Vanessa Cardui Research Articles

Sub-micrometer insights into the cytoskeletal dynamics and ultrastructural diversity of butterfly wing scales.

The color patterns that adorn lepidopteran wings are ideal for studying cell type diversity using a phenomics approach. Color patterns are made of chitinous scales that are each the product of a single precursor cell, offering a 2D system where phenotypic diversity can be studied cell by cell, both within and between species. Those scales reveal complex ultrastructures in the sub-micrometer range that are often connected to a photonic function, including iridescent blues and greens, highly reflective whites, or light-trapping blacks. We found that during scale development, Fascin immunostainings reveal punctate distributions consistent with a role in the control of actin patterning. We quantified the cytoskeleton regularity as well as its relationship to chitin deposition sites, and confirmed a role in the patterning of the ultrastructures of the adults scales. Then, in an attempt to characterize the range and variation in lepidopteran scale ultrastructures, we devised a high-throughput method to quickly derive multiple morphological measurements from fluorescence images and scanning electron micrographs. We imaged a multicolor eyespot element from the butterfly Vanessa cardui (V. cardui), taking approximately 200 000 individual measurements from 1161 scales. Principal component analyses revealed that scale structural features cluster by color type, and detected the divergence of non-reflective scales characterized by tighter cross-rib distances and increased orderedness. We developed descriptive methods that advance the potential of butterfly wing scales as a model system for studying how a single cell type can differentiate into a multifaceted spectrum of complex morphologies. Our data suggest that specific color scales undergo a tight regulation of their ultrastructures, and that this involves cytoskeletal dynamics during scale growth.

First record of Pantala flavescens (Anisoptera: Libellulidae) from the remote Amsterdam Island, southern Indian Ocean

Natural colonization of macroinvertebrates into the Sub-Antarctic area is generally accepted to be a rare event. In February 2017, two live adults of Pantala flavescens (Libellulidae) were recorded on the isolated Amsterdam Island (37°50′ S, 77°30′ E), southern Indian Ocean. This circumtropical species, common name the Globe Skimmer, can fly several thousand kilometers. This paper analyzes the weather conditions in this sector of the Indian Ocean in February 2017 to assess the probability of arrival of the dragonflies by air from their known migration route at lower latitudes between India and East Africa. The probability that this species could establish and form a permanent population on Amsterdam Island is discussed. Some favorable habitats are present but temperatures are probably too low to allow the dragonflies to complete their development. Odonata have never been observed on Sub-Antarctic islands and reports of natural arrival of insects into these islands mainly concern Lepidoptera. Here we also report observations of Vanessa cardui (Nymphalidae) which has established a permanent population on Amsterdam Island and has been observed on several occasions in the Crozet Archipelago.

Evidence for a southward autumn migration of nocturnal noctuid moths in central Europe.

Insect migrations are spectacular natural events and resemble a remarkable relocation of biomass between two locations in space. Unlike the well-known migrations of daytime flying butterflies, such as the painted lady (Vanessa cardui) or the monarch butterfly (Danaus plexippus), much less widely known are the migrations of nocturnal moths. These migrations - typically involving billions of moths from different taxa - have recently attracted considerable scientific attention. Nocturnal moth migrations have traditionally been investigated by light trapping and by observations in the wild, but in recent times a considerable improvement in our understanding of this phenomenon has come from studying insect orientation behaviour, using vertical-looking radar. In order to establish a new model organism to study compass mechanisms in migratory moths, we tethered each of two species of central European Noctuid moths in a flight simulator to study their flight bearings: the red underwing (Catocala nupta) and the large yellow underwing (Noctua pronuba). Both species had significantly oriented flight bearings under an unobscured view of the clear night sky and in the Earth's natural magnetic field. Red underwings oriented south-southeast, while large yellow underwings oriented southwest, both suggesting a southerly autumn migration towards the Mediterranean. Interestingly, large yellow underwings became disoriented on humid (foggy) nights while red underwings remained oriented. We found no evidence in either species for a time-independent sky compass mechanism as previously suggested for the large yellow underwing.

