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An embellishment that became a mutualism : Inquiries on male bee tibial bouquets and fragrance-producing orchids in Panama and oceanic islands (Apidae: Apinae, Euglossini; Orchidaceae: Epidendroideae)

Roubik, David W. and Knudsen, Jette T. LU (2016) In Flora
Abstract

We used comparative studies to investigate how and why floral and bee fragrances evolve, including courtship odors collected by male Euglossa mixta to form their tibial bouquet, on Coiba Island and other Panama forests. Fragrances of four orchid genera, two used extensively by E. mixta - Coryanthes and Mormodes - and two never used, Clowesia and Catasetum - were also analyzed. From among 636 chemicals in 93 male tibiae, 66 were also found in 30 floral head-space samples of orchids, in which 315 total volatile compounds were detected. Geographic variation was noteworthy in E. mixta, but no significant difference was found between mainland and island populations. The aromatic benzenoids methyl salicylate,... (More)

We used comparative studies to investigate how and why floral and bee fragrances evolve, including courtship odors collected by male Euglossa mixta to form their tibial bouquet, on Coiba Island and other Panama forests. Fragrances of four orchid genera, two used extensively by E. mixta - Coryanthes and Mormodes - and two never used, Clowesia and Catasetum - were also analyzed. From among 636 chemicals in 93 male tibiae, 66 were also found in 30 floral head-space samples of orchids, in which 315 total volatile compounds were detected. Geographic variation was noteworthy in E. mixta, but no significant difference was found between mainland and island populations. The aromatic benzenoids methyl salicylate, 2-hydroxy-6-nona-1,3-dienylbenzaldehyde (HNDB), and the monoterpene 1,8 cineole, nearly always occurred. Coryanthes or other orchids produce two of the chemicals, but no source of HNDB is known. No statistical evidence was found of bee preference for orchids with bouquets like those formed in bee hindlegs, yet Coryanthes and Mormodes produced the most monoterpenes and more resembled the bees, when compared to Catasetum and Clowesia. Coiba bee tibial bouquets averaged 56% as diverse as on mainland and Coiba has <50% the euglossine species of nearby mainland, but lacks those most similar to E. mixta, both in phylogeny and tibial bouquet. Coiba's diverse rain forest should contain many volatiles the bees seek. Because odor collection and production are costly, our findings strengthen hypotheses that odors are used to avoid interspecific reproductive interference. Despite finding large differences in the same orchid species, we do not know whether isolation of between 107 and 104 years produced differentiation. Fragrances seem analogous among orchids and bees, thus may lessen interspecific interference or competition, and promote outcrossing or favor embellishments, via female choice. Such adaptive reasons for fragrance variation within bee or orchid populations remain largely untested.

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author
organization
publishing date
type
Contribution to journal
publication status
epub
subject
keywords
Coiba Island, Coryanthes, Euglossa, Fragrance analysis, Pollination, Reproductive interference
in
Flora
publisher
Elsevier
external identifiers
  • scopus:85007490242
ISSN
0367-2530
DOI
10.1016/j.flora.2016.11.012
language
English
LU publication?
yes
id
3dce2790-2173-4bb1-87eb-a030b70d35fb
date added to LUP
2017-04-19 12:34:33
date last changed
2017-06-02 08:28:36
@article{3dce2790-2173-4bb1-87eb-a030b70d35fb,
  abstract     = {<p>We used comparative studies to investigate how and why floral and bee fragrances evolve, including courtship odors collected by male Euglossa mixta to form their tibial bouquet, on Coiba Island and other Panama forests. Fragrances of four orchid genera, two used extensively by E. mixta - Coryanthes and Mormodes - and two never used, Clowesia and Catasetum - were also analyzed. From among 636 chemicals in 93 male tibiae, 66 were also found in 30 floral head-space samples of orchids, in which 315 total volatile compounds were detected. Geographic variation was noteworthy in E. mixta, but no significant difference was found between mainland and island populations. The aromatic benzenoids methyl salicylate, 2-hydroxy-6-nona-1,3-dienylbenzaldehyde (HNDB), and the monoterpene 1,8 cineole, nearly always occurred. Coryanthes or other orchids produce two of the chemicals, but no source of HNDB is known. No statistical evidence was found of bee preference for orchids with bouquets like those formed in bee hindlegs, yet Coryanthes and Mormodes produced the most monoterpenes and more resembled the bees, when compared to Catasetum and Clowesia. Coiba bee tibial bouquets averaged 56% as diverse as on mainland and Coiba has &lt;50% the euglossine species of nearby mainland, but lacks those most similar to E. mixta, both in phylogeny and tibial bouquet. Coiba's diverse rain forest should contain many volatiles the bees seek. Because odor collection and production are costly, our findings strengthen hypotheses that odors are used to avoid interspecific reproductive interference. Despite finding large differences in the same orchid species, we do not know whether isolation of between 10<sup>7</sup> and 10<sup>4</sup> years produced differentiation. Fragrances seem analogous among orchids and bees, thus may lessen interspecific interference or competition, and promote outcrossing or favor embellishments, via female choice. Such adaptive reasons for fragrance variation within bee or orchid populations remain largely untested.</p>},
  author       = {Roubik, David W. and Knudsen, Jette T.},
  issn         = {0367-2530},
  keyword      = {Coiba Island,Coryanthes,Euglossa,Fragrance analysis,Pollination,Reproductive interference},
  language     = {eng},
  month        = {11},
  publisher    = {Elsevier},
  series       = {Flora},
  title        = {An embellishment that became a mutualism : Inquiries on male bee tibial bouquets and fragrance-producing orchids in Panama and oceanic islands (Apidae: Apinae, Euglossini; Orchidaceae: Epidendroideae)},
  url          = {http://dx.doi.org/10.1016/j.flora.2016.11.012},
  year         = {2016},
}