Butterfly Colour Research Articles

A long noncoding RNA at the cortex locus controls adaptive coloration in butterflies

Evolutionary variation in the wing pigmentation of butterflies and moths offers striking examples of adaptation by crypsis and mimicry. The cortex locus has been independently mapped as the locus controlling color polymorphisms in 15 lepidopteran species, suggesting that it acts as a genomic hotspot for the diversification of wing patterns, but functional validation through protein-coding knockouts has proven difficult to obtain. Our study unveils the role of a long noncoding RNA (lncRNA) which we name ivory, transcribed from the cortex locus, in modulating color patterning in butterflies. Strikingly, ivory expression prefigures most melanic patterns during pupal development, suggesting an early developmental role in specifying scale identity. To test this, we generated CRISPR mosaic knock-outs in five nymphalid butterfly species and show that ivory mutagenesis yields transformations of dark pigmented scales into white or light-colored scales. Genotyping of Vanessa cardui germline mutants associates these phenotypes to small on-target deletions at the conserved first exon of ivory. In contrast, cortex germline mutant butterflies with confirmed null alleles lack any wing phenotype and exclude a color patterning role for this adjacent gene. Overall, these results show that a lncRNA gene acts as a master switch of color pattern specification and played key roles in the adaptive diversification of wing patterns in butterflies.

Dynamic Color Regulation of the Lycaenid Butterfly Wing Scales

Butterfly coloration originates from the finely structured scales grown on the underlying wing cuticle. Most researchers who study butterfly scales are focused on the static optic properties of cover scales, with few works referring to dynamic optical properties of the scales. Here, the dynamic coloration effect of the multiple scales was studied based on the measurements of varying-angle reflection and the characterization of scale flexibility in two species of Lycaenid, Plebejus argyrognomon with violet wings and Polyommatus erotides with blue wings. We explored the angle-dependent color changeability and the color-mediating efficiency of wing scales. It was found that the three main kinds of flexible scales (cover, ground and androconia scales) were asynchronously bent during wing rotation, which caused the discoloration effect. The three layers of composite scales broaden the light signal when compared to the single scale, which may be of great significance to the recognition of insects. Specifically, the androconia scales were shown to strongly contribute to the overall wing coloration. The cover scale coloration was ascribed to the coherence scattering resulted from the short-range order at intermediate spatial frequencies from the 2D Fourier power spectra. Our findings are expected to deepen the understanding of the complex characteristics of biological coloration and to provide new inspirations for the fabrication of biomimetic flexible discoloration materials.

Frizzled2 receives WntA signaling during butterfly wing pattern formation.

Butterfly color patterns provide visible and biodiverse phenotypic readouts of the patterning processes. Although the secreted ligand WntA has been shown to instruct the color pattern formation in butterflies, its mode of reception remains elusive. Butterfly genomes encode four homologs of the Frizzled-family of Wnt receptors. Here, we show that CRISPR mosaic knockouts of frizzled2 (fz2) phenocopy the color pattern effects of WntA loss of function in multiple nymphalids. Whereas WntA mosaic clones result in intermediate patterns of reduced size, fz2 clones are cell-autonomous, consistent with a morphogen function. Shifts in expression of WntA and fz2 in WntA crispant pupae show that they are under positive and negative feedback, respectively. Fz1 is required for Wnt-independent planar cell polarity in the wing epithelium. Fz3 and Fz4 show phenotypes consistent with Wnt competitive-antagonist functions in vein formation (Fz3 and Fz4), wing margin specification (Fz3), and color patterning in the Discalis and Marginal Band Systems (Fz4). Overall, these data show that the WntA/Frizzled2 morphogen-receptor pair forms a signaling axis that instructs butterfly color patterning and shed light on the functional diversity of insect Frizzled receptors.

Acute and Long-Term Consequences of Co-opted doublesex on the Development of Mimetic Butterfly Color Patterns.