Simultaneous Recordings of Insect Visitors to Flowers Show Spatial and Temporal Heterogeneity

We compared insect visitors to 10 different flower species filmed simultaneously at two sites to assess whether insect taxa visiting at the two locations differed on a fine scale (<400 m apart). Although each of the 10 flower species had some insect taxa that were shared between sites, each also had unique visitors that appeared at a single site. Both the flowers and their insect visitors were generalists. Flowers were visited by an average of 16 different insect taxa. Insect taxa were observed visiting an average of three to four different flower species. The heterogeneity of floral visitors between sites is consistent with our proposed neighborhood model of pollination where flowers draw on insects in their area for pollination services and insects forage for nectar and pollen from flower species in their home ranges. Temporal heterogeneity can be dramatic. We recorded an influx of painted lady butterflies, which arrived in abundance on 12 June and were absent prior to then. Painted ladies dominated visits to flowers with hidden nectar sources (e.g., pale corydalis, blueberry, and bearberry). Spatial and temporal differences in insect visitors suggest ecological flexibility in pollination systems and may be important in insuring the persistence of flowers and insect visitors. Heterogeneity of insect visitors on a fine scale may structure gene flow among flowers and set the stage for local speciation in the angiosperms. The variation in the visitor community between sites highlights the importance of preserving multiple sites to insure the conservation of flowers and their insect visitors.

Pollen metabarcoding as a tool for tracking long-distance insect migrations.

Insects account for a large portion of Earth's biodiversity and are key players for ecosystems, notably as pollinators. While insect migration is suspected to represent a natural phenomenon of major importance, remarkably little is known about it, except for a few flagship species. The reason for this situation is mainly due to technical limitations in the study of insect movement. Here, we propose using metabarcoding of pollen carried by insects as a method for tracking their migrations. We developed a flexible and simple protocol allowing efficient multiplexing and not requiring DNA extraction, one of the most time-consuming part of metabarcoding protocols, and apply this method to the study of the long-distance migration of the butterfly Vanessa cardui, an emerging model for insect migration. We collected 47 butterfly samples along the Mediterranean coast of Spain in spring and performed metabarcoding of pollen collected from their bodies to test for potential arrivals from the African continent. In total, we detected 157 plant species from 23 orders, most of which (82.8%) were insect-pollinated. Taxa present in Africa-Arabia represented 73.2% of our data set, and 19.1% were endemic to this region, strongly supporting the hypothesis that migratory butterflies colonize southern Europe from Africa in spring. Moreover, our data suggest that a northwards trans-Saharan migration in spring is plausible for early arrivals (February) into Europe, as shown by the presence of Saharan floristic elements. Our results demonstrate the possibility of regular insect-mediated transcontinental pollination, with potential implications for ecosystem functioning, agriculture and plant phylogeography.

Insect pollinators diversity and abundance in Eruca sativa Mill. (Arugula) and Brassica rapa L. (Field mustard) crops.

Studies on the insect pollinators diversity and their relative abundance in Eruca sativa Mill. (Arugula) and Brassica rapa L. (field mustard) was carried out during spring season from February to April consecutively during all the three years of 2016–18. Insect pollinators observed belonged to four orders i.e. Hymenoptera, Diptera, Lepidoptera, and Coleoptera. A total of 20 major species of insect pollinators were recorded. The highest abundance of pollinator species belonged to Hymenoptera. The most prominent insect pollinator species were Apis mellifera followed by other three honey bee species of A. cerana, A. florea, and A. dorsata respectively. Some species of solitary bees were also recorded. From Diptera, four species of syrphid fly and one species from Muscidae family were also recorded. Insect pollinators recorded from order Lepidoptera were Pieris brassicae, Vanessa cardui, and Papilio demoleus. Lady bird beetle Coccinella septempunctata was recorded from Coleoptera order as occasional visitor. It was noticed that E. sativa attracted more insect pollinators than B. rapa which may be attributed to different amount and chemical properties of nectar, with number of pollen grains, and flower canopy of both crops. Further studies are needed to confirm the reasons for higher pollinator visitation to E. sativa than B. rapa through chemical analysis of nectar, amount of pollens, flower physiology and phenology of both crops.

