Tribe Euglossini Research Articles

A Historical Review of the Artificial Pollination of Vanilla planifolia: The Importance of Collaborative Research in a Changing World.

The natural fertilization of Vanilla planifolia has long been a matter of speculation. Stingless (tribe Meliponini) and orchid bees (tribe Euglossini) are often cited as effective pollinators, but direct evidence is notoriously lacking. As with other food-deceptive orchids, the natural fruit-set in V. planifolia is low and does not occur spontaneously outside its native range in Middle America. Fruiting has, therefore, necessitated human intervention through artificial pollination. How Vanilla first came to be artificially pollinated is a controversial issue spurring egotism and nationalism. There are numerous texts offering differing versions of the historical events that led to the discovery of the artificial fertilization of V. planifolia and its propagation as a crop. Historical records show Vanilla was simultaneously being pollinated in several parts of the world. I argue that the suspected independent simultaneous discoveries made in Liège, Paris, Padua, the Dutch colony of Java (Indonesia), and the French insular colonies Réunion (Bourbon), Guadeloupe, and Martinique are not unconnected. I conclude that they can be traced back to a single discoverer whose feat was spread around the globe by a tight network of corresponding naturalists. This view contrasts with previous authors. Finally, current concerns regarding Vanilla pollination and production are addressed, highlighting the need for immediate actions to conserve the genetic diversity of the crop's wild relatives to attenuate the effect of extreme climates in a changing world. A plea is made to shift the focus to Middle America, stimulating and supporting local research and conservation efforts and the allocation of funds from this billion-dollar industry.

FIRST RECORD OF EUFRIESEA BARE GONZÁLEZ & GAIANI AND NOTES ON THE DISTRIBUTION OF THREE SPECIES OF ORCHID BEES PERTAINING TO THE GENUS EUGLOSSA LATREILLE (APIDAE: EUGLOSSINI) IN COLOMBIA

Knowledge on the geographical distribution of orchid bee species in Colombia and most of the Neotropics depends on monitoring and sample methodologies implemented and facilities to access diverse natural regions. In addition, for research on the distribution of species, the taxonomic impediment is a problem for the identification and confirmation of some species, although the tribe Euglossini presents a relatively well-developed taxonomy. Herein is presented the first record of Eufriesea bare in Colombia, an orchid bee species known only in the Venezuelan Amazonian region; as well as the distribution of three euglossine species of the genus Euglossa.

New insights on the rare blind blister beetle genus Meloetyphlus (Coleoptera: Meloidae): occurrence in Colombia, SEM larval description, and molecular phylogenetic placement

Abstract Meloetyphlus Waterhouse is a monotypic genus of Meloidae ascribed to the tribe Tetraonycini, subfamily Meloinae. As for most blister beetles, its first-instar larvae (or triungulins) are parasites of bees, but M. fuscatus Waterhouse is the only species known to parasitize members of the tribe Euglossini (Hymenoptera: Apidae: Apinae). Despite being widely distributed in Central and South America, its presence in Colombia has never been confirmed. In this article, we document the occurrence of this genus in Colombia providing the first certain record for this country. In addition, some aspects of its parasitization of Eulaema nigrita Lepeletier are reported and illustrated with macrophotographs and a video. By the means of drawings and SEM micrographs, we provide the most detailed description of the first-instar larva of M. fuscatus to date and a comparison with the triungulin of the closely related Tetraonyx fulvus (LeConte). Finally, we investigated the phylogenetic position of Meloetyphlus using molecular data, to support its attribution to the tribe Tetraonycini.

