Wing Scales Research Articles

An ultra-broadband biomimetic microwave blackbody integrating superior mechanical properties inspired by lepidopteran wing scales

Effective absorption bandwidth (EAB) and mechanical properties of microwave-absorbing materials (MAMs) together determine the radar stealth performance of weaponry, which is the survival guarantee of weaponry in the battlefield. Unfortunately, limited by conventional structures, current MAMs can hardly meet the requirements of EAB (−10 dB) > 20 GHz and flexural strength >100 MPa simultaneously. Here, an ultra-broadband biomimetic microwave blackbody (BMB) with superior mechanical properties inspired by the optical structures of lepidopteran wing scales is designed and fabricated. In fact, the broadband absorption is mainly attributed to impedance matching of the quasi-grid-like biomimetic structure on the surface and scattering enhancement of the quasi-honeycomb-like biomimetic structure at the bottom. Notably, the BMB achieves an EAB (−10 dB) of 37.8 GHz (2.8–40 GHz), covering 97.8% of the S-Ka band. Besides, the BMB exhibits stable broadband absorption at an incidence angle of 0°–40°. More importantly, the BMB has a flexural strength of 229.8 MPa and a high damage tolerance, due to the reinforcement of basalt fiber and the “T” shaped cross-section. This study provides a novel inspiration and feasible approach for the structure-function integration of MAMs and would enable a wide range of radar stealth and electromagnetic shielding applications.

Assessment of the prospects of growing perennial grasses on landfills

Nineteen species of agricultural plants, recommended for cultivation in arid conditions of the USA, were tested on the dumps of the Ekibastuz coal mine. The most promising was Atriplex gardneri var. aptera - a North American plant that naturally inhabits the steppe regions of the USA. The group of promising species includes Leymus racemosus, Elymus trachycaulus, and Psathirostachys jnceus. Less promising species for biological reclamation include Calamovilfa longifolia, Bouteloua gracilis, Andropogon gerardii, Leymus arenarius, Pascopyrum smithii sv. Rosana, Pascopyrum smithii sv. Rodan, Elymus lanceolatus, Elytrigia intermedia, Agropyron cristatum, Atriplex canescens, Festuca ovina, and Elimus sibiricus. Lowly promising and unpromising species include Panicum virgatum, Agropyron cristatum x A. desertorum, Schizachyrium scoparium, and Bouteloua curtipendula. These plants are either not frost-resistant or cannot tolerate drought on the dumps.

Flavonoids are involved in salt tolerance through ROS scavenging in the halophyte Atriplex canescens.

The content of flavonoids could increase in A. canescens under saline conditions. Overexpression of AcCHI in transgenic A. thaliana promotes flavonoid biosynthesis, thereby functioning in the tolerance of transgenic plants to salt and osmotic stress by maintaining ROS homeostasis. Atriplex canescens is a halophytic forage shrub with excellent adaptation to saline environment. Our previous study showed that a large number of genes related to the biosynthesis of flavonoids in A. canescens were significantly up-regulated by NaCl treatments. However, it remains unclear whether flavonoids are involved in A. canescens response to salinity. In this study, we found that the accumulation of flavonoids significantly increased in either the leaves or roots of A. canescens seedling under 100 and 300mM NaCl treatments. Correspondingly, AcCHS, AcCHI and AcF3H, which encode three key enzymes (chalcone synthases (CHS), chalcone isomerase (CHI), and flavanone 3-hydroxylase (F3H), respectively) of flavonoids biosynthesis, were significantly induced in the roots or leaves of A. canescens by 100 or 300mM NaCl. Then, we generated the transgenic Arabidopsis thaliana overexpressing AcCHI and found that transgenic plants accumulated more flavonoids through enhancing the pathway of flavonoids biosynthesis. Furthermore, overexpression of AcCHI conferred salt and osmotic stress tolerance in transgenic A. thaliana. Contrasted with wild-type A. thaliana, transgenic lines grew better with greater biomass, less H2O2 content as well as lower relative plasma permeability in either salt or osmotic stress conditions. In conclusion, our results indicate that flavonoids play an important role in A. canescens response to salt stress through reactive oxygen species (ROS) scavenging and the key enzyme gene AcCHI in flavonoids biosynthesis pathway of A. canescens has the potential to improve the stress tolerance of forages and crops.

Variasi Bentuk dan Warna Sisik Sayap Kupu-Kupu dan Ngengat

Butterflies and moths are members of Lepidoptera with the main characteristic of having two pairs of membranous wings covered with scales. The wings of butterflies and moths have colored patterns that can be used as protection from predators. The aim of this study was to compare the shape, size, and color variations of the scales on the wings of butterflies and moths. Samples of butterflies and moths were collected from the Dramaga Bogor Agricultural University campus. In this study, 11 species of butterflies were used belonging to three families, namely Pieridae, Nymphalidae, and Papilionidae, and 9 species of moths in four families, namely Erebidae, Geometridae, Hesperiidae, and Uraniidae. Observation of scales was carried out with a compound microscope connected to a camera, and measured using imageJ. The shape of the wing scales of butterflies and moths was elongated and widened with the base of the scales and the number of teeth on the distal part varied. The shape of the serrations on the butterfly scales tends to be rounded, while on the moth it is tapered. Larger scale sizes are found on light-colored butterfly scales and dark-colored moth scales.

