Leaf Herbivory Research Articles

Biotic and abiotic factors associated with altitudinal variation in plant traits and herbivory in a dominant oak species.

It is generally thought that herbivore pressure is higher at lower elevations where climate is warmer and less seasonal, and that this has led to higher levels of plant defense investment at low elevations. However, the generality of this expectation has been called into question by recent studies. We tested for altitudinal gradients in insect leaf damage, plant defenses (phenolic compounds), and nutritional traits (phosphorus and nitrogen) in leaves of the long-lived tree Quercus robur, and further investigated the abiotic factors associated with such gradients. We sampled 20 populations of Q. robur distributed along an altitudinal gradient spanning 35-869 m above sea level, which covered most of the altitudinal range of this species and varied substantially in abiotic conditions, plant traits, and herbivory. Univariate regressions showed that leaf herbivory, phenolics, and phosphorus increased toward higher elevations, whereas leaf nitrogen did not vary with altitude. Multiple regression analyses indicated that temperature was the single most important factor associated with herbivory and appears to be strongly associated with altitudinal variation in damage. Leaf phenolics were also correlated with herbivory, but in a manner that suggests these chemical defenses do not underlie altitudinal variation in damage. In addition, we found that variation in leaf traits (phenolics and nutrients) was in turn associated with both climatic and soil variables. Overall, these findings suggest that altitudinal gradients in herbivory and defenses in Q. robur are uncoupled and that elevational variation in herbivory and plant traits responds mainly to abiotic factors.

Insect herbivory in a mature Eucalyptus woodland canopy depends on leaf phenology but not CO2 enrichment.

BackgroundClimate change factors such as elevated atmospheric carbon dioxide concentrations (e[CO2]) and altered rainfall patterns can alter leaf composition and phenology. This may subsequently impact insect herbivory. In sclerophyllous forests insects have developed strategies, such as preferentially feeding on new leaf growth, to overcome physical or foliar nitrogen constraints, and this may shift under climate change. Few studies of insect herbivory at elevated [CO2] have occurred under field conditions and none on mature evergreen trees in a naturally established forest, yet estimates for leaf area loss due to herbivory are required in order to allow accurate predictions of plant productivity in future climates. Here, we assessed herbivory in the upper canopy of mature Eucalyptus tereticornis trees at the nutrient-limited Eucalyptus free-air CO2 enrichment (EucFACE) experiment during the first 19 months of CO2 enrichment. The assessment of herbivory extended over two consecutive spring—summer periods, with a first survey during four months of the [CO2] ramp-up phase after which full [CO2] operation was maintained, followed by a second survey period from months 13 to 19.ResultsThroughout the first 2 years of EucFACE, young, expanding leaves sustained significantly greater damage from insect herbivory (between 25 and 32 % leaf area loss) compared to old or fully expanded leaves (less than 2 % leaf area loss). This preference of insect herbivores for young expanding leaves combined with discontinuous production of new foliage, which occurred in response to rainfall, resulted in monthly variations in leaf herbivory. In contrast to the significant effects of rainfall-driven leaf phenology, elevated [CO2] had no effect on leaf consumption or preference of insect herbivores for different leaf age classes.ConclusionsIn the studied nutrient-limited natural Eucalyptus woodland, herbivory contributes to a significant loss of young foliage. Leaf phenology is a significant factor that determines the level of herbivory experienced in this evergreen sclerophyllous woodland system, and may therefore also influence the population dynamics of insect herbivores. Furthermore, leaf phenology appears more strongly impacted by rainfall patterns than by e[CO2]. e[CO2] responses of herbivores on mature trees may only become apparent after extensive CO2 fumigation periods.Electronic supplementary materialThe online version of this article (doi:10.1186/s12898-016-0102-z) contains supplementary material, which is available to authorized users.

Forest defoliator pests alter carbon and nitrogen cycles.