Round-trip across the Sahara: Afrotropical Painted Lady butterflies recolonize the Mediterranean in early spring.

The Palearctic-African migratory circuit has been typically associated with birds. Very few insects are known to endure annual trans-Saharan circuits, but the Painted Lady butterfly (Vanessa cardui) is an exception. While it was demonstrated that this species massively migrates from Europe to the Afrotropics during the autumn, the existence of a reverse migration from the Afrotropics to Europe in the early spring remains hypothetical. Here, we analysed wing stable hydrogen isotope values (δ2H) of V. cardui migrants collected from February to April across the circum-Mediterranean region. We assessed their region of natal origin by comparing their wing isotope signature predicted δ2H values (isoscape). The results unambiguously demonstrate a sub-Saharan origin for many individuals, especially those collected in February, representing the first tangible evidence for a reverse northwards trans-Saharan migration in spring. This work supports the view that the Afrotropics (mostly exploited from September to February) is key in the V. cardui Palearctic-African population dynamics. This species relies on both temperate and tropical habitats to complete their multigenerational cycle, an unprecedented adaptation for butterflies and for most migratory insects. Such a migratory circuit has strong parallelisms with those of migratory birds.

Evaluation of the potential exposure of butterflies to genetically modified maize pollen in protected areas in Italy.

Environmental impacts of genetically modified crops are mandatorily assessed during their premarket phase. One of the areas of concern is the possible impact on nontarget organisms. Crops expressing Cry toxins might affect Lepidoptera larvae living outside cultivated fields, through pollen deposition on wild plants, which constitute their food source. While pollen toxicity varies among different events, possible exposure of nontarget species depends on the agro-environmental conditions. This study was conducted in two protected areas in Italy, characterized by different climatic conditions, where many Lepidoptera species thrive in proximity to maize cultivations. To estimate the possible exposure in absence of the actual stressor (e.g., Cry1-expressing maize plants), we conducted a two-year field survey of butterflies and weeds. Indicator species were selected-Aglais (Inachis) io in the Northern site and Vanessa cardui in the Southern site-and their phenology was investigated. Pollen dispersal from maize fields was measured by collection in Petri dishes. Duration and frequency of exposure was defined by the overlap between pollen emission and presence of larvae on host plants. Different risk scenarios are expected in the two regions: highest exposure is foreseen for A. io in the Northern site, while minimal exposure is estimated for V. cardui in the Southern site. In the latter case, locally grown maize cultivars flower in mid-summer in coincidence with an aestivation period for several butterfly species due to hot and dry conditions. Moreover, host plants of V. cardui are at the end of their life cycle thus limiting food availability.

The molecular basis for an ancient colour mutant in sweet pea (Lathyrus odoratus)

The classic A1 locus in sweet pea (Lathyrus odoratus) was investigated by Bateson, Punnett, and Saunders in the early 20th century history of Mendelian genetics. The mutation, in the form of the pink and white cultivar ‘Painted Lady’, is known from the 18th century. We show that this locus is associated with a single base pair mutation (332 G/A) in the flavonoid 3′,5′-hydroxylase (F3′5′H) gene. This results in an amino acid change (111 glycine/aspartic acid) in the conserved substrate recognition site 1 of the enzyme. The mutant flower lacks the blue pigment delphinidin and is thus pink and white, rather than purple and blue as in the wild-type. This single amino acid change at a functionally important site appears to convert the enzyme from primary F3′5′H activity to a relatively efficient F3′H, as suggested by heterologous transformation into Arabidopsis PAP1D (a mutant line that produces anthocyanin constitutively).