Novel phenotypes are increasingly recognized to have evolved by co-option of conserved genes into new developmental contexts, yet the process by which co-opted genes modify existing developmental programs remains obscure. Here, we provide insight into this process by characterizing the role of co-opted doublesex in butterfly wing color pattern development. dsx is the master regulator of insect sex differentiation but has been co-opted to control the switch between discrete nonmimetic and mimetic patterns in Papilio alphenor and its relatives through the evolution of novel mimetic alleles. We found dynamic spatial and temporal expression pattern differences between mimetic and nonmimetic butterflies throughout wing development. A mimetic color pattern program is switched on by a pulse of dsx expression in early pupal development that causes acute and long-term differential gene expression, particularly in Wnt and Hedgehog signaling pathways. RNAi suggested opposing, novel roles for these pathways in mimetic pattern development. Importantly, Dsx co-option caused Engrailed, a primary target of Hedgehog signaling, to gain a novel expression domain early in pupal wing development that is propagated through mid-pupal development to specify novel mimetic patterns despite becoming decoupled from Dsx expression itself. Altogether, our findings provide multiple views into how co-opted genes can both cause and elicit changes to conserved networks and pathways to result in development of novel, adaptive phenotypes.

Wide-gamut structural colours on oakblue butterflies by naturally tuned photonic nanoarchitectures.

The iridescent structural colours of butterflies, generated by photonic nanoarchitectures, often function as species-specific sexual signals; therefore, they are reproduced precisely from generation to generation. The wing scales of oakblue hairstreak butterflies (genus Arhopala, Theclinae, Lycaenidae, Lepidoptera) contain multi-layer photonic nanoarchitectures, which can generate a wide range of structural colours, from violet to green. By scanning (SEM) and cross-sectional transmission electron microscopy (TEM) investigation, the colour tuning mechanism of the cover scales was explored. We revealed that the characteristic size change of structural elements in similar photonic nanoarchitectures led to different structural colours that were examined by various reflectance spectrophotometry techniques. The measured structural properties of the naturally tuned photonic nanoarchitectures were used to calculate wing reflectances, which were compared with the measurement results. We found that the simulated structural colours were systematically redshifted by 95-126 nm as compared with the measured normal-incidence reflectance results. This is attributed to the swelling of the chitinous multi-layer structures during the standard TEM sample preparation and the tilt of the cover scales, which both affect the apparent layer thicknesses in the TEM cross-sections. We proposed a simulation correction and compared the results with the layer thicknesses measured on cryogenically prepared non-embedded SEM cross-sections.

Melanism and color saturation of butterfly assemblages: A comparison between a tropical rainforest and a xeric white forest

The study of butterfly coloration has helped to identify the ecological pressures involved in the evolution of animal coloration. However, almost all studies that addressed this issue have focused on species that inhabit more temperate environments, leaving the species and ecological factors of tropical regions mostly understudied. Here, our purpose was to evaluate whether butterfly assemblages from two distinct Neotropical biomes (i.e., tropical rainforest and xeric white forest) differ regarding their melanism and/or color saturation. Our hypotheses were that (1) tropical rainforest butterflies should be more melanic and color saturated, and that (2) butterflies from more open/arid tropical environments should be more melanic on their dorsal wing surfaces than on their ventral wings. Therefore, we quantified melanism and color saturation from dorsal and ventral surfaces of 121 different butterfly species. Comparisons show that rainforest butterflies, when contrasted to white forest butterflies, have more melanic dorsal wing surfaces, which might be seen as a form of protection against parasites. Our data also show that rainforest butterflies, but not white forest species, have darker dorsal wing surfaces, when compared to their own ventral surfaces, a trend that was also found for species inhabiting both biomes, which might be associated to thermoregulatory advantages. At last, our results also point that butterflies' dorsal wing sides present a higher variance between species (regardless of Biome), when compared to their own ventral wing side, an indication that some ecological factor (e.g., predation avoidance) might be exerting a strong homogenizing force on ventral wing coloration.

Bionic butterfly changes color as it flaps

Bionic butterfly changes color as it flaps

This bionic butterfly changes color as it flaps

This bionic butterfly changes color as it flaps

The genetic basis of structural colour variation in mimetic Heliconius butterflies.

Structural colours, produced by the reflection of light from ultrastructures, have evolved multiple times in butterflies. Unlike pigmentary colours and patterns, little is known about the genetic basis of these colours. Reflective structures on wing-scale ridges are responsible for iridescent structural colour in many butterflies, including the Müllerian mimics Heliconius erato and Heliconius melpomene. Here, we quantify aspects of scale ultrastructure variation and colour in crosses between iridescent and non-iridescent subspecies of both of these species and perform quantitative trait locus (QTL) mapping. We show that iridescent structural colour has a complex genetic basis in both species, with offspring from crosses having a wide variation in blue colour (both hue and brightness) and scale structure measurements. We detect two different genomic regions in each species that explain modest amounts of this variation, with a sex-linked QTL in H. erato but not H. melpomene. We also find differences between species in the relationships between structure and colour, overall suggesting that these species have followed different evolutionary trajectories in their evolution of structural colour. We then identify genes within the QTL intervals that are differentially expressed between subspecies and/or wing regions, revealing likely candidates for genes controlling structural colour formation.This article is part of the theme issue ‘Genetic basis of adaptation and speciation: from loci to causative mutations’.