Climate change may foster pest epidemics in forests, and thereby the fluxes of elements that are indicators of ecosystem functioning. We examined compounds of carbon (C) and nitrogen (N) in insect faeces, leaf litter, throughfall and analysed the soils of deciduous oak forests (Quercus petraea L.) that were heavily infested by the leaf herbivores winter moth (Operophtera brumata L.) and mottled umber (Erannis defoliaria L.). In infested forests, total net canopy-to-soil fluxes of C and N deriving from insect faeces, leaf litter and throughfall were 30- and 18-fold higher compared with uninfested oak forests, with 4333 kg C ha−1 and 319 kg N ha−1, respectively, during a pest outbreak over 3 years. In infested forests, C and N levels in soil solutions were enhanced and C/N ratios in humus layers were reduced indicating an extended canopy-to-soil element pathway compared with the non-infested forests. In a microcosm incubation experiment, soil treatments with insect faeces showed 16-fold higher fluxes of carbon dioxide and 10-fold higher fluxes of dissolved organic carbon compared with soil treatments without added insect faeces (control). Thus, the deposition of high rates of nitrogen and rapidly decomposable carbon compounds in the course of forest pest epidemics appears to stimulate soil microbial activity (i.e. heterotrophic respiration), and therefore, may represent an important mechanism by which climate change can initiate a carbon cycle feedback.

Three invasive insects alter Cycas micronesica leaf chemistry and predict changes in biogeochemical cycling

ABSTRACTLeaf litter chemical traits were measured for Cycas micronesica plants in Guam following leaf herbivory by the scale Aulacaspis yasumatsui, the butterfly Chilades pandava caterpillar, or the leaf miner Erechthias sp. to determine the influence of the non-native pests on litter quality. Scale herbivory increased litter phenols above those of undamaged leaves but did not influence lignin or cellulose concentrations. Butterfly caterpillar herbivory increased litter phenols above and decreased litter lignin below those of undamaged leaves, but did not influence cellulose concentrations. Leaf miner herbivory increased litter lignin concentrations above those of undamaged leaves, but did not influence phenols or cellulose concentrations. Herbivory influenced 8 of 12 essential elements that were quantified. Herbivory by all 3 insects increased nitrogen and potassium litter concentrations and decreased calcium and iron litter concentrations when compared with undamaged litter. The responses were idiosyncratic among herbivores for the remaining essential elements. Stoichiometry among the chemical constituents indicated that herbivory increased litter quality and predicted more rapid biogeochemical cycling in Guam's ecosystems as a result of these 3 non-native insect invasions.

Plant defense against leaf herbivory based on metal accumulation: examples from a tropical high altitude ecosystem

AbstractSpecies that evolved in high‐altitude grasslands, where soils are dystrophic and metal rich, developed adaptations for these extreme conditions, such as metal accumulation and sclerophyllous leaves, and these adaptations may secondarily affect insect herbivory activity. The present study investigates the hypothesis that costs related to accumulation of certain metals may be evolutionarily compensated for by decreasing leaf herbivory in some plant species from rupestrian fields. Studies were conducted in different locations at the Ferriferous Quadrangle, a metal‐rich region in south‐east Brazil, with four species adapted to high‐altitude grasslands: Eremanthus erythropappus, Eremanthus incanus, Lychnophora ericoides and Byrsonima variabilis. Sample design varied according to population sizes and spatial distribution of individuals. We found that concentrations of manganese (Mn) and iron (Fe) significantly reduced the herbivory in the leaves of E. erythroppapus and E. incanus, whereas aluminum (Al) reduced herbivory in L. ericoides, and Mn affected negatively the herbivory in B. variabilis. These results support the hypothesis that metal‐accumulating plants, as a response to the harsh environment in which they evolved, are protected against foliar damage caused by insect herbivores in rupestrian fields.

