Butterfly Wing Research Articles

General morphological analysis of Orosi windows and morpho butterfly wing's principles for improving occupant's daylight performance through interactive kinetic façade

Daylight contains dynamic features such as color and intensity that may vary over time. The ideas of Orosi windows and biomimetic kinetic lessons of butterfly wings are viewed as essential tactics for regulating dynamic daylight. As a result, this research looks at a methodological technique for providing an appropriate combination of kinetic behavior and movement with colorful glass compositions to boost occupants' daylight performance. The research is being carried out using a multidisciplinary method that includes general morphological analysis (GMA) and a kinetic design strategy. The methodology uses GMA for parametric exploration between interconnected principles of Orosi windows and biomimetic lessons of Morpho butterfly wings to make a matrix of relationships between parameters. The kinetic façade changes the depth and scale of the hexagonal modular elements across a south direction in Iran. Moreover, the most optimal depth and scale of the hexagonal grid regarding the daylight performance metrics have been used to change the composition of colored glasses by periodic movements due to dynamic sun-timing and occupant's positions. The annual daylight metrics analysis of all kinetic alternatives represents high daylight performance by UDI, EUDI, sDA of 93.5, 6.29, and 78.37, respectively. The facade increases the amount of UDI up to 5.61 times regarding the base case while decreasing the amount of EUDI in the room by an average of 91.8%. Concerning predicting the risk of glare, as a point in time metric, the façade prevents visual discomfort by keeping most scenarios in the imperceptible range.

Exploring the Transient Microbe Population on Citrus Butterfly Wings.

ABSTRACTMicrobes carve out dwelling niches in unusual environments. Insects, in general, have been hosts to microbes in different ways. Some insects incorporate microbes as endosymbionts that help with metabolic functions, while some vector pathogenic microbes that cause serious plant and animal diseases, including humans. Microbes isolated from insect sources have been beneficial and a huge information repository. The fascinating and evolutionarily successful insect community has survived mass extinctions as a result of their unique biological traits. Wings have been one of the most important factors contributing to the evolutionary success of insects. In the current study, wings of Papilio polytes, a citrus butterfly, were investigated for the presence of ecologically significant microbes within hours of eclosing under aseptic conditions. Scanning electron microscopy (SEM) revealed the presence of bacteria dwelling in crevices created by a specific arrangement of scales on the butterfly wing. A total of 38 bacterial isolates were obtained from the patched wings of the citrus butterfly, and Bacillus spp. were predominant among them. We probed the occurrence of these microbes to assess their significance to the insect. Many of the isolates displayed antibacterial, antifungal, and biosurfactant properties. Interestingly, one of the isolates displayed entomopathogenic potential toward the notorious agricultural pest mealybug. All the wing isolates were seen to cluster together consistently in a phylogenetic analysis, except for one isolate of Bacillus zhangzhouensis (Papilio polytes isolate [Pp] no. 28), suggesting they are distinct strains.IMPORTANCE This is a first study reporting the presence of culturable microbes on an unusual ecological niche such as butterfly wings. Our findings also establish that microbes inhabit these niches before the butterfly has contact with the environment. The findings in this report have opened up a new area of research which will not only help understand the microbiome of insect wings but might prove beneficial in other specialized studies.

Phenotypic Plasticity of the Mimetic Swallowtail Butterfly Papilio polytes: Color Pattern Modifications and Their Implications in Mimicry Evolution.

Butterfly wing color patterns are sensitive to environmental stress, such as temperature shock, and this phenotypic plasticity plays an important role in color pattern evolution. However, the potential contributions of phenotypic plasticity to mimicry evolution have not been evaluated. Here, we focused on the swallowtail butterfly Papilio polytes, which has nonmimetic and mimetic forms in females, to examine its plastic phenotypes. In the nonmimetic form, medial white spots and submarginal reddish spots in the ventral hindwings were enlarged by cold shock but were mostly reduced in size by heat shock. These temperature-shock-induced color pattern modifications were partly similar to mimetic color patterns, and nonmimetic females were more sensitive than males and mimetic females. Unexpectedly, injection of tungstate, a known modification inducer in nymphalid and lycaenid butterflies, did not induce any modification, but fluorescent brightener 28, another inducer discovered recently, induced unique modifications. These results suggest that phenotypic plasticity in nonmimetic females might have provided a basis of natural selection for mimetic color patterns during evolution.