Connectomics: From form to function in butterfly colour vision

A recent study has revealed how the connectivity of neurons in the lamina of the Asian swallowtail butterfly forms the basis of this insect's exceptional colour vision through two circuit motifs: colour opponency of photoreceptors and broadband colour integration by lamina neurons.

A novel distribution of supergene genotypes is present in the socially polymorphic ant Formica neoclara

BackgroundSupergenes are chromosomal regions with tightly linked clusters of alleles that control compound phenotypic traits. Supergenes have been demonstrated to contribute to the maintenance of polymorphisms within populations in traits as diverse as mimetic wing coloration in butterflies, mating strategies in birds, and malarial susceptibility in mosquitoes. A large supergene also underlies variation in social organization in Formica ants. Alternative supergene haplotypes are associated with the presence of either a single queen (monogyny) or multiple queens (polygyny) within colonies. Here, we assess the social structure and supergene status of the North American species Formica neoclara.ResultsWe sequenced a subset of the genome in 280 individuals sampled in populations from California to northern British Columbia using ddRADseq. We determined that F. neoclara is socially polymorphic in queen number, and we show that the social polymorphism is associated with alternative haplotypes at the social supergene. Intriguingly, polygyne colonies can harbor workers that are homozygous for both haplotypes as well as heterozygotes.ConclusionsThis colony genetic composition contrasts with other Formica species, in which almost all individuals in polygyne colonies have the polygyne-associated haplotype. The social polymorphism is present in widely distributed and genetically subdivided populations of F. neoclara. In studying this system in F. neoclara, we expand our understanding of the functional evolution of supergene haplotypes as they diverge in different lineages.

Mathematical modeling of the eyespots in butterfly wings

Butterfly wing color patterns are a representative model system for studying biological pattern formation, due to their two-dimensional simple structural and high inter- and intra-specific variabilities. Moreover, butterfly color patterns have demonstrated roles in mate choice, thermoregulation, and predator avoidance via disruptive coloration, attack deflection, aposematism, mimicry, and masquerade. Because of the importance of color patterns to many aspects of butterfly biology and their apparent tractability for study, color patterns have been the subjects of many attempts to model their development. Early attempts focused on generalized mechanisms of pattern formation such as reaction-diffusion, diffusion gradient, lateral inhibition, and threshold responses, without reference to any specific gene products. As candidate genes with expression patterns that resembled incipient color patterns were identified, genetic regulatory networks were proposed for color pattern formation based on gene functions inferred from other insects with wings, such as Drosophila. Particularly detailed networks incorporating the gene products, Distal-less (Dll), Engrailed (En), Hedgehog (Hh), Cubitus interruptus (Ci), Transforming growth factor-β (TGF-β), and Wingless (Wg), have been proposed for butterfly border ocelli (eyespots) which helps the investigation of the formation of these patterns. Thus, in this work, we develop a mathematical model including the gene products En, Hh, Ci, TGF-β, and Wg to mimic and investigate the eyespot formation in butterflies. Our simulations show that the level of En has peaks in the inner and outer rings and the level of Ci has peaks in the inner and middle rings. The interactions among these peaks activate cells to produce white, black, and yellow pigments in the inner, middle, and outer rings, respectively, which captures the eyespot pattern of wild type Bicyclus anynana butterflies. Additionally, our simulations suggest that lack of En generates a single black spot and lack of Hh or Ci generates a single white spot, and a deficiency of TGF-β or Wg will cause the loss of the outer yellow ring. These deficient patterns are similar to those observed in the eyespots of Vanessa atalanta, Vanessa altissima, and Chlosyne nycteis. Thus, our model also provides a hypothesis to explain the mechanism of generating the deficient patterns in these species.

