Euglossini Species Research Articles

Orchid bees respond to landscape composition differently depending on the multiscale approach

ContextMultiscale approaches are essential for understanding ecological processes and detecting the scale of effect. However, nested multiscale approaches retain the effect of the landscape attributes from the smaller spatial scales into the larger ones. Thus, decoupling the nested scales can reveal detailed ecological responses to landscape context, but this multiscale approach is poorly explored.ObjectivesWe evaluated the scale of effect of the forest cover (%) and landscape heterogeneity on Euglossini bee communities combining coupled and decoupled multiscale approaches.MethodsThe Euglossini males were sampled in forest patches from 15 landscapes within the Atlantic Forest, southeast Brazil. For simplicity, we defined that the coupled approaches represented the local scales and decoupled the regional scales. We decoupled the scales by cutting out the smaller scales inserted into larger ones. We estimated the relationship of the bee community attributes with forest cover (%) and landscape heterogeneity in local and regional scales using Generalized Linear Models.ResultsWe found a trend of positive effects of landscape heterogeneity on species richness for decoupled regional scales. Forest cover and landscape heterogeneity on coupled local scales positively affected the Euglossini species abundance. The scale of effect for Euglossini species abundance was on coupled local scales.ConclusionsCombining coupled and decoupled multiscale approaches was essential to determine the scale of effect of the landscape composition on bee communities. Therefore, it is crucial to measure the influence of the landscape context on biodiversity. Maintaining landscapes with larger forest cover and spatial heterogeneity is important for bee requirements.

In euglossine we trust as ecological indicators: a reply to Añino et al. (2019)

Orchid bees have been considered as good ecological indicators of habitat disturbances but recently Añino et al. (2019. Sociobiology, 66: 194-197) highlighted reasons why Euglossini role as indicators should be reevaluated. Despite agreeing with some points raised by them, we present an alternative view for the use of orchid bees as indicators. For us, the main problematic issues are: (i) the authors do not present a clear definition of ecological indicator, including its role as an indirect measure of biota response to disturbed environments; (ii) they do not properly acknowledge the relative good taxonomic status of orchid bees when compared with the remaining bees; (iii) and they do not distinguish the use of particular Euglossini species as indicators in certain circumstances. In spite of some knowledge gaps, we argue that Euglossini is a good candidate to be ecological indicators in tropical forests, maybe the best candidate among all the bees.

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.

Abrupt decrease in the diversity of Euglossini bees (Hymenoptera: Apidae) in a montane rainforest

Euglossini bees are more diverse in tropical and subtropical rainforests in the Neotropics and their distribution may have a strong influence of altitude. These bees are considered important pollinators being able to cross long distances in continuous forests. Euglossini males collect fragrances, mainly from orchids, used as precursors for sex pheromones, a fact that allows the use of synthesized compounds for their capture. The aim of this study was to evaluate the occurrence of Euglossini males in elevated sites of a montane rainforest (from 960 to 1,200 m) in southeastern Brazil (Atlantic Forest). Scent traps were distributed at three locations in different altitudes on one day per month over 19 months. Six traps with different baits were distributed at each location. Overall, the male Euglossini community presented a low number of species (seven) and individuals (110). Moreover, we detected a drastic decay in Euglossini species richness and abundance with increasing altitude, which suggests a limit for the occurrence of Euglossini populations around 1100 m in the study area. This community presented a high dominance degree with a single dominant species (Euglossa annectans). In addition, only one species of perfume orchid was abundant and flowered in the study area during our sampling period. The distribution of this orchid species corresponds to the occurrence of Euglossini males in the study area. Our results indicate that pollinator scarcity may compromise the establishment of perfume orchid populations at higher altitudes in the Atlantic Forest.