Exploring structural colour in uni- and multi-coloured butterfly wings and Ag+ uptake by scales

We discuss the origin of the structural colour of different butterfly wings in the light of the typical built-in microstructural arrangement of scales that are comprised of chitin-melanin layer and air-gaps. Three specimens of butterfly wings namely, Papilio Liomedon (black), Catopsilia Pyranthe (light green) and Vanessa Cardui (multi-coloured) were chosen and diffuse reflectance characteristics have been aquired for normal incidence of p-polarized light. Moreover, the time-dependent uptake of Ag+ into scales has led to swelling and spread of the chitinous ridges and ribs, with revelation of micro-beads in Catopsilia Pyranthe specimen. The reduction of the number of air-gaps between any two parallel ridges is attributed to the merging of adjacent gaps possessing a common boundary. The availability of Ag at the centre of a chosen ridge, for every wing type, follows an exponential growing trend, . Precise inclusion of nanoscale metals into natural photonic systems would provide new insight, while applying principles of photonics and plasmonics simultaneously.

Back to Africa: autumn migration of the painted lady butterfly Vanessa cardui is timed to coincide with an increase in resource availability

1. The painted lady Vanessa cardui is a long‐range migratory butterfly that performs an annual multi‐generational round‐trip between Europe and Africa. Each autumn it returns to northwest (NW) Africa, presumably to track changes in resources that follow a predictable climate‐related spatio‐temporal pattern.2. Data on the abundance of adult and immature stages in the Maghreb in 2014–2016 are used to test several hypotheses regarding the autumn migration of this species.3. A strong seasonal migratory strategy was confirmed by the all but total absence of the species in NW Africa at the end of summer and the arrival of huge numbers migrants in October and November. Migration was timed to coincide with an increase in host plant availability but not with any increase in nectar sources.4. Flower abundance was the main predictor of adult abundance in autumn, with Ditrichia viscosa, Verbesina encelioides, and Medicago sativa being key resources that attracted enormous numbers of butterflies to oases, ruderal habitats, and oueds. The distribution of immature stages was strongly predicted by host plant abundance (with traditional agriculture representing the most important breeding habitat) and latitude (most breeding occurred in the south of the region). Also, both adults and immature stages were more common inland than in coastal areas.5. Changes in age structure of the adult population were also noted. The number of fresh adults slowly increased, indicating that butterflies did not return in a single wave and that the first offspring of the first returners were already emerging when some butterflies were still arriving.

Systematic Review of the Effects of Chemical Insecticides on Four Common Butterfly Families

Safeguarding crop productivity by protecting crops from pest attacks entails the wide use of plant protection products that provide a quick, easy and cheap solution. The objective of this study is to understand the effects of insecticides used in agriculture on non-target butterflies, specifically on the families Lycaenidae, Nymphalidae, Hesperiidae and Papilionidae. To achieve this goal, a formal systematic review was performed according to European Food Safety Authority (EFSA) guidelines, by entering a combination of keywords on 3 online databases. Three reviewers independently extracted information on study characteristics and quality. The main results were collected and grouped by the insecticide used, butterflies species and family, and endpoints. The output was valuable but heterogeneous as the endpoints and methodologies of the studies reviewed were different. Few experimental studies on the effects of insecticides on the most common butterfly families have been published. Naled and permethrin are the most commonly used insecticides in the experiments, whilst the target organisms of these studies are Vanessa cardui, Danaus plexippus, Heliconius charitonius, belonging to the Nymphalidae family, and Eumaeus atala, belonging to the Lycaenidae family; the effects were evaluated on all developmental stages, with special attention to the larval phase. This systematic review highlights the need for more studies on the effects of chemical insecticides on non-target Lepidoptera in light of their ecological importance and the extensive use of these chemical products.

