Insect Community Composition Research Articles

Preliminary Study of Species-Area, Isolation and Impact of Environmental Heterogeneity on Insect Communities in Natural Patches in The Brazilian Pantanal

ABSTRACT: The Pantanal is the largest floodplain in the word with more than 140,000 km2, and the annual cycles of flood and drought are the most important factors that determine ecological interactions and patterns of diversity. Usually, capoes are elongated or rounded arboreal patches of herbaceous vegetation found in flooded fields. This study aimed to determine the effect of size, distance, and heterogeneity of capoes on selected components of insect communities in Brazilian Pantanal, testing the hypotheses that (I) larger capoes show greater ecological metrics, (II) the closer one is more similar in insect composition, and (III) heterogeneity affects the composition of the insect community. We used Malaise traps to capture insects. There was a positive relationship between richness and abundance and capao size and this influenced insect community composition. The distance between capoes also affected insect community composition. The variation in heterogeneity of capoes influenced community compositio...

Taxonomic Composition and Species Diversity of Insect Communities of Grass-Small Shrub Cover of Raised Bogs in Belarus

Taxonomic Composition and Species Diversity of Insect Communities of Grass-Small Shrub Cover of Raised Bogs in Belarus

Contrasting effects of ploidy level on seed production in a diploid tetraploid system.

Previous studies demonstrated the effects of polyploidy on various aspects of plant life. It is, however, difficult to determine which plant characteristics are responsible for fitness differences between cytotypes. We assessed the relationship between polyploidy and seed production. To separate the effects of flowering phenology, flower head size and herbivores from other possible causes, we collected data on these characteristics in single flower heads of diploid and tetraploid Centaurea phrygia in an experimental garden. We used structural equation modelling to identify the main pathways determining seed production. The results showed that the relationship between polyploidy and seed production is mediated by most of the studied factors. The different factors acted in opposing directions. Wider flower heads displayed higher above the ground suggested higher seed production in diploids. In contrast, earlier flowering and a lower abundance of herbivores suggested higher seed production in tetraploids. However, because phenology was the strongest driver of seed production in this system, the sum of all the pathways suggested greater seed production in tetraploids than in diploids. The pathway linking ploidy level directly to seed production, representing unstudied factors, was not significant. This suggests that the factors studied likely are drivers of the between-cytotype differences. Overall, this study demonstrated that tetraploids possess overall higher fitness estimated as seed production. Regardless of the patterns observed here, strong between year fluctuations in the composition and diversity of insect communities have been observed. The direction of the selection may thus vary between years. Consequently, understanding the structure of the interactions is more important for understanding the system than the overall effects of cytotype on a fitness trait in a specific year. Such knowledge can be used to model the evolution of species traits and plant-herbivore and plant-pollinator interactions in diploid-polyploid systems.

Substrate heterogeneity influences the trait composition of stream insect communities: an experimental in situ study

AbstractLocal distribution of stream insects is influenced by abiotic factors, such as substrate heterogeneity and amount of organic matter. We evaluated the influence of substrate heterogeneity on the functional structure and diversity of stream macroinvertebrate communities based on 4 traits: feeding habits, body size, body shape, and attachment to substrate. Heterogeneous substrate supported communities with higher functional diversity and richness than did homogeneous substrate. In addition, communities on heterogeneous substrate had more predators, shredders, filterer–collectors, and organisms with a large body size than did homogeneous substrate. In contrast, communities on homogeneous substrate had predominantly small organisms, case-builders, and scrapers. Our results suggest that in natural habitats, substrate heterogeneity selects specific combinations of traits especially related to size and feeding habit, which have strong implications for stream ecosystem functioning. As a result, one may ant...

