First records of four orchid bee species (Hymenoptera, Apidae: Euglossini) in Ecuador

First records of four orchid bee species (Hymenoptera, Apidae: Euglossini) in Ecuador  

Alexandra D. Hernández Hernández

Instituto Nacional de Biodiversidad (INABIO), Quito, Ecuador.

https://orcid.org/0000-0001-7774-759X  

Marcio L. de Oliveira

Instituto Nacional de Biodiversidad (INABIO), Quito, Ecuador [1]; Instituto Nacional de Pesquisas da Amazônia, Coordenação de Biodiversidade, Manaus, Brazil [2].

https://orcid.org/0000-0003-4917-3095  

David R. Diaz-Guevara

Instituto Nacional de Biodiversidad (INABIO), Quito, Ecuador.

https://orcid.org/0009-0001-4632-4460

Cristina Alarcón-Ortiz

Universidad Central del Ecuador, Carrera de Medicina Veterinaria, Quito, Ecuador.

https://orcid.org/0009-0000-2733-018

Alex Pazmiño-Palomino

Instituto Nacional de Biodiversidad (INABIO), Quito, Ecuador.

https://orcid.org/0000-0001-5270-2096   

ABSTRACT. Orchid bees (Hymenoptera, Apidae, Euglossini) play a vital role as key pollinators in the Neotropical forests. Their preference for forested areas makes these bees more susceptible to environmental changes, particularly in areas under severe human impact, such as the Chocó-Darien biodiversity hotspot. This study presents new data on orchid bees within the Canandé Biological Reserve, a lowland rainforest in the Chocó region of northwestern Ecuador. At this site, four species of orchid bees were recorded for the first time in Ecuador: Euglossa bursigera Moure, 1970, Euglossa crassipunctata Moure, 1968, Euglossa villosiventris Moure, 1968 and Eufriesea macroglossa (Moure, 1965). We also provide species-specific information on diagnosis, distribution maps, and high-resolution images. With these records, the total number of orchid bee species recorded in Ecuador now stands at 119.

Keywords: Apinae, Chocó, Euglossa, Eufriesea, rainforest

Citation: Hernández Hernández, A.D., de Oliveira, M.L., Diaz-Guevara, D.R., Alarcón-Ortiz, C., Pazmiño-Palomino, A. (2025) First records of four orchid bee species (Hymenoptera, Apidae, Euglossini) in Ecuador. Journal of Insect Biodiversity and Systematics, 11 (x), xx–xx.

Orchid bees belong to Euglossini (Apidae, Apinae), a tribe distributed from Northern Mexico to South America with a single species known in the southern United States (Griswold et al., 2015). This tribe plays a crucial role in pollination and ecological balance within tropical and subtropical forests in the Neotropics (Roubik & Hanson, 2004). Orchid bees, with their striking metallic colours, elongated tongues, and unique odor-collecting behaviour, have long fascinated scientists and nature enthusiasts (Hinojosa-Díaz et al., 2012). Despite this, knowledge of the diversity and distribution of this tribe in the New World keeps increasing. To date, 249 euglossine extant species have been described, Euglossa Latreille, 1802 is the genus with the highest richness, with 134 described species (Engel, 2021), followed by Eufriesea Cockerell, 1908, Eulaema Lepeletier, 1841, Exaerete Hoffmannsegg, 1817 and Aglae Lepeletier & Serville, 1825 and a few extinct species (Moure & Melo, 2023). The orchid bee fauna has been summarized in species checklists and other studies in 10 countries from Central and South America (Ramírez et al., 2002; Moure & Melo, 2023).

Ecuador, in particular, exhibits extraordinary species richness, with 115 known species, of which 68 belong to Euglossa, 23 to Eufriesea, 18 to Eulaema, five to Exaerete, and one to Aglae (Ramírez et al., 2002; Padron et al., 2018; Moure & Melo, 2023). Padron et al. (2018) published the first checklist of orchid bees in Ecuador, mentioning that most species have been found in tropical Amazon rainforests. However, much of the Ecuadorian territory remains unexplored. This is particularly true for the tropical lowland rainforest of the Chocó-Darién biodiversity hotspot in northwestern Ecuador, a region that remains largely unexplored. Chocó-Darién rainforests are characterized by a remarkable species richness and endemism in various plant and animal taxa (Yánez-Muñoz et al., 2010). At the same time, this zone is particularly threatened due to massive timber extraction, especially in the Ecuadorian portion (Vásquez, 2005). Within this hotspot, most of the orchid bee surveys have been concentrated in Panamá, leaving an important information gap in Colombia and Ecuador.

