Host Plant Composition Research Articles

Plant species richness, not hygrothermal stress, is the main predictor of gall‐inducing insect richness in Peruvian Amazon forests

AbstractPatterns of gall‐inducing insect diversity tend to be influenced by both habitat‐related and plant‐related characteristics. We investigated the distribution patterns of galling insects in four vegetation types (terra firme forest, white‐sand dry forest, white‐sand wet forest and palm swamp forest) of the Peruvian Amazon to test if the insect gall diversity (1) differs among different types of vegetation and (2) depends on host plant richness. In total, we found 11,579 galls belonging to 249 insect gall morphotypes, distributed across 30 botanical families and 75 plant species. Among host plant families, Fabaceae showed the greatest richness of insect gall morphotypes. We found that galling species richness was lower in palm swamp forest than in white‐sand forests, which can be explained by the lower richness of plants in this type of vegetation. However, we found no evidence of greater richness in xeric habitats (e.g., white‐sand dry forest) than in more mesic vegetation (terra firme forest), contradicting the hypothesis of hygrothermal stress. We also found that plant species richness was positively influenced with the richness and abundance of galling species, regardless of vegetation type. Galling insect species composition differed significantly between vegetation types, similarly to the floristic composition. Our findings show that the diversity of galling insects in the tropical rainforests of Peruvian Amazon are mainly influenced by host plant composition and host plant richness.Abstract in Spanish is available with online material.

Identifying candidate host plants for trap cropping against Drosophila suzukii in vineyards

AbstractThe spotted wing drosophila (SWD), Drosophila suzukii Matsumura (Diptera: Drosophilidae), is a serious pest in vineyards where it is difficult to control. Trap cropping, which involves manipulating the host plant composition in the crop vicinity to lure the pest away from grapes and towards more attractive host plant fruits, might be an interesting but so far neglected control approach to limit SWD egg-laying in grapes. An ideal trap crop should be more attractive to the pest than the actual crop and should ideally restrict pest development. We determined the attractiveness of fruits of 60 plant species for SWD egg-laying and their suitability for larval development in laboratory assays. Compared to grapes, 16 of the 60 fruits were strongly preferred by SWD females for egg-laying and additionally inhibited the development of SWD larvae into adults. Host preference was strongly influenced by the hardness of the fruit skin, and larval development was marginally affected by the acidity of fruits. However, none of the measured fruit traits had a significant effect on the emergence success of SWD. All 16 candidate trap crop plants should be further tested for their potential to reduce SWD infestation of grapes. We provide practical advice on the next steps to be taken for implementing a successful trap cropping strategy against SWD in commercial vineyards.

Ecological niches of epiphyllous bryophytes along Afrotropical elevation gradient

Understanding multiple environmental drivers governing tropical organisms' distribution and ecological niches is crucial for predicting their responses to ongoing rapid deforestation. While macroclimatic effects via energy and water availability are well predicted, less is known about locally modulating factors such as canopy structure, light and edaphic conditions. Here we show that minimum temperatures and ambient humidity drive the abundance and richness of leaf‐inhabiting epiphyllous bryophytes across 4‐km elevation gradient on Mount Cameroon, West Africa, separating epiphyll‐rich rainforests (0–2200 m a.s.l.) from epihyll‐poor fire‐driven afromontane savanna (2300–4000 m a.s.l.). However, local factors contribute more than half to the total abundance and richness variation, either directly (light) or indirectly (edaphic conditions) via their effects on host plant composition. The most abundant epiphyllous communities occur in vertically stratified upland rainforests between 600 and 1100 m elevation, where N‐fixing tree legumes dominate. Their canopy is relatively sparse, due to nutrient‐poor soils leached by high rainfall, leaving room for the development of diverse subcanopy tree and understory shrub and herb layers with epiphyll‐rich communities. Vertically homogenous lowland rainforests on fertile soils below 500 m, with dense overstory and shaded and species‐poor understory, have less developed epiphylls, as do seasonally dry montane forests between 2000 and 2300 m, or elephant fragmented forests between 1200 and 1600 m. We conclude that high temperature and humidity together with a vertically stratified canopy support epiphylls, whereas precipitation seasonality, disturbed vegetation with unstable microclimate, or dense, unstratified canopy discourage the development of epiphyllous communities. Our study illustrates that ecological niches of epiphyllous bryophytes are shaped by a complex interplay of multiple drivers, knowledge of which is essential for more realistic predictions of the impacts of current accelerated habitat loss on species distribution and diversity changes in the tropics.

