Euglossa Cordata Research Articles

Biologia de nidificação de Euglossa cordata (Apidae: Euglossini) em áreas abertas no Extremo Sul Baiano

The genus Euglossa comprises a group of approximately 110 cataloged bee species found throughout the Neotropical region. Among these species, Euglossa cordata (Linnaeus, 1758) has a wide distribution in different environments. This research aimed to analyze aspects of the nesting biology of E. cordata in open areas near Atlantic Forest fragments in the Extreme South of Bahia, Brazil. Collections were carried out using PET bottle traps, a methodology commonly employed for capturing Meliponini but adapted for the first time in this study, presenting a low cost and good applicability for studies on Euglossa bees. Ten traps were randomly distributed in open environments at the Federal Institute of Bahia. Three nests of E. cordata were found, with a total of thirteen brood cells and six female emergences in traps 2 and 3. In all nests, the cells were constructed in a circular manner and arranged close to each other. The cells were built with resin and had a scalene trapezoid shape with variations in diameter and length. Studies on bees of the Euglossini tribe, popularly known as orchid bees, often focus on males collected using odor baits. Conversely, studies on females and nesting biology are scarce. Thus, methodologies that facilitate the capture of females and Euglossini nests are extremely relevant for enhancing our understanding of the group.

Deforestation narrows pollen diet diversity of generalist orchid bees

Orchid bee species are important pollinators in the Neotropics. While male orchid bees are known to have a close interaction with odor-rewarding flowers, orchid bee females are often pollen generalists. In the current study, we investigated differences in the pollen diet diversity of orchid bees in various vegetation types and across sites with varying levels of forest cover by means of an analysis of the frass pellets of the orchid bee, Euglossa cordata (Linnaeus, 1758), and multiple species based on a literature review. The pollen grains found in the inner part of brood cells were used to assess the plant composition making up the diet of E. cordata in various areas of the state of São Paulo in Brazil. We found that this plant composition differed among vegetation types, and that diet specialization was lower in forested areas. Forest cover appeared to be the factor mostly associated with pollen richness in nests of E. cordata. Number of brood cells per nest were also associated with forest cover. The model used to assess the effect of forest cover on plant richness as part of brood diet of E. cordata was tested with the inclusion of published data and a newly generated data for E. annectans. This new data set allowed to understand the influence of forest in the pollen diet of multiple species in a more extensive geographic scale. Forest cover appeared to be important for a diversified pollen diet in several orchid bee species.Implications for insect conservationSince a diversified pollen diet offered to larva bees is associated with bee survival and health, our results indicate that orchid bees relying on areas with higher forest cover have a more resilient population. Such findings emphasize the importance of conservation of forests, especially in the Neotropical region where many pollinator species are adapted to continuous forest environments.

Phytogeographic regions and geographic distance do not predict genetic structure in the orchid bee Euglossa cordata

Herein, we investigated the genetic diversity and population structure of Euglossa cordata L., an orchid bee species widely distributed at the heterogeneous set of vegetal physiognomies encompassed in a transition zone (TZ) of different Brazilian biomes. We then tested whether phytogeographic regions would play some rule for the genetic diversity. Results revealed that only 12 and 28 out 78 pairs of samples showed some degree of genetic structure for microsatellites (F ST≤ 0.029; Dest ≤0.091; p < 0.05) and mtDNA(0.138 ≤mt-ϕST≤ 0.495; p < 0.05) markers, respectively. We found evidence of two and three genetic clusters in nuclear and mtDNA markers, but no significant structure based on phytogeographic regions or geographic distances. These findings point out that local idiosyncrasies and historic factors, but not different types of vegetation or geographic distances drive the patterns of the observed genetic structure. Drops in the diversity index and other estimators highlight that E. cordata may have experienced some local bottlenecks despite its resilience to anthropic interferences. These are the first records of relatively high genetic structure in E. cordata populations and have important implications for orchid bees’ conservation.