To address these gaps, a first study of Euglossini diversity was conducted in the Canandé Biological Reserve, one of the last large, well-preserved remnants of the lowland Chocó a rainforest in northwestern Ecuador. Among the species found, we recorded four Euglossini species for the first time in Ecuador: Euglossa bursigera Moure, 1970, Euglossa crassipunctata Moure, 1968, Euglossa villosiventris Moure, 1968, and Eufriesea macroglossa Moure, 1965. In this study, we offer complete diagnoses, distribution maps and high-resolution images for these species to help with their identification. Finally, this research contributes to the state of knowledge and perspectives on the diversity and distribution of orchid bees in Ecuador and the Chocó-Darién biodiversity hotspot.      

MATERIAL AND METHODS

Study area. The Canandé Biological Reserve (RBC) is located in the tropical region of Chocó-Darién hotspot in northwestern Ecuador, in the Esmeraldas province, between 230–600 m elevation. It is one of the largest private reserves in the country, with an area of 8488 hectares that belongs to the Fundación de Conservación Jocotoco. The vegetation is characterized by the Chocó Lowland Evergreen Forest (Ministerio de Ambiente de Ecuador, 2013) (Fig. 1). Sampling was conducted at two sites located within large, continuous patches of pristine rainforest within the RBC: 1. Gualpí de los Cayapas 0°34'02.1"N, 79°03'47.6"W, 400 m of elevation (October 11^th-26^th, 2022). 2. El Silencio, 0°30'56.3"N, 79°01'18.3"W, 335 m of elevation (May 29^th–June 6^th, 2023).

Field survey. For each sampling site, a single transect was established with six collection points spaced 100 meters apart. At each collection point, four trees were randomly selected, and two traps were placed on each tree - one in the canopy and one in the understory. Each trap consisted of a 1500-mL plastic bottle featuring three inlets in the upper third, each fitted with a plastic bottleneck. The bottlenecks had a layer of sand glued inside to facilitate bee access. Inside each trap, a piece of cotton saturated with an aromatic compound was tied to one end of a thin stick held by the bottle's lid. This trap design was chosen based on its common use in recent Euglossini bee studies (Ramalho et al., 2009; Ribeiro et al., 2022). Four different aromatic compounds were used in the traps: methyl salicylate, clove oil, Eucalyptus oil, and vanillin (Oliveira & Campos, 1995; Santos-Junior et al., 2014). The traps were active for six continuous days, with samples collected daily, resulting in a total sampling time of 144 hours per trap. To set the canopy traps, a slingshot was used to throw a string over a tree branch and lift the trap to the canopy, which was between 10–15 meters high. The collected specimens were preserved in 96% ethanol and organized by capture method, habitat, and sampling unit, with proper labelling.

Laboratory work and identification. Specimens collected were pinned, viewed under a stereomicroscope (Olympus^© SZ61), and identified to genus and morphospecies using the identification keys of Roubik & Hanson (2004) and Bonilla-Gómez & Nates-Parra (1992). Species-level identifications were made using specialized taxonomic keys for each genus: Eulaema (Oliveira, 2006), Exaerete (Kimsey, 1979; Oliveira & Nemesio, 2003; Oliveira, 2011), Eufriesea (Kimsey, 1982) and Euglossa (Engel, 2021; Dressler, 1982a, 1982b, 1982c; Bonilla-Gómez & Nates-Parra, 1992; Hinojosa-Díaz et al., 2012; Nemesio & Engel, 2012).

Figure 1. Habitat of the study area at Canandé Biological Reserve (RBC), northwestern Ecuador. [Image by Jorge Brito]

Bee specimens collected were compared with the Instituto Nacional de Biodiversidad Entomological Collection (MECN), an Ecuadorian orchid bee reference collection identified by specialists RL Dressler and ML Oliveira. Specimens were compared to high-resolution images of Euglossini reference specimens, including type material, available on the websites of the Smithsonian Tropical Research Institute (https://stricollections.org/) and the Smithsonian National Museum of Natural History (https://collections.nmnh.si.edu/search/). Finally, we confirmed each identified species with the original taxonomic descriptions. Photographic records were made with a Canon^® EOS 7D camera adapted with a 100 mm lens and Raynox^® DCR-250 2.5´ Super Macro Lens. Photo-stacking was done with Helicon Focus^® v. 7.5.6 (Helicon Soft Ltd.). Specimens were deposited in the Instituto Nacional de Biodiversidad Entomological Collection (MECN).

