Influência do mutualismo formiga-Hemiptera na frutificação de Byrsonima intermedia (a. Juss.; Malpighiaceae)

Abstract

The insect-plant interactions are derived from the overlap of the adaptive radiation period of both groups, establishing mutual benefits (pollination and dispersion) or acting as selection pressure (herbivory and biotic defense). Usually cost-altering strategies arise, such as in facultative mutualisms in which Hemiptera excrete honeydew (derived from the sap rich in sugars and amino acids) and attract ants, obtaining protection against predators as well as drive off herbivores of the host plant. Therefore, tritrophic interactions contain artifacts to overcome plant damage by associated advantages. Thus, the objective was to verify if the voluntary mutualism can interfere in the fruits set in the Malpighiaceae Byrsonima intermedia. To evaluate the effect of the Hemiptera and the ant-Hemiptera pair on fruit set, 40 reproductive stage plants were chosen in a Cerrado reserve, which were divided by experimental manipulation into three groups: i) control, with free access to ants and hemipterans; (ii) exclusion treatment, removal of hemipterans and prevention of access to ants; iii) treatment with infestation of hemipterans, without access to the ants. The results showed that the ratio between number of buds and fruits formed was higher in the treatment of hemipters than in the control and treatment groups, which did not differ. This effect may result from the presence of the ant, which allows indirect protection against herbivores to the plant. Additionally, it is suggested that there is compensation in the fruits set, due to the extra sending of nutrients to the inflorescences, which resulted in a better proportion of fruits in inflorescences infested only by the hemipterans.