Overlap of Ecological Niche Breadth of Euglossa cordata and Eulaema nigrita (Hymenoptera, Apidae, Euglossini) Accessed by Pollen Loads and Species Distribution Modeling

Urban areas can serve as biodiversity refuges for pollinators because of the high diversity of available floral and nesting resources. However, it remains unclear what plant species commonly used for urban landscaping provide floral resources that pollinators actively use. Here, we integrate data from the pollen and species distribution models of two abundant euglossine bees-the large-bodied Eulaema nigrita (Lepeletier, 1841) and the small-bodied Euglossa cordata (Linnaeus, 1758)-in urban areas to investigate their overlap in diet breadth and distribution. We hypothesized that because bees with larger body sizes tend to have larger foraging areas, large-bodied bees would have a wider diet breath than small-bodied bees. Contrary to our hypothesis, we found that Eg. cordata has a wider diet breadth than El. nigrita with the former species showing higher diversity of pollen types collected (per pollen load and on average across pollen loads). Pollen grains from Solanum paniculatum and Tradescantia zebrina represented 63% of the diet of Eg. cordata, whereas pollen from S. paniculatum and Psidium guajava represented 87% of the diet of El. nigrita. After overlaying the distribution of both bee species and the three most important pollen resources, the distribution models revealed that these three plant species can co-occur with both euglossine bees throughout a large portion of eastern Brazil near the coast. Thus, we conclude S. paniculatum, T. zebrina, and P. guajava should be considered key plants for the maintenance of these two urban euglossine bee species. The results of this study provide important information for urban landscaping programs that aim to protect and preserve pollinators.

Morphometric Changes in Three Species of Euglossini (Hymenoptera: Apidae) in Response to Landscape Structure

Fragmentation and expansion of agricultural activities are sufficient factors for strongly impacting the biodiversity. Thus, sustainable practices of land use, such as agroforestry systems, are adopted with proposal of improving environmental quality and restore ecological processes. In flying insects, fragmentation may cause changes in the wing shape and size. Therefore, we evaluated the wing size and shape of three species of Euglossini (Eulaema atleticana Nemésio, Euglossa cordata (Linnaeus) and Euglossa ignita Smith) at response to landscape structure. The analysed specimens were collected in five areas, four forest areas with strong anthropic influence and an agroforestry system area. The results of the wing shape analysis have showed that the individuals of the three collected species within the agroforestry system diverge significantly (p&lt;0.05) from those collected in the other areas. On the wings of Eg. cordata and Eg. ignita, differences in shape have occurred mainly in the medial region, which actively participates in the individual's flying ability. The wing size has showed meaningful difference only to the population of Eg. ignita (p=0,005). For Eg. cordata and El. atleticana, there was a significant correlation (r&lt;0.05) between the morphometric data and the landscape metrics, which shows a close relationship between these species and the forest cover. The wing shape and size pursue an important function for the individual's ability in the environment, such as dispersion capacity and fertility rate, respectively. We concluded that the morphometric differences can reveal the existence of environmental stress for the biodiversity, therefore, contribute for environmental quality monitoring studies.

Pollen Analysis of the Post-Emergence Residue of Euglossa Bees (Apidae: Euglossini) Nesting in an Urban Fragment

Euglossini bees are considered pollinators of a wide variety of plants in the Neotropical region, but little is known about their floral preferences. In this study, we identified the botanical species used as pollen and nectar sources by three Euglossa species (Euglossa cordata, Euglossa townsendi, and Euglossa securigera) using pollen residue found in brood cells from trap nests installed in an urban fragment in São Luís, Maranhão, Brazil. In 14 analyzed Eg. cordata nests, 23 pollen types were observed, in 7 Eg. townsendi nests, 10 pollen types were observed, and in 1 nest of Eg. securigera, 6 morph types were identified. Solanum (Solanaceae), Zanthoxylum (Rutaceae), Mimosa pudica (Fabaceae), and Chamaecrista (Fabaceae) pollen types were common to all three bee species. Principal components analysis showed 83.04% variability on the first two axes, demonstrating substantial similarity among the samples. Solanum, Mimosa pudica, and Zanthoxylum were the principal components in the ranking. Larger diversity values (mean = 0.80) in some samples indicate that the species gathered resources in a heterogeneous manner; this resembles the findings of other studies of Euglossa. In general, the bees exhibited overlapping niches with regard to the most abundant pollens in the nests, but the females showed individual plasticity when gathering the floral resources.

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.