Butterflies see wing colours change as mother-of-pearls flutter by

For centuries, our predecessors experimented with exotic pigments to create opulent ceramics and illuminated manuscripts. It was only in the 18th century that we discovered Mother Nature's alternative colour palette, produced by light reflecting from microscopic layers in feathers, skin and insect shells in a similar way to the shimmering rainbow hues of soap bubbles and oil films. ‘Earlier in my career, I was devoted to insect vision, but I was also constantly intrigued by the often brilliant colours of butterflies’, says Doekele Stavenga, from the University of Groningen, The Netherlands, who became increasingly fascinated by the intriguing physics of these so-called ‘structural colours’. After decades of investigating the startling shades of butterflies from all over the globe, he most recently turned his attention to the shimmering common mother-of-pearl butterfly (Protogoniomorpha parhassus) from Africa in the hope of discovering how they produce their opalescent glow.As butterfly wings are coated in scales, Stavenga suspected that thin layers in these structures were the cause of the mother-of-pearl butterfly's delicate iridescent pink hue. However, to be sure, he first had to shine light through the fragile wings. ‘The structural coloration of the wings was immediately and strikingly clear when comparing light reflecting from the wing with light that passed through it’, says Stavenga, who saw the rosy shade vanish when the wing was illuminated from beneath. And when Bodo Wilts, a colleague from the University of Fribourg, Switzerland, scrutinised the scales in fine detail using an electron microscope, they could clearly see box-like structures in the scales that would scatter light to produce the butterfly's pearlescence. Next, Stavenga focused a spot of bright white light on a wing from above, producing a fuchsia-coloured beam as the structures in the scales reflected only red and blue wavelengths, confirming that the delicate colour is produced by reflecting structures in the scales and not a rose-toned pigment in the wing.However, Stavenga also knew that the tones produced by these light-reflecting colour-generating structures depend on the position of a viewer relative to the structure, potentially altering the colour of an object as it moves. Could the wings of mother-of-pearl butterflies flash different tones as the animals flutter by? This time, Stavenga shone white light at angles ranging from directly above the wing to almost horizontally to one side (an oblique angle of 70 deg), recording the wavelengths that were reflected by the scales to find out whether the shade varied from different angles. Impressively, the wing's hue switched from pink to yellow as the light shifted from above to one side. And, when he calculated how the colours would change in the eyes of a butterfly – which see UV tones but not the red hues that we can see – the wings became a brighter shade of yellow and the light was more strongly polarized, making the wings stand out for creatures such as butterflies that see polarization.The mother-of-pearl butterfly's wings are perfectly tuned to generate flashes of colour as they flit past, and Stavenga suggests that the fluttering insect's flickering light show could help them to stand out from the crowd. ‘Only in the last decade has the importance of butterfly wing scales acting as thin film reflectors like soap bubbles become well recognized, and the mother-of-pearl butterfly is certainly the brightest, exemplary case’, he says.

Engaging the Community in Pollinator Research: The Effect of Wing Pattern and Weather on Butterfly Behavior

Community science, which engages students and the public in data collection and scientific inquiry, is often integrated into conservation and long-term monitoring efforts. However, it has the potential to also introduce the public to, and be useful for, sensory ecology and other fields of study. Here we describe a community science project that exposes participants to animal behavior and sensory ecology using the rich butterfly community of Northwest Arkansas, United States. Butterflies use visual signals to communicate and to attract mates. Brighter colors can produce stronger signals for mate attraction but can also unintentionally attract negative attention from predators. Environmental conditions such as weather can affect visual signaling as well, by influencing the wavelengths of light available and subsequent signal detection. However, we do not know whether the signals butterflies present correlate broadly with how they behave. In this study, we collaborated with hundreds of students and community members at the University of Arkansas (UARK) and the Botanical Gardens of the Ozarks (BGO) for over 3.5 years to examine relationships among wing pattern, weather, time of day, behavior, and flower choice. We found that both weather and wing color influenced general butterfly behavior. Butterflies were seen feeding more on cloudy days than on sunny or partly cloudy days. Brown butterflies fed or sat more often, while white butterflies flew more often relative to other butterfly colors. We also found that there was an interaction between the effects of weather and wing color on butterfly behavior. Furthermore, butterfly color predicted the choice of flower colors that butterflies visited, though this effect was influenced by the observer group (UARK student or BGO participant). These results suggest that flower choice may be associated with butterfly wing pattern, and that different environmental conditions may influence butterfly behavior in wing-pattern-specific ways. They also illustrate one way that public involvement in behavioral studies can facilitate the identification of coarse-scale, community-wide behavioral patterns, and lay the groundwork for future studies of sensory niches.

