Formigas protegem plantas sem atrativos no Cerrado?

Abstract

Multispecies interactions are diverse and much of the complexity of natural communities is theproduct of these interactions. In order to understand how these interactions may contribute to theants provide protection to plants, even if they do not invest in any attraction, such as extrafloralnectaries and domatias, we study trophic relationships established in a biological systeminvolving Solanum lycocarpum(Solanaceae) in a region of the Cerrado, Brasil. We conduct anexperiment with 80 plants, in which 40 plants were allowed free access to the ants and other 40limit this access with a grease applying insecticide at the base of the stem (before the experiment,we exclude all the ants from the plants). To check the effect of the exclusion of ants on theintensity of herbivory, we measured the leaf area damaged at baseline and peak flowering andfruit. After one year of the experiment, we collect and weigh all the ripe fruit, and counted theirseeds. We recorded 36 species of 17 families and six orders of insects in 80 plants. InsectsHemiptera represented the largest number of families (8) in the same order and the ants formedthe most diverse family of species (11 in four subfamilies). At the beginning of the experimentwith limited access of ants, leaf damage was similar in the two categories of treatment (with orwithout ants). Over time, individual plants had more damaged leaves than plants with free accessto ants, rose 12 cm less than the other plants and had low fruit set. Thus the exclusion of antsalter the community of herbivorous insects, acting as a driving force, directly influencing thediversity of insect species, and indirectly in the intensity of herbivory on plant growth and fruitproduction.