Do euglossine females reside in a single nest? Notes on Euglossa cordata (Hymenoptera: Apidae: Euglossini)

ABSTRACT Euglossa Latreille, 1802 do not live in large colonies, and these are usually maintained or “reactivated” by new females, subordinate to their mother, which construct and provision brood cells. This study aimed to obtain information about the natural history of Euglossa cordata (Linnaeus, 1758) specially focusing on nest behavior. Our specific objective was to answer the following question: do E. cordata females reside in a single nest? We construct 14 artificial nesting boxes and made them available for E. cordata bees in natural environment for seven months. During this time, we use a re-marking method to identify bee fidelity to a single nest box. More specifically, we record bee permanence in the nests, the time bees take to provision brood to new cells and the time taken to offspring emergence. A total of 12 boxes were colonized by E. cordata and 23 cells were built in an average of 9.78 ± 11 days per cell. Eleven females emerged from the cells in 48.6 ± 11 days. Although adult females moved between nests and sometimes used multiple nests at the same time, E. cordata showed a relatively high fidelity to a single nest (81.1% of the female bees stayed in a single nest more than 50% of time).

Floral sources used by the orchid bee Euglossa cordata (Linnaeus, 1758) (Apidae: Euglossini) in an urban area of south-eastern Brazil

Although orchid bees (Apidae: Euglossini) are known as key pollinators in tropical ecosystems, knowledge of their floral sources is still scarce, especially for those species commonly found in urban environments. We aimed to identify the pollen, nectar and resin sources used by the widespread species Euglossa cordata in an urban area in south-eastern Brazil. The residual pollen from 81 brood cells of nine nests reactivated between October 2013 and December 2014 was acetolysed and analysed. A total of 50 pollen types belonging to 20 botanical families were identified in the samples. Pollen sources included species from seven families; five of them were plants with poricidal anthers (Bixaceae, Commelinaceae, Fabaceae, Melastomataceae and Solanaceae). The mass-flowering trees Handroanthus chrysotrichus and H. heptaphyllus (Bignoniaceae) are firstly reported as important pollen sources to an orchid bee species. Nectar was collected primarily from plants with long, tubular corolla as Acanthaceae, Apocynaceae, Bignoniaceae and Convolvulaceae. The vine species Dalechampia stipulacea (Euphorbiaceae) acted as a floral resin source. All pollen sources consisted of native plants whereas some exotic plant species were visited for nectar collection. Although nesting in an area encompassed by a high proportion of invasive plant species, Euglossa cordata females preferred to visit native plants to gather floral resources.

Orchid Bees (Hymenoptera: Apidae: Euglossini) in Seasonally Dry Tropical Forest (Caatinga) in Brazil

Euglossini bees are important Neotropical pollinators, but there is a lack in the knowledge about this fauna in dry tropical environments. The aims of this study were to evaluate the richness and abundance of euglossine bees in two fragments of seasonally dry tropical forest (Caatinga), as well as to assess the distribution of euglossine species richness in the Caatinga environment. Males were collected along 12 consecutive months, using traps with aromatic baits. The species richness (S=5) was lower than in rainforests and savannas. Euglossa cordata (L.) was the dominant species in the assemblage, representing 70% of the individuals. The highest abundance occurred in the rainy season. Euglossini fauna presents low local species richness in Caatinga areas, however the beta diversity is higher, since assemblages in different habitats have differences in species composition.

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.

Cavities in bromeliad stolons used as nest sites by Euglossa cordata (Hymenoptera, Euglossini)

Herein, we describe nests of the orchid bee Euglossa cordata that were constructed in cavities of Aechmea distichantha (Bromeliaceae) stolons. We present data about nest and cell size, number of adults and brood, and analyses of larval provisions. The presence of E. cordata carcasses embedded in the resin of nest partitions indicates that these nests were used by multiple generations. Based on larval provisioning, E. cordata is polylectic and relies heavily on a few plant species.

The Orchid Bee Communities in different phytophysiognomies in the Atlantic Forest: from lowland to montane rainforests

To investigate species composition, diversity, richness, and monthly abundance of orchid bees in different types of dense rainforest, placed in different altitudes, the orchid bees were collected for 11 months in three vegetation types: dense montane ombrophilous forest (DMOF), dense submontane ombrophilous forest (DSOF, with two sites points), and dense lowland ombrophilous forest (DLOF). Were collected 1,945 males of 20 species using aromatic traps. The DMOF showed the highest species richness (19), and diversity (H’ = 2.42) , whereas the DSOF_1 showed the highest abundance (775). Euglossa cordata (Linnaeus) was the most abundant species in three areas, and Euglossa ignita Smith was the most abundant species in the DSOF_2 . Abiotic factors were correlated with some community parameters. Our study reveals the importance of preserving different phytophysiognomies within the same biome to conserve orchid bees.