Observations on Orchids and Euglossine Bees in Panama and Costa Rica

Many orchid flowers and sorne flowers of other families produce no nectar and are visited and pollinated primarily or exclusively by male euglossine bees. These bees brush on the surface of the flower with tufts of hair on the forefeet, and gather sorne aromatic substance which is then placed in their inflated hind tibiae. The bees are attracted by odor, and many of the flower odors are highly specific, attracting one or few bee species. The tribe Euglossini includes Euglossa, Eulaema, Euplusia, Eufriesea , and the parasitic genera Aglae and Exaerete . All genera of the orchid subtribe Stanhopeinae are pollinated by euglossine bees; observations are given here for Acineta superba, Coeliopsis hyacinthosma, Coryanthes maculata, Gongora (5 or 6 species), Kegeliella atropilosda, Lacaena spectabilis, Paphinia clausula, Peristeria (2 species), Polycycnis gratiosa, Sievekingia (2 species) and Stanhopea (3 species) . All members of the subtribe Catasetinae are also pollinated by euglossine bees, and observations are given for all three genera: Catasetum (3 species), Cycnoches (6 species) and Mormodes (7 species). Other orchid genera far which observations are given here are: Dichaea, Kefersteinia, Lycaste and Notylia. Euglossine pollination provides very effective isolating mechanisms, and has been important in the speciation of several orchid groups. Isolation by highly selective fragrance might permit sympatric speciation through odormodifying mutatian. Orchid species with sympatric cIose allies tend to be more specific in their pollination relationships than geographically isolated species. While the pollination relationships are highly specific, the same bee species may visit and pollinate several different (and distantly related) orchid species. In several cases, archid flowers attract accessory visitors, bees which do not function pollinators because of size or behavior. In general, euglossine pollination appears to be efficient, and the more advanced orchid species appear to be more efficiently pollinated than their primitive allies.

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).

The Impact of Different Phytophysiognomies on the Composition of Orchid Bee Communities (Hymenoptera: Apidae: Euglossini) in the Atlantic Forest in Brazil

We sampled bees of the tribe Euglossini in three close areas within a small region of Sao Paulo state that includes three different phytophysiognomies of the Atlantic Forest biome. Even though Euglossini bees are known for flying great distances, there were clear differences in the composition of bee communities, including differences in abundance and richness of species at specific points within the same biome. The area characterized by tropical rainforest was the richest in bee fauna of this group, followed by the mixed rainforest area, whereas no specimens of Euglossini were found in nearby high-altitude fields. The differences in composition and abundance of orchid bees in geographically close areas reveal the importance of the conservation of distinct habitat patches within a biome for bee conservation.

Cuticular Hydrocarbons of Orchid Bees Males: Interspecific and Chemotaxonomy Variation.

Recent studies have investigated the composition of compounds that cover the cuticle in social insects, but few studies have focused on solitary bees. Cuticular hydrocarbons may provide a tool for chemotaxonomy, and perhaps they can be used as a complement to morphology and genetic characters in phylogenetic studies. Orchid bees (Tribe Euglossini) are a highly diverse group of Neotropical bees with more than 200 species. Here, the cuticular hydrocarbons of 17 species were identified and statistical analysis revealed 108 compounds, which allowed for the taxonomic classification according to the genera. The most significant compounds discriminating the four genera were (Z)-9-pentacosene, (Z,Z)-pentatriacontene-3, (Z)-9-tricosene, and (Z)-9-heptacosene. The analyses demonstrated the potential use of CHCs to identify different species.

Observations on fragrance collection behaviour of euglossine bees (Hymenoptera, Apidae)

Male bees of the tribe Euglossini collect volatile chemicals secreted by orchids using dense patches of hair on the front tarsi. After collecting chemicals, the bee hovers while transferring these fragrances to invaginations on the hind tibiae. The fragrance collection and hovering behaviours are repeated multiple times. Here I report preliminary field observations on the length of fragrance collection and hovering phases in bees of the Eulaema meriana (Oliver, 1789) mimicry complex visiting the orchid Catasetum discolor in Kavanayén, Venezuela. I observed that in extended visits with many cycles of fragrance collection and hovering, the length of each collection phase gradually increased, while the length of hovering phase was static. This suggests either that chemicals secreted by orchids are in limited supply or that efficiency of fragrance collection drops.

Orchid Bees of forest fragments in Southwestern Amazonia

Bees of the tribe Euglossini are known as orchid-bees. In general, areas with more vegetation cover have greater abundance and diversity of these bees. This study investigated the effects of forest fragmentation on assemblages of the euglossine bees in the region of Rio Branco municipality, State of Acre, and surrounding areas. Ten forest fragments with varying sizes were selected for the study and were classified as urban or rural. The bees were sampled between December 2005 and August 2006. A total of 3,675 bees in 36 species and 4 genera were collected. In general abundance and richness of bees did not differ statistically between urban and rural fragments. The index of edge in fragments was a predictor of richness and diversity of bees. The connectivity estimated was also an adequate predictor for richness. Fragments with greater similarity in relation to their landscape structure were also more similar in relation to faunal composition.

