honeybees (Apis mellifera L.) are the major insect pollinators of many different crops. A drastic decline in the honey bee populations has been reported over the past decade. While many factors have contributed to this decline, pesticides, poor nutrition, and Varroa mites are the most common concerns noted by scientists and beekeepers. Aside from direct toxicity from pesticides, it has been observed that sublethal pesticide doses have effects on honey bee physiology and behavior such as oxidative stress, disruption of foraging and homing, and changes to honey bee neurophysiology. The primary objectives of this project were to examine honey bee gut microbiome, physiology, and pesticide exposure along an agricultural intensification gradient and to examine the interactive impacts of pesticide exposure and poor nutrition on honey bees in a controlled laboratory cage setting. Sixteen honey bee colonies were placed in four locations across Mississippi with varying degrees of natural forage availability.

Made available in DSpace on 2014-06-11T19:32:58Z (GMT). No. of bitstreams: 0 Previous issue date: 2005-08Bitstream added on 2014-06-13T19:22:54Z : No. of bitstreams: 1 arauco_emr_dr_botfmvz.pdf: 810943 bytes, checksum: 6acc5913059689bd4615fef648271508 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Universidade Estadual Paulista (UNESP) / O néctar é coletado pelas operárias coletoras e transportado em sua vesícula nectarífera para a colméia. Durante a sua transformação em mel, o néctar recebe enzimas provenientes das glândulas hipofaringeanas, as quais atuam em seu processamento. A invertase é uma das enzimas adicionadas ao néctar e promove a inversão da sacarose em frutose e glicose. Com o objetivo de se conhecer o pH ideal dessa enzima nas abelhas operárias foram extraídas as glândulas hipofaringeanas de abelhas com oito dias de idade. O método utilizado para a dosagem da invertase foi o do ácido 3-5þ dinitrosalicílico (DNS) para determinação de açúcares redutores, utilizando-se medida de leitura espectrofotométrica em absorbância da glicose em comprimento de onda (?) igual a 540nm. De acordo com os resultados, verificou-se que a atividade catalítica da enzima foi mais eficiente no pH 5,0 e em 40 minutos de reação em comparação com outros valores de pH e tempos de reação. Não foi possível a reutilização das glândulas. Desta forma, concluiu-se que a enzima invertase aumentou sua eficiência em função do tempo de reação de forma linear e significativa em pH 5,0. / The nectar is collected by the collecting workers that carry it in its nectar gallbladder to the beehive. During its transformation in honey, the nectar receives enzymes proceeding from the hypopharyngeal glands, which act in its processing. Invertase is one of enzymes added to the nectar and promotes the inversion of sacarose in fructose and glucose. With the aim of knowing the ideal pH, in the worker bees, the bee's hypopharyngeal glands with eight days of age had been extracted. The used method, for the dosage of invertase, had been the 3-5 ' dinitrosalisilic acid for determination of reducing sugars, using absorbance spectrophotometry data from the glucose in ? equal to 540nm. According to the results, it had been verified that the enzyme catalytic activity had been more efficient in pH 5,0 and in 40 minutes of reaction, comparing to other pH values and times of reaction. The glands reuse had not been possible. At this way, it was concluded that the invertase enzyme had increased its efficiency by the reaction time at linear and significant way in pH 5,0.