민통선 둠벙의 수서곤충과 식물 군집에 대한 수환경 특성의 영향

A small irrigation pond for a rice paddy field is a very important refuge for aquatic insects and plants. To reveal environmental factors determining species composition of aquatic insect and plant communities, we analyzed water chemistry and connection between pond and surrounding in five types of irrigation ponds based on water source and connection in CCZ of South Korea: stagnation, exchange-stagnation, spring, stagnation-spring, and exchangespring types. The stagnation type had the most stable water chemistry among the 16 irrigation ponds studied, and the spring type had the most variable water chemistry. Anion content was highest in the stagnation type, and cation content was highest in the exchange-stagnation type. 228 taxa including 63 wetland plants and 95 aquatic insect taxa were recorded. Six rare plant species and four rare aquatic insect species were identified. The stagnation-spring type had the highest species richness. There was no correlation between size and species richness. Multivariate analyses showed distinctive species assemblages among the irrigation pond types. This would indicate that water chemical change at annual cycle and connection influenced on the species assemblages in irrigation pond. In additional, irrigation pond contributes to regional biodiversity in agricultural areas, as irrigation pond provides heterogeneous communities for the freshwater ecosystem.

Are aphid parasitoids from mild winter climates losing their winter diapause?

Temperature is both a selective pressure and a modulator of the diapause expression in insects from temperate regions. Thus, with climate warming, an alteration of the response to seasonal changes is expected, either through genetic adaptations to novel climatic conditions or phenotypic plasticity. Since the 1980s in western France, the winter guild of aphid parasitoids (Hymenoptera: Braconidae) in cereal fields has been made up of two species: Aphidius rhopalosiphi and Aphidius matricariae. The recent activity of two other species, Aphidius avenae and Aphidius ervi, during the winter months suggests that a modification of aphid parasitoid overwintering strategies has taken place within the guild. In this study, we first performed a field survey in the winter of 2014/15 to assess levels of parasitoid diapause incidence in agrosystems. Then, we compared the capacity of the four parasitoid species to enter winter diapause under nine different photoperiods and temperature conditions in the laboratory. As predicted, historically winter-active species (A. rhopalosiphi and A. matricariae) never entered diapause, whereas the species more recently active during winter (A. avenae and A. ervi) did enter diapause but at a low proportion (maximum of 13.4 and 11.2%, respectively). These results suggest rapid shifts over the last three decades in the overwintering strategies of aphid parasitoids in Western France, probably due to climate warming. This implies that diapause can be replaced by active adult overwintering, with potential consequences for species interactions, insect community composition, ecosystem functioning, and natural pest control.

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.

Distance decay of similarity in fungivorous insect communities: assessing dispersal limitation using genetic data

AbstractWe evaluated how dispersal limitation affected spatial variation in the species composition of fungivorous insect communities inhabiting fruiting bodies of bracket fungi on scattered deadwoods. The insect communities showed significant distance decay of similarity pattern among deadwoods, which was not fully explained by differences in environmental conditions. To investigate whether insect dispersal limitation could explain the distance‐decay pattern, we analyzed mitochondrial haplotype data; limited dispersal is expected to generate an isolation‐by‐distance pattern of genetic structure in component species. However, genetic distance between deadwoods was not correlated with geographic distance in any species, and a simulation study suggested that the absence of genetic structure refutes the dispersal limitation hypothesis even when the resolution of genetic differences is not high, as in our study. Thus, dispersal limitation did not contribute to the observed community patterns within our study site, suggesting that unmeasured environmental factors may have played an important role. Our study demonstrates that genetic data can help determine whether dispersal limitation of component species is the primary cause of observed distance decay in community similarity.

Floral traits influence pollen vectors' choices in higher elevation communities in the Himalaya-Hengduan Mountains.

BackgroundHow floral traits and community composition influence plant specialization is poorly understood and the existing evidence is restricted to regions where plant diversity is low. Here, we assessed whether plant specialization varied among four species-rich subalpine/alpine communities on the Yulong Mountain, SW China (elevation from 2725 to 3910 m). We analyzed two factors (floral traits and pollen vector community composition: richness and density) to determine the degree of plant specialization across 101 plant species in all four communities. Floral visitors were collected and pollen load analyses were conducted to identify and define pollen vectors. Plant specialization of each species was described by using both pollen vector diversity (Shannon’s diversity index) and plant selectiveness (d’ index), which reflected how selective a given species was relative to available pollen vectors.ResultsPollen vector diversity tended to be higher in communities at lower elevations, while plant selectiveness was significantly lower in a community with the highest proportion of unspecialized flowers (open flowers and clusters of flowers in open inflorescences). In particular, we found that plant species with large and unspecialized flowers attracted a greater diversity of pollen vectors and showed higher selectiveness in their use of pollen vectors. Plant species with large floral displays and high flower abundance were more selective in their exploitation of pollen vectors. Moreover, there was a negative relationship between plant selectiveness and pollen vector density.ConclusionsThese findings suggest that flower shape and flower size can increase pollen vector diversity but they also increased plant selectiveness. This indicated that those floral traits that were more attractive to insects increased the diversity of pollen vectors to plants while decreasing overlap among co-blooming plant species for the same pollen vectors. Furthermore, floral traits had a more important impact on the diversity of pollen vectors than the composition of anthophilous insect communities. Plant selectiveness of pollen vectors was strongly influenced by both floral traits and insect community composition. These findings provide a basis for a better understanding of how floral traits and community context shape interactions between flowers and their pollen vectors in species-rich communities.Electronic supplementary materialThe online version of this article (doi:10.1186/s12898-016-0080-1) contains supplementary material, which is available to authorized users.