Tensile mechanical properties and finite element simulation of the wings of the butterfly Tirumala limniace.

This study examined the morphological characteristics and mechanical properties of the wings of Tirumala limniace. The wings of this butterfly, including the forewings and hindwings, are composed mainly of a flexible wing membrane and supporting wing veins. Scanning electron microscopy was employed to observe specific positions of the wing membrane and veins and reveal the morphological characteristics. Tensile experiments were conducted to evaluate the mechanical properties of the wings and proved that the multifiber layer structures have a significantly fixed orientation of fiber alignment. A butterfly wing model reconstructed in reverse based on the finite element method was used to analyze the static characteristics of the wing structure in detail. Evaluation of stress and strain after applying uniform loading, perpendicular loading, and torsion revealed that minor wing deformation occurred and was concentrated near the main wing vein, which verifies the steadiness of the butterfly wing structure. Additionally, the flapping of butterfly wings was simulated using computational fluid dynamics to study the flow field near the butterfly wings and the distribution of pressure gradient on the wings. The results confirmed the effect of wing veins on maintaining the flight performance.

Bioinspired butterfly wings triboelectric nanogenerator with drag amplification for multidirectional underwater-wave energy harvesting

Underwater-wave energy, as a kind of abundant but neglected renewable energy, is challenging to be efficiently harvested due to the low frequency and random moving direction. In this work, a bioinspired butterfly wings triboelectric nanogenerator (BBW-TENG) is proposed for multidirectional wave energy harvesting from the underwater environment, which is composed of a shell with bionic blades and the generation units. The parameters for the shape and number of blades are analyzed by computational fluid dynamics (CFD) to determine the optimal structural parameters and verify that the bionic blades have the characteristic of drag amplification. What’s more, the BBW-TENG responds sensitively to the multidirectional underwater-wave excitation, which demonstrates the ability to harvest multidirectional and low-frequency underwater-wave energy. The output performance of 400 V, 2.9 µA, and 0.31 µC can be generated with the frequency of 1.25 Hz. In practical applications, it is verified that the BBW-TENG can provide power supply for the electronic devices. And the BBW-TENG immersed in water for 45 days indicates excellent durability without diminished electrical performance. Therefore, this work gives a new approach of harvesting underwater-wave energy to long-term power supply for the distributed sensors.

Deformable model of a butterfly in motion on the example of Attacus atlas

Insect wings can undergo significant chordwise (camber) as well as spanwise (twist) deformation during flapping flight but the effect of these deformations is not well understood. The shape and size of butterfly wings leads to particularly large wing deformations, making them an ideal test case for investigation of these effects. High-speed videogrammetry was used to capture the wing kinematics and deformations. The movements of selected markers on the wings of a living insect was observed. Created characteristics showing the displacement in a three-dimensional coordinate system identified the kinematics and deformations of the butterfly's wings. These experimental results were then analyzed computationally using a high-fidelity, three-dimensional, unsteady Navier-Stokes flow solver. Computational fluid dynamics (CFD) simulations were carried out on the basis of the wing geometry of the large moth Attacus atlas. Six geometric and structural models of the Attacus atlas butterfly wing with various degrees of simplification were developed. Using these models, Fluid-Structure-Interaction (FSI) simulation studies were performed in the commercial Ansys software environment (Fluent and Mechanical). Computations of the wing beat cycle were carried out, obtaining pressure distributions, streamlines, vortex regions and cumulative force waveforms.