Submitted by Claudia Rocha (claudia.rocha@udesc.br) on 2018-02-26T14:27:28Z No. of bitstreams: 1 PGPV16MA198.pdf: 1078885 bytes, checksum: d8fc297fd799d14486911861079a1a6c (MD5) / Made available in DSpace on 2018-02-26T14:27:28Z (GMT). No. of bitstreams: 1 PGPV16MA198.pdf: 1078885 bytes, checksum: d8fc297fd799d14486911861079a1a6c (MD5) Previous issue date: 2016-07-29 / Capes / This study aimed to evaluate the behavior and health of hives of honeybees (Apis mellifera) used in pollination services in apple orchards in the municipality of Vacaria, RS. Conducted under the conventional production system. For that were evaluated during two consecutive seasons (2014/15 and 2015/16), the behavior of bees in the collection of flowers resources during the pollination period (09/23/14 to 10/20/14 – crop season 2014 / 15, 09.02.15 and 15.10.15 and between 2015/16 crop season), the occurrence of parasitism by Varroa destructor mites and infections caused by Nosema sp. areas of stored features, and areas of immature hives and A. mellifera used in the pollination of apple orchards. In the course of experiments, the hives had activities during evaluations with an average of 27.5 to 40.8’ bees observed in five minutes. Regardless of the place of origin of the hives or evaluation harvest, the nectar was the preferred feature by bees. It was found that 95% of the bees have sought nectar while only 5% of the search effected pollen. In both crops, beehives used had average ranging from 3.0 to 6.7% of parasitism by V. destructor. There was an increase in parasitism levels in the period of pollination, in high population hives, since hives with smaller populations have not followed the same behavior. The presence of spores Nosema sp. It was noted only in hives used in the harvest of 2014/15, and did not occur in the harvest of 2015/16. There are significant variations in the internal areas of stored resources and areas of immature of hives used for pollination of apple trees services, these related to places of origin, before the entry of the swarms in the orchards. It is that coming from places with large supply of resources are the most affected by the stay in the orchard. which they suffered decreases in the internal space of the hives by the withdrawal of nests in preparation for the stay in the orchards. This fact led to numerous swarming bees reflecting in food reserves and population status. / O presente estudo objetivou avaliar o comportamento e a sanidade de colmeias da abelha melífera (Apis mellifera) utilizadas em serviços de polinização em pomares de macieiras no município de Vacaria, RS. Conduzidos sob o sistema convencional de produção. Foram avaliados, no decorrer de duas safras consecutivas (2014/15 e 2015/16), o comportamento das abelhas na coleta de recursos florais no decorrer do período de polinização (23/09/14 a 20/10/14 - safra 2014/15, e entre 02/09/15 e 15/10/15 - safra 2015/16), a ocorrência de parasitismo pelo ácaro Varoa destructor e infecções causadas por Nosema sp., áreas de recursos armazenados, e áreas de imaturos em colmeias e de A. mellifera utilizadas na polinização de pomares macieiras. No decorrer do presente experimento as colmeias apresentavam atividades durante as avaliações com média de 27.5 a 40.8 abelhas observadas em cinco minutos. Independentemente do local de origem das colmeias ou safra de avaliação, o néctar foi o recurso preferido pelas abelhas. Foi verificado que 95% das abelhas buscaram o néctar enquanto apenas 5% efetuaram a busca de pólen. Em ambas as safras, as colmeias utilizadas apresentaram médias que variam de 8 3,0 a 6,7 % de parasitismo por V. destructor. Houve aumento nos níveis de parasitismo no período da polinização, em colmeias com alta população, já colmeias com populações menores não seguiram o mesmo comportamento. A presença de esporos de Nosema sp. foi constata apenas em colmeias utilizadas na safra de 2014/15, e não ocorreu na safra de 2015/16. Há variações significativas nas áreas internas de recursos armazenados e áreas de imaturos das colmeias utilizadas em serviços de polinização de macieiras, estas ligadas aos locais de origem, antes da entrada dos enxames nos pomares. Sendo que os vindos de locais com grande oferta de recursos são os mais prejudicados pela estada no pomar, os quais sofreram pelas diminuições no espaço internos das colmeias pela retirada de sobre ninhos em preparação para a estadia nos pomares. Fato que levou a inúmeras enxameações, refletindo nas reservas de alimentos e estado populacional

