Wing Pattern Research Articles

Robust biomimetic strain sensor based on butterfly wing-derived skeleton structure

A biomimetic strain sensor was designed and constructed based on Ir nanoparticles-modified multi-wall carbon nanotubes (Ir NPs@MWCNTs) and parallel Pt layer/dragon skin with carbonized butterfly wing patterns. This sensor exhibits high gauge factor (∼515.4), extensive tensile range (0%–96%), and swift response (∼300 ms), especially remarkable stability up to 60 000 cycles. The work mechanism has been proposed based on the experimental test and finite-element method. Some important applications such as human motion and micro-expression recognition have been confirmed using 3 × 3 flexible biomimetic sensor array.

Discovery of a new gall-inducing species, Aciurinaluminaria (Insecta, Diptera, Tephritidae) via multi-trait integrative taxonomy.

Integrative taxonomic practices that combine multiple lines of evidence for species delimitation greatly improve our understanding of intra- and inter-species variation and biodiversity. However, extended phenotypes remain underutilized despite their potential as a species-specific set of extracorporeal morphological and life history traits. Primarily relying on variations in wing patterns has caused taxonomic confusion in the genus Aciurina, which are gall-inducing flies on Asteraceae plants in western North America. However, species display distinct gall morphologies that can be crucial for species identification. Here we investigate a unique gall morphotype in New Mexico and Colorado that was previously described as a variant of that induced by Aciurinabigeloviae (Cockerell, 1890). Our analysis has discovered several consistent features that distinguish it from galls of A.bigeloviae. A comprehensive description of Aciurinaluminaria Baine, sp. nov. and its gall is provided through integrative taxonomic study of gall morphology, host plant ecology, wing morphometrics, and reduced-representation genome sequencing.

The ivory lncRNA regulates seasonal color patterns in buckeye butterflies

Long noncoding RNAs (lncRNAs) are transcribed elements increasingly recognized for their roles in regulating gene expression. Thus far, however, we have little understanding of how lncRNAs contribute to evolution and adaptation. Here, we show that a conserved lncRNA, ivory, is an important color patterning gene in the buckeye butterfly Junonia coenia. ivory overlaps with cortex, a locus linked to multiple cases of crypsis and mimicry in Lepidoptera. Along with a companion paper by Livraghi et al., we argue that ivory, not cortex, is the color pattern gene of interest at this locus. In J. coenia, a cluster of cis-regulatory elements (CREs) in the first intron of ivory are genetically associated with natural variation in seasonal color pattern plasticity, and targeted deletions of these CREs phenocopy seasonal phenotypes. Deletions of different ivory CREs produce other distinct phenotypes as well, including loss of melanic eyespot rings, and positive and negative changes in overall wing pigmentation. We show that the color pattern transcription factors Spineless, Bric-a-brac, and Ftz-f1 bind to the ivory promoter during wing pattern development, suggesting that they directly regulate ivory. This case study demonstrates how cis-regulation of a single noncoding RNA can exert diverse and nuanced effects on the evolution and development of color patterns, including modulating seasonally plastic color patterns.

Harnessing Nature's ingenuity to engineer butterfly-wing-inspired photoactive nanofiber patches for advanced postoperative tumor treatment

Postoperative tumor treatment necessitates a delicate balance between eliminating residual tumor cells and promoting surgical wound healing. Addressing this challenge, we harness the innovation and elegance of nature's ingenuity to develop a butterfly-wing-inspired photoactive nanofiber patch (WingPatch), aimed at advancing postoperative care. WingPatch is fabricated using a sophisticated combination of electrostatic spinning and spraying techniques, incorporating black rice powder (BRP) and konjac glucomannan (KGM) into a corn-derived polylactic acid (PLA) nanofiber matrix. This fabrication process yields a paclitaxel-infused porous nanofiber architecture that mirrors the delicate patterns of butterfly wings. Meanwhile, all-natural composites have been selected for their strategic roles in postoperative recovery. BRP offers the dual benefits of photothermal therapy and antibacterial properties, while KGM enhances both antibacterial effectiveness and tissue regeneration. Responsive to near-infrared light, WingPatch ensures robust tissue adhesion and initiates combined photothermal and chemotherapeutic actions to effectively destroy residual tumor cells. Crucially, it simultaneously prevents infections and promotes wound healing throughout the treatment process. Its effectiveness has been confirmed by animal studies, and WingPatch significantly improves treatment outcomes in both breast and liver tumor models. Thus, WingPatch exemplifies our dedication to leveraging natural world's intricate patterns and inventiveness to propel postoperative care forward.