Reproductive biology of endemic Solanum melissarum Bohs (Solanaceae) and updating of its current geographic distribution as the basis for its conservation in the Brazilian Cerrado.

The genus Solanum (family Solanaceae) includes more than 1400 species and has buzz-pollinated flowers with poricidal anthers. The present study aimed to describe the distribution, breeding system and pollination mechanism of Solanum melissarum, a species endemic to Brazil. The study of breeding system was conducted in an urban forest fragment in Jataí, GO. Distribution data were gathered from floristic surveys and digital plant databases. The floral morphology and the pollination mechanism were studied on through field observations and preserved flowers. The breeding system was determined through hand pollination treatments. The species has a distribution only in the Brazilian Atlantic forest coastal, and this study provides the first records of S. melissarum for the state of Goiás. The pendulous flowers have poricidal anthers close to the stigma, with membranous thecae joined by a connective bearing osmophores that attract males of Euglossa cordata bees. As they collect fragrances, the bees press the thecae and pollen is released through a bellows mechanism. Based on the hand-pollination treatments, this species is self-incompatible. Isolated forest fragments may not include enough pollinators to ensure the pollination of plants with specialized systems. However, they are essential for the conservation of species with interesting phytogeographic patterns, such as the vicariance observed in S. melissarum, and for the conservation of regional diversity.

Surrounded by foes: Parasitism in Euglossa spp. (Apidae, Euglossini) caused by six species of natural enemies

Although the tribe Euglossini includes more than 200 described species belonging to five genera, information on natural enemies of those bees is scarce. This paper reports attacks on nests by natural enemies and the parasitism of adult females of species of the genus Euglossa. Euglossa nests were obtained using trap-nests, distributed in different sites among three cities in the state of São Paulo, Brazil: São Carlos, Ribeirão Preto, and Indaiatuba. During the period of study 46 nests of Euglossa were obtained. Euglossa cordata occupied 22 traps, E. townsendi occupied seven traps, and E. truncata Rebêlo & Moure occupied one trap. It was not possible to identify the species of Euglossa from other 16 traps. Three parasitoids and two cleptoparasites were associated with the nests. Cells were attacked by the parasitoid wasp Polistomorpha fasciata (Westwood) (Leucospidae) (3 nests), by the gregarious parasitoid wasp Aximopsis masneri Gates (Eurytomidae) (2 nests) and by the beefly Anthrax oedipus Fabricius (Bombyliidae) (2 nests). Nests were also attacked by two cleptoparasitic bees of the family Megachilidae: Coelioxys costaricensis Cockerell (1 nest) and Hoplostelis nigritula (Friese) (2 nests). Moreover, seven E. cordata females and one E. townsendi female were parasitized by the endoparasitoid fly Melaloncha ronnai Borgmeier (Phoridae).

Do Distinct Biomes Influence the Cuticular Chemical Profile in Orchid Bees?

Cuticular chemical profiles of Euglossa cordata L. males were analyzed to test whether ecological predictors affect their composition and relative proportion. Males were collected in areas of Caatinga and Atlantic Forest from Brazil during two distinct seasonal periods. We found 48 compounds from the cuticular extracts of males, which consisted of hydrocarbons (71.39%), acetates (16.79%), esters (10.5%), alcohols and others (1.31%). We verified that when specimens were separated between biomes, they did not show a qualitative differentiation, but a small quantitative variation of compounds was found between some alkanes. We suggest that these results reflect stability of epicuticular compounds even under variable environmental conditions.

The primitively social behavior of Euglossa cordata (Hymenoptera, Apidae, Euglossini): a view from the perspective of kin selection theory and models of reproductive skew

The present study investigated the level of reproductive skew during the reactivation processes of 11 nests of Euglossa cordata. Behavioral observations associated with kinship analysis between offspring and females involved in these processes were carried out. Different types of associations between females occurred in these reactivations: between mothers and daughters, sisters, cousins, and unrelated females. Behavioral observations and Mendelian segregation analysis at 12 microsatellite loci attributed all the offspring to the dominant female of each nest. The results revealed a full reproductive skew at the different processes of reactivation, irrespective of the type of association between females. Thus, our data indicate that reproductive skew was not associated with genetic relatedness in E. cordata.