Resumo: O néctar é coletado pelas operárias coletoras e transportado em sua vesícula nectarífera para a colméia. Durante a sua transformação em mel, o néctar recebe enzimas provenientes das glândulas hipofaringeanas, as quais atuam em seu processamento. A invertase é uma das enzimas adicionadas ao néctar e promove a inversão da sacarose em frutose e glicose. Com o objetivo de se conhecer o pH ideal dessa enzima nas abelhas operárias foram extraídas as glândulas hipofaringeanas de abelhas com oito dias de idade. O método utilizado para a dosagem da invertase foi o do ácido 3-5þ dinitrosalicílico (DNS) para determinação de açúcares redutores, utilizando-se medida de leitura espectrofotométrica em absorbância da glicose em comprimento de onda (?) igual a 540nm. De acordo com os resultados, verificou-se que a atividade catalítica da enzima foi mais eficiente no pH 5,0 e em 40 minutos de reação em comparação com outros valores de pH e tempos de reação. Não foi possível a reutilização das glândulas. Desta forma, concluiu-se que a enzima invertase aumentou sua eficiência em função do tempo de reação de forma linear e significativa em pH 5,0. / Abstract: The nectar is collected by the collecting workers that carry it in its nectar gallbladder to the beehive. During its transformation in honey, the nectar receives enzymes proceeding from the hypopharyngeal glands, which act in its processing. Invertase is one of enzymes added to the nectar and promotes the inversion of sacarose in fructose and glucose. With the aim of knowing the ideal pH, in the worker bees, the bee's hypopharyngeal glands with eight days of age had been extracted. The used method, for the dosage of invertase, had been the 3-5 ' dinitrosalisilic acid for determination of reducing sugars, using absorbance spectrophotometry data from the glucose in ? equal to 540nm. According to the results, it had been verified that the enzyme catalytic activity had been more efficient in pH 5,0 and in 40 minutes of reaction, comparing to other pH values and times of reaction. The glands reuse had not been possible. At this way, it was concluded that the invertase enzyme had increased its efficiency by the reaction time at linear and significant way in pH 5,0. / Orientador: Sílvia Regina Cunha Funari / Coorientador: Carlos Ducatti / Doutor

Identifying the resources that limit bee populations is essential both for bee conservation and pollination management in agroecosystems. Land-use change typically leads to decreased habitat availability for wild pollinators including loss of nesting habitat, which is an essential but often-overlooked resource for wild bees. Cavity-nesting bees, such as many Osmia spp. (Hymenoptera: Megachilidae), occupy holes in wood or reeds to build their nests; due to their nesting habits, they are frequently scarce in agricultural settings, although, under the right circumstances, these bees can be ideal pollinators of apple and other orchard crops. Artificial nesting structures (“bee hotels”, “trap nests”, or “nest boxes”) are used to study cavity-nesting bees and have been posited as solutions for promoting bee conservation. To evaluate the effects of additional nesting habitat on the local abundance of Osmia spp., and on bees more generally, artificial nesting structures for cavity-nesting bees were installed at 24 sites in apple orchards around Ottawa in 2021 and 2022. Each site had two treatments: one with nest boxes, and one without (control). Transect walks were conducted to measure overall bee contact (including contact by Osmia spp.) with apple blossoms and, after the end of apple bloom, with flowers in the undergrowth and/or in shrubs. Numbers of apple buds and developing fruit were also recorded. Osmia spp. and overall bee numbers were both significantly higher in the treatment with nest boxes (44% and 15% higher, respectively, in 2021, and 113% and 47% higher, respectively, in 2022); however, there was no difference in fruit set (apple count/bud count) between the two treatments. Thus, nest boxes seem to locally increase Osmia spp. numbers as well as total bee numbers, but they have no apparent effect on apple yield, likely because apple production was not pollinator limited in the years of this study. These findings suggest that bee populations in apple orchards are limited by nesting resources, which has important implications for orchard management practices and bee conservation policy.