Dietary self‐selection and rules of compromise by fifth‐instar Vanessa cardui

AbstractWe examined dietary self‐selection and rules of compromise for protein (P) and digestible carbohydrate (C) intake by fifth‐instar Vanessa cardui L. (Lepidoptera: Nymphalidae: Nymphalini). We presented six fat‐free diet pairs to larvae in a choice trial to determine the ‘intake target’. In addition, we fed larvae seven fat‐free single diets differing in dietary nutrient ratio in no‐choice trials to determine the rules of compromise they exhibit when constrained to a singular, sub‐optimal dietary source. In choice trials, caterpillars regulated nutrient intake to a ratio of 1 protein to 1.09 carbohydrate (1P:1.09C), exhibiting tighter regulation of protein than of carbohydrate. Furthermore, larvae from different diet pair treatments did not differ in pupal mass or stadium duration. In no‐choice experiments, larvae reduced consumption on increasingly protein‐biased diets and increased consumption on increasingly carbohydrate‐biased diets, relative to a 1P:1C ratio diet. Differences in carbohydrate consumption were much greater between no‐choice treatments than differences in protein consumption. Dietary nutrient ratio affected pupal mass when accounting for initial larval mass. Pupal mass decreased as nutrient ratio was shifted off of 1P:1C, but to a greater extent when the ratio was skewed toward carbohydrate. Stadium duration increased as nutrient ratio diverged from 1P:1C, being more pronounced when shifted toward carbohydrate than toward protein. Regulation to near 1P:1C is consistent with results found for other Lepidoptera, and the rule of compromise exhibited by V. cardui is consistent with that expected for a generalist herbivore.

Genetic Basis of Melanin Pigmentation in Butterfly Wings.

Despite the variety, prominence, and adaptive significance of butterfly wing patterns, surprisingly little is known about the genetic basis of wing color diversity. Even though there is intense interest in wing pattern evolution and development, the technical challenge of genetically manipulating butterflies has slowed efforts to functionally characterize color pattern development genes. To identify candidate wing pigmentation genes, we used RNA sequencing to characterize transcription across multiple stages of butterfly wing development, and between different color pattern elements, in the painted lady butterfly Vanessa cardui This allowed us to pinpoint genes specifically associated with red and black pigment patterns. To test the functions of a subset of genes associated with presumptive melanin pigmentation, we used clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 genome editing in four different butterfly genera. pale, Ddc, and yellow knockouts displayed reduction of melanin pigmentation, consistent with previous findings in other insects. Interestingly, however, yellow-d, ebony, and black knockouts revealed that these genes have localized effects on tuning the color of red, brown, and ochre pattern elements. These results point to previously undescribed mechanisms for modulating the color of specific wing pattern elements in butterflies, and provide an expanded portrait of the insect melanin pathway.

Keanekaragaman, perilaku kunjungan, dan efektivitas serangga penyerbuk pada tanaman mentimun (Cucumis sativus Linn.)

Cucumber is a monoceous plant and require pollinators for pollination process. Diversity and foraging activity of pollinators affect the effectiveness of pollination, which can improve the yields. The aim of this research were to study the diversity, foraging behavior, and effectiveness of insect pollinators on cucumber plants. Scan sampling was used as on of the methodology for observing pollinator diversity, while foraging behavior was observed using focal sampling. Pollination effectiveness were measured based on the number of fruit set of opened and caged plants. Fifteen species were found as pollinator of cucumber, i.e., Xylocopa confusa Perez, Xylocopa latipes (Drury), Xylocopa caerulea Fabricius, Ceratina bryanti Cockerell, Amegilla burnensis Lieftinck, Nomia quadridentata Bingham, Nomia sp., Megachile unbripennis Smith, Megachile aff. disjuncta Fabricius, Megachile conjuncta Smith, Campsomeris javana Lepeletier, Syrphus sp., Parasyrphus sp., Eurema hecabe Linnaeus, and Vanessa cardui Linnaeus. The longest visit on cucumber flower pattern was by Syrphus sp. (50.71 seconds/flower), while the shortest visit was by X. confusa (4.78 seconds/flower). Pollination by insects increase 100% production as measured by healthy fruit per plant. Pollination also increase 77.61% of seeds number per fruit and 28.57% of seed weight.