Plant genotype influences aquatic‐terrestrial ecosystem linkages through timing and composition of insect emergence

AbstractTerrestrial leaf litter provides aquatic insects with an energy source and habitat structure, and species differences in litter can influence aquatic insect emergence. Emerging insects also provide energy to riparian predators. We hypothesized that plant genetics would influence the composition and timing of emerging insect communities among individual genotypes of Populus angustifolia varying in litter traits. We also compared the composition and timing of emerging insect communities on litter from mixed genotypes of three cross types of a hybridizing cottonwood complex: P. angustifolia, P. fremontii, and their F1 hybrids. Using litter harvested from an experimental common garden, we measured emerging insect community composition, abundance, and production for 12 weeks in large litter packs affixed with emergence traps. Five major findings emerged. (1) In support of the genetic similarity hypothesis, we found that, among P. angustifolia tree genotypes, litter from more closely related genotypes had more similar litter thickness, nitrogen concentrations, decomposition rates, and emerging insect communities. (2) Genetic similarity was not correlated with other litter traits, although the litter fungal community was a strong predictor of emerging insect communities. (3) Litter decomposition rate, which was the strongest predictor of emerging aquatic insect communities, was influenced by litter thickness, litter N, and the litter fungal community. (4) In contrast to strong community composition differences among P. angustifolia genotypes, differences in community composition between P. fremontii and P. angustifolia were only marginally significant, and communities on F1 hybrids were indistinguishable from P. angustifolia despite genetic and litter trait differences. (5) Mixed litter packs muted the genetic effects observed in litter packs consisting of single genotypes. These results demonstrate that the genetic structure of riparian forests can affect the composition and timing of aquatic insect emergence. Because many riparian trees are clonal, including P. angustifolia, large clone size is likely to result in patches of genetically structured leaf litter that may influence the timing and composition of insect emergence within watersheds. Riparian restoration efforts incorporating different tree genotypes could also influence the biodiversity of emerging aquatic insects. Our work illustrates the importance of plant genes for community and ecosystem processes in riparian corridors.

Life history traits predict insect species responses to large herbivore overabundance: a multitaxonomic approach

There is increasing concern over the ecological impact of markedly increasing numbers of large herbivores (hereafter large herbivore overabundance) on forest ecosystems. To predict the ecological consequences of large herbivore overabundance, it is first necessary to understand how biological communities respond to large herbivore overabundance. Here, we examined the relationships between the life history traits of five insect taxonomic groups (moths, dung beetles, longicorn beetles, carabid beetles, and carrion beetles) and their responses to deer overabundance in Hokkaido, northern Japan. Insects were collected from three study sites: enclosure (20 deer/km2), control (10 deer/km2), and exclosure (0 deer/km2). The different taxonomic and functional insect species differed in their response to deer overabundance. The abundance (number of individuals) of longicorn beetles, dung beetles, and arbor-feeding moths was higher in the enclosure site than in the control site, whereas that of carabid beetles, carrion beetles, and herb- or shrub-feeding moths was higher in the control site than in the enclosure site. These results suggest that the type of food and the level of dependence on the understory are key traits determining insect sensitivity to deer overabundance. In addition, large or flightless species responded negatively to deer overabundance. Overall, this study demonstrated a significant change in insect communities following experimental deer overabundance, suggesting that large herbivore overabundance leads to the homogenization of biological communities. Unfortunately, because insects have diverse functions in forest ecosystems, such marked changes in both abundance and composition of insect communities will decrease ecosystem functions and resilience.