This project examined multiple aspects of the reproductive biology of the wetland invasive species, purple loosestrife (<i>Lythrum salicaria</i> L.), in central Saskatchewan. An examination of insect taxa visiting the three floral morphs of <i>Tristylous</i> L. <i>salicaria</i>, as well as a ranking of the pollination efficiency of individual insect species, an apparent first for L salicaria, was undertaken. Surface features of the floral nectary of L. <i>salicaria</i>, as well as floral nectar secretion dynamics, were also investigated. This project also re-visited some of the previous work done on this invasive species, including various floral organ morphometrics in relation to heterostyly, and aspects of the tristylous breeding system including self-fertilization, and fertilization potential of both illegitimate pollination and legitimate pollination.<p>The trimorphic nature of the sexual floral organs of L. <i>salicaria</i> were well defined in Saskatchewan. Significant differences in length (long-, intermediate- and short-style lengths) exist between all three floral morphs. Lengths of the staminal filaments (long, intermediate, and short) were also significantly different. Also the floral nectary in L. <i>salicaria</i> is located in a depression formed at the interface of the hypanthium and the gynoecium. Several stomata are located at regular intervals along the nectary surface, and may constitute the escape route for floral nectar. No morphological differences in nectary structure were apparent among the three floral morphs.<p>Nectar secretion dynamics of L. <i>salicaria</i> were examined between the three floral morphs throughout two summer days in 2006. Peak average nectar volumes and nectar sugar quantities were detected at 3:00 pm, and, interestingly, no significant differences were detected between floral morphs, in accordance with nectary morphology. The estimated secretion rates for L. <i>salicaria</i> ranged from 61 83 µg of nectar sugar per flower per hour.<p>Hand-pollination experiments carried out over the summers of 2006 and 2007 at three field sites in and around Saskatoon have verified the strong self-incompatibility in the breeding system of this tristylous species. Intramorph pollination, using illegitimate pollen, did not result in fertilisation, whereas legitimate hand-pollination experiments yielded multiple pollen tubes at the style base, without exception.<p><i>Lythrum salicaria</i> in central Saskatchewan was visited by several bee taxa including honeybees (<i>Apis mellifera</i> L.), bumblebees (Bombus spp.), leafcutter bees (Megachile spp.), and sweat bees (Lasioglossum spp.). A single visit by <i>Anthophora furcata</i> (Panzer) was also recorded in 2007. Generally, bee visits led to high levels of pollination success as determined by fluorescence microscopy of pollen tubes following single insect visits to previously-unvisited flowers. However, most visits by hoverflies (Syrphidae) were non-pollinating. Visits by Pieris rapae (L.), yellowjacket wasps (Vespidae) and some non-syrphid flies (Diptera) also yielded no pollen tubes at the style base.<p>A study of the ultrastructure and development of the floral nectary of the purple loosestrife cultivar Morden Gleam (<i>Lythrum virgatum</i> L. x L. alatum Pursh.) showed that starch build up in pre-secretory nectary tissues declined throughout secretion, and is virtually absent in post-secretory nectary tissues. The lack of a direct vascular supply to the floral nectary suggests that the starch breakdown products likely make up most of the floral nectar carbohydrates. Surface features of the floral nectary in Morden Gleam closely resembled those of L. salicaria, located in the valley formed between the hypanthium and gynoecium. Nectary stomata, occasionally in pairs, likely serve as outlets for nectar in this cultivar.

