Assessment of genetic diversity and population structure of Eulaema nigrita (Hymenoptera: Apidae: Euglossini) as a factor of habitat type in Brazilian Atlantic forest fragments

In many organisms, habitat affects ecological and genetic diversity and, for certain species, it is expected that a large population should have higher genetic diversity than a smaller population. We analysed the genetics of males of the orchid bee, Eulaema nigrita (Hymenoptera: Apidae) and examined the links between local abundance and habitat with genetic diversity. We also investigated the impact of landscape features on genetic population structure, through microsatellite and mitochondrial DNA analysis, among populations found across 700 km of Brazilian Atlantic forest fragments. We found that genetic variation was not a function of local abundance, but it correlated significantly with habitat. There was significant but low genetic differentiation among populations. We found a single mitochondrial DNA haplotype in all sequenced specimens, which may be widespread throughout the Atlantic forest. Our results reinforce the idea that orchid bees can fly long distances. High-dispersal capacity, together with insufficient time in eventual isolation, can directly contribute to the high degree of similarity among populations for this species, despite their wide geographical distribution.

Range Expansion of the Cleptoparasitic Orchid Bee Aglae caerulea in the Pantanal of Mato Grosso, Brazil

In the present study, a new occurrence of Aglae caerulea Lepeletier & Audinet-Serville is reported within a few km of the seasonal flooded plain limits of the Pantanal in the Paraguay basin, reinforcing the idea that this species coexists with its hostess Eulaema nigrita, one of the most common species catalogued in several habitats surveyed in the biome. After 18 months of sampling and no A. caerulea male attracted to the baits, methyl cinnamate was added to the set of fragrances available in the field. During four weeks in May and one week in June 2018, a total of 11 males of A. caerulea were attracted to the new bait in the gallery forest of São Vicente Range. With this most recent record, we expand the ranges of occurrence to the north-eastern border of the Pantanal of Barão de Melgaço, in Mato Grosso, Brazil. Future expeditions in the Pantanal of Mato Grosso and Mato Grosso do Sul should record this cleptoparasitic species from southern to western Paraguay river basin, to reduce the biogeographical gaps in this peculiar tribe of corbiculate bees. The cleptoparasitic species A. caerulea may be recorded when adequate field studies and collections are made from the seasonal floodplain habitats to karstic habitats (dry forests) along the Pantanal border.

Abundância e riqueza de espécies de euglossini (hymenoptera: apidae) em diferentes fragmentos no município de Mojuí dos Campos, Pará, Brasil

As abelhas da tribo Euglossini (Hymenoptera: Apidae) são extremamente importantes na polinização das florestas neotropicais e por serem sensíveis a mudanças em seu habitat, são consideradas excelentes bioindicadores de qualidade ambiental. Nesse contexto, o presente estudo objetivou (i) comparar a riqueza de espécies e abundância de indivíduos de Euglossini entre fragmento de floresta, pastagem e plantação de soja; (ii) identificar a preferência pelas iscas odoríferas; e (iii) avaliar o efeito de borda sobre a riqueza de espécies e abundância de indivíduos. O estudo foi realizado no município de Mojuí dos Campos, Pará, Brasil, em três áreas: fragmento de floresta, pastagem e plantação de soja. Utilizou-se seis iscas odoríferas para atrair os machos: eugenol, eucaliptol, vanilina, benzoato de benzila, cinamato de metila e geraniol. Foram coletados 1668 indivíduos distribuídos em quatro gêneros e 11 espécies. Existe diferença significativa na abundância de Euglossini entre os ambientes (F(2,24) = 4,1007; p = 0,029), a maior abundância ocorreu na área de pastagem (866-52%). Houve diferença significativa tanto na abundância (F(5, 156) = 15,811; p < 0,001) quanto na riqueza de espécies (F(5, 156) = 70,039; p < 0,001) de Euglossini entre as iscas. Vanilina mostrou-se a isca mais atrativa e geraniol a menos atrativa. Não há diferença significativa na abundância (F(2, 24) = 1,8505; p = 0,178) e riqueza de espécies de Euglossini (F(2, 24) = 0,299; p = 0,744) entre os transectos borda, intermediário e centro, o que pode estar relacionado com a proximidade entre as áreas e a capacidade das abelhas de voar longas distâncias. Outro fator que pode influenciar nesse resultado, é a capacidade de dispersão dessas abelhas, que possibilita a exploraração localidades próximas. Fatores climáticos, diferença na volatilidade das substâncias, faixa etária das populações, pureza e composição isométricas das substâncias e ofertas de fontes naturais podem ter influenciado nesse resultado. Apesar dos resultados mostrarem um alto grau de degradação na área estudada, é necessário a realização de mais estudos, que levem em conta o tamanho dos fragmentos e o número de Eulaema nigrita em relação a outras espécies para que se possa obter dados mais precisos sobre os impactos dos diferentes usos da terra na diversidade das abelhas Euglossini.

