Floral visitors and reproductive strategies in five melittophilous species of Bignoniaceae in Southeastern Brazil

Abstract

In order to evaluate the pollination strategies of Bignoniaceae, the floral biology and the floral visitors in five species, three cerrado shrubs (Arrabidaea brachypoda (DC.) Bor., Jacaranda decurrens Cham., and Jacaranda oxyphylla Cham.), and two lianas from the border of a semideciduous seasonal forest (Arrabidaea samydoides (Cham.) Sandw., and Arrabidaea triplinervia H. Baill.) were studied in Botucatu, São Paulo State, Southeastern Brazil. The flowering periods were partially overlapping, especially between species in the same habitat. All the five species were functionally allogamous, melittophilous, nototribic and mainly pollinated by long tongued large bees. Some medium-sized and small pollen-foraging bees were occasional legitimate visitors, whereas others visitors were robbers/thieves. Each species showed a particular set of pollinators. Only two pollinator species were observed in more than one bignon. There was no partition of pollinators even among the species of bignons blooming at the same time at the same habitat.