AOBPreview published online on June 20, 2008
Annals of Botany, doi:10.1093/aob/mcn092
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Cockroaches as Pollinators of Clusia aff. sellowiana (Clusiaceae) on Inselbergs in French Guiana
1 Department of Botany, Faculty of Science, Charles University in Prague, Benátská 2, CZ-12801 Prague 2, Czech Republic
2 The Silva Tarouca Research Institute for Landscape and Ornamental Gardening, Kv
tnové námstí 391, CZ-25243 Pr
honice, Czech Republic
3 Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nám. 2, CZ-16610 Prague 6, Czech Republic
4 Herbarium, Systematic Botany, Department of Biological Sciences, University of Aarhus, Ole Worms Allé, Building 1137, 8000 Århus C, Denmark
5 Institute of Systematic Botany and Ecology, University of Ulm, Albert-Einstein-Allee 11, D-89081 Ulm, Germany
* For correspondence. E-mail vlasakb{at}gmail.com
Received: 14 February 2008 Returned for revision: 2 April 2008 Accepted: 16 May 2008
Background and Aims: A report is made on a new species of Clusia related to C. sellowiana that dominates the vegetation of the Nouragues inselberg in French Guiana. The focus is on the pollination biology and on the remarkable relationship of this plant species to Amazonina platystylata, its cockroach pollinator. This appears to be only the second record of pollination by cockroaches.
Methods: Pollination ecology was investigated by combining morphological studies, field observations and additional experiments. Floral scent was analysed by gas chromatography–mass spectrometry. The role of acetoin, the major component of the scent of this species of Clusia, in attracting pollinators was examined in field attraction experiments. The ability of cockroaches to perceive acetoin was investigated by electroantennography (EAG).
Key Results: The Clusia species studied produces seeds only sexually. Its nocturnal flowers are visited by crickets, ants, moths and cockroaches. A species of cockroach, Amazonina platystylata, is the principal pollinator. The reward for the visit is a liquid secretion produced by tissues at the floral apex and at the base of the ovary. Although the cockroaches have no structures specialized for pollen collection, their body surface is rough enough to retain pollen grains. The cockroaches show significant EAG reactions to floral volatiles and acetoin, suggesting that the floral scent is a factor involved in attracting the cockroaches to the flowers.
Conclusions: The results suggest that the plant–cockroach interaction may be quite specialized and the plant has probably evolved a specific strategy to attract and reward its cockroach pollinators. Acetoin is a substance involved in the chemical communication of several other cockroach species and it seems plausible that the plant exploits the sensitivity of cockroaches to this compound to attract them to the flowers as part of the pollination syndrome of this species.
Key words: Clusia, cockroaches, acetoin, pollination, floral scent, floral reward, plant–animal interaction, inselberg, French Guiana, Amazonina platystylata