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.

Integrative description of Thaeides ramoni sp. nov. (Lepidoptera: Lycaenidae), a sympatric sibling species of Thaeides theia (Hewitson, 1870) found in the Sierra Nevada de Santa Marta, Colombia

We present evidence from DNA barcodes, wing pattern and distribution to support the hypothesis that an entity flying in sympatry with Thaeides theia in the Sierra Nevada de Santa Marta, is an undescribed biological species named herein as Thaides ramoni Prieto, sp. nov. Adult specimens and genital structures are illustrated for both species along with molecular and morphological diagnostic characters. In addition, we present some considerations about the taxonomy of the species in the Thaeides muela group.

Evolution of Opsin Genes in Caddisflies (Insecta: Trichoptera).

Insects have evolved complex and diverse visual systems in which light-sensing protein molecules called "opsins" couple with a chromophore to form photopigments. Insect photopigments group into three major gene families based on wavelength sensitivity: long wavelength (LW), short wavelength (SW), and ultraviolet wavelength (UV). In this study, we identified 123 opsin sequences from whole-genome assemblies across 25 caddisfly species (Insecta: Trichoptera). We discovered the LW opsins have the most diversity across species and form two separate clades in the opsin gene tree. Conversely, we observed a loss of the SW opsin in half of the trichopteran species in this study, which might be associated with the fact that caddisflies are active during low-light conditions. Lastly, we found a single copy of the UV opsin in all the species in this study, with one exception: Athripsodes cinereus has two copies of the UV opsin and resides within a clade of caddisflies with colorful wing patterns.

Evolutionary patterns and functional effects of 3D chromatin structures in butterflies with extensive genome rearrangements

Chromosome rearrangements may distort 3D chromatin architectures and thus change gene regulation, yet how 3D chromatin structures evolve in insects is largely unknown. Here, we obtain chromosome-level genomes for four butterfly species, Graphium cloanthus, Graphium sarpedon, Graphium eurypylus with 2n = 30, 40, and 60, respectively, and Papilio bianor with 2n = 60. Together with large-scale Hi-C data, we find that inter-chromosome rearrangements very rarely disrupted the pre-existing 3D chromatin structure of ancestral chromosomes. However, some intra-chromosome rearrangements changed 3D chromatin structures compared to the ancestral configuration. We find that new TADs and subTADs have emerged across the rearrangement sites where their adjacent compartments exhibit uniform types. Two intra-chromosome rearrangements altered Rel and lft regulation, potentially contributing to wing patterning differentiation and host plant choice. Notably, butterflies exhibited chromatin loops between Hox gene cluster ANT-C and BX-C, unlike Drosophila. Our CRISPR-Cas9 experiments in butterflies confirm that knocking out the CTCF binding site of the loops in BX-C affected the phenotypes regulated by Antp in ANT-C, resulting in legless larva. Our results reveal evolutionary patterns of insect 3D chromatin structures and provide evidence that 3D chromatin structure changes can play important roles in the evolution of traits.

Optix and cortex/ivory/mir-193 again: the repeated use of two mimicry hotspot loci.

The extent to which evolution is repeatable has been a debated topic among evolutionary biologists. Although rewinding the tape of life perhaps would not lead to the same outcome every time, repeated evolution of analogous genes for similar functions has been extensively reported. Wing phenotypes of butterflies and moths have provided a wealth of examples of gene re-use, with certain 'hotspot loci' controlling wing patterns across diverse taxa. Here, we present an example of convergent evolution in the molecular genetic basis of Batesian wing mimicry in two Hypolimnas butterfly species. We show that mimicry is controlled by variation near cortex/ivory/mir-193, a known butterfly hotspot locus. By dissecting the genetic architecture of mimicry in Hypolimnas misippus and Hypolimnas bolina, we present evidence that distinct non-coding regions control the development of white pattern elements in the forewing and hindwing of the two species, suggesting independent evolution, and that no structural variation is found at the locus. Finally, we also show that orange coloration in H. bolina is associated with optix, a well-known patterning gene. Overall, our study once again implicates variation near the hotspot loci cortex/ivory/mir-193 and optix in butterfly wing mimicry and thereby highlights the repeatability of adaptive evolution.

