Research Article
Research Article
A missing piece in the puzzle: the presence of Euglossa viridissima in the Baja California Peninsula (Hymenoptera, Apidae)
expand article infoArmando Falcón-Brindis, Ricardo Ayala§, María Luisa Jiménez, Ismael A. Hinojosa-Díaz§
‡ Centro de Investigaciones Biológicas del Noroeste, La Paz, Mexico
§ Universidad Nacional Autónoma de México, Mexico City, Mexico
Open Access


Orchid bees are a conspicuous component of the neotropical bee fauna, with a few species reaching the northernmost natural distribution for the group in northwestern continental Mexico. Among them, Euglossa viridissima Friese is here reported for the first time in the Cape Region of the Baja California peninsula, Mexico, where no species of the group have been found previously. These records are presented, their biogeographical implications discussed, and some interpretations of the local factors that influence the bees is presented.


Biogeography, Cape Region, oases, orchid bees, neotropics


Under the recent documentation of the decline of local pollinator populations (Biesmeijer et al. 2006, Burkle et al. 2013), it is important to monitor the bee fauna composition at local levels (Potts et al. 2010, Goulson et al. 2015). The discovery of species not previously found in particular areas is part of such endeavors. Isolated new records of species are noteworthy particularly in cases involving taxa of exotic origin, from distant or unrelated biogeographic areas, or when they represent a considerable expansion of their known native range. Orchid bees are well known for their external morphological features such as metallic body coloration and long mouthparts, and also for the peculiar perfume collecting behavior of the males (Dressler 1982, Roubik and Hanson 2004). The Euglossini are the only bees within the corbiculate clade (Apini, Bombini, Euglossini, and Meliponini) that are restricted to the neotropics (Cardinal and Packer 2007, Engel et al. 2009), reaching their northernmost distribution in northwestern Mexico, where at least three species of the around 35 found in the country have been recorded (Búrquez 1997, Gonzalez et al. 2017). Orchid bees are powerful long distance flyers, such that females have been found to fly several kilometers while foraging (Janzen 1971, López-Uribe et al. 2008), and males have been recaptured nearly 100 km away (Pokorny et al. 2015). Some euglossine species have been recently discovered in areas that expand considerably their known native range (Anjos-Silva et al. 2006, Anjos-Silva 2007, 2008, Silva and Rebêlo 2009). A notable example of an introduction to a distant area is Euglossa dilemma Bembé & Eltz which was discovered in 2003 in southern Florida, and is now naturalized (Skov and Wiley 2005, Pemberton and Wheeler 2006). This species is a cryptic sibling species of E. viridissima Friese from which it was recently split (Eltz et al. 2011). Euglossa viridissima occurs from Guatemala throughout southern and central Mexico, being one of the few euglossine species that reach the northwestern continental areas of Mexico (Búrquez 1997, Hinojosa-Díaz et al. 2009) with no previous records (before this work) in the Baja California Peninsula. During the development of a wider faunistic bee survey in the state of Baja California Sur, euglossine bees were first observed in the Cape Region. Here the confirmation of these observations is presented, with first records of E. viridissima from the Cape Region of Baja California which represent the first for any euglossine species in the area. The biogeographical implications of these records and local factors that could influence its distribution is briefly discussed.

Materials and methods

The Cape Region of Baja California Sur (BCS), Mexico, is a biogeographic province with distinctive floristic and faunistic elements (Morrone 2005, Halffter et al. 2008). From a paleogeographic approach, it is considered a big island (200 km from continental Mexico) as it has undergone isolation processes (last vicariance event around 3 MYA) since the peninsula’s origins 5-10 MYA (Brusca and Moore 2013, González-Trujillo et al. 2016), favoring high rates of endemism in the region (Wiggins 1980, Roberts 1989). The vegetation of the region includes low deciduous tropical dry forest communities, xeric scrublands, and ecotones between both. The ecotones mark the delimitation of the Cape Region within the subdivision of the Sonoran desert (Axelrod 1978, Rzedowski 2006). An important component of the vegetation of the area are the oases, which are patches of vegetation associated with fresh water springs, which provide water, food and shelter in the middle of arid conditions of the peninsula (Arriaga and Rodríguez-Estrella 1997).