Cross Cultivation on Homologous/Heterologous Plant-Based Culture Media Empowers Host-Specific and Real Time In Vitro Signature of Plant Microbiota

Alliances of microbiota with plants are masked by the inability of in vitro cultivation of their bulk. Pure cultures piled in international centers originated from dissimilar environments/hosts. Reporting that plant root/leaf-based culture media support the organ-specific growth of microbiota, it was of interest to further investigate if a plant-based medium prepared from homologous (maize) supports specific/adapted microbiota compared to another prepared from heterologous plants (sunflower). The culture-independent community of maize phyllosphere was compared to communities cross-cultivated on plant broth-based media: CFU counts and taxa prevalence (PCR-DGGE; Illumina MiSeq amplicon sequencing). Similar to total maize phyllospheric microbiota, culture-dependent communities were overwhelmed by Proteobacteria (>94.3–98.3%); followed by Firmicutes (>1.3–3.7%), Bacteroidetes (>0.01–1.58%) and Actinobacteria (>0.06–0.34%). Differential in vitro growth on homologous versus heterologous plant-media enriched/restricted various taxa. In contrast, homologous cultivation over represented members of Proteobacteria (ca. > 98.0%), mainly Pseudomonadaceae and Moraxellaceae; heterologous cultivation and R2A enriched Firmicutes (ca. > 3.0%). The present strategy simulates/fingerprints the chemical composition of host plants to expand the culturomics of plant microbiota, advance real-time in vitro cultivation and lab-keeping of compatible plant microbiota, and identify preferential pairing of plant-microbe partners toward future synthetic community (SynComs) research and use in agriculture.

Cecidomyiidae (Diptera) in the State of Santa Catarina, Brazil

The first checklist of gall midges (Diptera: Cecidomyiidae) in the state of Santa Catarina (SC) is organized based on literature review. Species distribution, discussion regarding endemism, and a list of host plants in the state are provided for the first time. We compare the composition of cecidomyiid species with other states of Brazil. Twenty-three species of gall midges occur in SC, all gall-inducers. They are distributed in 14 genera, being Lopesia Rübsaamen, 1908 and Bruggmannia Tavares, 1906 the best represented. The most speciose genera of Cecidomyiidae in SC are among the most speciose in Brazil, so this result matches the Brazilian pattern. Cecidomyiids are associated with 18 host plant species distributed in 12 families. Although SC comprises a low percentage of the Brazilian fauna of Cecidomyiidae (8.7%), two species are known only from the state. The Sorensen`s index showed that the fauna of SC and São Paulo (SP) are the most similar to each other. The similarity of gall-inducing insects can be related to the host plant composition and phytogeographic domain.

Tree diversity and functional leaf traits drive herbivore-associated microbiomes in subtropical China.

Herbivorous insects acquire microorganisms from host plants or soil, but it remains unclear how the diversity and functional composition of host plants contribute to structuring herbivore microbiomes. Within a controlled tree diversity setting, we used DNA metabarcoding of 16S rRNA to assess the contribution of Lepidoptera species and their local environment (particularly, tree diversity, host tree species, and leaf traits) to the composition of associated bacterial communities. In total, we obtained 7,909 bacterial OTUs from 634 caterpillar individuals comprising 146 species. Tree diversity was found to drive the diversity of caterpillar‐associated bacteria both directly and indirectly via effects on caterpillar communities, and tree diversity was a stronger predictor of bacterial diversity than diversity of caterpillars. Leaf toughness and dry matter content were important traits of the host plant determining bacterial species composition, while leaf calcium and potassium concentration influenced bacterial richness. Our study reveals previously unknown linkages between trees and their characteristics, herbivore insects, and their associated microbes, which contributes to developing a more nuanced understanding of functional dependencies between herbivores and their environment, and has implications for the consequences of plant diversity loss for trophic interactions.