New data on distribution of Phoenicurusia transcaucasicus (Miller, 1923) (Lepidoptera, Lycaenidae) with description of a new subspecies from Iran

Distribution of Phoenicurusia transcaucasicus (Miller, 1923) in Iran and neighbouring territories is clarified based on analysis of DNA barcodes, the male genitalia and wing pattern of adults. Our study revealed the widespread distribution of Ph. transcaucasicus throughout northern, northeastern and central Iran. Based on integrative analysis, a new subspecies, Ph. transcaucasicus flamma ssp. n., is described from the Zagros Mountains, the Central Iranian Range and the Alborz Mountains. Compared to the nominotypical subspecies, the new subspecies differs in well-developed orange pattern both of dorsal and ventral sides of the wings, shape of the valva in the male genitalia and distinct COI haplotypes. Additionally, distinct phylogenetic lineage of Ph. transcaucasicus is reported from Kerman Province. Diagnostic characters of the species of Ph. phoenicurus (Lederer, 1870) group of Iran are illustrated.

Mating preferences act independently on different elements of visual signals in Heliconius butterflies

Abstract Mating cues are often comprised of several elements, which can act independently, or in concert to attract a suitable partner. Individual elements may also function in other contexts, such as anti-predator defense or camouflage. In Heliconius butterflies, wing patterns comprise several individual color pattern elements, which advertise the butterflies’ toxicity to predators. These wing patterns are also mating cues and males predominantly court females that possess the same wing pattern as their own. However, it is not known whether male preference is based on the full wing pattern or only individual pattern elements. We compared preferences of male H. erato lativitta between female models with the full wing pattern and those with some pattern elements removed. We found no differences in preference between the full wing pattern model and a model with pattern elements removed, indicating that the complete composition of all elements is not essential to the mating signal. Wing pattern preferences also contribute to pre-mating isolation between two other Heliconius taxa, H. erato cyrbia, and H. himera; therefore, we next compared preferences for the same models in these species. H. erato cyrbia and H. himera strongly differed in preferences for the models, potentially providing a mechanism for how pre-mating isolation acts between these species. These findings suggest that contrasting levels of selective constraint act on elements across the wing pattern.

Schistophleps kendricki sp. nov. (Lepidoptera: Erebidae: Arctiinae) from Bangladesh with an overview of the genus

Schistophleps Hampson, 1891 is one of the most frequently occurring genera of tiger moths, widely distributed in the Oriental and Australian regions. However, a lion’s share of the species belonging to this genus are poorly known except the original descriptions. In this article, we provide a brief overview of all known species currently assigning to this genus. We divide the species into albida, bicolora, bipuncta, flavia, fulvia, hyalina, and subtilis species groups on the basis of wing pattern elements along with geographic distributions, and four highly obscure species are discussed as a miscellaneous group. Among the species, Schistophleps bipuncta Hampson, 1891 is the most frequently occurring taxon having a distribution stretching all over the South East Asia. However, the variable wing maculations and other features, reflected through the observations on various citizen science platforms from different regions of the Indian subcontinent indicate to a sibling species yet to discover. Herein, we describe the species as Schistophleps kendricki Rayhan, Bucsek, & Jahan sp. nov., from Chittagong, Bangladesh that is similar to the Schistophleps bipuncta species group in wing maculation, but markedly differs from all of its closely allied congeners in the genitalia configurations in having characteristic modification of uncus. Besides, a comparison of observations on different citizen science platforms from the Indian subcontinent is provided that suggests the possible distribution of this new species throughout the Bengal including West Bengal, India and Bangladesh.

Pattern Matters in the Aposematic Colouration of Papilio polytes Butterflies.

Many toxic animals display bright colour patterns to warn predators about their toxicity. This sometimes leads other sympatric palatable organisms to evolve mimetic colour patterns to also evade predation. These mimics, however, are often imperfect, and it is unclear how much their colour patterns can vary away from the model before they become ineffective. In this study, we investigated how predation risk of the palatable Common Mormon butterfly (Papilio polytes) is affected by two alterations of its wing pattern that make it progressively more distinct from its model, the Common Rose (Pachliopta aristolochiae). We deployed butterfly paper models in the field, where all models displayed the same colours but had different patterns. In the first modification from the Wildtype pattern, we exchanged the position of the red and white colour patches but kept the overall pattern constant. In the second modification, we created an eyespot-like shape from the pre-existing pattern elements by moving their positions in the wing, altering the overall wing pattern. Both modifications increased attack risk from predators relative to Wildtype patterns, with the eyespot-like modification having the highest predation risk. Our results show that avian predators can distinguish between all three patterns tested, and that pattern is important in aposematic signals. Predators learn to avoid aposematic colours, not in isolation, but as part of specific patterns.

