Potential pollinators of Comolia ovalifolia DC Triana (Melastomataceae) and Chamaecrista ramosa (Vog.) H.S. Irwin and Barneby var. ramosa (Leguminosae-Caesalpinioideae), in restinga, Bahia, Brazil

Abstract

Comolia ovalifolia DC Triana (Melastomataceae) and Chamaecrista ramosa (Vog.) H.S. Irwin and Barneby var. ramosa (Leguminosae-Caesalpinioideae) are tropical plant species found in restinga (herbaceous-shrubby, sandy costal ecosystems). They have flowers with poricidal anthers and are pollinated by bees. The study sought to analyse potential pollinators of both plants during visits to their flowers in a restinga area in Bahia. The flowering displayed by both species was considered continuous and long duration, constantly providing pollen to floral visitors. C. ovalifolia was visited by 17 species of bees and C. ramosa by 16 species, predominantly from the Apidae family (with a similarity index of 74%). The behavior displayed by these visiting bees was of vibrating anthers. The small-sized Euglossa sp. Latreille, 1802 and Florilegus similis Urban, 1970 bees played less of a role as pollinators, since they rarely touched the flower stigma during harvests and were thus considered opportunist visitors or casual pollinators. Centris decolorata Lepetier, 1841 (= C. leprieuri) and Xylocopa subcyanea Perez, 1901 are large bees and were considered efficient pollinators of C. ovalifolia and C. ramosa because of the higher frequency and constancy of their visits, and their favourable behaviour and size for pollen transfer between flowers, which guarantees the survival of these native restinga plant species.

Pollinator Sharing in Specialized Bee Pollination Systems: a Test with the Synchronopatric Lip Flowers of Centrosema Benth (Fabaceae)

“…Despite the low contribution of secondary nectar robbers to the structural divergences between Centrosema pollination systems (i.e., 4% dissimilarity), the Centridini bees deserve attention because of the distinctive roles of "cheaters"on structuring flower-visitor webs (Genini et al, 2010). Centridini is one of the most abundant bee group in tropical coastal restinga and sand dunes (Ramalho & Silva, 2002;Viana & Kleinert, 2006;Oliveira-Rebouças & Gimenes, 2011;Rosa & Ramalho, 2011), and therefore its low abundance on Centrosema flowers would not sustain the hypothesis of random interactions proportional to abundances in the habitat (Vázquez, 2005;Vázquez & Aizen, 2004). Behaving as secondary nectar robbers in Centrosema flowers is probably a response of Centridini bees to a contingent relationship: encounters facilitated by the abundance of these bees in the habitat (Ramalho & Silva, 2002;Rosa & Ramalho, 2011) and by the long flowering periods of Centrosema species.…”

Pollinator-mediated competition between two co-flowering Neotropical mangrove species, Avicennia germinans (Avicenniaceae) and Laguncularia racemosa (Combretaceae)

“…Further, each plant species could be more attractive to a different sub-set of shared pollinators, partitioning the pollination services by having different 'major' and 'minor' pollinator species (e.g. Flanagan et al, 2011;Oliveira-Rebouças and Gimenes, 2011). Finally, the plants could facilitate one another by increasing the attractiveness of the general area, thereby increasing the total number of pollinators in the area and increasing the reproductive success of both species, despite sharing pollinators (e.g.…”

Ecologia e biologia reprodutiva de Evolvulus pterocaulon (Convolvulaceae) condicionada pelo ambiente no Cerrado

“…Consequentemente, a eficiência da polinização e o posterior sucesso reprodutivo aumentam como já visto em outros estudos (Schmitt 1983, Robertson 1992, Klinkhamer & de Jong 1993, Schoonhoven et al, 2005 Características corporais e as limitações fisiológicas dos visitantes florais podem gerar padrões de visitação condicionados a fatores como luminosidade e temperatura (Ramalho et al 1991). De acordo com Oliveira-Rebouças & Gimenes (2011), as atividades de abelhas em algumas espécies de plantas estão associadas a intensidade luminosa assim também como a ação conjunta de fatores como temperatura, umidade relativa, que podem aumentar a atração de maior número de abelhas para as flores. Assim como as abelhas, os Lepidópteros apresentam alta sensibilidade a variações meteorológicas, principalmente os de pequeno porte encontrados no estudo, sendo encontrados forrageando somente no final das manhãs, das 10:00 horas até as 11:00 horas, em períodos tanto de altas temperaturas e radiação solar, mas com baixa umidade relativa.…”