Predator refuges for conservation biological control in an intermediately disturbed system: the rise and fall of a simple solution

Summary Managed systems harvested at intermediate time‐scales have advantages over annual short‐cycled systems in maintaining top‐down control of insect herbivores, and the flexible harvest regimes in these systems provide opportunities for habitat management that can stabilize predator–prey population dynamics across harvests – resulting in reduced risk of pest outbreaks. In a large‐scale field experiment, we explored whether retaining refuges, that is preserving parts of the stand to reduce predator mortality, could reduce the risk of pest insect outbreaks in willow short‐rotation coppice. Population densities of three omnivorous predator species and three outbreaking herbivorous leaf beetle species were monitored over four years after coppice (stem harvest) in eight stands with refuges (treatment) and eight stands without refuges (control). Predation pressure was estimated in years three and four. Contrary to our predictions, leaf beetle densities were higher in stands with refuges and predator densities were higher in stands without refuges. Leaf beetle egg mortality increased with total predator density, but did not differ between stands with and without refuges. These unexpected results can be attributed to interactions between dispersal and patch age. The altered phenology of coppiced stems may have triggered leaf beetle aggregation in refuges and migration from stands without refuges. A behavioural response to resource concentration in retained old patches likely transformed the predator refuge from a ‘source’ to a ‘sink’. Synthesis and applications. This study shows that retaining refuges in willow short‐rotation coppice to facilitate predator population recovery after harvest can come at the cost of more attractive herbivore habitats – and thus increased pest problems. We conclude that crop refuges in systems with intermediate disturbance regimes pose new challenges for conservation biological control, in particular the need to consider how patch age affects dispersal and recolonization of both pest and predators.

Foliar nectar enhances plant-mite mutualisms: the effect of leaf sugar on the control of powdery mildew by domatia-inhabiting mites.

Mite domatia are small structures on the underside of plant leaves that provide homes for predacious or fungivorous mites. In turn, mites inhabiting domatia defend the plant by consuming leaf herbivores and pathogens, which can result in a domatia-mediated, plant-mite defence mutualism. Several recent studies have suggested that plants receive enhanced benefits when they provide a foliar food source, such as sugars secreted from extrafloral nectaries, to mite mutualists alongside mite domatia. However, the effect of foliar sugar on reducing leaf pathogen load via domatia-inhabiting mites has not been directly investigated. To fill this gap, the links between foliar sugar addition, domatia-inhabiting mite abundance, and pathogen load were experimentally evaluated in wild grape. Furthermore, because the proposed combined benefits of providing food and housing have been hypothesized to select for the evolutionary correlation of extrafloral nectaries and domatia across plant lineages, a literature survey aimed at determining the overlap of mite domatia and extrafloral nectaries across plant groups was also conducted. It was found that leaves with artificial addition of foliar sugar had 58-80 % more mites than leaves without foliar sugar addition, and that higher mite abundances translated to reduced powdery mildew (Erysiphe necator) loads on leaves. It was found that mite domatia and extrafloral nectaries occur non-randomly in the same clades across Eudicots. Genera with both traits are reported to highlight candidate lineages for future studies. Together, the results demonstrate that foliar sugar can indeed enhance the efficacy of domatia-mediated plant-mite mutualisms, and suggest that this synergism has the potential to influence the co-distribution of foliar nectar and mite domatia across plants.

Galling Insect Species Richness and Leaf Herbivory in an Abrupt Transition Between Cerrado and Tropical Dry Forest

Galling species (GS) and leaf-chewing insects differ in resource use and sensitivity to microclimatic factors. We tested the effects of the harsh environmental, plant richness, and density on GS attack and the leaf damage inflicted by leaf-chewing insects along an abrupt transition between the savanna and tropical dry forest in Brazil. We found 134 GS on 406 trees belonging to 75 species in 30 sampled plots during the rainy season. Higher GS number was found in xeric habitats, according to the gradient: cerrado > transition > dry forest, whereas opposite pattern was found for the percentage of leaf area removed by insects. In general, plant richness and density significantly affected GS richness. On the other hand, herbivore responses to tree density (at intraspecific level) depended largely on host tree species evaluated. Our results provide evidence for the harsh environmental hypothesis on galling richness in xeric habitats, and plant species richness and density positively explained the increase in local GS richness. The high GS richness sampled demonstrates that more attention should be directed to the biodiversity and conservation of abrupt transition areas in cerrado, given their success and possible extensive radiation in there. In this perspective, the conservation of areas with higher plant species number and density may have primordial implications to preserve the diverse and specific GS richness associated to these close habitats.

