Studies on reproduction of Cassia spectabilis (L.) and on diversity, frequency and constancy of the insects visiting the Leguminosae at different hours were carried out. Observations in the field concerned insect behavior and were followed by their captures, and influence of the abiotic factors was recorded. A pollen viability test showed that 98% was positive. A test for manual pollination suggested that C. spectabilis is autocompatible, but xenogamy is the predominant system of reprodution. Inflorescences were visited by a large number of insects, with predominance of bees. The visiting time of flowers of C. spectabilis by insects had a peak between 8 and 14 h and the lowest ocurrence period were between 7 and 8 h and 17 and 18 h. While Xylocopa frontalis Olivier, X. suspecta Camargo & Moure, Bombus morio Swederus and Centris scopipes Friese have the morphology and the behavior adapted for pollinators legitimate; C. similis F., Oxaea flavescens Klug and Epicharis rustica flava Cockerell were considered occasional pollinators. Pseudaugochloropsis graminea (F.), Tetragonisca angustula Latreille and A. mellifera L. were considered pirates or robbers. The "buzz pollination" is the method used by the bees to pollen collect.
Insecta; bee; flower; pollination; buzzing