Orchid bees (Apidae: Euglossini) in Cerrado remnants in northeast Brazil

ABSTRACTThere is a general lack of information concerning the diversity of bees belonging to the Euglossini tribe in Cerrado areas closest to the Brazilian Amazon. The state of Maranhão is situated in the northeast Brazilian Cerrado and has become the agricultural frontier of the country due to the advancement of monoculture and cattle farming. These activities have suppressed animal and plant populations in large areas of the Cerrado remnants, for which we have not yet obtained adequate scientific knowledge of local species. The objective of this study was to conduct a survey of Euglossini fauna in the northeast Cerrado. We evaluated the variation in species richness, composition and abundance between two distinct vegetation types: Cerrado sensu stricto (s.s.) and gallery forest. Male bees were captured from 7:00 a.m. to 5:00 p.m. over two consecutive days. Captures were carried out once per month from July 2012 to December 2013, using a combination of passive and active collection techniques, including baited traps, as well as a collector with an entomological net to collect bees near traps. We collected a total of 766 Euglossini males belonging to 24 species and five genera. The most abundant species were Eulaema bombiformis, Eulaema nigrita and Eulaema cingulata for the gallery forest site, whereas Eulaema nigrita, Euglossa melanotricha and Euglossa cordata were more abundant in the Cerrado s.s. The gallery forest yielded a higher number of male Euglossini (n = 503, 21 species) compared with the Cerrado s.s. (n = 263, 16 species). The presence of seven exclusive species in the gallery forest and three in the Cerrado s.s. indicated that both environments are important for the maintenance of Euglossini species in this region and highlight the increasing need for conservation programmes for the protection of Cerrado environments.

New Geographical Records of Two Species ofEufrieseaCockerell, 1908 (Apidae: Euglossini) in Santa Catarina, Brazil, and the Use of a New Fragrance to Attract Orchid Bees

The genus Eufriesea is usually represented by few species, and in most cases, by low number of individuals in samples collected from the Atlantic Forest biome, Brazil. The present study extends the geographic distribution of Eufriesea dentilabris (Mocsary, 1897) and E. mussitans Fabricius, 1787, which are recorded for the first time in the southern state of Santa Catarina, Brazil. Males of E. dentilabris were collected with pollinia of Catasetum flowers (Orchidaceae). We discuss the use of a new aromatic bait with a mint base which is inexpensive and was attractive to four Euglossini species: Eufriesea dentilabris, Eufriesea violacea (Blanchard, 1840), Eulaema cingulata (Fabricius, 1804) and Eulaema nigrita Lepeletier, 1841.

Temporal variation in the abundance of Orchid Bees (Hymenoptera: Apidae) in a Neotropical Hygrophilous Forest

Although bees are important pollinators in several ecosystems around the world, studies on bee diversity in hygrophilous forests are scarce. This type of vegetation is restricted to permanently wet soils and, therefore, has particular floristic, structure and physiognomy. The goal of the present study was to inventory and analyze the temporal variation of the euglossine bees that occur in a neotropical hygrophilous forest. In order to sample male bees we used four chemical baits, eucalyptol, eugenol, vanillin, and methyl salicylate. The captures were made once a month, from March 2010 to February 2011, from 9:00 am to 12:00 pm. We captured 113 individuals of three genera and five species (in decreasing order of abundance): Eulaema nigrita Lepeletier, 1841 (n=52), Euglossa pleosticta Dressler, 1982 (34), Exaerete smaragdina (Guérin-Méneville, 1844) (12), Euglossa carolina Nemésio, 2009 (11), and Euglossa fimbriata Rebêlo & Moure, 1968 (4). The most attractive bait was eucalyptol (n=98), followed by vanillin (11), and eugenol (4). Both temperature and rainfall affected significantly the distribution of the number of males throughout the year. The highest number of Euglossini species and individuals was sampled in the warm and rainy season, with activity peaks varying among species.

Old Fragments of Forest Inside an Urban Area Are Able to Keep Orchid Bee (Hymenoptera: Apidae: Euglossini) Assemblages? The Case of a Brazilian Historical City

Retention of habitat fragments within the urban matrix can provide critical resources for the maintenance of regional biodiversity while still providing socio-economic value. Euglossini bees are important components in a community as they are important pollinators for economically valuable plants as well as hundreds of orchid species. However, some species are very sensitive to environmental impacts like urbanization. This study presents the role of antique urban fragments in a historical city in Brazil and compares it with a conservation area on the aspects of orchid bee assemblage, such as richness, composition, and abundance. Four fragments inside the city of Ouro Preto and three inside Parque Estadual do Itacolomi (PEIT) were sampled for Euglossini bees. Sorensen similarity index was used to compare community composition. The Mantel test was applied to verify the hypothesis that an urban center is a barrier for the mobility of the individuals. Fourteen Euglossini species from the region were registered. Close to 75% of the sampled bees were collected from the PEIT sampling areas. The fragments presented differences in Euglossini richness and abundance. A majority of the sampled fragments were dominated by the Eulaema cingulata Fabricius, Eulaema nigrita Lepeletier, and Euglossa securigera Dressler species. We found differences on community composition between the fragments localized in PEIT and those located in the urban center. The data suggest that there is a possible flux of individuals between the sampled fragments. The various small forest fragments in Ouro Preto, primarily in backyards, may also serve as stepping stones between sampled fragments.