Susceptibility of silver birch (Betula pendula) to herbivorous insects is associated with the size and phenology of birch – implications for climate warming

ABSTRACTSusceptibility of trees to herbivorous insects is often associated with the tree growth and phenology, both of which are sensitive to a warming climate. Therefore, changes in these traits may affect the intensity of herbivory on trees in the future. We grew silver birch (Betula pendula) populations differing in their growth and phenology in a common garden experiment, and studied the effect of these plant traits on the leaf herbivory, insect herbivore density and community composition of herbivores in two consecutive years, 2011 and 2012. Differences in size and the timing of growth cessation among the birch genotypes were related to differences in herbivore community compositions and herbivory. In 2011, the most intensive herbivore damage was observed on birch genotypes of small size, late bud burst and early growth cessation, and these genotypes originated from high-latitude populations. The differences among birch genotypes in their susceptibility to herbivore damage may lead to differences in their competitive abilities. While climate warming will affect phenology and growth of plants, our study shows, that it may indirectly affect herbivory and herbivore communities as well.

Florivory shapes both leaf and floral interactions

AbstractFlorivory, or the consumption of flowers, is a ubiquitous interaction that can reduce plant reproduction directly by damaging reproductive tissues and indirectly by deterring pollinators. However, we know surprisingly little about how florivory alters plant traits or the larger community of species interactions. Although leaf damage is known to affect floral traits and interactions in many systems, the consequences of floral damage for leaf traits and interactions are unknown. We manipulated floral damage in Impatiens capensis and measured effects on floral attractive traits and secondary chemicals, leaf secondary chemicals, floral interactions, leaf herbivory, and plant reproduction. We also examined relationships between early season floral traits and floral interactions, to explore which traits structure floral interactions. Moderate but not high florivory significantly increased relative selfed reproduction, leading to a shift in mating system away from outcrossing. Florivory increased leaf secondary compounds and decreased leaf herbivory, although mechanisms other than leaf chemistry may be responsible for some of the reduced leaf damage. Florivory altered four of seven measured interactions, including increased subsequent florivory and reduced flower spiders, although only leaf damage effects were significant after correcting for multiple tests. Pretreatment concentrations of floral anthocyanins and condensed tannins were associated with reduced levels of many floral antagonisms, including florivory, nectar larceny, and flower spider abundance, suggesting these traits play a role in floral resistance. Overall, our results indicate a broad range of community and potential evolutionary consequences of florivory through structuring subsequent floral interactions, altering leaf secondary chemicals, and shaping leaf herbivory.

Defense pattern of Chinese cork oak across latitudinal gradients: influences of ontogeny, herbivory, climate and soil nutrients.

Knowledge of latitudinal patterns in plant defense and herbivory is crucial for understanding the mechanisms that govern ecosystem functioning and for predicting their responses to climate change. Using a widely distributed species in East Asia, Quercus variabilis, we aim to reveal defense patterns of trees with respect to ontogeny along latitudinal gradients. Six leaf chemical (total phenolics and total condensed tannin concentrations) and physical (cellulose, hemicellulose, lignin and dry mass concentration) defensive traits as well as leaf herbivory (% leaf area loss) were investigated in natural Chinese cork oak (Q. variabilis) forests across two ontogenetic stages (juvenile and mature trees) along a ~14°-latitudinal gradient. Our results showed that juveniles had higher herbivory values and a higher concentration of leaf chemical defense substances compared with mature trees across the latitudinal gradient. In addition, chemical defense and herbivory in both ontogenetic stages decreased with increasing latitude, which supports the latitudinal herbivory-defense hypothesis and optimal defense theory. The identified trade-offs between chemical and physical defense were primarily determined by environmental variation associated with the latitudinal gradient, with the climatic factors (annual precipitation, minimum temperature of the coldest month) largely contributing to the latitudinal defense pattern in both juvenile and mature oak trees.