Fluvial geomorphology and aquatic‐to‐terrestrial Hg export are weakly coupled in small urban streams of Columbus, Ohio

AbstractAlthough mercury (Hg) contamination is common in stream ecosystems, mechanisms governing bioavailability and bioaccumulation in fluvial systems remain poorly resolved as compared to lentic systems. In particular, streams in urbanized catchments are subject to fluvial geomorphic alterations that may contribute to Hg distribution, bioaccumulation, and export across the aquatic‐to‐terrestrial boundary. In 12 streams of urban Columbus, Ohio, we investigated the influence of fluvial geomorphic characteristics related to channel geometry, streamflow, and sediment size and distribution on (1) Hg concentrations in sediment and body burdens in benthic larval and adult emergent aquatic insects and (2) aquatic‐to‐terrestrial contaminant transfer to common riparian spiders of the families Pisauridae and Tetragnathidae via changes in aquatic insect Hg body burdens as well as in aquatic insect density and community composition. Hydrogeomorphic characteristics were weakly related to Hg body burdens in emergent insects (channel geometry) and tetragnathid spiders (streamflow), but not to Hg concentrations in sediment or benthic insects. Streamflow characteristics were also related to emergent insect density, while wider channels were associated with benthic insect community shifts toward smaller‐bodied and more tolerant taxa (e.g., Chironomidae). Thus, our results provide initial evidence that fluvial geomorphology may influence aquatic‐to‐terrestrial contaminant Hg transfer through the collective effects on emergent insect body burdens as well as on aquatic insect community composition and abundance.

ХӨХХОТЫН ЗҮҮН ТОЙРОГИЙН ШАВЖИЙН ЗҮЙЛИЙН ОЛОН ЯНЗ БАЙДЛЫГ ТОГТООХ БҮЛГЭМДЛИЙН СУДАЛГАА

An investigation had been made into the insect communities in Hohhot farmland. Between January and December 2011-2012, in order to approach the effects of different habitat types in Hohhot on insect diversity, an investigation was conducted on the insects in four types of habitats in Hohhot, Inner Mongolia. On the basis of a comprehensive investigation, combined with the Shannon-Wiener diversity index, evenness index, dominance index, the systematic analysis of Hohhot, the insect community composition in different seasons. A total of 5305 insects were collected , belonging to 164 species, 75 families and 11 orders, among which, Orthoptera, Hemiptera, Coleoptera, Diptera, Hymenoptera were the dominant taxa. The insect species diversity and evenness, summer>autumn>spring; dominance, spring>autumn>summer.

Diversity and Temporal Variation in the Orchid Bee Community (Hymenoptera: Apidae) of a Remnant of a Neotropical Seasonal Semi-deciduous Forest

Multiple biotic and abiotic variables control the composition, diversity, and temporal fluctuations of insect communities. In particular, the assembly of bee communities is strongly influenced by climatic factors as well as variation in food resource availability, which in turn also fluctuates in response to the same factors. The goal of the present study was to investigate the species composition, the species richness and the abundance of the euglossine bees in a remnant of the seasonal semi-deciduous forest of northeastern Sao Paulo state, and evaluate the temporal variation in those parameters over time. From January to December 1990, males of euglossine bees were sampled using three aromatic baits. We collected 643 males belonging to 12 species and three genera. Euglossa imperialis Cockerell was the most abundant species, followed by Eulaema nigrita Lepeletier and Euglossa melanotricha Moure. The composition and species richness showed temporal variation throughout the year, with the highest values being observed during the rainiest months. Such variations occurred by the presence of males from six species which were sampled only during the rainiest months. Of the five most abundant species, Eg. imperialis and Eg. melanotricha were the only species sampled throughout the year. Only El. nigrita and Eg. melanotricha , had the monthly abundance of males correlated with precipitation. Based on the assumption that male euglossine capture rates reflect actual abundance at the sampled habitats, we believe that Eg. imperialis , usually represented by few male in other studies, has a population very well established in the habitat here studied.

Evidence for the persistence of food web structure after amphibian extirpation in a Neotropical stream.