Community Ecology of Euglossine Bees in the Coastal Atlantic Forest of São Paulo State, Brazil

The Atlantic Forest stretches along Brazil's Atlantic coast, from Rio Grande do Norte State in the north to Rio Grande do Sul State in the south, and inland as far as Paraguay and the Misiones Province of Argentina. This biome is one of the eight biodiversity hotspots in the world and is characterized by high species diversity. Euglossini bees are known as important pollinators in this biome, where their diversity is high. Due to the high impact of human activities in the Atlantic Forest, in the present study the community structure of Euglossini was assessed in a coastal lowland area, Parque Estadual da Serra do Mar - Núcleo Picinguaba (PESM), and in an island, Parque Estadual da Ilha Anchieta (PEIA), Ubatuba, São Paulo State, Brazil. Sampling was carried out monthly, from August 2007 to July 2009, using artificial baits with 14 aromatic compounds to attract males. Twenty-three species were recorded. On PEIA, Euglossa cordata (L.) (Hymenoptera: Apidae) represented almost two thirds of the total species collected (63.2%). Euglossa iopoecila (23.0%) was the most abundant species in PESM but was not recorded on the island, and Euglossa sapphirina (21.0%) was the second most frequent species in PESM but was represented by only nine individuals on PEIA. The results suggest that these two species may act as bioindicators of preserved environments, as suggested for other Euglossini species. Some authors showed that Eg. cordata is favored by disturbed environments, which could explain its high abundance on Anchieta Island. Similarly, as emphasized by other authors, the dominance of Eg. cordata on the island would be another factor indicative of environmental disturbance.

Genetic differentiation of the Euglossini (Hymenoptera, Apidae) populations on a mainland coastal plain and an island in southeastern Brazil

Euglossini bees are among the main pollinators of plant species in tropical and subtropical forests in Central and South America. These bees are known as long-distance pollinators due to their exceptional flight performance. Here we assessed through microsatellite loci the gene variation and genetic differentiation between populations of four abundant Euglossini species populations sampled in two areas, Picinguaba (mainland) and Anchieta Island, Ubatuba, São Paulo State, southeastern Brazil. There was no significant genetic differentiation between the island and mainland samples of Euglossa cordata (Fst=0.008, P=0.60), Eulaema cingulata (Fst=0.029, P=0.29) and Eulaema nigrita (Fst=0.062, P=0.38), but a significant gene differentiation between mainland and island samples of Euglossa stellfeldi (Fst=0.028, P=0.016) was detected. As expected, our results showed that the water body that separates the island from the mainland does not constitute a geographic barrier for these Euglossini bees. The absence of populational structuring of three out the four species studied corroborates previous reports on those bees, characterized by large populations, with high gene diversity and gene flow and very low levels of diploid males. But the Eg. stellfeldi results clearly point that dispersal ability is not similar to all euglossine bees, what requires the development of different conservationist strategies to the Euglossini species.

Habitat Fragmentation Effects on the Orchid Bee Communities in Remnant Forests of Southeastern Brazil

The effect of habitat fragmentation on the structure of orchid bee communities was analyzed by the investigation of the existence of a spatial structure in the richness and abundance of Euglossini species and by determining the relationship between these data and environmental factors. The surveys were carried out in four different forest fragments and one university campus. Richness, abundance, and diversity of species were analyzed in relation to abiotic (size of the area, extent of the perimeter, perimeter/area ratio, and shape index) and biotic characteristics (vegetation index of the fragment and of the matrix of each of the locations studied). We observed a highly significant positive correlation between the diversity index and the vegetation index of the fragment, landscape and shape index. Our analysis demonstrated that the observed variation could be explained mainly by the vegetation index and the size of the fragment. Variations in relative abundance showed a tendency toward an aggregated spatial distribution between the fragments studied, as well as between the sampling stations within the same habitat, demonstrating the existence of a spatial structure on a small scale in the populations of Euglossini. This distribution will determine the composition of species that coexist in the area after fragmentation. These data help in understanding the differences and similarities in the structure of communities of Euglossini resulting from forest fragmentation.