Species Distribution of Euglossini Bees (Hymenoptera: Apidae) at an Altitudinal Gradient in Northern Santa Catarina

Euglossini bees are found from southern USA to Central Argentina and southern Brazil. Variations in latitude and altitude can influence the distribution of these bees. This study focused in recognizing the Euglossini species in northern Santa Catarina state, evaluating the distribution over the gradient between sea level and 800 meters altitude. The bees were collected in six locations, between Spring and Summer from 2013 to 2015, using cotton balls containing the following odor baits: benzyl benzoate, 1,8 cineole, eugenol, menthol and vanillin. A total of 794 bees were sampled, belonging to 10 different species, including a possible new species. In terms of abundance Eufriesea Cockerell, 1908 (4 species) accounted for 552 individuals, followed by Euglossa Latreille, 1802 (5 species) with 218 and Eulaema Lepeletier, 1841 (2 species) 24 individuals. Five species were not found above altitude of 400 meters. Eufriesea violacea Blanchard, 1840, Euglossa annectans Dressler, 1982, and Eulaema nigrita Lepeletier, 1841 were the only species found in every location along the altitudinal gradient, but their abundance declines toward higher altitudes. The results surpassed the known orchid bee species for Santa Catarina state from 9 to 14 and confirmed the expected tendency of richness and abundance reduction toward the highlands.tendency of richness and abundance reduction toward the highlands.

Orchid bees (Hymenoptera, Apidae, Euglossini) are seasonal in Seasonal Semideciduous Forest fragments, southern Brazil

Seasonal fluctuations in the abundance of orchid bees have already been reported. The variations in population dynamics may be expected to occur in more predictable and pronounced manners in environments with a clear distinction between rainy and dry seasons, where climatic variables are regarded to be good predictors of populational patterns. The main goal of this paper is to investigate the seasonality of males of orchid bees in fragments of Seasonal Semideciduous Forest in southern Brazil. Data comprise bait samples from five one-year periods on four forest fragments. The seasonality of species abundance was tested with circular statistics. Results suggest two phenological patterns, one for Eufriesea violacea (Blanchard), Eulaema nigrita Lepeletier and Euglossa cordata (Linnaeus), whose abundances are concentrated in late spring and early-middle summer and another for Euglossa fimbriata Moure with a tendency to be collected in middle-late summer and early autumn. These patterns are discussed, as well the possible driven factors, (i) the species life cycle and nesting behavior, (ii) synchrony with resource, and (iii) climate. We can postulate an important impact of climate change in local euglossine assemblage due to the small populations and marked seasonality.

Fauna de Euglossina (Hymenoptera: Apidae) de um fragmento de Mata Atlântica do Alto Oeste Potiguar, Rio Grande do Norte

<p>As abelhas da subtribo Euglossina encontram-se amplamente distribuídas na região Neotropical, sendo mais diversificadas nas florestas úmidas. Objetivou-se realizar um levantamento das espécies desta subtribo em um fragmento de Mata Atlântica, um remanescente de brejo de altitude, localizado em uma região do Semiárido Brasileiro. O estudo foi conduzido no município de Portalegre, Rio Grande do Norte, entre os meses de fevereiro e agosto de 2015. A coleta de dados foi realizada mensalmente entre às 08h00 e 16h00, com a utilização de armadilhas contendo as essências eucaliptol, eugenol e vanilina. Foram coletados um total de 123 machos, distribuídos em quatro gêneros e seis espécies, sendo elas: <em>Eufriesea danielis </em>(43,09%), <em>Euglossa melanotricha </em>(25,20%), <em>Euglossa cordata </em>(15,45%), <em>Eulaema nigrita </em>(13,82%), <em>Euglossa fimbriata </em>(1,63%) e <em>Exaerete dentata</em> (0,81%). O intervalo entre 08h00 e 10h00 foi o de maior atividade, com 54,4% do total dos machos coletados. A comunidade de abelhas da região estudada apresentou maior preferência pelo eucaliptol, atraindo cinco espécies e 67 indivíduos (53,6%). A espécie <em>Eufriesea danielis </em>é reportada pela primeira vez para a região Nordeste do Brasil, enquanto que <em>Exaerete dentata </em>tem seu primeiro registro para o estado do Rio Grande do Norte.</p><p align="center"><strong><em>Euglossina (Hymenoptera: Apidae) fauna of a fragment of the Atlantic Rainforest of the Alto Oeste Potiguar, Rio Grande do Norte, Brazil</em></strong></p><p><strong>Abstract:</strong> The bees of the Euglossina subtribe are widely distributed in the Neotropical region, being more diversified in the humid forests. The purpose of this research was to carry out a survey of the species of this subtribe in a fragment of Atlantic Forest, a remnant of altitude swamp, located in a region of the Brazilian Semiarid. The study was conducted in the municipality of Portalegre, Rio Grande do Norte, between February and August 2015. Data collection was performed monthly between 08h00 and 16h00, using traps containing the eucalyptol, eugenol and vanillin essences. A total of 123 males, distributed in four genera and six species were collected, which are: <em>Eufriesea danielis </em>(43.09%), <em>Euglossa melanotricha </em>(25.20%), <em>Euglossa cordata </em>(15.45%), <em>Eulaema nigrita </em>(13.82%), <em>Euglossa fimbriata </em>(1.63%) and <em>Exaerete dentata</em> (0.81%). The interval between 8:00 a.m. and 10:00 was the most active, with 54.4% of the total collected males. The community of the bees studied region showed greater preference for eucalyptol, attracting five species and 67 individuals (53.6%). The species <em>Eufriesea danielis</em> is reported here the first time for the Northeast region of Brazil, while <em>Exaerete dentata </em>has its first record for the state of Rio Grande do Norte.</p>