Wing morphology and eyespot pattern of Erebia medusa (Lepidoptera, Nymphalidae) vary along an elevation gradient in the Carpathian Mountains

Wing morphology and eyespot pattern of Erebia medusa (Lepidoptera, Nymphalidae) vary along an elevation gradient in the Carpathian Mountains

Spectral tuning of biotemplated ZnO photonic nanoarchitectures for photocatalytic applications.

The photocatalytic activity of a flat surface can be increased by micro- and nanostructuring the interface to increase the area of the contact surface between the photocatalyst and the solute, and moreover, to optimize charge carrier transfer. Further enhancement can be achieved by using photonic nanostructures, which exhibit photonic band gap (PBG). Structurally coloured butterfly wings offer a rich ‘library’ of PBGs in the visible spectral range which can be used as naturally tuned sample sets for biotemplating. We used conformal atomic layer deposition of ZnO on the wings of various butterfly species (Arhopala asopia, Hypochrysops polycletus, Morpho sulkowskyi, Polyommatus icarus) possessing structural colour extending from the near UV to the blue wavelength range, to test the effects arising from the nanostructured surfaces and from the presence of different types of PBGs. Aqueous solutions of rhodamine B were used to test the enhancement of photocatalytic activity that was found for all ZnO-coated butterfly wings. The best reaction rate of decomposing rhodamine B when illuminated with visible light was found in 15 nm ZnO coated M. sulkowskyi wing, the reflectance of which had the highest overlap with the absorption band of the dye and had the highest reflectance intensity.

Antennapedia and optix regulate metallic silver wing scale development and cell shape in Bicyclus anynana butterflies.

Butterfly wing scales can develop intricate cuticular nanostructures that produce silver colors, but the underlying genetic and physical basis of such colors is mostly unexplored. Here, we characterize different types of wild-type silver scales in Bicyclus anynana butterflies and show that the varying thickness of the air layer between two cuticular laminas is most important for producing silvery broadband reflectance. We then address the function of five genes-apterous A, Ultrabithorax, doublesex, Antennapedia, and optix-in silver scale development by examining crispants with either ectopic gains or losses of silver scales. Simultaneous transformations of three parameters-loss of the upper lamina, increased lower lamina thickness, and increased pigmentation-occur when silver scales become brown and vice versa when brown scales become silver. Antennapedia and optix are high-level regulators of different silver scale types and determine cell shape in both sexes. Moreover, Antennapedia is involved in determining ridge and crossrib orientation.

Fourier transform infra-red (FTIR) spectrochemical analyses of Pieridae butterfly wings

Fourier transform infrared (FTIR) spectroscopic technique was carried out in wings of nine different Pierid butterflies to deduce the functional groups and properties of cuticular hydrocarbons which play a pivotal role in exhibiting charismatic colour patterns, controlling body temperature, attracting potential mates and camouflaging against predators. There were three major types of hydrocarbons present in all butterfly wings including alkanes, alkenes and methyl hydrocarbons. The second predominant compounds found in the butterfly wing region include alkyl halides, alcohols and phenols. There were no significant differences in the functional groups among the wings of butterflies. FTIR analysis of nine different Pierid butterfly wings showed many relative sizes of peaks. There were no significant differences in the chemical composition of wings but the colour differences were observed among the nine different butterflies. It was inferred that not majorly due to the differences in the cuticular hydrocarbons and may be due to the presence of different microstructures like scales, ridges and grooves.

The Comparative approach to bio-inspired design: integrating biodiversity and biologists into the design process.

Biodiversity provides a massive library of ideas for bio-inspired design, but the sheer number of species to consider can be daunting. Current approaches for sifting through biodiversity to identify relevant biological models include searching for champion adapters that are particularly adept at solving a particular design challenge. While the champion adapter approach has benefits, it tends to focus on a narrow set of popular models while neglecting the majority of species. An alternative approach to bio-inspired design is the comparative method, which leverages biodiversity by drawing inspiration across a broad range of species. This approach uses methods in phylogenetics to map traits across evolutionary trees and compare trait variation to infer structure-function relationships. Although comparative methods have not been widely used in bio-inspired design, they have led to breakthroughs in studies on gecko-inspired adhesives and multifunctionality of butterfly wing scales. Here we outline how comparative methods can be used to complement existing approaches to bioinspired design, and we provide an example focused on bio-inspired lattices, including honeycomb and glass sponges. We demonstrate how comparative methods can lead to breakthroughs in bio-inspired applications as well as answer major questions in biology, which can strengthen collaborations with biologists and produce deeper insights into biological function.

