Biologia reprodutiva de Pyrostegia venusta (Ker-Gawl) Miers (Bignoniaceae) e comportamento de forrageamento dos visitantes florais predominantes

Pyrostegia venusta (Ker-Gawl) Miers is a semiwoody liana of dense foliage, and consider able one of the main plants invading of pastures in the Cerrados. This study aimed at to describe the breeding fenology, to analyze the foraging activity of the floral visitors, and to evaluate the system of predominant breeding in P. venusta in an area of urban-rural bordering zone. Therefere, the flowers characteristics were registered, accomplished pollination controlled tests were, collections of the flow ers visitors and studied the behavior of the predominant species. Pyrostegia venusta flowered between April and September. The largest breeding successes occured with geitonogamy (66.7%), cross-pollination (63.3%) and manual self-pollination (36.7%), defining the presence of self-compatibly and necessary of animals pollinators. In the flowers, 1,085 specimens of insects were captured, of which Apis mellifera L., 1758 (Apidae), Camponotus sp.1 (Formicidae), and Trigona spinipes (Fabr. 1793) (Apidae) were the predominant species. It is here suggested that the plant presents ornitofily syndrome, as the hummingbirds Phaethornis eurynome Lesson, 1832 (Phaethornidae) e Hylocharis chrysura Shaw 1812 (Throchilidae) the possible pollinator species of that plant in the studied area.