Sampling was carried out from May to November 2016 at 14 localities in the Cape Region (Table 1). Using insect nets the sampling of blooming areas was emphasized, specifically those of Tecoma stans. Additionally, chemical attractants (eugenol and eucalyptus oil) were tested intending to collect male bees in those localities where activity of the orchid bees was thought to be more likely, that is, San Bartolo, Santiago, and Todos Santos. The baited traps consisted of 600 ml plastic bottles following protocols used in South America (Sydney and Gonçalves 2015) arranged in 100 m lineal transects (ten traps per transect, 10m separation among individual traps). On each locality mentioned above one transect was set, with the traps staying for 24 h in every case.

Table 1.

Sampled localities in the Cape Region, Baja California Sur State, Mexico.

Locality Coordinates Elevation (m)
Cabo Pulmo 23°26'06.70"N, 109°25'58.00"W 24
El Triunfo 23°48'12.90"N, 110°06'31.60"W 482
Las Cuevas 23°30'52.50"N, 109°41'23.50"W 125
La Ribera 23°33'21.80"N, 109°33'00.90"W 35
Los Planes 23°58'41.70"N, 109°58'18.20"W 24
Melitón Albáñez 23°38'26.80"N, 110°17'02.00"W 163
Santiago 23°28'37.90"N, 109°42'36.70"W 113
San Antonio de la Sierra 23°40'22.40"N, 109°55'51.10"W 947
San Bartolo 23°44'18.07"N, 109°50'48.85"W 389
San Dionisio 23°32'16.80"N, 109°47'53.60"W 371
Santuario de los cactus 23°44'45.10"N, 110°06'43.60"W 435
Sierra de la Laguna 23°33'06.60"N, 109°59'07.00"W 1752
San Pedrito 23°23'23.40"N, 110°12'26.90"W 17
Todos Santos 23°26'57.53"N, 110°13'35.35"W 32


Of the 14 Cape Region localities sampled, E. viridissima (Figs 1–4) was found only in Todos Santos on the Pacific slope, Santiago and San Bartolo on the Gulf of California slope (Fig. 5).

Figures 1–4. 

Male details of E. viridissima found in Baja California Sur State. 1 Habitus (lateral view) 2 Facial aspect 3 Ventral view of metasoma 4 Mesotibia.

Figure 5. 

Localities in which was registered the presence of E. viridissima in the Cape Region. Biogeographic Provinces map from CONABIO (1997).

In total, 33 specimens (19 males, 14 females) of E. viridissima were collected. Per locality, 30 specimens (17 males, 13 females) came from Todos Santos; all were collected in August, a single female from San Bartolo collected in April, and two males from Santiago collected in October. Most of the specimens were caught in oases vegetation (96.7%). All the bees were captured while visiting flowers of Tecoma stans. The male specimens of E. viridissima were not attracted to the traps baited with chemical attractants.

Voucher specimens are deposited into in the entomological collection at the CIBNOR (La Paz, Mexico).


The finding of Euglossa viridissima as the first record of an orchid bee species on the Baja California peninsula has several implications. Biogeographically, E. viridissima has the northernmost natural distribution within Euglosines (Búrquez 1999, Roubik and Hanson 2004, Hinojosa-Díaz et al. 2009, Ramírez et al. 2010). In addition, this finding represents both a new and distinctive biogeographic area to the distribution of the species, and a new Neotropical bee record to the mainly Nearctic peninsula (Morrone 2005). Before our records of E. viridissima in the Cape Region of the peninsula, no other euglossines had been reported from there (Ayala et al. 1996, Moure et al. 2007, Ascher and Pickering 2017).