Long-distance autumn migration across the Sahara by painted lady butterflies: exploiting resource pulses in the tropical savannah.

The painted lady, Vanessa cardui, is a migratory butterfly that performs an annual multi-generational migration between Europe and North Africa. Its seasonal appearance south of the Sahara in autumn is well known and has led to the suggestion that it results from extremely long migratory flights by European butterflies to seasonally exploit the Sahel and the tropical savannah. However, this possibility has remained unproven. Here, we analyse the isotopic composition of butterflies from seven European and seven African countries to provide new support for this hypothesis. Each individual was assigned a geographical natal origin, based on its wing stable hydrogen isotope (δ2Hw) value and a predicted δ2Hw basemap for Europe and northern Africa. Natal assignments of autumn migrants collected south of the Sahara confirmed long-distance movements (of 4000 km or more) starting in Europe. Samples from Maghreb revealed a mixed origin of migrants, with most individuals with a European origin, but others having originated in the Sahel. Therefore, autumn movements are not only directed to northwestern Africa, but also include southward and northward flights across the Sahara. Through this remarkable behaviour, the productive but highly seasonal region south of the Sahara is incorporated into the migratory circuit of V. cardui.

Discovery of mass migration and breeding of the painted lady butterflyVanessa carduiin the Sub-Sahara: the Europe-Africa migration revisited

Migratory behaviour has repeatedly evolved across taxa as an adaptation to heterogeneity in space and time. However, insect migration is still poorly understood, partly because of the lack of field data. The painted lady butterfly Vanessa cardui undertakes a long-distance annual migration between Europe and Africa. While spring flights from the Maghreb to Europe are well characterized, it is not known how far the European autumn migrants travel into Africa and whether they massively cross the Sahara Desert. We conducted fieldwork in four African countries (Chad, Benin, Senegal, and Ethiopia) in autumn and documented southward migrants in central Chad and abundant breeding sites across the tropical savannah as far south as the Niger River in the west and the Ethiopian highlands in the east. Given directionality and timing, these migrants probably originated in Europe and crossed the Mediterranean, the Sahara and the Sahel, a hypothesis that implies the longest (>4000 km) migratory flight recorded for a butterfly in a single generation. In the light of the new evidence, we revise the prevailing spatiotemporal model for the annual migration of V. cardui to incorporate tropical Africa, which could potentially be regarded as the missing geographic link between autumn (southwards) and spring (northwards) movements.

Physiological Perturbation Reveals Modularity of Eyespot Development in the Painted Lady Butterfly, Vanessa cardui.

Butterfly eyespots are complex morphological traits that can vary in size, shape and color composition even on the same wing surface. Homology among eyespots suggests they share a common developmental basis and function as an integrated unit in response to selection. Despite strong evidence of genetic integration, eyespots can also exhibit modularity or plasticity, indicating an underlying flexibility in pattern development. The extent to which particular eyespots or eyespot color elements exhibit modularity or integration is poorly understood, particularly following exposure to novel conditions. We used perturbation experiments to explore phenotypic correlations among different eyespots and their color elements on the ventral hindwing of V. cardui. Specifically, we identified which eyespots and eyespot features are most sensitive to perturbation by heat shock and injection of heparin—a cold shock mimic. For both treatments, the two central eyespots (3 + 4) were most affected by the experimental perturbations, whereas the outer eyespot border was more resistant to modification than the interior color elements. Overall, the individual color elements displayed a similar response to heat shock across all eyespots, but varied in their response to each other. Graphical modeling also revealed that although eyespots differ morphologically, regulation of eyespot size and colored elements appear to be largely integrated across the wing. Patterns of integration, however, were disrupted following heat shock, revealing that the strength of integration varies across the wing and is strongest between the two central eyespots. These findings support previous observations that document coupling between eyespots 3 + 4 in other nymphalid butterflies.

