Circadian rhythms on nectar and pollen collection by foragers of Melipona bicolor bicolor (Hymenoptera, Apidae, Meliponinae) - Hilário, Sérgio Dias; Fidalgo, A O; Imperatriz-Fonseca, Vera Lucia; Kleinert, Astrid de Matos Peixoto (International Congress of Entomology, 2000)