The importance, role and promise of endophytic bacteria in horticulture

The article highlights current research that discusses the importance, role and application potential of endophytic bacteria in industrial horticulture. A review of national and foreign publications on the prevalence, taxonomic composition and function of endophytic bacteria in agricultural and horticultural plant objects is presented. Key endophytic bacterial phyla and genera associated with agricultural plants have been previously characterised. The authors consider the main plant organs and tissues that harbour endophytic bacteria, routes of bacterial colonisation and host-to-host transmission, endophyte relationships with the host species, as well as the genotype, seasonal period, environment, taxonomic and varietal composition of host plants. The host-microbiome relationship is intimate and mutually beneficial. Endophytic bacteria positively impact organogenesis and embryogenesis in agricultural plants, transforming phosphorus and atmospheric nitrogen into plant-absorbable forms and producing hormones that stimulate plant growth. Endophytic flora are able to produce vitamins, siderophores, phytohormones, antibiotic like-substances and phytopathogen-antagonistic exoenzymes, which play a role in enhancing a plant’s resistance to disease and stress, while simultaneously increasing its yield. Current evidence indicates the ability of endophytic bacteria isolated from garden crops to produce indolyl acetic acid, solubilise phosphates, potentially stimulate plant growth and suppress antagonistic phytopathogens. Endophytic bacteria are important regulators of growth, development and fruiting in garden crops, sustaining their reproduction and thus having a strong potential for use in biopreparations in industrial horticulture.

Таксономічний склад кормових рослин гусені совкоподібних (Lepidoptera: Noctuoidea) в умовах напівприродних екосистем приміської зони міста Житомир

Унаслідок проведених досліджень зібрано 2154 екземпляри комах, що належать до 125 видів совкоподібних, які належать до 3 родин і 24 підродин. Проаналізовано розподіл гусені совкоподібних у виявлених родинах та підродинах Noctuoidea відносно основних життєвих форм рослин, а також таксономічний склад кормових рослин. Встановлено, що частка хортофагів становить 53 %. Частка дендрофагів та хорто-дендрофагів є приблизно однаковою (22 та 25 % відповідно). Виявлено, що гусінь совкоподібних досліджуваного району трофічно пов'язана зі 105 родинами 3 відділів наземних рослин флори України. З'ясовано, що частка представників відділів папоротеподібних (Polypodiophyta) та голонасінних (Pinophyta) незначна: 5,7 та 1 % відповідно. Кормовими рослинами з відділу Polypodiophyta є представники 6 родин. З відділу голонасінних як кормові рослини виявлено представників однієї родини – Pinaceae. Досліджено, що переважаючу частку кормових рослин виявлених видів совкоподібних становлять покритонасінні рослини (Magnoliophyta) – 93,3 %. З класом однодольних (Liliopsida) облігатно пов'язано 10 видів; з дводольними (Magnoliopsida) облігатно пов'язано 45 видів. Найбільшу кількість видів виявлено на представниках родин Rosaceae, Asteraceae та Poaceae (71, 69 та 68 виявлених видів відповідно). Встановлено, що більшість шкідливих видів за харчовою спеціалізацією є хортофільними поліфагами із широкими трофічними зв'язками.

The role of selected plant metabolites in host plant choice by caterpillars of Acrobasis advenella (Zincken, 1818) (Lepidoptera, Pyralidae)

Abstract Acrobasis advenella is an oligophagous species feeding on plants of the Rosaceae family. The differences in concentrations of host plant quality components, above all primary metabolites and the presence or absence of secondary metabolites, directly affects herbivore growth and development. The objectives of this research were to determine the food preferences of 1st instar larvae according to the chemical composition of host plants. The highest acceptance of rowan in the free choice test by 1st instar larvae, as compared to hawthorn and black chokeberry, is positively influenced by the high content of total sugars and phenolic acids. The conclusion to be drawn from the results is that the differences in food choice by 1st instar larvae feeding on fruits could have been due to the different chemical compositions of the fruit.

Woodland habitat quality prevails over fragmentation for shaping butterfly diversity in deciduous forest remnants

The effects of forest fragmentation on biodiversity can be partitioned into habitat loss and increased isolation of habitat fragments. Habitat quality may however prevail over the effects of fragment area and isolation, especially for mobile animals such as butterflies. To test this hypothesis we surveyed butterfly communities in 36 deciduous forest fragments embedded in a conifer plantation matrix, along two orthogonal gradients of fragment area and isolation. We also sampled eight deciduous riparian forests to compare the complete pool of forest butterflies, expected to be found in riparian forests, to the composition of deciduous fragments. We quantified the effects of deciduous woodland area, isolation and quality on total and forest butterfly richness, community composition and several Community-Weighted Mean traits known to mediate butterfly responses to habitat fragmentation. For the 36 fragments, forest butterfly richness and community composition were not affected by fragment area or isolation but by habitat quality, especially host-plant composition. Riparian forests had higher forest butterfly richness and hosted more habitat specialists, with higher sensitivity to temperature extremes, than deciduous forest remnants. We thus provide new evidence that habitat quality can prevail over fragment area and isolation in shaping the composition of butterfly communities in mosaic landscapes.