Mature Larvae of Euglossine Bees, a Comparative Study (Apoidea: Apidae: Euglossini)

ABSTRACT Herein are described and illustrated the mature larvae of the following species assigned to the Euglossini: Eufriesea surinamensis (Linnaeus), Eufriesea mussitans (Fabricius), Euglossa (Euglossa) cordata (Linnaeus), Eulaema (Apeulaema) polychroma (Mocsary). They are compared both with one another and with previous accounts of other taxa assigned to the tribe, and a taxonomic key is presented. The paper concludes with a preliminary larval characterization of the tribe.

Island isolation reduces genetic diversity and connectivity but does not significantly elevate diploid male production in a neotropical orchid bee

There is concern about the worldwide decline of bees, in which genetic factors may play a role. As populations of these haplodiploid insects suffer habitat fragmentation and subsequent isolation, theory predicts an increase in inbreeding and a concomitant increase in inviable or sterile diploid males, a product of reduced allelic diversity at the sex determining locus, which could lead to a diploid male extinction vortex. To test this idea, we genotyped 1,245 males of one orchid bee, Euglossa cordata, a species with low diploid male production on the mainland. We genotyped bees from the Brazilian mainland and three islands using five highly variable microsatellite loci. Allelic richness was lowest on the most remote island 38 km from the mainland and, though the degree of differentiation across localities was modest (global FST = 0.034; global \({\text{G}}_{\text{ST}}^{'} = 0. 1 5 3\), both P < 0.001) and isolation by distance was weak (Mantel test, r = 0.614, P = 0.056), sea was revealed to be a significant barrier to inferred historic gene flow (partial Mantel test of distance over sea, r = 0.831, P = 0.003). Only seven males were diploid (mean diploid male production, DMP, 0.6 %). Though the proportion of diploid males was highest on the most remote island (1.3 %), differences in DMP across study areas were statistically non-significant. Thus island isolation leads to reduced genetic variation at putatively neutral microsatellite loci, but E. cordata nevertheless seems to maintain allelic diversity at the sex locus, possibly because of sufficient gene flow, or because it is a locus under balancing selection, or because of the joint action of these two evolutionary forces: migration and selection. These and other bee species may be able to maintain sufficient variability at the sex locus to avoid entering the DM extinction vortex, even on relatively isolated islands or habitat fragments.

A scientific note on the first records of Melaloncha Brues, 1904 (Diptera: Phoridae) parasitizing Euglossini and Centridini bees

The phorid genus Melaloncha Brues, 1904, also known as bee-killing flies, actually comprises 167 species and can be found mostly in the Neotropical region (Brown 2009). Most of the Melaloncha are endoparasitoids of corbiculate, eusocial bees, as stingless bees (Meliponini), bumble bees (Bombus Latreille), and honey bees (Apis mellifera (Linnaeus)) (Ramirez 1982; Brown 2006). Additionally, there are records of species of the genus Melaloncha attacking a noncorbiculate bee of the family Halictidae and a social wasp of the genus Polybia (Lutz and Brown 2013; Wcislo et al. 2004). This note comprises the first records of Melaloncha parasitizing Euglossini and Centridini bees. Melaloncha specimens were collected in southeastern Brazil parasitizing Euglossa cordata (Linnaeus), Euglossa townsendi Cockerell, and Centris analis (Fabricius). The Euglossa parasitoids were identified as Melaloncha ronnai Borgmeier while the Melaloncha attacking C. analis could not be identified to species as only its pupa was collected. M. ronnai is one of the best studied species of the genus, with its life cycle thoroughly described from specimens attacking A. mellifera (Ronna 1936). Considering that A. mellifera was introduced in the Neotropical region, the original host ofM. ronnai was still considered doubtful (Brown 2004). All the examined specimens are deposited in the Museu de Zoologia da Universidade de Sao Paulo, Brazil (MZSP). M. ronnai Borgmeier (Figure 1a–c, puparium)