RESULTS

Taxonomic hierarchy

Class Insecta Linnaeus, 1758

Order Hymenoptera Linnaeus, 1758

Superfamily Apoidea Latreille, 1802

Family Apidae Latreille, 1802

Genus Euglossa Latreille, 1802

Subgenus Glossurella Dressler, 1982

Euglossa (Glossurella) bursigera Moure, 1970 (Figs 2, 7A)

Material examined. 5♂♂ (MECN-HYM-8056, MECN-HYM-8082, MECN-HYM-8119 to 8121), ECUADOR: Esmeraldas Province, Eloy Alfaro, Telembí, Gualpí de los Cayapas; 0°34'02.1"N, 79°03'47.6"W; 400 m alt., 13.X.2022, A. Pazmiño | D. Díaz leg., bottle trap Vainillina | Clove | Eucalyptus oil; 8♂♂ (MECN-HYM-8805 to 8812), Quinindé, Malimpia, El Silencio; 0°30'56.3"N, 79°01'18.3"W; 335 m alt.; 23.V.2023; D. Díaz | M.S. Basantes | E. Marcayata leg., bottle trap Eucalyptus oil | Vanillin | Clove.

Identification. Within the subgenus Glossurella, Eug. bursigera can be differentiated by the following combination of characters: Shape of metatibia triangular (posterior angle acute); scape cylindrical; length of labio-maxillary complex reaching or barely surpassing tip of metasoma; malar length about ½ width of mid-flagellomeres; separation of the tip of metatibial organ slit from the ventral margin of metatibia slightly over maximum width of organ slit; tiny mid-mandibular tooth, adjacent to the outer tooth; punctuation of tergum-II decreasing in size over broad band (Dressler, 1982c; Hinojosa-Díaz et al., 2012).

Distribution. Colombia, Costa Rica, Ecuador (new record), Honduras, Nicaragua, and Panamá (Hinojosa-Díaz et al., 2012; Nova León, 2021). Lowland rainforest up to 800 m elevation.

Figure 2. Euglossa (Glossurella) bursigera Moure, 1970. A. Habitus, lateral view, scale bar = 3 mm;
B. Habitus, dorsal view, scale bar = 2 mm; C. Head, frontal view, scale bar = 1 mm; D. Velvet area and tufts of mid-tibia. [Images by Marissa Barreno and Alex Pazmiño-Palomino]

Subgenus Trachyglossa Engel, 2021

Euglossa (Trachyglossa) crassipunctata Moure, 1968 (Figs 3, 4, 7B)

Material examined. 2♂♂ (MECN-HYM-8079, MECN-HYM-8080), ECUADOR: Esmeraldas Province, Eloy Alfaro, Telembí, Gualpí de los Cayapas; 0°34'02.1"N, 79°03'47.6"W; 400 m alt., 13.X.2022, A. Pazmiño | D. Díaz leg.,  bottle trap Eucalyptus oil.

Identification. Within the subgenus Trachyglossa, Eug. crassipunctata should be differentiated by the following combination of characters: Mesoscutum, mesoscutellum, and majority of the body brilliant metallic green or green-blue; clypeus blue or green-blue, episternum and scutum not coarsely punctured; tibial hairline fringe covering almost the entire length of the hind tibial slit; sternum VIII apically coming to a sharp, narrow point, with posterolateral projections of anterior section prominently angled; gonostylus with broader base (Fig. 4); posterior mesotibial tuft well developed and triangular, much larger and encompassing nearly entire bordering area of depressed integument (Roubik & Hanson, 2004; Bonilla-Gómez & Nates-Parra, 1992; Nemesio & Engel, 2012; ML Oliveira obs. pers.).

Distribution. Brazil, Colombia, Costa Rica, Ecuador (new record), French Guiana, Honduras, Nicaragua, and Panamá (Ramírez et al., 2002; GBIF, 2024).