This project examined multiple aspects of the reproductive biology of the wetland invasive species, purple loosestrife (<i>Lythrum salicaria</i> L.), in central Saskatchewan. An examination of insect taxa visiting the three floral morphs of <i>Tristylous</i> L. <i>salicaria</i>, as well as a ranking of the pollination efficiency of individual insect species, an apparent first for L salicaria, was undertaken. Surface features of the floral nectary of L. <i>salicaria</i>, as well as floral nectar secretion dynamics, were also investigated. This project also re-visited some of the previous work done on this invasive species, including various floral organ morphometrics in relation to heterostyly, and aspects of the tristylous breeding system including self-fertilization, and fertilization potential of both illegitimate pollination and legitimate pollination.<p>The trimorphic nature of the sexual floral organs of L. <i>salicaria</i> were well defined in Saskatchewan. Significant differences in length (long-, intermediate- and short-style lengths) exist between all three floral morphs. Lengths of the staminal filaments (long, intermediate, and short) were also significantly different. Also the floral nectary in L. <i>salicaria</i> is located in a depression formed at the interface of the hypanthium and the gynoecium. Several stomata are located at regular intervals along the nectary surface, and may constitute the escape route for floral nectar. No morphological differences in nectary structure were apparent among the three floral morphs.<p>Nectar secretion dynamics of L. <i>salicaria</i> were examined between the three floral morphs throughout two summer days in 2006. Peak average nectar volumes and nectar sugar quantities were detected at 3:00 pm, and, interestingly, no significant differences were detected between floral morphs, in accordance with nectary morphology. The estimated secretion rates for L. <i>salicaria</i> ranged from 61 83 µg of nectar sugar per flower per hour.<p>Hand-pollination experiments carried out over the summers of 2006 and 2007 at three field sites in and around Saskatoon have verified the strong self-incompatibility in the breeding system of this tristylous species. Intramorph pollination, using illegitimate pollen, did not result in fertilisation, whereas legitimate hand-pollination experiments yielded multiple pollen tubes at the style base, without exception.<p><i>Lythrum salicaria</i> in central Saskatchewan was visited by several bee taxa including honeybees (<i>Apis mellifera</i> L.), bumblebees (Bombus spp.), leafcutter bees (Megachile spp.), and sweat bees (Lasioglossum spp.). A single visit by <i>Anthophora furcata</i> (Panzer) was also recorded in 2007. Generally, bee visits led to high levels of pollination success as determined by fluorescence microscopy of pollen tubes following single insect visits to previously-unvisited flowers. However, most visits by hoverflies (Syrphidae) were non-pollinating. Visits by Pieris rapae (L.), yellowjacket wasps (Vespidae) and some non-syrphid flies (Diptera) also yielded no pollen tubes at the style base.<p>A study of the ultrastructure and development of the floral nectary of the purple loosestrife cultivar Morden Gleam (<i>Lythrum virgatum</i> L. x L. alatum Pursh.) showed that starch build up in pre-secretory nectary tissues declined throughout secretion, and is virtually absent in post-secretory nectary tissues. The lack of a direct vascular supply to the floral nectary suggests that the starch breakdown products likely make up most of the floral nectar carbohydrates. Surface features of the floral nectary in Morden Gleam closely resembled those of L. salicaria, located in the valley formed between the hypanthium and gynoecium. Nectary stomata, occasionally in pairs, likely serve as outlets for nectar in this cultivar.