Phylogeny, diversification patterns and historical biogeography of euglossine orchid bees (Hymenoptera: Apidae)

The orchid bees constitute a clade of prominent insect pollinators distributed throughout the Neotropical region. Males of all species collect fragrances from natural sources, including flowers, decaying vegetation and fungi, and store them in specialized leg pockets to later expose during courtship display. In addition, orchid bees provide pollination services to a diverse array of Neotropical angiosperms when foraging for food and nesting materials. However, despite their ecological importance, little is known about the evolutionary history of orchid bees. Here, we present a comprehensive molecular phylogenetic analysis based on ∼4.0 kb of DNA from four loci [cytochrome oxidase (CO1), elongation factor 1-α (EF1-α), arginine kinase (ArgK) and RNA polymerase II (Pol-II)] across the entire tribe Euglossini, including all five genera, eight subgenera and 126 of the approximately 200 known species. We investigated lineage diversification using fossil-calibrated molecular clocks and the evolution of morphological traits using disparity-through-time plots. In addition, we inferred past biogeographical events by implementing model-based likelihood methods. Our dataset supports a new view on generic relationships and indicates that the cleptoparasitic genus Exaerete is sister to the remaining orchid bee genera. Our divergence time estimates indicate that extant orchid bee lineages shared a most recent common ancestor at 27–42 Mya. In addition, our analysis of morphology shows that tongue length and body size experienced rapid disparity bursts that coincide with the origin of diverse genera (Euglossa and Eufriesea). Finally, our analysis of historical biogeography indicates that early diversification episodes shared a history on both sides of Mesoamerica, where orchid bees dispersed across the Caribbean, and through a Panamanian connection, thus reinforcing the hypothesis that recent geological events (e.g. the formation of the isthmus of Panama) contributed to the diversification of the rich Neotropical biota. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 100, 552–572.

Age structure of male Euglossa imperialis (Hymenoptera: Apidae: Euglossini) at nectar and chemical sources in Panama

Bees in the tribe Euglossini (Apidae) form an important component of the pollinator fauna in lowland, Neotropical forests (Dressler 1982, Janzen 1971, Williams 1982). The community structure and seasonality of male euglossine bees are relatively well known because they can be attracted to chemical baits (Ackerman 1983a, Dodson et al. 1969, Janzen et al. 1982, Pearson & Dressler 1985). The male bees are important pollinators of many orchids (Dressler 1968, Williams 1982) from which they collect fragrant chemicals; these chemicals are also collected from other plants and decaying vegetation (Ackerman 1983b, Dressler 1982). Male bees are known to store collected chemicals in hind tibial organs (Dressler 1982) and, it is presumed, use these chemicals to synthesize sex pheromones (Williams & Whitten 1983). Mating occurs in territories to which males attract female bees (Dodson 1966, Kimsey 1980). Recently, Schemske & Lande (1984) found that captive male Euglossa imperialis show elevated levels of territorial behaviour when provided with cineole, a fragrant chemical that readily attracts male bees, compared to control bees maintained without a chemical source. Although the exact function of the fragrant chemicals is still unknown, these were the first results that clearly implicated fragrance collection in male reproductive behaviour. Schemske & Lande (1984) noted that the male E. imperialis provided with a daily source of cineole actively collected the fragrance only on the first day of the 11 day experiment. One potential explanation for this observation is that males require only one collection of chemical fragrance before establishing territories. Thus, only the youngest bees in the population would be expected

The behavioural and structural aspects of grooming and related activities in euglossine bees (Hymenoptera: Apidae)

The movements and structures involved in grooming, resin and pollen manipulation, and collection of aromatic material are described for members of the tribe Euglossini. These bees typically groom with each leg while hanging by their mandibles, working from the head backwards. Collection and transfer of aromatic material is described after re‐evaluation using fluorescent powder. Resin collection involves asynchronous ipsilateral transfer of the resin to the hindtibia. Pollen collection, in contrast, involves synchronous ipsilateral transfer. Areas of the body that are not groomed are illustrated, and the various plants and animals that exploit these regions discussed. The similarities between the behaviours of euglossines and bumblebees supports the idea that they are closely related.