Genetic differentiation of urban populations of Euglossa cordata from the state of São Paulo, Brazil

Males and females of Euglossa cordata collected inside flowers of Thevetia peruviana in urban areas of eleven cities of the state of Sao Paulo were analysed using allozymes and nine microsatellite loci. The analyses revealed that these populations have a high genetic diversity and are under genetic equilibrium, showing low population structuring and rare diploid males; consequently, high gene flow and effective population size (Ne) are inferred. These findings corroborate previous biological observations and phylogeographic evidence that report dispersion over long distances of Euglossini species in South America.

A scientific note on the occurrence of Euglossini bees in the Caatinga, a Brazilian tropical dry forest

Euglossini bees (Apidae) are an exclusively Neotropical monophyletic group of five genera (Aglae, Eufriesea, Euglossa, Eulaema, and Exaerete) with 190 species, (Rebelo, 2001; Ramirez, 2005). In Brazil, the second most diverse country in Euglossini species (Ramirez et al., 2002), 80 species are referred for the Amazon, 57 for the Atlantic forest, and 23 for the Cerrado (Rebelo, 2001). Despite this high richness, new species continue to be described (Ramirez, 2005) and known species are still being recorded from new locations (Nemesio and Silveira, 2004). The Caatinga, a semi-arid ecosystem unique from Brazil, is a deciduous forest with scrub vegetation. It occurs in areas of low and highly seasonal rainfall (500–700 mm/year), and covers 800 000 km2 of Brazil’s territory (ca. 8.6%) in the northeastern region (Leal et al., 2003). It was estimated that more than 40% of its plant species relies on bees for pollination (Machado and Lopes, 2004). However, the Caatinga apifauna is still poorly known (Zanella, 2000; Zanella and Martins, 2003). The aim of this paper is to review and report new records of Euglossini bees for the Caatinga region. We inventoried five sites located in the states of Pernambuco (PE) and Ceara (CE), Brazil (see material online) by attracting Euglossini males using odour

Do euglossine males (Apidae, Euglossini) leave tropical rainforest to collect fragrances in sugarcane monocultures?

Euglossine bees are known to be long-distance pollinators in tropical rainforests. But there is controversy concerning to the flight ranges of these bees between forest fragments. In an isolated fragment of Atlantic Rainforest in Pernambuco, NE Brazil, surrounded by sugarcane monocultures, it was examined if euglossine males leave closed rainforest to collect fragrances. In a straight-line transect leading from forest into a sugarcane plantation, euglossine males were simultaneously captured by scent baits at seven distinct points: inside the forest, forest edge, outside the forest in the sugarcane fields at distances of 10 m, 50 m, 100 m, 250 m and 500 m from the forest edge. A total of 945 euglossine bees of 16 species were recorded. The results demonstrate different relations of the Euglossini species to the closed forest. Males of 11 species did not leave the forest. Such species, together with the plants they are linked to, seem to be the most threatened by habitat fragmentation. Only bees of five species were found at the scent baits in the sugarcane fields. Already the 10 m sampling point outside the forest showed a drastic reduction in species richness, indicating that the forest edge functions as a barrier for most euglossine species.

Machos de Euglossini deixam a floresta tropical para coletar fragrâncias em uma monocultura de cana-de-açúcar?

Euglossine bees are known to be long-distance pollinators in tropical rainforests. But there is controversy concerning to the flight ranges of these bees between forest fragments. In an isolated fragment of Atlantic Rainforest in Pernambuco, NE Brazil, surrounded by sugarcane monocultures, it was examined if euglossine males leave closed rainforest to collect fragrances. In a straight-line transect leading from forest into a sugarcane plantation, euglossine males were simultaneously captured by scent baits at seven distinct points: inside the forest, forest edge, outside the forest in the sugarcane fields at distances of 10 m, 50 m, 100 m, 250 m and 500 m from the forest edge. A total of 945 euglossine bees of 16 species were recorded. The results demonstrate different relations of the Euglossini species to the closed forest. Males of 11 species did not leave the forest. Such species, together with the plants they are linked to, seem to be the most threatened by habitat fragmentation. Only bees of five species were found at the scent baits in the sugarcane fields. Already the 10 m sampling point outside the forest showed a drastic reduction in species richness, indicating that the forest edge functions as a barrier for most euglossine species.