The Impact of Environmental Conditions on Efficiency of Host Plant DNA Barcoding for Polyphagous Beetles.

Recently, several papers were published dealing with host plant identification for selected species of insects, including beetles. These studies took advantage of the DNA barcoding approach and generally showed that it is possible to identify diet composition from plant DNA present in insect guts. However, none of these studies considered how the impact of environmental conditions affected the likelihood of insect feeding and, therefore, the presence of host plant DNA that could be amplified and sequenced. In the present study, individuals of the polyphagous weevil Centricnemus leucogrammus (Germar, 1824) (Curculionidae: Entiminae) were used to test the hypothesis that harsh environmental conditions limited its feeding activity. The diet of 50 specimens collected during favourable conditions in the middle of the species reproductive period was compared against the diet of 50 specimens collected during harsh environmental conditions. Results clearly showed that almost no weevils fed during rainy and cold conditions and only a minority of individuals (20%) fed during the drought condition (on drought-resistant plants). It is important to consider such factors in any studies dealing with host plant identification and feeding behaviour. Results of ecological studies could lead to erroneous conclusions, e.g., underestimation of number and composition of host plants in the diet of studies species.

A DNA metabarcoding study of a polyphagous beetle dietary diversity: the utility of barcodes and sequencing techniques.

Recently developed techniques of DNA barcoding and next-generation sequencing (NGS) overcome previous limitations of evaluation of animal diet composition and together are promising method in molecular ecology. The objective was to compare standard ABI Sanger sequencing with new high throughput sequencing (Illumina MiSeq) technique and the two selected plant barcodes (rbcL gene and trnL intron) in terms of the identification of host plant composition for the selected beetle species--the Centricnemus leucogrammus weevil. A comparison of two sequencing techniques showed that NGS (in this case Illumina) gave more exhaustive results than the Sanger method. Moreover, it was proven that a two-locus barcoding systems (rbcL and trnL) is sufficient for host plant identification from DNA isolated from insect bodies, at least at the genus level. A comparison of host plant composition among distant populations revealed that the studied species did not feed uniformly across its range. This probably reveals an ecological adaptation of geographically and genetically isolated populations. These findings, beside broadening basic knowledge on the use of barcoding and sequencing techniques for host plant identifications in insect populations, can have implications for conservation studies and strategies for rare and endangered species.

Differences in the sugar composition of the honeydew of polyphagous brown soft scale Coccus hesperidum (Hemiptera: Sternorrhyncha: Coccoidea) feeding on various host plants

Plant chemical composition is an important determinant of host plant-insect interactions. For many insects sugars are the main factors determining the acceptability of a plant. This study investigated changes in plant chemical composition and differences in sugar composition of different host plants induced by the feeding of Coccus hesperidum L. (Hemiptera: Sternorrhyncha: Coccoidea). Present in plant extracts and honeydew there were three monosaccharide sugars: glucose, fructose and arabinose, and one disaccharide - sucrose. Arabinose was only found in extracts of Ficus benjamina plants. The sugar content of the honeydew was greater than in the extracts of control plants and lower than that in the extracts of infested plants. The honeydew collected from C. hesperidum feeding on the three plant species differed significantly in sugar content. Extracts of coccid infested plants of the three species used in this study contained more sugar than the un-infested control plants. The results show that honeydew composition of scale insects differ and the differences reflect the chemical composition of the host plants.

Eco-evolutionary spatial dynamics in the Glanville fritillary butterfly

Demographic population dynamics, gene flow, and local adaptation may influence each other and lead to coupling of ecological and evolutionary dynamics, especially in species inhabiting fragmented heterogeneous environments. Here, I review long-term research on eco-evolutionary spatial dynamics in the Glanville fritillary butterfly inhabiting a large network of approximately 4,000 meadows in Finland. The metapopulation persists in a balance between frequent local extinctions and recolonizations. The genetic spatial structure as defined by neutral markers is much more coarse-grained than the demographic spatial structure determined by the fragmented habitat, yet small-scale spatial structure has important consequences for the dynamics. I discuss three examples of eco-evolutionary spatial dynamics. (i) Extinction-colonization metapopulation dynamics influence allele frequency changes in the phosphoglucose isomerase (Pgi) gene, which leads to strong associations between genetic variation inPgiand dispersal, recolonization, and local population dynamics. (ii) Inbreeding in local populations increases their risk for extinction, whereas reciprocal effects between inbreeding, population size, and emigration represent likely eco-evolutionary feedbacks. (iii) Genetically determined female oviposition preference for two host plant species exhibits a cline paralleling a gradient in host plant relative abundances, and host plant preference of dispersing females in relation to the host plant composition of habitat patches influences immigration (gene flow) and recolonization (founder events). Eco-evolutionary spatial dynamics in heterogeneous environments may not lead to directional evolutionary changes unless the environment itself changes, but eco-evolutionary dynamics may contribute to the maintenance of genetic variation attributable to fluctuating selection in space and time.