Male Eufriesia purpurata, a DDT-collecting euglossine bee in Brazil

While studying the ecology of the malaria vector Anopheles (Nyssorhynchus) darlingi Root along the Ituxi River, Amazonas, Brazil, we observed aggregates of bees on the walls of houses that were routinely sprayed with DDT. Several bees collected from DDT-treated house walls in August 1978 were identified as male specimens of Eufriesia purpurata (Moscary) of the tribe Euglossini (Hymenoptera: Apoidae). (The bees were identified as Euplusia purpurata by Anthony Raw, Laboratorio de Ecologia, Universidade de Brasilia. The change of generic name from Euplusia to Eufriesia is based on ref. 1.) These bees were well known to the local residents as the insects that eat DDT and we present here the first documentation that they (1) are attracted to DDT, (2) actively collect large quantities of DDT from treated house walls and (3) suffer no apparent insecticidal effects. We also found that the frequency of house visiting is most intense during July to September. Most bees arrive at houses before 12.00 h, remain 2–3 h and return on subsequent days to collect more DDT. Noise produced by bees as they collected DDT was a notable disturbance to 76% of 21 families interviewed along the Ituxi River.

Pollination of Two Species of Dalechampia (Euphorbiaceae) in Mexico by Euglossine Bees

The large genus Dalechampia, including over 100 species of great vegetative diversity, has a basically uniform pseudanthial inflorescence. Investigation of two sympatric species in Mexico has shown considerable divergence in pollination adaptations. In D. spathulata, male euglossine bees are attracted by and collect aromatic substances secreted by the extra-floral gland of the inflorescences. In D. magnistipulata, female euglossine bees are attracted by and collect sticky resins secreted by the homologous gland. This study adds a new genus and family to the list of plant taxa exhibiting the male euglossine pollination syndrome which has been so well documented in tropical orchids. It also further elucidates a unique mode of pollinator attraction by resin production which has been reported from only one other plant genus. THE IMPORTANCE OF BEES of the tribe Euglossini in pollinating flowers in the American tropics has been pointed out by a number of workers (Dodson 1966, Janzen 1971, Zucchi et al. 1969). Perhaps most attention has been given to pollination relationships between male euglossine bees and orchids, which involve a number of coevolved adaptations on the part of both plant and insect (Dodson and Frymire 1961, Vogel 1963, Dodson et al. 1969, Dressler 1968, van der Pijl and Dodson 1971). In this paper we are reporting for the first time pollination by euglossine bees of two sympatric species of Dalechampia, a large genus of Euphorbiaceae with more than 100 species of primarily American distribution (Pax and Hoffmann 1919, Webster and Burch 1968). No visits to flowers of Dalechampia by euglossine bees have ever been reported in the literature; in two published accounts, stingless bees (Meliponini) have been reported as floral visitors to Dalechampia scandens L. in Brazil and to D. bidentata Bl. in Java (MMuller 1879, Cammerloher 1931). Both of the reports mention visits by worker bees, which collect resins from the inflorescences of Dalechampia for use in nest-building. The inflorescence structure in Dalechampia is unique in the Euphorbiaceae: the flowers are subtended by two large, often brightly colored, bracts so that the inflorescence as a whole functions as a bilabiate pseudanthium (Michaelis 1924, Venkata Rao 1971, Webster and Webster 1972). Above the insertion of the bracts, there is a cyme of three sessile pistillate flowers and a terminal highly modified pleiochasium of usually 9-12 staminate flowers. Part of the bractlets of the staminate inflorescence are converted into secretory structures, forming en masse a large conspicuous gland which in most species exudes a highly sticky resinous compound (figs. 1, 3). Euglossine bees (tribe Euglossini, family Apidae) are important pollinators in the neotropical region; females collect pollen for brood provisioning, and both male and female bees ingest nectar as the energy source for flight and maintenance. Visits by euglossines for pollen or nectar have been recorded for a large number of plants in the neotropics, including species in the Caesalpiniaceae, Marantaceae, Melastomaceae, Ochnaceae, Solanaceae, Verbenaceae, etc. (Dodson 1966, Zucchi et al. 1969, Janzen 1971, Armbruster pers. obs.). Male euglossine bees also collect volatile compounds, usually from angiosperm inflorescences. The following families contain taxa reported to produce compounds attractive to male euglossine bees: Araceae, Bignoniaceae, Gesneriaceae, Mimosaceae, Myrtaceae, Orchidaceae, and Solanaceae (Dodson 1966, Zucchi et al. 1969, Dressler, pers.

