title: Mutual reproductive dependence of distylic Cordia leucocephala (Cordiaceae) and oligolectic Ceblurgus longipalpis (Halictidae, Rophitinae) in the Caatinga.
abstract: OBJECTIVE
  The close relationship between distylic Cordia leucocephala and the bee Ceblurgus longipalpis, both endemic to the Caatinga, north-east Brazil, was investigated, emphasizing reproductive dependence, morphological adaptations of the partners, and pollen flow.
  
  
  METHODS
  In the municipality of Pedra, in the Caatinga of Pernambuco, the breeding system and reproductive success of C. leucocephala, its interaction with flower visitors and inter- and intramorph pollen flow were determined.
  
  
  RESULTS
  The bee Ceblurgus longipalpis, the unique flower visitor and effective pollinator of self-incompatible Cordia leucocephala, presents morphological features adapted to exploit hidden pollen and nectar in the long and narrow corolla tubes. Pollen of low-level anthers is collected with hairs on prolonged mouthparts and pollen of high-level anthers with clypeus, mandibles, and labrum, showing pollen removal from both levels with the same effectiveness. In both morphs, this results in similar legitimate, i.e. intermorph cross-pollen flow. Illegitimate pollen flow to stigmas of pin flowers, however, was much higher than to stigmas of thrum flowers. Moreover, more illegitimate pollen was transported to stigmas of pin and less to those of thrum flowers when compared with legitimate pollen flow.
  
  
  CONCLUSIONS
  The study reveals a one-to-one reproductive inter-dependence between both partners. Data indicate that this relationship between bee species and plant species is one of the rare cases of monolecty among bees. Monotypic Ceblurgus longipalpis, the only rophitine species of Brazil, evolved prolonged mouthparts rare among short-tongued bees that enable them to access pollen from flowers with short-level anthers hidden for bees of other species, and nectar at the base of the flower tube.
authors.affiliation: Universidade Federal de Pernambuco, Recife, PE, Brazil. miletpinheiro@hotmail.com
authors.forename: Paulo
authors.initials: P
authors.lastname: Milet-Pinheiro
authors.forename: Clemens
authors.initials: C
authors.lastname: Schlindwein
mesh_terms: D000818:Animals; D001516:Bees / Q000502:physiology*; D031213:Cordia / Q000033:anatomy & histology / Q000502:physiology*; D035264:Flowers / Q000033:anatomy & histology / Q000502:physiology; D054817:Pollination / Q000502:physiology; D012098:Reproduction / Q000502:physiology*
references.citation: Proc Natl Acad Sci U S A. 2006 Oct 10;103(41):15118-23
references.pmid: 17015826
references.citation: Annu Rev Entomol. 1996;41:257-86
references.pmid: 15012330
references.citation: Evolution. 2008 Oct;62(10):2487-507
references.pmid: 18637958
references.citation: Ann Bot. 2009 Jun;103(9):1459-69
references.pmid: 19228701
references.citation: Ann Bot. 2009 Jun;103(9):1445-57
references.pmid: 19304996
references.citation: Oecologia. 2005 Dec;146(3):394-403
references.pmid: 16133196
references.citation: Ann Bot. 2009 Mar;103(5):727-33
references.pmid: 19126635