Seasonal variation of responses to herbivory and volatile communication in sagebrush (Artemisia tridentata) (Asteraceae).

Plants can respond to insect herbivory in various ways to avoid reductions in fitness. However, the effect of herbivory on plant performance can vary depending on the seasonal timing of herbivory. We investigated the effects of the seasonal timing of herbivory on the performance of sagebrush (Artemisia tridentata). Sagebrush is known to induce systemic resistance by receiving volatiles emitted from clipped leaves of the same or neighboring plants, which is called volatile communication. Resistance to leaf herbivory is known to be induced most effectively after volatile communication in spring. We experimentally clipped 25% of leaves of sagebrush in May when leaves were expanding, or in July when inflorescences were forming. We measured the growth and flower production of clipped plants and neighboring plants which were exposed to volatiles emitted from clipped plants. The treatment conducted in spring reduced the growth of clipped plants. This suggests that early season leaf herbivory is detrimental because it reduces the opportunities for resource acquisition after herbivory, resulting in strong induction of resistance in leaves. On the other hand, the late season treatment increased flower production in plants exposed to volatiles, which was caused mainly by the increase in the number of inflorescences. Because the late season treatment occurred when sagebrush produces inflorescences, sagebrush may respond to late herbivory by increasing compensation ability and/or resistance in inflorescences rather than in leaves. Our results suggest that sagebrush can change responses to herbivory and subsequent volatile communication seasonally and that the seasonal variation in responses may reduce the cost of induced resistance.

Native species seedling growth in the ecological restoration of riparian forest

This study evaluates the process of ecological restoration by monitoring the height of seedlings of native species in the Cerrado and the factors that affect their growth in riparian forest restoration. The growth pattern of the species were calculated with the average heights, generating linear regression models tested with ANOVA and compared by the likelihood test. The average of the frequencies of leaf herbivory, stem herbivory and absence of sheets (predation, dehydration and malnutrition) was analyzed by cluster analysis (Ward method) as possible factors that influence the growth. The average growth of 13 species was 50.39 cm.year-1, ranging from 15.5 cm.year-1 to 100.1 cm.year-1. Of the thirteen species, eight had growth above 40 cm.year-1, with potential to recover degraded areas. Five species showed significant differences in the linear equations of growth: Calophyllum brasiliense, Croton urucurana, Inga laurina, Myrsine guianensis and Tibouchina stenocarpa. Possible interactions with growth factors (leaf herbivory, stem herbivory and no leaves) resulted in the formation of two groups of species. Among the factors evaluated, overall, the species of both groups had higher leaf herbivory. The leaf herbivores and the absence of leaves affected the two groups differently, which may indicate susceptibility of different species from herbivores. The evaluation of the factors that interfere with growth after planting seedlings can help in adaptive management of areas in restoration process.Keywords: leaf herbivory, stem herbivory, height, recovery of degraded land, gallery forest.

