Biodiversity and forage behavior of bees in Italian pumpkin crop (Cucurbita pepo)

Abstract

The aim of this experiment was to study the biodiversity of pollinators in Italian pumpkin crop in 2013, 2014 and 2015, in relation to the visiting insects in male and female flowers, the type of collection and their forage behavior, in Ribeirão Preto, SP. The opening and closing of flowers and the attractiveness of the male flowers to the female flowers were evaluated. The frequency and type of collection of flower visitors were obtained by counting in the first 10 minutes of each hour with three replicates in each year. Was observed that the flowers open at 6:00 a.m. and closed about 1:00 p.m. The female flowers begin to close at 12 noon and soon after the male ones close also, reducing the activity of the pollinators. Several bee species collect nectar and pollen from pumpkin flowers: Africanized honey bees Apis mellifera, stingless bees Trigona spinipes, native bees Exomalopsis analis, Peponapis fervens and species of the family Halictidae. The most frequent insect in the flowers was Africanized honey bee (79.25%) followed by the stingless bee Trigona spinipes (20.75%). The honey bee visited the flowers from 7:00 a.m. to 1:00 p.m. and preferred to collect nectar in male flowers (61.0%) when compared to pollen in male flowers (22.3%) and nectar in female flowers (16.7%). Due to forage behavior all bees observed were considered as pollinators of the Italian pumpkin crop.