Molecular logic behind the three-way stochastic choices that expand butterfly colour vision.

Butterflies rely on color vision extensively to adapt to the natural world. Most species express a broad range of color sensitive Rhodopsins in three stochastically distributed types of ommatidia (unit eyes)1–3. The retinas of Drosophila deploy just two main types, where fate is controlled by the binary stochastic decision to express the transcription factor Spineless (Ss) in R7 photoreceptors4. We investigated how butterflies instead generate three stochastically distributed ommatidial types, resulting in a more diverse retinal mosaic that provides the basis for additional color comparisons and an expanded range of color vision. We show that the Japanese Yellow Swallowtail (Papilio xuthus, Papilionidae) and the Painted Lady (Vanessa cardui, Nymphalidae) have a second R7-like photoreceptor in each ommatidium. Independent stochastic expression of Ss in each R7-like cell results in expression of a Blue (Ss-ON) or a UV (Ss-OFF) Rhodopsin. In Papilio, these choices of Blue/Blue, Blue/UV, or UV/UV in the two R7s are coordinated with expression of additional Rhodopsins in the remaining photoreceptors, and together define the three types of ommatidia. Knocking out ss using CRISPR/Cas95,6 leads to the loss of the Blue fate in R7-like cells and transforms retinas into homogeneous fields of UV/UV-type ommatidia, with all corresponding features. Hence, the three possible outcomes of Ss expression define the three ommatidial types in butterflies. This developmental strategy allowed the deployment of an additional red-sensitive Rhodopsin in Papilio, allowing for the evolution of expanded color vision with a richer variety of receptors7,8. This surprisingly simple mechanism that makes use of two binary stochastic decisions coupled with local coordination may prove to be a general means of generating an increased diversity of developmental outcomes.

Why stay in a bad relationship? The effect of local host phenology on a generalist butterfly feeding on a low-ranked host.

BackgroundIn plant-feeding insects, the evolutionary retention of polyphagy remains puzzling. A better understanding of the relationship between these organisms and changes in the metabolome of their host plants is likely to suggest functional links between them, and may provide insights into how polyphagy is maintained.ResultsWe investigated the phenological change of Cynoglossum officinale, and how a generalist butterfly species, Vanessa cardui, responded to this change. We used untargeted metabolite profiling to map plant seasonal changes in both primary and secondary metabolites. We compared these data to differences in larval performance on vegetative plants early and late in the season. We also performed two oviposition preference experiments to test females’ ability to choose between plant developmental stages (vegetative and reproductive) early and late in the season. We found clear seasonal changes in plant primary and secondary metabolites that correlated with larval performance. The seasonal change in plant metabolome reflected changes in both nutrition and toxicity and resulted in zero survival in the late period. However, large differences among families in larval ability to feed on C. officinale suggest that there is genetic variation for performance on this host. Moreover, females accepted all plants for oviposition, and were not able to discriminate between plant developmental stages, in spite of the observed overall differences in metabolite profile potentially associated with differences in suitability as larval food.ConclusionsIn V. cardui, migratory behavior, and thus larval feeding times, are not synchronized with plant phenology at the reproductive site. This lack of synchronization, coupled with the observed lack of discriminatory oviposition, obviously has potential fitness costs. However, this “opportunistic” behavior may as well function as a source of potential host plant evolution, promoting for example the acceptance of new plants.Electronic supplementary materialThe online version of this article (doi:10.1186/s12862-016-0709-x) contains supplementary material, which is available to authorized users.