Figure 3. Euglossa (Trachyglossa) crassipunctata Moure, 1968. A. Habitus, lateral view, scale bar = 1 mm;
B. Habitus, dorsal view, scale bar = 1 mm; C. Head, frontal view, scale bar = 1 mm; D. Velvet area and tufts of mid-tibia. [Images by Marissa Barreno and Marcio Oliveira]

Figure 4. Male terminalia of Euglossa crassipunctata Moure, 1968 (MECN-HYM-8079). A. Genital capsule, ventral view; B. Genital capsule, dorsal view; C. Seventh metasomal sternum; D. Eighth metasomal sternum. Dissection prepared by Alexandra Hernández and Marissa Barreno. [Images by Alex Pazmiño-Palomino and Josue Franco]

Subgenus Euglossa (Euglossa) Latreille, 1802

Euglossa (Euglossa) villosiventris Moure, 1968 (Figs 5, 7C)

Material examined. 32♂♂ (MECN-HYM-7642 to 7673), ECUADOR: Esmeraldas Province, Eloy Alfaro, Telembí, Gualpí de los Cayapas; 0°34'02.1"N, 79°03'47.6"W; 400 m alt., 13.X.2022, A. Pazmiño | D. Díaz leg.,  bottle trap Vainillina | Methyl salicylate; 3♂♂ (MECN-HYM-8813 to 8815), Quinindé, Malimpia, El Silencio; 0°30'56.3"N, 79°01'18.3"W; 335 m alt.; 25.V.2023; D. Díaz | M.S. Basantes | E. Marcayata leg., bottle trap Vainillina.

Identification. Within the subgenus Euglossa s.str., Eug. villosiventris can be differentiated by the combination of the following characters: mandible bidentate; posterior mid-tibial tuft present (though may be very small), an anterior tuft of median tibia slightly divided, lobules indistinguishable; sternum II with a single large tuft of confluent hairs occupying almost the entire structure; clypeus green; body colour blue-violet; terminal tergites green or bronze (Dressler, 1982b; Roubik & Hanson, 2004; Bonilla-Gomez & Nates-Parra, 1992).

Distribution. Colombia, Costa Rica, Ecuador (new record), Nicaragua, Panamá, and Venezuela (Ramírez et al., 2002; Ospina-Torres et al. 2015).

Genus Eufriesea Cockerell, 1908

Eufriesea macroglossa (Moure, 1965) (Figs 6, 7D)

Material examined. 4♂♂ (MECN-HYM-8046 to 8049), ECUADOR: Esmeraldas Province, Eloy Alfaro, Telembí, Gualpí de los Cayapas; 0°34'02.1"N, 79°03'47.6"W; 400 m alt., 13.X.2022, A. Pazmiño | D. Díaz leg., bottle trap Methyl salicylate | Vanillin | Clove; 1♂ (MECN-HYM-8816), Quinindé, Malimpia, El Silencio; 0°30'56.3"N, 79°01'18.3"W; 335 m alt., 25.V.2023; D. Díaz | M.S. Basantes | E. Marcayata leg.; bottle trap Vainillin.

Identification.  Within the macroglossa group, the species Euf. macroglossa can be distinguished by the steel blue male face and purple female face, male midtibial brush continuous with an anterior felty patch, and gonostylar dorsal lobe as long as the ventral one. Among the most similar species, the colour of the terga distinguishes them: Euf. venusta generally has brilliantly orange to coppery terga, Euf. lucida has more greenish terga, Euf. macroglossa has reddish/yellowish terga, and Euf. nigrescens has dark purplish terga (Kimsey, 1982).

Distribution. Colombia, Costa Rica, Ecuador (new record), and Panamá (Ramírez et al., 2002).

Figure 5. Euglossa (Euglossa) villosiventris Moure, 1968. A. Habitus, lateral view, scale bar = 2 mm;
B. Habitus, dorsal view, scale bar = 2 mm; C. Head, frontal view, scale bar = 1.7 mm; D. Velvet area and tufts of mid-tibia. [Images by Marissa Barreno and Alex Pazmiño-Palomino]

Figure 6. Eufriesea macroglossa (Moure, 1965). A. Habitus, lateral view, scale bar = 2 mm; B. Habitus, dorsal view, scale bar = 2 mm; C. Head, frontal view, scale bar = 2 mm; D. Velvet area and tufts of mid-tibia. [Images by Marissa Barreno and Alex Pazmiño-Palomino]

DISCUSSION

Our study presents the first confirmed records of four orchid bee species in Ecuador. These findings significantly expand the known range of these species: For Eug. bursigera, the nearest known record is over 700 kilometers away, located in the Antioquia department of Colombia (Nova León, 2021). For Eug. villosiventris, the closest confirmed record lies more than 130 kilometers away from our sampling site in the Nariño department of Colombia (Ospina-Torres et al., 2015). The nearest known record of E. crassipunctata is more than 280 Kilometers to the northeast of our sampling localities in Putumayo department, Colombia (GBIF, 2024). Finally, the Ecuadorian records of Eufriesea macroglossa are over 1000 kilometers away from the nearest record in Telamanca, Limón province of Costa Rica, marking it the southernmost known occurrence of this species (GBIF, 2024).