Species losses are predicted to simplify food web structure, and disease-driven amphibian declines in Central America offer an opportunity to test this prediction. Assessment of insect community composition, combined with gut content analyses, was used to generate periphyton-insect food webs for a Panamanian stream, both pre- and post-amphibian decline. We then used network analysis to assess the effects of amphibian declines on food web structure. Although 48% of consumer taxa, including many insect taxa, were lost between pre- and post-amphibian decline sampling dates, connectance declined by less than 3%. We then quantified the resilience of food web structure by calculating the number of expected cascading extirpations from the loss of tadpoles. This analysis showed the expected effects of species loss on connectance and linkage density to be more than 60% and 40%, respectively, than were actually observed. Instead, new trophic linkages in the post-decline food web reorganized the food web topology, changing the identity of "hub" taxa, and consequently reducing the effects of amphibian declines on many food web attributes. Resilience of food web attributes was driven by a combination of changes in consumer diets, particularly those of insect predators, as well as the appearance of generalist insect consumers, suggesting that food web structure is maintained by factors independent of the original trophic linkages.

Habitat filtering and adult dispersal determine the taxonomic composition of stream insects in an urbanizing landscape

Summary Suitability of the local habitat (‘habitat filtering’) and dispersal between stream reaches determines the composition of insect communities, and urban land use may affect both processes. While urban streams are often poor habitats for insects and dispersal between them is often hindered, conservation and restoration activities generally focus solely on the local (in‐stream) environment. We determined whether in‐stream habitat filtering (a ‘local’ process) or dispersal between reaches (a ‘regional’ process) controlled assemblage composition in a landscape subject to ongoing urban development (‘urbanizing’). We compared models incorporating geographic distance between sites, environmental dissimilarity, and land‐use/land‐cover attributes of dispersal pathways in an attempt to explain the dissimilarity of stream insect assemblages. Distance and land‐use/land‐cover attributes were characterised along both overland (straight line) and corridor pathways. Both in‐stream habitat filtering and dispersal affected assemblage composition, but habitat had a stronger influence. Overland distance was a better predictor of assemblage dissimilarity than corridor distance, implying stream insect dispersal occurs across catchment boundaries as well as along stream corridors. The best model incorporated land‐use/land‐cover attributes along dispersal pathways, which supported the idea that urban land‐use in the terrestrial environment mediates dispersal. Conservation and restoration strategies for streams in urbanizing landscapes that focus on local habitat quality and ignore dispersal are missing a potentially important mechanism affecting insect assemblage composition. While the primary focus should be on maintaining or improving the local habitat, potential dispersal pathways should also be considered.

If we build – they mostly come: partial functional recovery but persistent compositional differences in wetland beetle community restoration

There is growing evidence of restoration success for wetland plant communities. However, little research has been done on the associated invertebrate community. We test whether restoring plant communities after peat extraction is sufficient for restoring the taxonomic and functional composition of beetle communities. We monitored taxonomic and trait‐based community metrics for beetle assemblages on restoration islands that were up to 13 years old and compared these with the adjacent “target” undisturbed peat bog. Recovery of beetle abundance, species richness, and trophic structure on the islands was remarkably rapid (i.e. within a decade) and converged on that of the undisturbed peat bog within 13 years after restoration commenced. In contrast, small, native, and poor‐dispersing taxa were persistently less abundant on the islands than in the undisturbed peat bog, causing persistent differences in species composition, even on the oldest islands. These poor‐dispersers probably need assistance to reach the islands and possibly ongoing intervention to allow them to survive there. Our findings emphasize the potential for functional trait analysis to reveal barriers to full restoration of insect community composition.

Habitat configuration affects spatial pattern of β diversity of insect communities breeding in oyster mushrooms