Effects of Varying Temperature on Leaf Phenology and Herbivory of Dominant Tree Species in Subtropical Evergreen Broad-Leaves Forest in Eastern China

ABSTRACT The aim of this work was to analyse the response of dominant tree species to the changing climate in a subtropical evergreen broad-leaved forest in China. We investigated the main leaf phenology and herbivory parameters of four typical trees (i.e., Schima superba, Castanopsis fargesii, Castanopsis sclerophylla and Cyclobalanopsis sessilifolia) in spring from 2010 to 2014 in the Tiantong National Forest Research Station in eastern China. The results showed that the accumulated temperature was the principle factor which affected the leaf phenology and herbivory. All four trees got an earlier, shorter and more synchronised leaf expansion in years with higher accumulated temperature, and also they suffered more sever leaf damage in these years. However the trees responded differently to climate warming in leaf phenology and herbivory. The S. superba and Ca. sclerophylla were more sensitive to the varying accumulated temperature than the Ca. fargesii and Cy. sessilifolia both in leaf phenology and her...

An equation for determining percentage of herbivory on Pinguicula moranensis ' A correction

Recently Alcalá et al. (2010) explored the potentially defensive function of sticky traps in Pin- guicula moranensis. Specifically, the authors assessed the defensive role of glandular trichomes in the interaction between P. moranensis and its insect herbivores. Alcalá et al. (2010) offered a unique digital photography tool and a method for determining the amount of herbivory. To create a baseline level of insect herbivory the authors developed an equation to determine the percentage of leaf herbivory. Unfortunately, the equation published in the article contained an error. The goal of this article is to offer a correction to the error.

Ontogenic variation and effect of collection procedure on leaf biomechanical properties of Mediterranean seagrass Posidonia oceanica (L.) Delile

AbstractLeaf mechanical traits are important to understand how aquatic plants fracture and deform when subjected to abiotic (currents or waves) or biotic (herbivory attack) mechanical forces. The likely occurrence of variation during leaf ontogeny in these traits may thus have implications for hydrodynamic performance and vulnerability to herbivory damage, and may be associated with changes in morphologic and chemical traits. Seagrasses, marine flowering plants, consist of shoot bundles holding several leaves with different developmental stages, in which outer older leaves protect inner younger leaves. In this study we examined the long‐lived seagrass Posidonia oceanica to determine ontogenic variation in mechanical traits across leaf position within a shoot, representing different developmental stages. Moreover, we investigated whether or not the collection procedure (classical uprooted shoot versus non‐destructive shoot method: cutting the shoot without a portion of rhizome) and time span after collection influence mechanical measurements. Neither collection procedure nor time elapsed within 48 h of collection affected measurements of leaf biomechanical traits when seagrass shoots were kept moist in dark cool conditions. Ontogenic variation in mechanical traits in P. oceanica leaves over intermediate and adult developmental stages was observed: leaves weakened and lost stiffness with aging, while mid‐aged leaves (the longest and thickest ones) were able to withstand higher breaking forces. In addition, younger leaves had higher nitrogen content and lower fiber content than older leaves. The observed patterns may explain fine‐scale within‐shoot ecological processes of leaves at different developmental stages, such as leaf shedding and herbivory consumption in P. oceanica.

A conserved pattern in plant-mediated interactions between herbivores.

Plant-mediated interactions between herbivores are important determinants of community structure and plant performance in natural and agricultural systems. Current research suggests that the outcome of the interactions is determined by herbivore and plant identity, which may result in stochastic patterns that impede adaptive evolution and agricultural exploitation. However, few studies have systemically investigated specificity versus general patterns in a given plant system by varying the identity of all involved players. We investigated the influence of herbivore identity and plant genotype on the interaction between leaf-chewing and root-feeding herbivores in maize using a partial factorial design. We assessed the influence of leaf induction by oral secretions of six different chewing herbivores on the response of nine different maize genotypes and three different root feeders. Contrary to our expectations, we found a highly conserved pattern across all three dimensions of specificity: The majority of leaf herbivores elicited a negative behavioral response from the different root feeders in the large majority of tested plant genotypes. No facilitation was observed in any of the treatment combinations. However, the oral secretions of one leaf feeder and the responses of two maize genotypes did not elicit a response from a root-feeding herbivore. Together, these results suggest that plant-mediated interactions in the investigated system follow a general pattern, but that a degree of specificity is nevertheless present. Our study shows that within a given plant species, plant-mediated interactions between herbivores of the same feeding guild can be stable. This stability opens up the possibility of adaptations by associated organisms and suggests that plant-mediated interactions may contribute more strongly to evolutionary dynamics in terrestrial (agro)ecosystems than previously assumed.