Flight Distances of Male Euglossine Bees in Orchid Pollination

Flight Distances of Male Euglossine Bees in Orchid Pollination

SELECTIVE ATTRACTION OF MALE EUGLOSSINE BEES TO ORCHID FLORAL FRAGRANCES AND ITS IMPORTANCE IN LONG DISTANCE POLLEN FLOW.

It has been known for some time that male bees of the tribe Euglossini visit and often pollinate various orchid flowers (Dodson and Frymire, 1961a, 1961b; Dodson, 1962, 1967; Vogel, 1963, 1966; van der Pijl and Dodson, 1966; Dressler, 1967, 1968a, 1968b). The syndrome of pollination was discussed by Dressler (1968b). He noted that the orchid flowers that are pollinated exclusively by male euglossine bees are very fragrant, but are almost always lacking in nectar; therefore, no food is present. The source of the attraction was recognized as the fragrance of the flower, but the identity of the odor components was not known for a number of years. Eleven compounds from orchid floral fragrances were identified (Hills et al., 1968), but only some of the compounds were shown to be attractants of male euglossine bees (Adams, 1968; Dodson et al., 1969). Adams showed that some of the compounds from orchid fragrances modified the attraction potential of other fragrance components, and that some of the compounds were not attractive to male euglossine bees. Several additional compounds have been identified from orchid floral fragrances (Dodson and Williams, unpublished), some of which have been demonstrated in field tests to be active attractants of male euglossines, while other compounds have been shown to modify or reduce the attraction potential of various other odor components. The behavior of the bees on the flowers and at the isolated odor components has

POLLINATION BY EUGLOSSINE BEES.

The relationships between some orchid flowers and male bees were first observed in Darwin's time (Criiger, 1865), but the peculiarities of these interactions have been recognized only within the last decade. Our knowledge of the relationships has increased greatly in recent years, especially through the efforts of Dodson (Dodson and Frymire, 1961, etc.). While our understanding is still quite imperfect, its botanical aspects are relatively clear, and a discussion of from this viewpoint may be of value. The tribe Euglossini includes six genera; the males of the four non-parasitic genera, Eufriesea, Euglossa, Eulaema and Euplusia, show a characteristic behavior pattern on many flowers. The bees are attracted primarily by odor. When they visit an flower, they brush on the surface of the flower with pads of hair on the forefeet. The bees characteristically brush for a short time and then hover near the flower while scrubbing their legs together and evidently placing some substance in their inflated hind tibiae. The bees usually repeat this behavior several or many times, sometimes remaining as long as 90 minutes at one inflorescence. Dodson and Frymire ( 1961 ) suggest that the bees become somewhat inebriated during their visits at orchid flowers. Vogel (1963, see also Dressler, 1967) has suggested that the bees are gathering a terpenoid Duftstoff, or odor substance, from the surface of the flower and placing this in their tibiae, but the nature of the substance and its role in the biology of the bee are both problematical at present. The flowers which are visited only by males usually lack nectar, but are very fragrant. The females, of course, visit and pollinate many nectarand pollen-producing flowers, but I will use the phrase euglossine pollination only for the special relationship which involves the male bees. Some 30 genera of orchids (including relatively unrelated groups) show this relationship with the bees, as do some species of Anthurium and Spathiphyllum (Araceae) and Drymonia and Gloxinia (Gesneriaceae). It should be emphasized that the bees do not obtain their food from these flowers, but visit a variety of other flowers which produce nectar, especially Apocynaceae, Marantaceae and some Rubiaceae. SPECIFICITY