Aerodynamic Analysis of Hovering Flapping Wing Using Multi-Plane Method and Quasi-Steady Blade Element Theory

In the design of flapping-wing micro-size air vehicles capable of hovering, wings serve as the primary source of hovering power, making the analysis of aerodynamics and aerodynamic efficiency crucial. Traditional quasi-steady models treat the wings as single rigid plane, neglecting the deformable characteristics of flexible wings. This paper proposes a multi-plane method that, in conjunction with various design parameters of flexible wings in a two-dimensional plane, analyzes their deformation characteristics under the assumption of multiple planes in three-dimensional space, and describes the deformation of wings during flapping. By combining the quasi-steady aerodynamic model, aerodynamic analysis of the deformed wings can be conducted. The relationship between the slack angle, wing flapping position, and wing deformation are analyzed, along with their effects on aerodynamics and aerodynamic efficiency. Experiments validate the deformation patterns of wings during flapping and compare the simulated aerodynamic forces with measured ones. The results indicate that wing deformation can be accurately described by adjusting the parameters in the multi-plane method and that the aerodynamic analysis using this method closely approximates the average lift results. Additionally, the multi-plane method establishes a connection between wing morphology and aerodynamic forces and efficiency, providing valuable insights for aerodynamic analysis.

Study on the intraspecific variation of Capila lineata lineata Chou & Gu, 1994, with some taxonomic notes on the related taxa (Hesperiidae, Pyrginae)

Study on the intraspecific variation of Capila lineata lineata Chou & Gu, 1994, with some taxonomic notes on the related taxa (Hesperiidae, Pyrginae)

Resource-based trade-offs and the adaptive significance of seasonal plasticity in butterfly wing melanism.

Phenotypic plasticity is the ability of an organism to alter its phenotype in response to environmental cues. This can be adaptive if the cues are reliable predictors of impending conditions and the alterations enhance the organism's ability to capitalize on those conditions. However, since traits do not exist in isolation but as part of larger interdependent systems of traits (phenotypic integration), trade-offs between correlated plastic traits can make phenotypic plasticity non- or maladaptive. We examine this problem in the seasonally plastic wing melanism of a pierid (Order Lepidoptera, Family Pieridae) butterfly, Pieris rapae L. Several wing pattern traits are more melanized in colder than in warmer seasons, resulting in effective thermoregulation through solar absorption. However, other wing pattern traits, the spots, are less melanized during colder seasons than in warmer seasons. Although spot plasticity may be adaptive, reduced melanism of these spots could also be explained by resource-based trade-offs. Theory predicts that traits involved in resource-based trade-offs will be positively correlated when variation among individuals in resource acquisition is greater than variation among individuals in resource allocation strategies, and negatively correlated when variation in allocation is greater than variation in acquisition. Using data from both field studies and laboratory studies that manipulate dietary tyrosine, a melanin precursor, we show that when allocation to thermoregulatory melanism (ventral hindwing, and basal dorsal fore- and hindwing "shading") varies substantially this trait is negatively correlated with spot melanism. However, when there is less variation in allocation to thermoregulatory melanism we find these traits to be positively correlated; these findings are consistent with the resource-based trade-off hypothesis, which may provide a non- or maladaptive hypothesis to explain spot plasticity. We also show that increased dietary tyrosine results in increased spot melanism under some conditions, supporting the more general idea that melanism may involve resource-based costs.

Species Delimitation of Some Melanargia Species (Lepidoptera, Nymphalidae, Satyrinae) in The Southeastern Anatolia Region Based On The mtCOI Gene

Among the Palearctic species, butterflies of the genus Melanargia are known for their black and white wing patterns. The morphological character polarization of this genus is full of varying combinations of subgenus, species complex, and subspecies status. Its taxonomy is open to debate, especially in species and subspecies categories, with definitions mostly based on wing color. In recent years, cryptic species, phenotypically masked species, and species with intense intraspecific variation have been identified through the determination of lineages under the leadership of molecular systematics. The mtCOI gene, which is especially described as a species signature, is an important DNA barcode used for Lepidoptera. In the presented study, the mtCOI gene sequence of the populations of Melanargia larissa, M.grumi, M.hylata, M.syriaca, and M.russiae species in the southeastern Anatolia region was determined for the first time. To determine the boundaries of these species, gene characterization and genetic distances were carried out according to the Kimura-2 Parameter, and putative species analyses were carried out by the ABGD method. Trees were constructed with Maximum likelihood and Bayesian inference algorithms to determine the phylogenetic relationships between species of the genus. In light of these analyses, it has been shown that the genetic distance of morphological species M. larissa, M. grumi, M.hylata, and M. syriaca is not at the species level and that M.larissa maintains its species status according to the principle of priority. In addition, the M.russiae population presented in this study forms a monophyletic clade with other populations of the same species in the phylogenetic tree, proving that this taxon is a stable species.