Made available in DSpace on 2014-06-11T19:22:59Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-04-25Bitstream added on 2014-06-13T20:10:19Z : No. of bitstreams: 1 jacob_cro_me_rcla.pdf: 1789232 bytes, checksum: 4d1aeb62cf1a6763869b8890da8b652a (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Recentemente as abelhas têm sido devidamente valorizadas como importantes polinizadoras de flores silvestres e cultivadas. A densidade populacional de muitos polinizadores tem diminuído devido, principalmente, à intensificação agrícola e ao uso de pesticidas, prejudicando os serviços de polinização. A metodologia clássica para estimar a toxicidade dos produtos químicos para insetos é determinar a dose letal média (DL50) ou a concentração letal média (CL50), podendo então estabelecer doses que sejam mais seguras aos organismos não-alvo ou benéficos. Além dos efeitos de toxicidade aguda, levando a morte das abelhas, doses subletais dos inseticidas podem provocar alterações comportamentais e fisiológicas nos indivíduos, que ao longo do tempo acarretarão em sérios prejuízos na manutenção da colônia. Um dos inseticidas amplamente utilizado é o fipronil, este atua ligando-se aos receptores do ácido gama-aminobutírico (GABA), interrompendo os canais de cloro, resultando na perda de sinalização inibitória neural. Na literatura pode-se encontrar diversos trabalhos que utilizam como modelo principal a abelha Apis mellifera, porém, é importante ressaltar a diversidade existente entre as abelhas nativas no Brasil, os meliponíneos, e sua participação na conservação da biodiversidade, assim como na polinização de áreas de cultivo, o que torna extremamente importante estudos com essa abelha. Com a finalidade de entender como o fipronil interfere morfo e fisiologicamente em abelhas sem ferrão, a região de interesse deste estudo foram os corpos pedunculados, já que estes são centros cerebrais complexos e tidos como local de convergência multisensorial. Para auxiliar no mapeamento metabólico, utilizou-se como marcador a enzima citocromo oxidase e a enzima caspase-3, técnicas utilizadas na observação de atividade neural... / A few decades the bees are considered an important indicator of high environmental sensitivity, and appreciated as important pollinators of wildflowers and cultivated. The population density of many pollinators have declined to harmful levels to pollination services manly due to agricultural intensification and the use of pesticides. The classic methodology of estimating the effects of chemicals for insects is to determine the median lethal dose (LD50) or median lethal concentration (LC50) that can then establish doses that do not harm non-target organisms or beneficial. Besides the effects of acute toxicity, leading to death bees, sublethal doses of insecticides can cause physiological and behavior changes of individuals over time, resulting in serious harm to maintain the colony. One of the widely used insecticides is fipronil, its acts by binding to gamma-aminobutyric acid (GABA) disrupting chloride channels, resulting in loss of inhibitory neural signaling. In the literature one can find several works using as main bee model Apis mellifera, however, it is important to highlight the diversity of Brazilian native bees, the stingless bees, and their participation in biodiversity conversation, as well as in the pollination of cultivated land. In order to understand how fipronil affect morpho and physiologically the stingless bee S. postica, the region of interest in this study were the mushroom bodies, since these are complex brain centers and used as a place of multisensory convergence. This work established the contact LD50 and Ingestion LC50 to the fipronil insecticide for foragers workers stingless bee Scaptotrigona postica in 0.54ng/bee and 0.24ng/μL of the food after 24 hours, respectively, confirming the high toxicity of this phenylpyrazole, in the groups submitted to contact contamination, were identify morphological... (Complete abstract click electronic access below)