Does Plant Origin Influence the Fitness Impact of Flower Damage? A Meta-Analysis

Herbivory has been long considered an important component of plant-animal interactions that influences the success of invasive species in novel habitats. One of the most important hypotheses linking herbivory and invasion processes is the enemy-release hypothesis, in which exotic plants are hypothesized to suffer less herbivory and fitness-costs in their novel ranges as they leave behind their enemies in the original range. Most evidence, however, comes from studies on leaf herbivory, and the importance of flower herbivory for the invasion process remains largely unknown. Here we present the results of a meta-analysis of the impact of flower herbivory on plant reproductive success, using as moderators the type of damage caused by floral herbivores and the residence status of the plant species. We found 51 papers that fulfilled our criteria. We also included 60 records from unpublished data of the laboratory, gathering a total of 143 case studies. The effects of florivory and nectar robbing were both negative on plant fitness. The methodology employed in studies of flower herbivory influenced substantially the outcome of flower damage. Experiments using natural herbivory imposed a higher fitness cost than simulated herbivory, such as clipping and petal removal, indicating that studies using artificial herbivory as surrogates of natural herbivory underestimate the real fitness impact of flower herbivory. Although the fitness cost of floral herbivory was high both in native and exotic plant species, floral herbivores had a three-fold stronger fitness impact on exotic than native plants, contravening a critical element of the enemy-release hypothesis. Our results suggest a critical but largely unrecognized role of floral herbivores in preventing the spread of introduced species into newly colonized areas.

Herbivory and the success of Ligustrum lucidum: evidence from a comparison between native and novel ranges

Invasive plant species may benefit from a reduction in herbivory in their introduced range. The reduced herbivory may cause a reallocation of resources from defence to fitness. Here, we evaluated leaf herbivory of an invasive tree species (Ligustrum lucidum Aiton) in its native and novel ranges, and determined the potential changes in leaf traits that may be associated with the patterns of herbivory. We measured forest structure, damage by herbivores and leaf traits in novel and native ranges, and on the basis of the literature, we identified the common natural herbivores of L. lucidum. We also performed an experiment offering leaves from both ranges to a generalist herbivore (Spodoptera frugiperda). L. lucidum was more abundant and experienced significantly less foliar damage in the novel than in the native range, in spite of the occurrence of several natural herbivores. The reduced lignin content and lower lignin : N ratio in novel leaves, together with the higher herbivore preference for leaves of this origin in the laboratory experiment, indicated lower herbivore resistance in novel than in native populations. The reduced damage by herbivores is not the only factor explaining invasion success, but it may be an important cause that enhances the invasiveness of L. lucidum.

Effect of light environment on intra-specific variation in herbivory in the carnivorous plant Pinguicula moranensis (Lentibulariaceae)

ABSTRACTIdentifying the factors that affect a plant’s probability of being found and damaged by herbivores has been a central topic in the study of herbivory. Although herbivory could have important negative consequences on carnivorous plants, their interaction with herbivores remains largely unexplored. We evaluated the effect of spatial variation in light environment (sunny, shade and full-shade sites) on the pattern of leaf herbivory and florivory of the carnivorous plant Pinguicula moranensis. Plants’ overall probability of leaf damage was high (74.24%). Mean herbivory was four times higher in the sunny and shade sites than the observed in the full-shade site. Nearly 8% of plants suffered damage to reproductive structures, although the probability of florivory was similar among sites. Discussion addressed the inter-site variation in mean herbivory considering the effect of light exposure and the impact that herbivory could have on fitness components of this carnivorous plant.