Taxonomic revision of Asapharcha Meyrick, 1920 (Lepidoptera, Gelechiidae), with descriptions of four new species

The Afrotropical genus Asapharcha Meyrick, 1920 is recognized as a senior synonym of Lacistodes Meyrick, 1921, syn. nov. and Melitoxestis Meyrick, 1921, syn. nov. Nine species of Asapharcha are recognized as valid, four of which are described as new: A. angustella sp. nov. (South Africa), A. lacistoides sp. nov. (Namibia, Ethiopia, Sudan), A. ochrocapitella sp. nov. (Zimbabwe), and A. unipunctella sp. nov. (Namibia). Two new synonyms are proposed: Asapharcha crateropa Meyrick, 1930 syn. nov. of Lacistodes tauropis Meyrick, 1921, and Lacistodes brunneostola Janse, 1960, syn. nov. of Asapharcha strigifera Meyrick, 1920. Three new generic combinations are proposed: Asapharcha centrotypa (Meyrick, 1920) (Melitoxestis), comb. nov., Asapharcha fuscomaculata (Bidzilya & Mey, 2011) (Lacistodes), comb. nov., Asapharcha hirsuta (Janse, 1958) (Lasiarchis), comb. nov. The female genitalia of A. strigifera are described for the first time. Asapharcha tauropis is recorded for the first time from Kenya and Ethiopia. All species of Asapharcha are diagnosed, and an identification key to all species of the genus is provided. Wing pattern and genitalia of all species are illustrated, and an updated checklist of the genus is given.

Discovery of a peculiar insular race of Ravenna nivea (Nire, 1920) (Lepidoptera: Lycaenidae) endemic to Yinggeling Mountain of Hainan, suggesting heterogeneous geological history of mountain formation of the island.

A peculiar population of Ravenna nivea (Nire, 1920) was discovered from the Yinggeling Mountain Mass of central Hainan. Its wing pattern and COI barcode data show considerable distinction from other geographic populations of R. nivea, including that of Bawangling, approximately only 40 km away and also located in Hainan. The p-distance value of the COI barcode between the Yinggeling and Bawangling populations was 1.1%, considerably higher than the value (0.6%) between Bawangling population and populations in eastern China, where the subspecific name howarthi Saigusa, 1993 applies. The population is regarded as a distinct subspecies ngiunmoiae Lo & Hsu, subsp. nov. The distinctness and high degree of COI haplotype diversity of R. nivea found in Hainan and Taiwan suggest continental islands may serve as glacial refugees for the butterfly and other organisms during previous glaciations, and the presence of the relict populations of montane butterflies like R. nivea may provide useful clues towards a better understanding of the geological history of mountain formation within islands.

Phenotypic plasticity in tropical butterflies is linked to climatic seasonality on a macroevolutionary scale.

Phenotypic plasticity can be adaptive in fluctuating environments by providing rapid environment-phenotype matching and this applies particularly in seasonal environments. African Bicyclus butterflies have repeatedly colonized seasonal savannahs from ancestral forests around the late Miocene, and many species now exhibit seasonal polyphenism. On a macroevolutionary scale, it can be expected that savannah species will exhibit higher plasticity because of experiencing stronger environmental seasonality than forest species. We quantified seasonality using environmental niche modeling and surveyed the degree of plasticity in a key wing pattern element (eyespot size) using museum specimens. We showed that species occurring in highly seasonal environments display strong plasticity, while species in less seasonal or aseasonal environments exhibit surprisingly variable degrees of plasticity, including strong to no plasticity. Furthermore, eyespot size plasticity has a moderate phylogenetic signal and the ancestral Bicyclus likely exhibited some degree of plasticity. We propose hypotheses to explain the range of plasticity patterns seen in less seasonal environments and generate testable predictions for the evolution of plasticity in Bicyclus. Our study provides one of the most compelling cases showing links between seasonality and phenotypic plasticity on a macroevolutionary scale and the potential role of plasticity in facilitating the colonization of novel environments.