Abstract: Because Tachia guianensis (Gentianaceae) is a “non-specialized myrmecophyte” associated with 37 ant species, we aimed to determine if its presence alters the ant guild associated with sympatric “specialized myrmecophytes” (i.e., plants sheltering a few ant species in hollow structures). The study was conducted in a hilly zone of a neotropical rainforest where two specialized myrmecophytes grow at the bottom of the slopes, another at mid-slope, and a fourth on the hilltops. Tachia guianensis, which occurred everywhere, had its own guild of associated ant species. A network analysis showed that its connections with the four other myrmecophytes were rare and weak, the whole resulting in a highly modular pattern of interactions with one module (i.e., subnetwork) per myrmecophyte. Three ant species parasitized three out of the four specialized myrmecophytes (low nestedness noted), but were not or barely associated with T. guianensis that therefore did not influence the parasitism of specialized myrmecophytes. © 2018, Springer-Verlag GmbH Germany, part of Springer Nature.

Abstract: Context: Many aquatic communities are linked by the aerial dispersal of multiple, interacting species and are thus structured by processes occurring in both the aquatic and terrestrial compartments of the ecosystem. Objectives: To evaluate the environmental factors shaping the aquatic macroinvertebrate communities associated with tank bromeliads in an urban landscape. Methods: Thirty-two bromeliads were georeferenced to assess the spatial distribution of the aquatic meta-habitat in one city. The relative influence of the aquatic and terrestrial habitats on the structure of macroinvertebrate communities was analyzed at four spatial scales (radius = 10, 30, 50, and 70 m) using redundancy analyses. Results: We sorted 18,352 aquatic macroinvertebrates into 29 taxa. Water volume and the amount of organic matter explained a significant part of the taxa variance, regardless of spatial scale. The remaining variance was explained by the meta-habitat size (i.e., the water volume for all of the bromeliads within a given surface area), the distance to the nearest building at small scales, and the surface area of buildings plus ground cover at larger scales. At small scales, the meta-habitat size influenced the two most frequent mosquito species in opposite ways, suggesting spatial competition and coexistence. Greater vegetation cover favored the presence of a top predator. Conclusions: The size of the meta-habitat and urban landscape characteristics influence the structure of aquatic communities in tank bromeliads, including mosquito larval abundance. Modifications to this landscape will affect both the terrestrial and aquatic compartments of the urban ecosystem, offering prospects for mosquito management during urban planning. © 2017, Springer Science+Business Media B.V.