Renan Fernandes Moura, Liégy Resende dos Santos, Vitor Miguel da Costa Silva, Roberth Fagundes, Kleber Del-Claro
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引用次数: 0
Abstract
Extrafloral nectaries (EFNs) are nectar-secreting plant glands not related to pollination. Several not mutually exclusive hypotheses explain the ecological function of EFNs. We focused on the (1) protection hypothesis, which predicts the attraction of natural enemies by the extrafloral nectar, providing indirect defense to plants against herbivores, and the (2) ant-distracting hypothesis, which predicts the distraction of ants away from sap-sucking herbivores secreting sugary rewards (honeydew). We aimed to test both hypotheses simultaneously to understand the relative ecological roles of EFNs in a model plant from the Brazilian Cerrado. We experimentally manipulated plant groups according to the presence or absence of EFNs and hemipterans during two years of field study (2018 and 2019). We found some support for both hypotheses. Extrafloral nectaries reduced the damage caused by herbivores by attracting predatory ants, although plants with both EFNs and hemipterans showed the highest herbivory reduction in 2018. The presence of neither EFNs nor hemipterans was associated with increased fruit production. The honeydew, which had higher sugar concentrations than the extrafloral nectar, was used by ants for longer periods. However, more than 70% of the ants were observed feeding on the extrafloral nectar instead of honeydew. We suggest that the relatively high quantity of EFNs can compensate for their lower quality and still reduce the number of ants attending and protecting hemipterans, ultimately mitigating plant damage. In summary, EFNs may fit multiple functions depending on the ecological context.
期刊介绍:
Arthropod-Plant Interactions is dedicated to publishing high quality original papers and reviews with a broad fundamental or applied focus on ecological, biological, and evolutionary aspects of the interactions between insects and other arthropods with plants. Coverage extends to all aspects of such interactions including chemical, biochemical, genetic, and molecular analysis, as well reporting on multitrophic studies, ecophysiology, and mutualism.
Arthropod-Plant Interactions encourages the submission of forum papers that challenge prevailing hypotheses. The journal encourages a diversity of opinion by presenting both invited and unsolicited review papers.