Abstract

DA SILVA, airon M; BRUCKNER, Claudio H; PICANCO, Marcelo  and  MOLINA-RUGAMA, Adrián J. Número floral, clima, densidad poblacional de Xylocopa spp. (Hymenoptera: Anthophoridae) y polinización del maracuyá (Passiflora edulis f. flavicarpa). Rev. biol. trop [online]. 1999, vol.47, n.4, pp.711-718. ISSN 0034-7744.

The relationship of weather conditions, passion fruit vines (Passiflora edulis f. flavicarpa) flower number, density of carpenter bees (Xylocopa spp., Hymenoptera: Anthophoridae) and effective pollinization was studied in Viçosa, Minas Gerais, Brazil. Low levels of viable fruits (14.3%) were observed when there were less flowers/ row (< 0.8 flowers in anthesis/ linear meter). When densities of flowers in anthesis were between 0.8 and 1.2, there was a higher proportion of viable flowers and more visits by Xylocopa spp. (maximum: seven visits/ flower). Above 1.2 flowers in anthesis/ linear meter there was a linear increase in the proportion of viable fruits and visits by Xylocopa spp. However; numbers were lower than in days with 0.8-1.2 flowers in anthesis/ linear meter. The highest bee density (ca. 49 bees/ ha/ hr) was between 2: 00 and 3: 00 pm (temperature, relative humidity and insolation around 26 °C, 55% and 0.6 respectively). At higher temperatures and relative humidities, there was a decrease in Xylocopa spp. density, while higher densities high at more elevated insolation.

Keywords : Passifloraceae; bees; weather; fruit set; reproductive success.