The Cape Region of the Baja California Peninsula is separated from the nearest Mexican mainland by the Gulf of California by around 200 km, much further than the nearly 100 km that a male E. viridissima was registered to fly when attracted to a bait in the Yucatán Peninsula (Pokorny et al. 2015). While most of the South American expansion records are likely due to the bees own dispersal capabilities (Anjos-Silva et al. 2006, Anjos-Silva 2007, 2008, Silva and Rebêlo 2009, Silva et al. 2013, Martins et al. 2016), the E. viridissima records from Baja California are unlikely to have gotten there by long distance migration. Alternatively, these bees are cavity nesters (May-Itzá et al. 2014), making it possible that occupied nests would survive the carrying from the continental lands to the peninsula. Also possible is that they were brought over accidentally along with normal commerce. The morphological conspicuousness of these bees (Figs 1–4) makes it hard to think that they have been in the area for long with no one noticing them before, so our best guess is that as these bees are a relatively recent arrival.

Euglossa viridissima appears to be well-established on Baja California, since the three sampled points (Fig. 5) are rather spread over the Cape Region and both sexes were relatively abundant at Todos Santos. However, the potential distribution modeled by Hinojosa-Díaz et al. (2009) predicted there was not suitable habitat anywhere in the peninsula of Baja California for E. viridissima, as understood then, but for Eulaema polychroma, one of the other orchid bee species reaching the northwestern continental areas of Mexico.

Our floristic observations of the host plant differ from Arriaga and León de la Luz (1989), who found T. stans as a predominant species in some patches at the Pacific hills compared to the Gulf slope. Weather conditions are complex when comparing these two slopes in the Cape Region. Roberts (1989) mentioned that climatic and physiographic conditions make the Gulf slope more humid and hotter than the west side of the peninsula. However, Díaz and Troyo (1997) found drier and hotter oases in the east slope influenced by local phenomena. Arriaga and León de la Luz (1989) explained higher plant richness at the Pacific slope because its cooler and more humid conditions compared to the Gulf slope.

It is possible that abiotic factors (e.g. moisture, temperature) have more of an effect on populations than food availability. We do not discard the possibility that natural enemies also play an important role on these boundaries (e.g. more humid places increase likelihood to fungus attacks on immature stages). The new finding of E. viridissima at the Cape Region highlights its biological relevance as an important element of the Neotropical area. In addition, since the oases of the Baja California peninsula are shaped by different factors such as water availability, type of soil, geographical position, and degree of anthropogenic disturbance, the biological communities may respond to such insular-like conditions, presenting variation in structure and abundance (Jiménez et al. 2015, Arriaga and Rodríguez-Estrella 1997). Furthermore, considering the about 21 species of orchids restricted to some deep valleys or higher elevations (>600 m) in Sierra de La Laguna, BCS (Medel-Narváez pers. com. Jan. 20th 2017), it makes conceivable to think of possible euglossines-plant interactions, but also to find specific relationships with endemic orchid species. However, further research on these subjects is encouraged.

Overall, the records of E. viridissima in the Cape Region of the Baja California peninsula represent an important piece of information regarding these bee’s distribution and likely dispersal or ecological capabilities. They also bring the opportunity to stress the need to sample the local bee faunas, in a time when pollinators are known to be declining in different parts of the world.


The authors thank to Carlos Palacios C. and Daniel E. Garavito H. for field assistance. Claudia J. Pérez E. for her kind help to take the bee´s photographs. Alfonso Medel N. and Reymundo Domínguez C. for gentle plant identification and supporting information about local vegetation. Funding was provided by CIBNOR. AFB received a scholarship (273254) from CONACyT, México.