The effect of forest soil and community composition on ectomycorrhizal colonization and seedling growth

Plant–soil feedbacks have been observed in many forest communities, but the role of the mycorrhizal community in perpetuating feedback loops is still poorly understood. Mycorrhizal community composition is closely linked to soil properties and host plant composition, which highlights their potential importance in plant–soil–fungus loops. Eastern hemlock (hemlock; Tsuga canadensis) seedlings were grown in soil bioassays in growth chambers and transplanted under closed forest canopy to examine the effect of hardwood and hemlock forest soil on seedling growth, survival, and ectomycorrhizal fungi (EMF) colonization. Seedlings propagated in hemlock forest soil had greater height growth compared with sterile control soil and achieved greater mycorrhizal colonization than seedlings grown in hardwood forest soils after 9 months in a growth chamber. Outplanted seedlings grown in hemlock communities achieved significantly greater increment growth than those seedlings grown in hardwood communities (mean height difference (95% CI) = 0.39 cm (0.14–0.63 cm)), although final survival and EMF colonization was similar between forest types. EMF diversity (Shannon-Wiener index (SE) = 1.88 (0.28) and 1.23 (0.44) for hardwood and hemlock, respectively) and community assemblage (Jaccard index (SE) = 19.0% (4%)) differed between the two forest communities. EMF community assemblage was associated with both the forest type (i.e. plant community/microsite effects) and initial soil type (i.e. soil characteristics/resistant inoculum). The results support previously observed positive feedbacks between conspecifics under hemlock forest communities and provides evidence for the role of the EMF community within this feedback loop. Alternatively, the reduced growth of hemlocks under hardwoods may be attributed to the different EMF community associated with that forest.

A population model for the peach fruit moth, Carposina sasakii Matsumura (Lepidoptera: Carposinidae), in a Korean orchard system

A population model for the peach fruit moth, Carposina sasakii Matsumura, was constructed to understand the population dynamics of this pest species and to develop an effective management strategy for various orchard (apple, peach, apple + peach) systems. The model was structured by the five developmental stages of C. sasakii: egg, larva, pupa, larval-cocoon (overwintering larva), and adult. The model consisted of a series of component models: (1) a bimodal spring adult emergence model, (2) an adult oviposition model, (3) stage emergence models of eggs, larvae, and pupae, (4) a larval survival rate model in fruits, (5) a larval-cocoon formation model, and (6) an insecticide effect model. Simulations using the model described the typical patterns of C. sasakii adult abundance in various orchard systems well, and was specific to the composition of host plants: three adult abundance peaks (first peak, mid-season peak, and last peak) a year with decreased peaks after the first peak in monoculture orchards of late apple, two adult peaks a year with a much higher last peak in monoculture orchards of early peach, and three adult peaks a year with much higher later peaks in mixed orchards of late apple and early peach. The average deviation between model outputs and actual records for first and second adult peak dates was 2.8 and 3.9 d, respectively, in simulations without an insecticide effect. The deviation decreased when insecticide effects were incorporated into the model. We also performed a sensitivity analysis of our model, and suggest possible applications of the model.

Fire effects on insect herbivores in an oak savanna: the role of light and nutrients

Abstract 1. Environmental heterogeneity created by prescribed burning provided the context for testing whether the distribution of an oak specialist (the lace bug, Corythuca arcuata) could be explained by stoichiometric mismatches between herbivore and host plant composition.2. Field observations showed that lace bug density was seven‐fold higher in frequently burned than in unburned units.3. Lace bug density did not increase with leaf nutrient concentrations, but was instead associated with higher light levels, higher concentrations of leaf carbon (C), lignin and total phenolics, and lower levels of cellulose. In addition, lace bugs reared on high‐light leaves had higher levels of survivorship than those fed on low‐light leaves.4. Sampling restricted to full‐sun leaves was used to test whether fire‐related changes in leaf nitrogen (N) and phosphorus (P) concentrations have a secondary influence on lace bug success. This sampling provided only limited evidence for nutrient limitation, as decreases in leaf N and P were associated with an increase in lace bug mass but a decrease in density.5. It is concluded that burning probably promotes lace bug population growth by increasing canopy openness, light penetration, and the availability of C‐based metabolites, and thus simple stoichoimetric mismatches between herbivores and host plants are not of primary importance in this system.

