Entomofauna visitante de Peltophorum dubium (Spreng.) Taub. (Leguminosae- Caesalpinoideae) na região de Dourados, Mato Grosso do Sul

Abstract

Flowering entomofauna in Peltophorum dubium (Spreng.) Taub. in the area of Dourados, MS. Floral biology, reproduction system and insects visiting, were studied in P.dubium, being observed the diversity, frequency, abundance and constancy of species visiting at different hours. The flowers possess diurnal anthesis, sweetened odor, and the concentration of sugar in the nectar was of 34%. The results of reproduction system suggest that P. dubium is autocompatible, however, the xenogamy was the predominant system of reproduction. During its flowering period, it was verified a great diversity of floral visitors belonging to five orders, being most constituted by bees. The medium presence of visiting among the different hours in the period of the 06h:00min. to the 16h:00min. didn't present significant difference, decreasing up to the 17h:00min. The environmental factors (temperature, relative humidity, wind velocity and luminosity) influenced the frequency and distribution of the insects. As for the behavior in relation to the flower, it was observed that Xylocopa sp., Bombus sp. and Oxaea flavescens Klug, 1807 they possess size and appropriate behavior to the pollination of P. dubium being considered legitimate pollinators. The other bees, Apis mellifera Linnaeus, 1758, Augochloropsis sp.2 e sp.3, Trigona spinipes Fabricius, 1793, Geotrigona mombuca Smith, 1863, Scaptotrigona depilis Moure, 1942 and Exomalopsis sp.3 were considered occasional pollinators or nectar thieves.