  • Anjos-Silva EJ (2007) Occurrence of Eulaema (Apeulaema) pseudocingulata Oliveira (Hymenoptera: Apidae: Euglossini) in the Platina Basin, Mato Grosso State, Brazil. Neotropical Entomology 36(3): 484–486.
  • Anjos-Silva EJ, Camillo E, Garófalo CA (2006) Occurrence of Aglae caerulea Lepeletier & Serville (Hymenoptera: Apidae: Euglossini) in the Parque Nacional da Chapada dos Guimarães, Mato Grosso State, Brazil. Neotropical Entomology 35(6): 868–870.
  • Arriaga L, León de la Luz J (1989) The Mexican tropical deciduos forest of Baja California Sur: a floristic and structural approach. Vegetatio 84: 45–52.
  • Arriaga L, Rodríguez-Estrella R (1997) Los oasis de la península de Baja California. Centro de Investigaciones Biológicas del Noreste. La Paz, Baja California Sur, México, 292 pp.
  • Axelrod DI (1978) The origin of coastal and sage vegetation, Alta and Baja California. American Journal of Botany 65(10): 1117–1131.
  • Ayala R, Griswold TL, Yanega D (1996) Apoidea (Hymenoptera). In: Llorente J, García AN, González E (Eds) Biodiversidad taxonomía y biogeografía de artrópodos de México: Hacia una síntesis de su conocimiento.CONABIO – UNAM, México, 423–464.
  • Biesmeijer JC, Roberts SPM, Reemer M, Ohlemuller R, Edwards M, Peeters T, Schaffers AP, Potts SG Kleukers R, Thomas CD, Settele J, Kunin WE (2006) Parallel declines in pollinators and insect–pollinated plants in Britain and the Netherlands. Science 313: 351–354.
  • Brusca RC, Moore W (2013) A natural history of the Santa Catalina Mountains, Arizona, with an introduction to the Madrean Sky Islands. Arizona–Sonora Desert Museum Press, Tucson, AZ, 232 pp.
  • Burkle LA, Marlin JC, Knight TM (2013) Plant–pollinator interactions over 120 years: loss of species, co–occurrence, and function. Science 339(6127): 1611–1615.
  • Búrquez A (1997) Distributional limits of euglossine and meliponine bees (Hymenoptera: Apidae) in northwestern Mexico. Pan-Pacific Entomologist 73: 137–140.
  • Díaz S, Troyo E (1997) Balance hidrológico y análisis de aridez. In: Arriaga L, Rodríguez-Estrella R (Eds) Los oasis de la Península de Baja California.Centro de Investigaciones Biológicas del Noroeste, La Paz, Baja California Sur, México, 35–49.
  • Eltz T, Fritzsch F, Pech JR, Zimmermann Y, Ramírez SR, Quezada-Euan JJG, Bembé B (2011) Characterization of the orchid bee Euglossa viridissima (Apidae: Euglossini) and a novel cryptic sibling species, by morphological, chemical, and genetic characters. Zoological Journal of the Linnean Society 163: 1064–1076.
  • Engel MS, Hinojosa-Díaz IA, Rasnitsyn AP (2009) A honey bee from the Miocene of Nevada and the Biogeography of Apis (Hymenoptera: Apidae: Apini). Proceedings of the California Academy of Sciences 60(3): 23–38.
  • Gonzalez VH, Griswold T, Simões M (2017) On the identity of the adventive species of Eufriesea Cockerell in the USA: systematics and potential distribution of the coerulescens species group (Hymenoptera, Apidae). Journal of Hymenoptera Research 55: 55–105.
  • González-Trujillo R, Correa-Ramírez MM, Ruiz-Sanchez E, Méndez Salinas E, Jiménez ML, García-De León FJ (2016) Pleistocene refugia and their effects on the phylogeography and genetic structure of the wolf spider Pardosa sierra (Araneae: Lycosidae) on the Baja California Peninsula. Journal of Arachnology 44(3): 367–379.
  • Goulson D, Nicholls E, Botías C, Rotheray EL (2015) Bee declines driven by combined stress from parasites, pesticides, and lack of flowers. Science 347(6229): 1255957.