RESUMO O trabalho foi desenvolvido em uma área de cerrado de 1 ha., localizada na Estação Ecológica de Jataí, no município de Luiz Antônio - SP. A fauna de abelhas e suas fontes de alimento foram amostradas quinzenalmente, durante dois anos de coletas (setembro de 1991 a agosto de 1993), foi estudada a sua composição, riqueza, abundância relativa, fenologia e visita às flores através de levantamentos padronizados. Foram coletados 3659 indivíduos, pertencentes a 142 espécies e a 57 gêneros de 6 famílias de Apoidea, sendo que Apidae foi a melhor representada em número de indivíduos e Anthophoridae em número de espécies. Com relação à fenologia, as espécies foram mais abundantes no período de menor precipitação (maio a novembro de 1992). As abelhas visitaram 72 espécies de plantas para a coleta de néctar, pólen e óleo. As famílias Asteraceae, Leguminosae e Bignoniaceae foram as melhores representadas em número de espécies. Didymopanax vinosum (Araliaceae) e Pyrostegia venusta (Bignoniaceae) foram as espéceis vegetais mais visitadas. Quanto à fenologia do florescimento, a maior diversidade de espécies de plantas floridas foi verificada no verão e outono; já no inverno, houve uma queda acentuada de espécies floridas. Estabeleceu-se como espécies dominantes de abelhas, aquelas que estiveram melhor representadas em número de indivíduos (Apis mellifera, Trigona hyalinata) e as espécies dominantes de plantas, aquelas que atraíram um número significativo de espécies de abelhas (Didymopanax vinosum, Pyrostegia venusta). Esses dados serviram para determinar os grupos de abelhas mais relacionados quanto às flores visitadas e os grupos de plantas mais semelhantes quanto aos visitantes. De um modo geral, os Apoidea mostraram-se generalistas na utilização de recursos, tendo sido encontrados em várias espécies de plantas. No entanto, algumas espécies de abelhas coletoras de óleo da família Anthophoridae (Centridini), mostraram preferência por flores de Byrsonima intermedia e Heteropterys byrsonimifolia (Malpighiaceae). / ABSTRACT The research was undertaken in a cerrado area (1 hectare) located at Estação Ecológica de Jataí, Luiz Antônio Municipality, São Paulo State, SE Brazil. Bees foranging for food on flowers were standardizedly sampled at every 15 days, for two years (September, 1991 to August, 1993). Host plants were sampled also. The study aims at an approach towards: faunal-floral composition, species richness, relative abundance, flower visiting habits, etc. Concerning bees, (Apoidea), 3659 individuals were collected which represent 142 species, 57 genera and 6 families. Among the collected families, Apidae representatives were the most abundant in number of individuals, while the Anthophoridae were top-ranked in number of collected species. Relatively to phenology, higher species-abundance peaks were connected to periods of less pluviosity, that is, from May to November, 1992. In their foraging for nectar, pollen and oil, sampled bees visited 72 plant species, among which Asteraceae, Leguminosae and Bignoniaceae were the best represent at specific level. Didymopanax vinosum (Araliaceae) and Pyrostegia venusta (Bignoniaceae) were the plants preferably visited. Concerning flowering phenology, flowers were most abundant during summer and autumm; conversely, winter-periods presented the lowest levels of flowering. Dominant bee species were considered as those best represented relatively to collected number of individuals (e.g., Apis mellifera, Trigona hyalinata). On the vegetation side, dominant plant species referes to those taxa which attracted the most significant number of bees (e.g., Didymopanax vinosum, Pyrostegia venusta). Such definitios were important to determine the connexions between bee groups-visited flowers; and, the relationships between plant groupsvisitors, as well. Since most species were found visiting several plant species, the sampled bees can be regarded as generalists, primarily. However, in their oil-collecting activity some Anthophoridae species (Centridini) showed remarkakle preferences relatively to Malpighiaceae flowers: Byrsonima intermedia and Heteropterys byrsonimifolia.

Diferenças no timing da melanização e esclerotização do exoesqueleto são evidentes quando se compara a morfologia externa de abelhas de hábitos sociais e as solitárias. A esta diferença convencionamos chamar de heterocronia da maturação cuticular, o termo heterocronia significando variações no tempo relativo, ou ritmo, de um evento ontogenético em relação ao ancestral ou entre taxons. Propusemos que as abelhas sociais, que após a ecdise permanecem na colônia por vários dias, alcançariam a maturidade de alguns sistemas orgânicos, entre eles o tegumento, muito mais tarde que as espécies de abelhas solitárias que ao emergir partem imediatamente para atividades extra-nidais. Neste contexto, o objetivo deste trabalho consistiu em testar esta hipótese utilizando o tegumento em maturação das espécies de abelhas sociais, Apis mellifera e Frieseomelitta varia, e da espécie solitária Centris analis, em