Theory predicts that spatial structure can mediate interactions that affect species diversity in a patchy environment. A rarely considered effect of spatial structure on biodiversity is the interplay of spatial habitat arrangement with species interactions at multiple spatial scales. We investigated how spatial habitat arrangement and predation mediate the assembly of the larval communities of fungivorous insects breeding in the oyster mushroom, Pleurotus ostreatus (Jacq. ex Fr.) P.Kumm in a North American woodland. In a two‐way factorial design, we varied the spatial arrangement of mushroom clumps (‘clustered', ‘patchy', and ‘uniform'; 3 levels) crossed with predator exclusion (access allowed or not; 2 levels) to study their joint effects on patterns of α, β and γ diversity of the fungivorous insect communities. Partitioning diversity into these three components suggested that neither spatial nor predation treatments significantly affected α, β and γ diversity. We found that an intermediate inter‐clump distance (i.e., the ‘patchy' treatment) increased spatial autocorrelation in insect community composition within experimental blocks, particularly in the mushrooms to which predators had access. The spatial structuring in β diversity indicates that the arrangement of mushroom clumps can structure β diversity of fungivorous larval communities through direct effects on the species themselves (e.g., increased aggregation and habitat choice of ovipositing females of fungivorous insects), as well as effects mediated through the presence and behavior of predators (e.g., spatially structured selective foraging by predators acting as a filter on which species were in the clumps). The naturally patchy nature of mushroom fruiting may transform the spatial pattern of β diversity by altering the behavior of ovipositing females, or by weakening the negative effect of larval competition.

Insect-flower interaction network structure is resilient to a temporary pulse of floral resources from invasive Rhododendron ponticum.

Invasive alien plants can compete with native plants for resources, and may ultimately decrease native plant diversity and/or abundance in invaded sites. This could have consequences for native mutualistic interactions, such as pollination. Although invasive plants often become highly connected in plant-pollinator interaction networks, in temperate climates they usually only flower for part of the season. Unless sufficient alternative plants flower outside this period, whole-season floral resources may be reduced by invasion. We hypothesized that the cessation of flowering of a dominant invasive plant would lead to dramatic, seasonal compositional changes in plant-pollinator communities, and subsequent changes in network structure. We investigated variation in floral resources, flower-visiting insect communities, and interaction networks during and after the flowering of invasive Rhododendron ponticum in four invaded Irish woodland sites. Floral resources decreased significantly after R. ponticum flowering, but the magnitude of the decrease varied among sites. Neither insect abundance nor richness varied between the two periods (during and after R. ponticum flowering), yet insect community composition was distinct, mostly due to a significant reduction in Bombus abundance after flowering. During flowering R. ponticum was frequently visited by Bombus; after flowering, these highly mobile pollinators presumably left to find alternative floral resources. Despite compositional changes, however, network structural properties remained stable after R. ponticum flowering ceased: generality increased, but quantitative connectance, interaction evenness, vulnerability, H’2 and network size did not change. This is likely because after R. ponticum flowering, two to three alternative plant species became prominent in networks and insects increased their diet breadth, as indicated by the increase in network-level generality. We conclude that network structure is robust to seasonal changes in floral abundance at sites invaded by alien, mass-flowering plant species, as long as alternative floral resources remain throughout the season to support the flower-visiting community.

Large differences in the composition of herbivore communities and seed damage in diploid and autotetraploid plant species

Herbivory is one of the key interactions affecting plant fitness. Despite the large amount of data available on the effects of herbivores on various plant groups, we still know very little information about the interactions of herbivores with individuals having different ploidy levels. We studied the relationship of diploid and tetraploid Centaurea phrygia in natural and experimental garden conditions to the community of pre-dispersal seed predators developing in flower heads of the plants. In addition, we collected a set of data on flowering phenology, and flower head morphology and chemistry to investigate potential mechanisms underlying the differences between cytotypes. The two cytotypes are strongly differentiated in their flower head morphology and chemistry as well as in their flowering phenology, with flower heads of diploids being larger, containing more secondary metabolites and flowering later. Also, the two cytotypes strongly differed in the composition of insect communities in the flower heads and tetraploids suffered higher seed damage than the diploids. The differences between cytotypes in seed damage were generally consistent across datasets, indicating that the differences are not due to differences in the habitats in which the cytotypes occur but are due to differences in particular biological characteristics of the plants. The diversity and composition of insect communities, however, strongly varied between years and environments. Flowering phenology could explain part, but not all of the differences observed between cytotypes, indicating that other factors such as flower head morphology or chemistry could also play a role. The study indicated that the differences between the two cytotypes are important determinant of the plant–herbivore interactions in the system. Although we identified multiple factors that could explain the different associations, further research is needed to assess the relative importance of each of these factors. © 2015 The Linnean Society of London, Biological Journal of the Linnean Society, 2015, 115, 270–287.