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Palm swamp forests are wetland ecosystems typical of the Brazilian Cerrado, which in recent decades have undergone intense changes due to land use alterations and climate change. As a result of these disturbances, many palm swamps have been experiencing significant drying, which can also affect adjacent vegetation. In the present study, we evaluated whether the drying of palm swamps affects the structure of plant–herbivore networks located in adjacent savanna areas in Brazil. Our results show that savanna areas adjacent to dry zones of palm swamps have fewer interactions, fewer interacting species, and a less specialized topology, which corroborates our expectations. Our findings indicate that the drying of palm swamps also has propagated impacts on adjacent savanna vegetation, impairing more specialized interactions in these environments. On the other hand, contrary to expectations, plant–herbivore networks in dry zones displayed higher modularity, lower nestedness and lower robustness than those in wet zones, suggesting that in dry environments, species tend to compartmentalize their interactions, even with lower interaction specialization. This is the first study to investigate the impacts of environmental drying on the structure of plant–herbivore networks in tropical ecosystems, highlighting the complexity of these effects and their differential impact on specialized and generalized interactions. Understanding these dynamics is crucial for developing effective conservation and management strategies in the face of ongoing environmental changes. [ABSTRACT FROM AUTHOR]

Human-induced habitat modification is among the main factors that threaten biodiversity on the planet. For highly specialized herbivorous insects, such as galling insects, anthropogenic disturbances that affect plants can have great effects on insects. In this sense, in the present study, we investigated the diversity of host plants and gall-inducing insects in anthropized and preserved remnants of Neotropical savannas in the Brazilian Cerrado. Sampling was performed in 30 plots (10 × 10 m) distributed in six study areas. Of these total, fifteen plots were in areas with anthropized vegetation and fifteen plots in areas with preserved vegetation. Overall, we recorded 67 species of gall-inducing insects and 39 species of host plants. We found that the diversity of both host plant species and gall-inducing insects differed significantly between areas, being higher in preserved plots than in anthropized plots. Our results revelated that changes in the species richness and composition of gall-inducing insects from preserved environments to anthropized environments were mediated by changes in the richness and composition of the plant species, respectively. Our study stands out as the first to demonstrate that plant diversity drives responses of gall-inducing insects to human disturbance in Neotropical savannas. Our findings indicate that the preservation of natural vegetation is important for the conservation of plant assemblages and their gall-inducing insects in urban environments. [ABSTRACT FROM AUTHOR]

Phytophagous mites represent a diverse group of Arachnida, however, the patterns of their interactions with their host plants remain little explored. Herein we compare structural patterns of plant-phytophagous mite networks of forest and open habitats in Brazil. We adopted network size, network connectance and network modularity to characterize plant-mite network structure. We analyzed 11 plant-mite networks composed by 106 mite species, 96 host-plant species, and 342 distinct interactions. Tetranychidae and Eriophyidae were the most speciose mite families while Euphorbiaceae and Fabaceae were the most relevant host-plant families, hosting 67 and 16 mite species, respectively. We did not find any differences in network size and modularity between biomes and habitat types. However, network connectance was lower for open vegetation habitats than for forest habitat networks. Open areas can constrain the selection of defensive traits by plant species, leading phytophagous mites to consume plant species more selectively, which generates low connectivity in networks of these environments. The small number of plant-mite networks described here highlights the need for more efforts to increase knowledge about plant mites in Brazilian natural vegetation. [ABSTRACT FROM AUTHOR]