Visitantes florais em Campomanesia adamantium (Cambessédes) O. Berg - Myrtaceae: uma avaliação dos processos e interações entre planta-polinizadores

Abstract

Many species of the Cerrado are fruits producers and have important organoleptic characteristics, besides attracting a significant amount of insects. Bees are flower visitors. They are better adapted to flowers pollination in many different environments, including the Cerrado landscape. Their relations are based on a mutual dependent system, where the plants provide food for bees, especially pollen and nectar, and in return it receives the benefits of transference of pollen. Campomanesia adamantium belongs to the Myrtaceae family with about 140 genera. They are known popularly as guavira, gabiroba, etc. It is a branched shrub which typically occurs in bushes with small creamy white flowers, in the countryside and in typical Cerrado savanna, and in abundance in the state of Mato Grosso do Sul. The present research aimed to assess the reproductive system, phenology events, floral biology morphological changes during the development of the foraging behavior of the floral visitors and seeks to identify the effective pollinator (s) of the C. adamantium. The insects were collected in the first 15 minutes of each hour from 06:00 a.m to 07:00 p.m, sacrificed in a chamber containing deadly ethyl acetate solution, kept in separated bottles, according to the period of collection, for later being sorted and identified at the Laboratory of Apiculture of the FCBA (LAP .) The remaining 45 minutes of each hour was devoted to observing the behavior of floral visitors of C. adamantium. The evaluation of the reproductive system of the guavira plant were developed to controlled pollination tests involving cross-pollination , geitonogamy, apomixis, manual pollination and the spontaneous self-control (natural pollination). We recorded monthly the presence and the absence of budding phenophase, deciduous, buds, flowers and fruits in a population of 25 individual plants. Production was observed on average 42.6 ± 14.15 buds per inflorescence. Anthesis occurred around 05:00 a.m, leaving the receptivity of the stigma until 01:00 p.m. From the flower opening (anthesis), until the presence of mature fruits, it had an average of 63 days to the entire development process. The resources offered to the visitors were pollen and nectar, the structure of the flower and its white color also acted in the attraction of pollinators. The fruit-flower was 0.66, representing a low-cost energy in the reproductive process, ensuring a significant amount of fruit. The species with self-incompatibility needed pollinators for a significant production of fruit. The predominant reproductive system was the cross-pollination, being done effectively by bees. The main feature offered to visitors was the pollen. We sampled 31 species of visitors including the following orders: Hymenoptera (79.30%), Coleoptera (11.34%), Diptera (9.1%) and Hemiptera (0.24%). Among the group of Hymenoptera, three species were dominant, they are: Apis mellifera africanized, Brachygastra sp. (Wasp) and Trachymyrmex sp. (Ant). Honeybees Apis mellifera stood out as effective pollinators representing 53.24% of visitors collected. Most wasps, ants and some Coleoptera collected were associated with the herbivory activity of plant tissues.