Host Specialization in Plant-galling Interactions: Contrasting Mites and Insects

Abstract

Galling arthropods represent one of the most specialized herbivore groups. On an evolutionary scale, different taxa of insects and mites have convergently adapted to a galling lifestyle. In this study, we have used a multi-taxonomic approach to analyze the interaction specialization between gall-inducing mites and insects and their host plants in the Nitra City Park (Nitra, Slovakia). We used four ecological descriptors for describe plant-galling interactions: number of host plant species used by each arthropod species, galling specificity on host plant species (specificity), exclusivity of interactions between galling and plant species (specialization) and overlap of the interactions between arthropod species (similarity). We have found 121 species of gall-inducing arthropods, totaling 90 insects and 31 mites occurring on 65 host plant species. Our results reveal that mites have high specialization and low similarity of interactions in comparison to insects. A multiple-taxonomic comparison showed that these differences are triggered by gall-wasps (Hymenoptera: Cynipidae), the taxon with the lowest levels of specificity of plant-galling interactions (i.e., occurring on different host plant species). Our findings are indicative of different patterns of interaction between distinct gall-inducing arthropods taxa and their host plants, despite the ecological convergence of different taxa to a highly specialized herbivorous habitat.

First characterization of a taxonomically well‑resolved trophic network composed by host plants and gall midges (Diptera: Cecidomyiidae) in the Neotropical region

“…We found a high specialization of interactions between host plants and gall midges in the present study, confirming previous studies (Carneiro et al, 2009;Araújo et al, 2019b). All species of gall midges were recorded on a single host plant species (i.e., monophagous species).…”

“…Our plant-galling network also showed a low number of links per species (0.608) and a high modularity (0.958), corroborating the pattern observed in other galling networks (Araújo et al, 2017;Araújo & Kollar, 2019). Our results provide evidence that supports the high specificity and specialization of plant-galling interactions (Araújo et al, 2019b). Furthermore, our results show that the network of host plants and gall midges is few robust to coextinctions.…”

“…The percentage of specialist species recorded in our study is higher than found by Carneiro et al (2009) which recorded 92% of monophagous gall midges for Brazil. In other study, Araújo et al (2019b) recorded that 79% of gall-midge species were monophages in the Slovakia. These results suggest a lower specialization of gall midges in temperate environments when compared to the Neotropical region, which have more specific gallers in their host plants, as observed for the Restinga of Barra de Maricá.…”

Gall-inducing arthropods in a Neotropical savanna area in the EPA of Rio Pandeiros (Bonito de Minas, MG, Brazil): effects of plant species richness and super-host abundance

“…Eriophyids are galling mites than can induce galls in more than 500 host plant species (Petanovíc & Kielkiewicz, 2010). In Brazil eriophyids are rarely include in gall inventories, but in other parts of globe some studies have highlighted the importance of the group for galling fauna (e.g., Nasareen & Ramani, 2014;Araújo et al, 2019a). According review of Maia (2006) gall-inducing insects of the orders Hemiptera and Lepidoptera are less common in the Neotropical region, which corroborates the results of the present study where these groups represented less of 8% of gall-inducers.…”

“…Plant-animal interactions between herbivorous arthropods and their host plants encompass the greatest diversity of terrestrial species (Price, 2002). Among herbivorous arthropods, gall-inducing species represent the most specialized guild (Araújo et al, 2019a), because they are the only arthropods capable of manipulating physiological and anatomical plant structures inducing the formation of galls (review in Miller III & Raman, 2019). Arthropod galls are structures formed by hyperplasia and hypertrophy of plant tissues, inside which the inductor development and feed (Fernandes et al, 2014).…”