  • Halffter G, Llorente-Bousquets J, Morrone JJ (2008) La perspectiva biogeográfica histórica. In: Sarukhán J (Ed.) Capital natural de México.Vol. I. Conocimiento actual de la biodiversidad. Conabio, Mexico City, 67–86.
  • Hinojosa-Díaz IA, Feria-Arroyo T, Engel MS (2009) Potential distribution of orchid bees outside their native range: The cases of Eulaema polychroma (Mocsáry) and Euglossa viridissima Friese in the USA (Hymenoptera: Apidae).15: 421–428.
  • Jiménez ML, Nieto-Castañeda IG, Correa-Ramírez MM, Palacios-Cardiel C (2015) Las arañas de los oasis de la región meridional de la península de Baja California, México. Revista Mexicana de Biodiversidad 86: 319–331.
  • López-Uribe MM, Oi CA, Del Lama MA (2008) Nectar-foraging behavior of Euglossine bees (Hymenoptera: Apidae) in urban areas. Apidologie 39: 410–418.
  • Martins DC, Albuquerque PMC, Silva FS, Rebêlo JMM (2016) First record of Aglae caerulea (Hymenoptera, Apidae, Euglossini) in Brazilian Cerrado east of the Amazon Region, Maranhão State, Brazil. Brazilian Journal of Biology 76(2): 554–556.
  • May-Itzá WJ, Medina Medina LA, Medina S, Paxton RJ, Quezada-Euán JJG (2014) seasonal nest characteristics of a facultatively social orchid bee, Euglossa viridissima, in the Yucatan Peninsula, Mexico. Insectes Sociaux 61: 183–190.
  • Morrone JJ (2005) Hacia una síntesis biogeográfica de México. Revista Mexicana de Biodiversidad 76(2): 207–252.
  • Moure JS, Melo GAR, Faria Jr LRR (2007) Euglossini Latreille, 1802. In: Moure JS, Urban D, Melo GAR (Eds) Catalogue of Bees (Hymenoptera, Apoidea) in the Neotropical Region. Sociedade Brasileira de Entomologia, Curitiba, Brazil, 214–255. Electronic resource: [Last accessed 24.VII.2017]
  • Pokorny T, Loose D, Dyker G, Quezada-Euán JJG, Eltz T (2015) Dispersal ability of male orchid bees and direct evidence for long-range flights. Apidologie 46: 224–237.
  • Potts SG, Biesmeijer JC, Kremen C, Neumann P, Schweiger O, Kunin WE (2010) Global pollinator declines: Trends, impacts and drivers. Trends in Ecology and Evolution 25(6): 345–353.
  • Ramírez SR, Roubik DW, Skov C, Pierce NE (2010) Phylogeny, diversification patterns and historical biogeography of euglossine orchid bees (Hymenoptera: Apidae). Biological Journal of the Linnean Society 100: 552–572.
  • Roberts NC (1989) Baja California plant field guide. Natural History Publishing Company, La Jolla, California, 309 pp.
  • Roubik DW, Hanson PE (2004) Orchid bees of tropical America: biology and field guide. Instituto Nacional de Biodiversidad, INBio, Santo Domingo de Heredia, Costa Rica, 352 pp.
  • Rzedowski J (2006) Vegetación de México. 1ra. Edición digital. Comisión Nacional para el Conocimiento y Uso de la Biodiversidad, México, 504 pp.
  • Silva O, Rebêlo JMM (2009) Primeiro Registro de Euglossa stilbonota Dressler (Apidae: Euglossini) fora da Floresta Amazônica: Implicações Biogeográficas. Neotropical Entomology 38(6): 880–882.
  • Silva DP, Aguiar AJC, Melo GAR, Anjos–Silva EJ, Marco Jr P (2013) Amazonian species within the Cerrado savanna: new records and potential distribution for Aglae caerulea (Apidae: Euglossini). Apidologie 44: 673–683.
  • Sydney NV, Gonçalves RB (2015) Is the capture success of orchid bees (Hymenoptera, Apoidea) influenced by different baited trap designs? A case study from southern Brazil. Revista Brasileira de Entomologia 59: 32–36.
  • Wiggins IL (1980) Flora of Baja California. Stanford University Press, Stanford, California, 1025 pp.