Distal-less and spalt are distal organisers of pierid wing patterns

Two genes, Distal-less (Dll) and spalt (sal), are known to be involved in establishing nymphalid butterfly wing patterns. They function in several ways: in the differentiation of the eyespot’s central signalling cells, or foci; in the differentiation of the surrounding black disc; in overall scale melanisation (Dll); and in elaborating marginal patterns, such as parafocal elements. However, little is known about the functions of these genes in the development of wing patterns in other butterfly families. Here, we study the expression and function of Dll and sal in the development of spots and other melanic wing patterns of the Indian cabbage white, Pieris canidia, a pierid butterfly. In P. canidia, both Dll and Sal proteins are expressed in the scale-building cells at the wing tips, in chevron patterns along the pupal wing margins, and in areas of future scale melanisation. Additionally, Sal alone is expressed in the future black spots. CRISPR knockouts of Dll and sal showed that each gene is required for the development of melanic wing pattern elements, and repressing pteridine granule formation, in the areas where they are expressed. We conclude that both genes likely play ancestral roles in organising distal butterfly wing patterns, across pierid and nymphalid butterflies, but are unlikely to be differentiating signalling centres in pierids black spots. The genetic and developmental mechanisms that set up the location of spots and eyespots are likely distinct in each lineage.

Crossing Phylums: Butterfly Wing as a Natural Perfusable Three-Dimensional (3D) Bioconstruct for Bone Tissue Engineering.

Despite the advent of promising technologies in tissue engineering, finding a biomimetic 3D bio-construct capable of enhancing cell attachment, maintenance, and function is still a challenge in producing tailorable scaffolds for bone regeneration. Here, osteostimulatory effects of the butterfly wings as a naturally porous and non-toxic chitinous scaffold on mesenchymal stromal cells are assessed. The topographical characterization of the butterfly wings implied their ability to mimic bone tissue microenvironment, whereas their regenerative potential was validated after a 14-day cell culture. In vivo analysis showed that the scaffold induced no major inflammatory response in Wistar rats. Topographical features of the bioconstruct upregulated the osteogenic genes, including COL1A1, ALP, BGLAP, SPP1, SP7, and AML3 in differentiated cells compared to the cells cultured in the culture plate. However, butterfly wings were shown to provide a biomimetic microstructure and proper bone regenerative capacity through a unique combination of various structural and material properties. Therefore, this novel platform can be confidently recommended for bone tissue engineering applications.

Lepidopterans of economic importance in Cameroon: A systematic review

Lepidoptera represents one of the most abundant and diverse insect groups globally, with more than 178,159 species described in more than 4000 genera. This paper discusses the economic importance of these insects in Cameroon. The work was built on a comprehensive review of 60 relevant published articles from 1955 to 2021. Results show a great diversity of insects of economic importance belonging to the order Lepidoptera, of which 51 are known at the species level, eleven at the genus level, and many others not yet identified. Their economic importance is somehow conflicting, with a mix of harmful and beneficial species. Some are threats to agricultural production as pests at various plant stages, the Fall Armyworm being one of the worst. Their impact on food security is well documented and led to the conclusion that lepidopterans are the most important group of agricultural pests to be studied and controlled for sustainable production under climate change. Meanwhile, beside the use of butterfly wings for craft and artwork, lepidopterans are also a group valued as an excellent marketable food source in Cameroon's humid forest regions. Larval stages are sold fresh, dried or parboiled in rural and urban markets. This review concludes that there is a need in the context of food security to deeply evaluate the diversity, geographical distribution and seasonality of lepidopterans and their economic importance, and to promote sustainable management of those with positive economic importance and better control of those with negative impacts. • Lepidoptera group in Cameroon has harmful and beneficial effect on food security • Fall armyworm have been found on cultivated crops in Cameroon • A diversity of edible Lepidoptera is consumed in 5 of 10 Regions of Cameroon • Silk producing and decorative lepidopterans are also encountered in Cameroon • Perspective is to reevaluate the diversity of Lepidoptera importance in Cameroon

