title: Components of pollination effectiveness in Psychotria suerrensis, a tropical distylous shrub.
abstract: In this paper I report components of effectiveness for pollinators of a tropical distylous shrub, Psychotria suerrensis (Rubiaceae), which is visited by a variety of bees, wasps, and butterflies, and by two species of hummingbirds. In the field, I measured the following components of effectiveness: frequency of visits, evenness of visits across plants, and diurnal pattern of visits. I also used flight-cage experiments to compare pollentransfer abilities of euglossine bees and heliconiid butterflies. Euglossine bees visited more frequently, visited earlier in the day, and visited a higher proportion of plants in the population than did other taxa. In flight cage experiments, bees and butterflies transferred similar amounts of pollen overall, but bees transferred significantly more inter-morph (compatible) pollen. For each component measured, euglossine bees appeared to be the most effective pollinators.
authors.affiliation: Department of Ecology and Evolution, State University of New York at Stony Brook, 1194-5245, Stony Brook, NY, USA.
authors.forename: Judy L
authors.initials: JL
authors.lastname: Stone
keywords: Distyly; Euglossine bee; Heliconiid butterfly; Pollinator effectiveness; Psychotria