Pollination of two species of Ferocactus: interactions between cactus-specialist bees and their host plants

Autor: Margrit E. McIntosh
Rok vydání: 2005
Předmět:
Zdroj: Functional Ecology. 19:727-734
ISSN: 1365-2435
0269-8463
DOI: 10.1111/j.1365-2435.2005.00990.x
Popis: Summary 1Resolving the controversy over the prevalence of generalization in plant–pollinator interactions requires field studies characterizing the pollination effectiveness of all a plant's floral visitors. Herein, the pollination effectiveness of all visitors to two species of barrel cactus (Ferocactus) was quantified. 2Flowers of both species were pollinated almost exclusively by cactus-specialist bees: 99% (F. cylindraceus (Engelm.) Orcutt) and 94% (F. wislizeni (Engelm.) Britt. and Rose) of all seeds produced in this study resulted from cactus bee visits. 3For F. cylindraceus, the cactus-specialist Diadasia rinconis was the most abundant visitor. For F. wislizeni, three cactus-specialists (including D. rinconis) plus generalists in the family Halictidae (which did not act as pollinators) each accounted for a quarter of all visits. 4Diadasia rinconis visits to F. wislizeni flowers were more effective (per-visit) than visits by the other two cactus-specialists. 5Pollen-collecting and nectar-collecting visits were equally effective. Nectar-collecting visits were the most abundant. 6Apart from the non-pollinating halictids, floral visitors surprisingly did not include commonly co-occurring generalist bees. 7These data suggest that, just as apparently specialized flowers may be visited by a diverse assemblage of generalists, so apparently generalized flowers may be visited predominantly by specialists, and that these specialists may perform virtually all of the pollination.
Databáze: OpenAIRE
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