Photonic Crystals: A Review as Promising Tool for the Selective Detection of Toxic Gases

Photonic crystals (PhCs) based sensing nanotechnology has gained a lot of attention because of its unique structural and morphological characteristics. With the potential utility, these PhC materials are promising as sensitive, selective, economical, portable, and visually detectable gas/vapor sensors for environment quality monitoring. This review focuses on current progress in the natural and artificial PhCs for gas sensing. We will discuss different PhCs including morpho butterfly wings and their nanostructure mimics, porous silicon, Bragg stacks, and colloidal crystals. Moreover, their fabrication techniques for PhCs sensing materials, structural modifications, and sensing mechanisms will be analyzed. In this review article, we highlighted the problem and solution as emerging trends for recent advances in PhCs-based sensors and their applications in environmental monitoring and pollution control. Furthermore, this study envisions new methodologies for PhCs-based sensors that will be highly advanced and effective.

Head and Tail Oxidized Terpenoid Esters from Androconia of Heliconius erato Butterflies.

Heliconius erato is a neotropical butterfly species that is part of a complex mimicry ring, with colorful wing patterns. For intraspecific communication, males use pheromones that are released from two different scent-emitting structures. Scent glands located near the abdominal claspers of males, containing antiaphrodisiac pheromones, release a highly complex mixture of compounds that is transferred to females during mating, rendering them unattractive to other males. On the other hand, androconia, scent-emitting scale areas on the wings of male butterflies, release a structurally more restricted set of compounds that likely serves an aphrodisiac role. We report here on two structurally related compounds that are the major androconial constituents, produced in high amounts and are not volatile due to their high molecular mass. Their structures were established by extensive analysis of mass, infrared, and NMR spectra, as well as microderivatization reactions of the natural extract. After establishing synthetic access, the compounds were unequivocally identified as two unusual head and tail oxidized terpenoids, (4E,8E,12E)-4,8,12-trimethyl-16-oxoheptadeca-4,8,12-trien-1-yl oleate (1) and stearate (2). Although behavioral assays are necessary to fully comprehend their role in the chemical communication of the species, hypotheses for their use by the butterflies are also discussed.

Universal cooling patterns of the butterfly wing scales hierarchy deduced from the heterogeneous thermal and structural properties of Tirumala limniace (Lepidoptera: Nymphalidae, Danainae).

The radiative cooling of butterfly wing scales hierarchy has great value in understanding how poikilotherms adapt to the environment and developing bionic materials. However, it remains unclear what the cooling system is like and how the variation of hierarchy affects the cooling efficiency. Therefore, the correlation between the variations of the structure and emissivity of scale hierarchy is thoroughly investigated in Tirumala limniace (Cramer, 1775), whose thermal properties are highly heterogeneous among different wings and regions but similar between males and females. Patterns were deduced from the biological and model simulation experiments. The scale hierarchy varies at the micro- to nanolevel on both surface and section, corresponding to the variating emissivity. Scales on wing veins and margins have large nanostructured units with small lumens and are distinctly thickened, which bring extraordinarily high emissivity. The variations of light and dark scales, respectively, lead to the high emissivity of the middle region of wings and the front wings. Generally, the elevation of the inner surface area and the thickness of the chitin is the key to enhancing the cooling efficiency. For the first time, the effects of the variation of hierarchy toward emissivity of the mid-infrared spectrum are systematically clarified. It is demonstrated that wing scales integrally differentiate in coping with the heterogeneous cooling needs, which may benefit in balancing multifunctions and the development toward the adaptation to the abiotic environment. The study provides insights into the comprehensive thermoregulation system of butterflies and the further development of radiative cooling materials.