Can the plant‐mediated impacts on aphids of elevated CO2 and drought be predicted?

AbstractThe effects of drought and elevated CO2 on the performance of sap‐feeding aphids is considered. It is assumed that, for these stressors, the major influence will act through altering host plant composition and therefore diet. Changes in the plant may affect the ability to locate phloem tissues, while changes in composition of the sieve element forming the aphid diet may have more direct effects. It is concluded that plant response to conditions where carbon is present in excess (elevated CO2) or its consumption is exceeded by its availability (drought) is heterogeneous at the cellular level. The complexities of the response of the plant to components of climate change are paralleled by the diversity of the responses of aphids to drought and elevated CO2. Potential control points are discussed and it is concluded that current knowledge, both descriptive and mechanistic, supports the view that it is unreasonable to expect that a single plant component can predict the general response of aphids to climate change. Instead, it is more likely that aphids use a variety of cues when interacting with their host plants, and individual species respond to changes in their diet differently. Further work examining the response of both plant and aphid transcriptome and metabolome will support or contradict this hypothesis.

An altitudinal comparison of caterpillar (Lepidoptera) assemblages on Ficus trees in Papua New Guinea

AbstractAim This analysis of caterpillar (Lepidoptera) beta‐diversity between tropical lowlands and highlands attempts to separate the effects of between‐site (1) turnover of herbivore species on particular host plants, (2) changes in host use by herbivores, and (3) turnover of plant species on changes in herbivore assemblages.Location Two rain forest areas 130 km and 1700 altitudinal metres apart were studied in Papua New Guinea: one in the lowlands (100 m a.s.l.) on the northern coast of the island and one in the central New Guinean cordillera at 1800 m a.s.l.Methods The analysis is based on caterpillar feeding records obtained by quantitative sampling and rearing of caterpillars from four Ficus species studied in the mountains and 21 Ficus species and 62 plant species from other genera and families studied in the lowlands, including three Ficus species studied in both areas.Results Only 17% of species feeding on Ficus in the highlands also occurred in the lowlands. These species represented 1–46% of individuals in caterpillar assemblages on particular Ficus hosts. Widespread species included both Ficus specialists and generalists feeding on numerous plant families. Some of the Ficus specialists changed their preferred host species with altitude. High species turnover was not explained by changes in the species composition of host plants with altitude as lowland and montane assemblages feeding on the same Ficus species showed high turnover. Despite the rarity of widespread caterpillars, the lowland and montane Ficus assemblages were remarkably similar in their dominance structure, species richness, host specificity, generic composition and familial composition.Main conclusions Ficus‐feeding Lepidoptera assemblages between tropical lowlands and highlands are characterized by substantial species turnover not explained by altitudinal changes in the composition of the vegetation. Further, species‐rich plant genera can support caterpillar assemblages with relatively low beta‐diversity compared with species‐poor genera as caterpillars can switch their host preferences from one congeneric host species to another along an altitudinal gradient. Closely related plant species can thus represent a broad, continuously distributed resource along such gradients.

Metapopulation-level adaptation of insect host plant preference and extinction–colonization dynamics in heterogeneous landscapes

Species living in highly fragmented landscapes typically occur as metapopulations with frequent turnover of local populations. The turnover rate depends on population sizes and connectivities, but it may also depend on the phenotypic and genotypic composition of populations. The Glanville fritillary butterfly ( Melitaea cinxia) in Finland uses two host plant species, which show variation in their relative abundances at two spatial scales: locally among individual habitat patches and regionally among networks of patches. Female butterflies in turn exhibit spatial variation in genetically determined host plant preference within and among patch networks. Emigration, immigration and establishment of new populations have all been shown to be strongly influenced by the match between the host plant composition of otherwise suitable habitat patches and the host plant preference of migrating butterflies. The evolutionary consequences of such biased migration and colonization with respect to butterfly phenotypes might differ depending on spatial configuration and plant species composition of the patches in heterogeneous patch networks. Using a spatially realistic individual-based model we show that the model-predicted evolution of host plant preference due to biased migration explains a significant amount of the observed variation in host plant use among metapopulations living in dissimilar networks. This example illustrates how the ecological extinction–colonization dynamics may be linked with the evolutionary dynamics of life history traits in metapopulations.