Host plant identity and condition shape phytophagous insect communities on urban maple (Acer spp.) trees

Abstract

By mitigating the negative effects of urbanization, urban trees contribute significantly to the well-being of urban citizens. However, trees themselves are also exposed to urban stress that can influence tree condition and tree-herbivore interactions. Maple species (Acer spp.) are among the most commonly planted trees in urban areas throughout North America and Europe. Among these species, field, sycamore, and Norway maple are native to Europe, but tolerate environmental stress to varying degrees. Here, we compared the phytophagous insect communities in the canopy of these tree species in the city of Budapest, Hungary. We also examined the stress level [expressed as peroxidase (POD) enzyme activity], and physiological condition (expressed as degree of leaf necrosis and leaf fall) of the maple trees, and their relationship to herbivore abundance. We observed higher total abundance of phytophagous insects on field and sycamore maple compared to Norway maple. Most herbivorous species were associated with field maple, sycamore had the highest aphid densities, and Norway maple harbored the least specific phytophagous insect community. Field maple trees were in the best condition while Norway maple trees in the worst condition, i.e., with the highest proportion of necrotic leaf surface area. The super-abundant planthopper species, Metcalfa pruinosa positively affected the POD activity of trees, but did not influence their condition. On the contrary, M. pruinosa abundance was driven by tree condition, with higher numbers on healthier trees. Our findings suggest that the abundance of phytophagous insects in the canopy of maple trees is highly determined by tree condition, and in this study field maple had the highest and Norway maple the lowest tolerance for urban stress.

Arthropod community composition in urban landscapes is shaped by both environmental filtering and dispersal limitation

“…While forest cover was predictive of foliage arthropod community variation, the dissimilarity of tree species on which arthropods were collected was a stronger predictor. Even within genera, different species of trees support distinct herbivorous arthropod communities [40], and these different herbivore communities may in turn shape arthropod predator communities, with greater tree diversity corresponding to greater spider abundance [41]. The importance of variation in the environment with regard to multiple factors - in this case, habitat and diet - reinforces the value of assessing drivers of community composition for groups which utilize different components of the same landscape.…”

Sugar feeding by invasive mosquito species on ornamental and wild plants

“…Another plant host that appeared more than once in our results using both barcodes was the maple tree ( Acer spp.). Maple trees are some of the most frequently planted ornamental trees in North America 52 . These trees produce flowers and generally bloom from March to June.…”

Sugar feeding by invasive mosquito species on ornamental and wild plants

“…Another plant host that appeared several times in our results using both barcodes was the maple tree (Acer spp.). Maple trees are some of the most frequently planted ornamental trees in North America [59]. These trees do produce flowers and generally bloom from March to June.…”