The Chocó’s rainforest remains an under-explored biodiversity hotspot for many zoological groups, including bees (Yánez-Muñoz et al. 2010). It is believed that further studies of the bee fauna of Chocó will lead to more important discoveries about these fascinating taxa. Ecuador's location at the southernmost extent of the Chocó region where rainforest ecosystems meet the tropical Andes, creates a unique site for the existence of endemic species (Sarkar et al., 2009). These ecosystems in Ecuador are under significant threat from rapid timber extraction, mining and land use change (Roy et al., 2018; Sarkar et al., 2009).

Figure 7. Distribution maps of the species recorded for the first time in Ecuador. A. Euglossa bursigera (violet hexagons); B. Euglossa crassipunctata (red crosses); C. Euglossa villosiventris (blue circles);
D. Eufriesea macroglossa (green triangles).

This makes it urgent to explore biodiversity in the Ecuadorian portion of the Chocó-Darién hotspot, home to many endemic species, including potentially threatened insects (Barria, 2022).

In conclusion, these findings bring the total number of known orchid bee species in Ecuador to 119, an increase from the preliminary list of 115 species provided by Padrón et al. (2018). However, it is important to conduct further bee inventories to understand the current distribution of orchid bees with a particular emphasis on Ecuador. Bee diversity in Ecuador remains largely underexplored. Currently, a national checklist is available only for the Euglossini tribe (Padrón et al., 2018). The absence of comprehensive checklists for other bee groups presents a significant challenge for entomologists and zoologists studying these important pollinators, especially in the tropics.

AUTHOR′S CONTRIBUTION

The authors confirm their contribution to the paper as follows: A.D. Hernández Hernández: Conceptualization, Investigation, Writing – original draft; M.L. de Oliveira: Investigation, Validation, Writing – review & editing; D.R. Díaz-Guevara: Investigation, Visualization, Resources, Writing – review & editing; C. Alarcón-Ortiz:  Investigation, Data Curation, Writing – review & editing; A. Pazmiño-Palomino: Conceptualization, Methodology, Validation, Supervision, Project administration, Writing – original draft, Writing – review & editing. The authors read and approved the final version of the manuscript.

FUNDING

Expeditions and lab work processing were funded by the Fundación de Conservación Jocotoco through a specific agreement with Instituto Nacional de Biodiversidad – INABIO. Lab and writing work were undertaken at INABIO labs and biological collections.

AVAILABILITY OF DATA AND MATERIAL

The specimens listed in this study are deposited in the Instituto Nacional de Biodiversidad Entomological Collection (MECN) and are available from the curator, upon request.

ETHICS APPROVAL AND CONSENT TO PARTICIPATE

This study only included arthropod material, and all required ethical guidelines for the treatment and use of animals were strictly adhered to in accordance with international, national, and institutional regulations. No human participants were involved in any studies conducted by the authors for this article.

CONSENT FOR PUBLICATION

Not applicable.

CONFLICT OF INTERESTS

The authors declare that there is no conflict of interest regarding the publication of this paper.

ACKNOWLEDGMENTS

We are especially grateful to David Parra from Fundación Jocotoco. A special acknowledgement to Chiara Correa, who helped to organize the expedition to Gualpí de los Cayapas. INABIO colleagues supported all the field, lab, and writing work, especially Andrea Paredes-Bracho, Estefany Lincango, Michael S. Basantes, Esther Marcayata, Pablo Sánchez, Mario Yanez-Muñoz, Felipe Campos, Diana Fernández, Pablo Moreno, Jorge Brito, Francisco Prieto, and Diego J. Inclán. Pablo Sánchez provided support in the development of the sampling design presented in the Methodology section. Specimens were collected under research permit No. MAAE-ARSFC-2022-2206 and MAATE-ARSFC-2023-3332 granted by Ministerio de Ambiente, Agua y Transición Ecológica de Ecuador. Thanks to Marissa Barreno and Josue Franco for help in taking nice photos of the bee specimens and for reviewing and editing a version of the manuscript. We thank Dr. Michael S. Caterino (Clemson University, US) for reviewing the English language and providing important comments on our manuscript. Finally, we are grateful for the comments of two anonymous reviewers who significantly improved the quality of this work. This is a contribution to the series The Wild Bees of Ecuador.