From urban edge to forest core: how non-native species restructure ecological networks

The Permanent Preservation Area (PPA) of Morro da Glória, Brazil, is crucial for conserving biodiversity. Nevertheless, its location near an urban area makes it vulnerable to invasion by non-native species. This study reports, for the first time, an ecological interaction involving multiple species within this PPA, including the invasive ant Tetramorium bicarinatum, the whitefly Aleurothrixus floccosus, the non-native fungus Penicillium coffeae, and two host plants: the exotic Citrus sinensis and the native Eugenia uniflora. This interaction has not previously been documented in the literature or zoological catalogs. For monitoring, study areas were marked and observed three times daily throughout the spring and summer. The fungus was identified using molecular biology techniques, whereas the insects and plants were identified using taxonomic keys. Observations indicated that the fungus rapidly colonized whitefly nymphs and leaf surfaces, leading to increased defoliation through indirect stress on the plants. Citrus sinensis served as a pest reservoir, leading to the spillover of pests to native plants. The ant effectively exploited two food sources: honeydew and fungal biomass. This tri-trophic relationship highlights the potential risks posed by interactions of multiple non-native species within protected areas, reinforcing the necessity to monitor these PPAs.