Abstract

NUNEZ-AVELLANEDA, LUIS ALBERTO  and  ROJAS-ROBLES, ROSARIO. Reproductive biology and pollination ecology of the milpesos palm Oenocarpus bataua in the Colombian Andes. Caldasia [online]. 2008, vol.30, n.1, pp.101-125. ISSN 0366-5232.

Between August 2005 and July 2006 we studied phenology, floral biology and the reproductive system in a population of Oenocarpus bataua (Palmae) in the Colombian Andes. We evaluated the pollinations system and we determined abundance, behavior and pollination effectiveness. The flowering occurs throughout the year with a peak between December and January. The inflorescence has a male phase, followed by a non-sexual phase and finally the female phase. The flower anthesis is nocturnal with production of floral scents and temperature increment in the inflorescences. During the male phase the temperature of the inflorescence was 5.8 ºC, higher than the environmental temperature and higher than the increased temperature in the female phase 4.2 ºC. The floral scents are conformed by a-gurjunene, cyclosativene and trans-caryphyllene as predominant compounds. The flowers were visited by 81 species of arthropod, mainly Coleoptera. The inflorescences in the male phase are visited by insects searching for food (pollen, vegetables weaves, prey) or a place to mate. The female flowers offer no reward, and attract visitors by odor mimicry. Like in other palms, the similarity between chemical compounds of the floral scents of the inflorescences in male and female phase of O. bataua is high (92%). O. bataua is monoecious, xenogamic, self-incompatible and dichogams with marked protrandus. We did not find evidence of transportation of pollen to great distances by the wind and apparently the pollination is mainly by Coleoptera. The following species were the most effective pollinators: Baridinae Gene 4, sp. 1, Phyllotrox sp. 35, Anchylorhynchus sp. 2, Anchylorhynchus tricarinatus (Curculionidae) and Mystrops sp. 1 (Nitidulidae), which are responsible for 97% of the flow of pollen between inflorescences. The mutual dependency, the degree of interrelation and the similar geographic distribution between O. bataua and its pollinators, suggests an important degree of specialization previously non demonstrated for this species.

Keywords : Arecaceae; effectiveness pollinators; floral scents; cantharophily; thermogenesis.

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