High-Quality Genome Assembly and Comprehensive Transcriptome of the Painted Lady Butterfly Vanessa cardui.

The painted lady butterfly, Vanessa cardui, has the longest migration routes, the widest hostplant diversity, and one of the most complex wing patterns of any insect. Due to minimal culturing requirements, easily characterized wing pattern elements, and technical feasibility of CRISPR/Cas9 genome editing, V. cardui is emerging as a functional genomics model for diverse research programs. Here, we report a high-quality, annotated genome assembly of the V. cardui genome, generated using 84× coverage of PacBio long-read data, which we assembled into 205 contigs with a total length of 425.4 Mb (N50 = 10.3 Mb). The genome was very complete (single-copy complete Benchmarking Universal Single-Copy Orthologs [BUSCO] 97%), with contigs assembled into presumptive chromosomes using synteny analyses. Our annotation used embryonic, larval, and pupal transcriptomes, and 20 transcriptomes across five different wing developmental stages. Gene annotations showed a high level of accuracy and completeness, with 14,437 predicted protein-coding genes. This annotated genome assembly constitutes an important resource for diverse functional genomic studies ranging from the developmental genetic basis of butterfly color pattern, to coevolution with diverse hostplants.

Partially coupled reaction norms of pupal colour and spot size in a butterfly

Many species cope with heterogeneous environments through adaptive phenotypic plasticity, and plasticity of body colour is a widely used means of minimizing predation risk. Pupal colour in many butterflies is a plastic trait sensitive to pupation substrate, with green and brown pupae primarily formed on leaf and off-leaf substrates respectively. This is thought to be an example of adaptive phenotypic plasticity because the green and brown pupae are better camouflaged against their respective backgrounds. We tested whether pupal ‘spots’—paired circular markings on the anterior abdominal pupal segments of many butterflies—are also phenotypically plastic. Using experiments on the tropical satyrine butterfly Mycalesis mineus, we confirm that pupal spot size is plastic. Because it is known that pupation substrate influences pupal colour in this species, we tested whether substrate also influences pupal spot size. Further, we explored whether there was a correlation between pupal colour and spot size. We tested the effects of pupation substrate and pupal colour on both absolute spot size and spot size relative to body size. Pupal spot size (absolute and relative) was correlated with both pupal colour and pupation substrate. Brown pupae had larger spots, and green pupae formed off-leaf had intermediate sized spots compared to green pupae formed on leaves and brown pupae, the latter of which always formed off-leaf. Thus, the reaction norm of pupal spot size is partially coupled with both pupal colour and pupation substrate in this species. Since pupation substrate in turn influences pupal colour, the correlated traits of pupal colour and pupal spot could comprise a single functional suite, suggesting a developmental link. We speculate that pupal spots may function against predation, but further studies are needed to understand their possible adaptive significance.

Butterfly dichromatism primarily evolved via Darwin's, not Wallace's, model.

Sexual dimorphism is typically thought to result from sexual selection for elaborated male traits, as proposed by Darwin. However, natural selection could reduce expression of elaborated traits in females, as proposed by Wallace. Darwin and Wallace debated the origins of dichromatism in birds and butterflies, and although evidence in birds is roughly equal, if not in favor of Wallace's model, butterflies lack a similar scale of study. Here, we present a large‐scale comparative phylogenetic analysis of the evolution of butterfly coloration, using all European non‐hesperiid butterfly species (n = 369). We modeled evolutionary changes in coloration for each species and sex along their phylogeny, thereby estimating the rate and direction of evolution in three‐dimensional color space using a novel implementation of phylogenetic ridge regression. We show that male coloration evolved faster than female coloration, especially in strongly dichromatic clades, with male contribution to changes in dichromatism roughly twice that of females. These patterns are consistent with a classic Darwinian model of dichromatism via sexual selection on male coloration, suggesting this model was the dominant driver of dichromatism in European butterflies.

