Leaf miner and plant galler species richness on Acacia: relative importance of plant traits and climate

Abstract

Diversity patterns of herbivores have been related to climate, host plant traits, host plant distribution and evolutionary relationships individually. However, few studies have assessed the relative contributions of a range of variables to explain these diversity patterns across large geographical and host plant species gradients. Here we assess the relative influence that climate and host plant traits have on endophagous species (leaf miners and plant gallers) diversity across a suite of host species from a genus that is widely distributed and morphologically variable. Forty-six species of Acacia were sampled to encapsulate the diversity of species across four taxonomic sections and a range of habitats along a 950 km climatic gradient: from subtropical forest habitats to semi-arid habitats. Plant traits, climatic variables, leaf miner and plant galler diversity were all quantified on each plant species. In total, 97 leaf mining species and 84 plant galling species were recorded from all host plants. Factors that best explained leaf miner richness across the climatic gradient (using AIC model selection) included specific leaf area (SLA), foliage thickness and mean annual rainfall. The factor that best explained plant galler richness across the climatic gradient was C:N ratio. In terms of the influence of plant and climatic traits on species composition, leaf miner assemblages were best explained by SLA, foliage thickness, mean minimum temperature and mean annual rainfall, whilst plant gall assemblages were explained by C:N ratio, %P, foliage thickness, mean minimum temperature and mean annual rainfall. This work is the first to assess diversity and structure across a broad environmental gradient and a wide range of potential key climatic and plant trait determinants simultaneously. Such methods provide key insights into endophage diversity and provide a solid basis for assessing their responses to a changing climate.

Hypoxia and hypercarbia in endophagous insects: Larval position in the plant gas exchange network is key

“…The multiple climatic factors combined with the various plant traits, however, make it difficult to test directly this hypothesis using a biogeographical climatic gradient (Bairstow et al, 2010). Indeed, humidity seems to play an important and confounding role in setting the richness of gallers and miners, with greater species richness in xeric and mesic environments for gallers and miners, respectively (Bairstow et al, 2010). This effect of humidity likely depends on thermal context, so an extension of our framework is required to test these hypotheses.…”

“…Indeed, in insects in general, anoxia tolerance may be a central feature of metabolic cold adaptation (Hodkinson and Bird, 2004). The multiple climatic factors combined with the various plant traits, however, make it difficult to test directly this hypothesis using a biogeographical climatic gradient (Bairstow et al, 2010). Indeed, humidity seems to play an important and confounding role in setting the richness of gallers and miners, with greater species richness in xeric and mesic environments for gallers and miners, respectively (Bairstow et al, 2010).…”

Are dominant plant species more susceptible to leaf‐mining insects? A case study at Saihanwula Nature Reserve, China

“…High incidences and abundances of leafminers on dominant plants have been demonstrated at global, regional, and community levels (Dai et al., 2017). For example, the highest reported abundance and richness values of leaf‐mining insects are found for members of Fagaceae and Myrtaceae (i.e., the most dominant plant families in the Northern and Southern Hemispheres, respectively) (Bairstow, Clarke, McGeoch, & Andrew, 2010; Claridge & Wilson, 1982; Dai, Xu, & Cai, 2014; Dai, Xu, & Ding, 2013; Faeth & Mopper, 1981; Ishida, Hattori, & Kimura, 2004; Kollár & Hrubík, 2009; Lopez‐Vaamonde, Godfray, & Cook, 2003; Nakamura, Hattori, Ishida, Sato, & Kimura, 2008; Opler & Davis, 1981; Sato, 1991; Sinclair & Hughes, 2008a,b). The variation in leafminer species richness among different host plants might be described by the species–area (i.e., leafminer species to host plant area) or species–apparency (i.e., leafminer species to host plant apparency) relationship (Dai et al., 2017; MacArthur & Wilson, 1967; Opler, 1974).…”

Insect Leaf-Chewing Damage Tracks Herbivore Richness in Modern and Ancient Forests

“…For most extant endophytic feeding, it is well known that many insect species make single, distinct DTs on single host species at a site [1], [5], [9], [14], [15]. However, external feeders (leaf-chewers; Figs.…”