Electrochemical polishing assisted selective laser melting of biomimetic superhydrophobic metallic parts

Metallic superhydrophobic surfaces can be widely used in pipeline transportation, oil–water separation, anti-icing, biomedicine and industrial production owing to their excellent properties. The biologically non-smooth superhydrophobic structure provides a biomimetic prototype for superhydrophobic metal surface processing. However, processing micro-nano biomimetic structures on the internal surface of complex pipelines is difficult because of the limitations of traditional molding processes. Herein, a superhydrophobic butterfly wing is imitated via the selective laser melting technology to print a pit prototype on the surface during the complex parts forming, and then the bio-inspired superhydrophobic internal surface of the 316L stainless steel is successfully prepared by the processes of electrochemical polishing, chemical etching, fluorosilane modification, and low temperature drying, sequentially. The morphology, wettability, corrosion resistance, and elemental composition of the obtained surface are characterized. The results show that a uniform pit-shaped micro-nano composite structure is formed on the surface, the contact angle is up to 155°, the rolling angle is less than 10°, and the corrosion resistance is significantly improved. Finally, a complex superhydrophobic inner surface square tube with application value is successfully prepared, and its excellent superhydrophobicity and self-cleaning properties are verified. This fabrication method provides an idea for the complication of metal superhydrophobic structures, and will promote the application of additive manufacturing in the engineering field.

3D Modelling for Photonic Crystal Structure in Papilio maackii Wing Scales.

As a typical representative of natural structural colors, the wings of butterflies living in different zones present colors due to different chromogenic mechanisms. In this work, Papilio maackii, a common species of butterfly living in China, was studied in order to clarify the photophysics of its wing scales. A FESEM was applied to observe the microstructure of the scales, and we found that they have a periodic photonic crystal structure. X-ray photoelectron spectroscopy was applied to clarify the wings’ chemical composition. Additionally, the optical properties of the scales were investigated using a UV-vis-NIR microspectrophotometer. Then, a simplified three-dimensional photonic crystal model was built according to the microstructure of the wing scales, and the plane-wave expansion method was used to calculate the band gap. The correlation between the calculated band gap and the practical reflective spectrum was also established for the wing scales of Papilio maackii.

The DNA Binding Diversity of the SIX Homeodomain Transcription Factor Family

Transcription factor (TF) DNA‐binding specificity is determined by how their DNA‐binding domain (DBD) interacts with DNA. TFs are identified by the sequence homology shared with described DBDs, which allows them to be classified into families. It is highly widely accepted that similar DBDs recognize similar DNA motifs. However, changes in a TF can lead to changes in its DNA recognition. TFs are critical for development and have been found since the beginning of animals, how their DNA binding changes through time has not been fully studied. TFs members of the sine oculis homeobox (SIX) homeodomain family are found from sponges to humans and are considered atypical members of the homeodomain family. They regulate numerous developmental processes, with phenotypic features spanning from eye development in flies, red color patterning in Heliconius butterfly wings to brain development in humans. How evolutionary related TFs diversify their function has not been fully understood, especially changes to their DNA binding specificity. Using full length SIX proteins from Drosophila melanogaster, Heliconius erato, and Homo sapiens, we performed in vitro Systematic Evolution of Ligands by Exponential Enrichment (SELEX‐seq) to identify the DNA binding specificity. Our preliminary data shows the majority bind to their canonical binding motif (TGATAC), except for six4 members which prefer TGACAC. Interestingly, the way they bind to these motifs differs. Both sine oculis and six4 homologs require a 5’‐GA flanking the core motif. While optix related members prefer a shorter flaking region with less dependence on 5’‐GA. This is interesting since optix is more evolutionarily related to six4 than to sine oculis. In addition, we found that Heliconius erato optix can bind both as a homodimer with a preferred spacing of 2‐bp between binding sites or as a monomer. Our results provide new insights in the binding diversity found in the SIX family of TFs and predict genomic targets of these understudied TF family.