Feather morphological predictors of angle-dependent color changes in parrot plumage

Among the most ornate animal traits in nature are the angle-dependent (e.g. iridescent) structural colors of many fishes, damselflies, birds, beetles, and butterflies. Though we now have a solid understanding of the mechanisms that create angle-dependent coloration in several groups, we know little about whether pigmentary colors reflect light in an angle-dependent fashion or if similar or different mechanisms govern angle-dependent reflectance from pigmentary versus structural colors. Here for the first time we describe non-iridescent angle-dependent coloration from the tail and wing feathers of several parrot species (Aves: Psittaciformes). We employed a novel approach—by calculating chromatic and achromatic contrasts (in just noticeable differences, JNDs) of straight and angled measurements of the same feather patch—to test for perceptually relevant angle-dependent changes in coloration on dorsal and ventral feather surfaces. We found, among the 15 parrot species studied, significant angle dependence for seven of our eight feather JND parameters. We then measured micro-scale features on each side of feathers, including size and color of barbs and barbules, to attempt to predict interspecific variation in degree of angle-dependent reflectance. We found that barb height, plumage-color type (e.g. melanin, structural), and differences between barb-barbule coloration (measured using Euclidean distances) were the strongest predictors of angle-dependent coloration. Interestingly, there was no significant phylogenetic signal in any of the angle-dependence models tested. These findings deepen our views on the importance of microscopic feather features in the production of directional animal coloration, especially in tissues that are colored predominantly by pigments and appear to be statically colored.

The Arctiid Archetype: A New Lepidopteran Groundplan

The nymphalid groundplan (NGP) has proven to be extraordinarily useful in the study of butterfly color patterns because it allows for the identification of homologous elements across species. It has long been thought that the NGP is broadly applicable to all Lepidoptera, implying that the characters which make-up butterfly color patterns are homologous to those found in the moths. However, this conjecture remains mostly untested. We analyzed the wing patterns of the hyper-diverse arctiid tiger moths, which are represented worldwide by approximately 11,000 species, and found that the color patterns of these animals can be parsed into a limited toolkit of homologous characters. Some of the pattern elements identified, such as the basal and central symmetry system, are present on the NGP, but their morphology is often quite different from what is seen in the butterflies. The border ocelli of the NGP appear to be absent altogether in the Arctiidae, and conversely, two distal pattern element we term the ‘van Bemmelen’ and ‘terminal’ bands are present in the color patterns of many arctiids, but are not represented on the NGP. In light of the observed differences, we derive a new theoretical groundplan based on the original NGP that we refer to as the ‘arctiid archetype.’ This model provides a comprehensive framework for understanding how the wing patterns of these animals develop, and yields novel insight into their evolutionary history.

Discolouring the Amazon Rainforest: how deforestation is affecting butterfly coloration

Butterflies are among the most colourful organisms in the world and colour plays a central role in many of their life-history strategies. However, the efficacy of coloration strategies in these and other animals could be affected by sudden environmental changes, including anthropogenic disturbances such as habitat loss and fragmentation. Here we investigate the effect of forest disturbance gradients on the colours of fruit-feeding butterflies in the Amazon Rainforest. The disturbance gradients tested represented habitat-size (continuous primary forests versus forest fragments of 1, 10 and 100 ha) and succession gradients (continuous primary forests, 30 year old secondary forests, and three year old early successional forests). Using digital image analysis, we obtained intrinsic measures of butterfly colour patches corresponding to hue, saturation, brightness, in addition to measures of the contrast among patches and of the overall wing-colour diversity corresponding to 220 individuals, belonging to 60 species. Our results showed that butterflies in the secondary forest and continuous primary forest are more colourful than those found in early succession and fragments of forests. Individuals occurring in forests of early succession showed higher average values of hue and saturation, but lower brightness. Accompanying changes in colour composition, wing-colour diversity among species was lower in human-disturbed habitats, such as those of early forest succession and secondary forest. Forest fragments have smaller effects on butterfly colour composition, indicating that well-structured forest habitats can house butterfly assemblages with more diverse phenotypic features and colours. We show how high deforestation rates in recent years is linked with negative changes in functional coloration strategies (e.g. camouflage, warning colours), something that has to date been poorly explored or demonstrated for butterflies. Specifically, human interference has apparently placed butterflies under strong selection for lower diversity in their colours and range of defensive strategies. Those species that are most colourful are the first to be locally extinguished, likely due to removal of native vegetation and increased exposure to predators, and more broadly owing to inhospitable environmental conditions. This illustrates an accelerated loss of local fauna and a “discolouration” of the Amazonian butterflies due to anthropogenic impacts.