Nerea Montes1,2, Jonatan Rodríguez1,2 and Luís González1,2
1Plant Ecophysiology Group, Department of Plant Biology and Soil Science, University of Vigo, 36310 Vigo, Spain
2CITACA, Agri-Food Research and Transfer Cluster, Campus da Auga, University of Vigo, 32004-Ourense, Spain
Over the past few decades, biodiversity conservation awareness has led to an increase in the amount of research done on this topic. Different studies have shown the correlation between diversity loss and the introduction of invasive species. Some of them, focusing on plant-pollinator interaction networks. However, few studies are known to relate plant-herbivore interaction networks with invasive species and none with the capeweed, Arctotheca calendula (L.) Levyns. We hypothesize that if A. calendula reduces plant biodiversity, it can create, in a short-scale, heterogeneities in herbivore distributions in the NW Iberian Peninsula. The aims were to assess the distribution and frequency of herbivorous invertebrates, as well as the diversity of native plant species, for comparing the plant-herbivore interactions in invaded areas by A. calendula and adjacent native ones. To achieve these objectives, we did a total of 400 quadrat surveys at ten populations, in both continental and insular habitats, during spring 2019 (from March to June). Differences between native and invaded areas were observed, concerning invertebrates and plant species. Higher variety of herbivores and plant species were shown in native areas. Orders such as Hemiptera, Stylommatophora or Thysanoptera were dominant in A. calendula specimens, particularly Aphidae and Helicidae families. On the other hand, although individuals from the families Aphidae and Helicidae were found in the native areas, Aphrophoridae was the most abundant group. In terms of dissimilarities, few differences between the continental and insular populations of A. calendula were found. Overall, the results suggest that A. calendula attracts more and different taxa of herbivores than the native vegetation, but it also reduces plant diversity. However, interspecific competition seems to be a stronger force than herbivore pressure leading to plant diversity loss. Our study points to the need for invasion biology to include a plant-herbivore perspective to clarify the consequences of these changes.