estudos comparativos de expressão gênica, ultraestrutura e quantificação de hidrocarbonetos cuticulares (CHCs). Para isto utilizamos sequenciamento de mRNA (RNA-seq), microscopia eletrônica de transmissão (MET) e cromatografia de gás e espectrometria de massas (CG/MS). Os perfis de expressão de genes da via de melanização/esclerotização cuticular (ebony e tan) diferenciaram as espécies sociais da solitária, assim como a expressão de genes com função na via de metabolismo de quitina (Cda5, Idgf4 e chitooligosacchariodolytic-domain-like) e de genes codificadores de proteínas estruturais da cutícula (CPR14, CPR17, CPR18, CPR25, CPR23, CPR26, Apd-3 e Apd-like). Genes com função na regulação da maturação cuticular (FTZ-F1, E74, Hr46 e Hr4) se mostraram co-expressos nas espécies sociais e os perfis de expressão destes genes, exceto Hr46, e de outros reguladores (Ethr, Hr38, Rickets e Ptx-1) também diferenciaram as espécies sociais da solitária. Ressaltamos em nossas análises os genes do ciclo circadiano, cuja expressão tem relação com a deposição de quitina cuticular, além de genes de vias de pigmentação não melanínicas. As análises de MET, abrangendo outras três espécies de abelhas (Bombus brasilienses: primitivamente eussocial; Euglossa cordata: facultativamente social; Tetrapedia diversipes: solitária), mostraram diferenças consistentes entre a ultraestrutura e espessura das cutículas das espécies sociais e solitárias, o que reforçou nossos resultados de RNA-seq. A quantificação absoluta dos CHCs diferenciou as abelhas sociais da solitária, consistente com a hipótese de heterocronia da maturação cuticular e com os perfis de expressão de genes envolvidos na biossíntese de CHCs. Assim, além de desvendar transcriptomas de tegumento de três espécies de abelhas, a comparação da expressão gênica aliada à análise de ultraestrutura da cutícula e quantificação de CHCs levaram à caracterização de diferenças no processo de maturação cuticular entre as espécies sociais e solitárias / Differences in the timing of exoskeleton melanization and sclerotization processes are evident when comparing the external morphology of social and solitary bee species. Such differences may constitute a relevant example of cuticular maturation heterochrony, this term referring to a genetic change in timing of an ontogenetic process relative to an ancestor or between taxons. We proposed that social bees, which remain protected inside the colony for many days before initiating outside nest activities, would reach the maturity of some organic systems, such as the integument (epidermis and cuticle), later than solitary bees, which start such activities immediately after ecdysis. We tested this hypothesis in a comparative study of the developing integument of eusocial bees, Apis mellifera and Frieseomelitta varia, and the solitary bee Centris analis. Using RNA-seq, we verified that the expression profiles of genes involved in cuticular melanization and sclerotization (ebony and tan), chitin deposition and organization (Cda5, Idgf4, chitooligosacchariodolytic-domain-like), and cuticle formation (CPR14, CPR17, CPR18, CPR25, CPR23, CPE26, Apd-3, Apd-like) were positively, correlated between the two eusocial species, but not between the eusocial and the solitary species. Some of the genes with roles in regulating exoskeleton maturation (FTZ-F1, E74, Hr46, Hr4) were co-expressed only in the eusocial species. The expression profiles of these genes (except Hr46) and other regulatory genes (Ethr, Hr38, Rickets, Ptx-1) were also positively correlated exclusively in the eusocial bees. We also highlighted the expression of genes involved in non-melanin pigment production and the expression of circadian rhythm genes that could be related to chitin layers deposition. Transmission electron microscopy analysis of the integument of the two eusocial and the solitary bee species, in addition to other three bee species (the primitively eusocial Bombus brasilienses; the facultatively social Euglossa cordata; the solitary bee Tetrapedia diversipes), showed differences in cuticle ultrastructure and thickness, thus supporting the RNA-seq data. In agreement with our hypothesis, CHC quantifications were consistent with the expression levels of genes involved in CHC biosynthesis, thus differentiating the superficial cuticle layer of the eusocial and solitary species. Together, the integument transcriptomes, ultrastructure, and CHC quantification allowed us to characterize differences in the timing of cuticle maturation in social and solitary bees