Evaluation of molecular and morphological diversity of the rangeland species of Atriplex canescens (Amaranthaceae) in Iran

Atriplex canescens is a polymorphic species that can be deciduous or evergreen depending on the climate. Having an extensive root system, it controls soil erosion very well and is resistant to drought. The present study examined the morphological and genetic diversity of 13 Iranian populations. Multivariate statistical analyses were performed on 25 morphological characteristics (quantitative and qualitative). To assess genetic diversity, eight primers were applied, resulting in 42 bands. With the ANOVA test, all quantitative morphological characteristics among the studied populations were significantly different. Similarly, the AMOVA test revealed that the genetic content of the studied populations was different. Genetic distance and geographic distance were significantly correlated in Mantel's test. Based on morphological studies and the effects of environmental factors (latitude, longitude, and altitude) on genetic structure, different genetic branches have been proposed for A. canescens.

Hybrid Bio-Nanocomposites by Integrating Nanoscale Au in Butterfly Scales Colored by Photonic Nanoarchitectures

Plasmonic metallic nanoparticles, like Au, can be used to tune the optical properties of photonic nanoarchitectures occurring in butterfly wing scales possessing structural color. The effect of the nanoscale Au depends on the location and the amount deposited in the chitin-based photonic nanoarchitecture. The following three types of Au introduction methods were compared regarding the structural and optical properties of the resulting hybrid bio-nanocomposites: (i) growth of Au nanoparticles inside the nanopores of butterfly wing scales by a light-induced in situ chemical reduction of HAuCl4 in aqueous solution containing sodium citrate, as a new procedure we have developed, (ii) drop-drying of the aqueous Au sol formed during procedure (i) in the bulk liquid phase, and (iii) physical vapor deposition of Au thin film onto the butterfly wing. We investigated all three methods at two different Au concentrations on the wings of laboratory-bred blue-colored male Polyommatus icarus butterflies and characterized the optical properties of the resulting hybrid bio-nanocomposites. We found that the drop-drying and the in situ growth produced comparable redshift in the spectral position of the reflectance maximum associated with the chitin-based photonic nanoarchitecture in the wing scales, while the 5 nm or 15 nm thick Au layers vacuum deposited onto the butterfly wing behaved like an optical filter, without inducing spectral shift. The in situ growth in the photonic nanoarchitecture under intense illumination produced uniform Au nanoparticles located in the pores of the biological template, which is more advantageous for further applications. An additional benefit of this method is that the Au nanoparticles do not aggregate on drying, like in the case of drop-drying of preformed Au nanoparticles from the citrate-stabilized sol.

Survival of experimentally buried large, winged seeds from open sandy habitats defies the established theory of relatedness between seed size, shape, and longevity

Accumulated evidence indicates that species with small, rounded seeds predominantly maintain a persistent soil seed bank, while those having larger and less isodiametric seeds have a transient seed bank. We assumed that species in certain special habitats may be exceptions to this rule. In habitats with sandy soil and open vegetation, the seeds do not necessarily have to penetrate the deeper soil layers through cracks in the soil. Instead, the seeds can become buried by a windblown layer of sand, thus seed morphology does not really affect the burial process. To test our hypothesis, we selected five semi-desert shrubs and one perennial herb of open sandy grasslands, all of which had large and flattened seeds. For each species, 12 repetitions of 50 seeds were buried in the soil. Seeds were recovered after 3, 20 and 26 months of burial and subjected to germination tests. Seeds of each species germinated in all test occasions, with final germination as follows: Atriplex canescens 89.0%, Haloxylon ammodendron 11.5%, H. persicum 11.5%, Pteropyrum aucheri 43.5%, Xylosalsola richteri 12.0% and Asclepias syriaca 26.0%. The results confirm the hypothesis that each of the six species is capable of forming a persistent soil seed bank. The results also show that in habitats where seed burial can take place passively through windblown soil, plant species might bypass the tradeoff between seed size/shape and seed longevity.

Impact of soil residual auxin herbicide on seedling emergence and biomass differs between soil types, water pulse event, and seedling species

Synthetic‐auxin herbicides are often used to control woody plants and aid in grassland restoration. Seed‐based restoration is common alongside herbicide applications and there may be unintended effects of these herbicides on dryland plants at the seed and seedling stages. Additionally, abiotic conditions at the time of herbicide application may influence herbicide–soil–plant interactions. We conducted a greenhouse study to examine the effects of a common shrub‐control herbicide mix and its interaction with soil type and a post‐herbicide water pulse on common desert plant seeds and seedlings. In this greenhouse study, we found that a subset of species responded negatively to soil residual herbicide activity of a mixture of aminopyralid, clopyralid, and triclopyr at the seed and seedling stages. Species sensitive to soil herbicide residues were primarily shrub and forb species that are often the target species of herbicide applications for woody plant control, such as honey mesquite (Prosopis glandulosa) and creosote bush (Larrea tridentata). However, two shrub species (four‐wing saltbush [Atriplex canescens], soaptree yucca [Yucca elata]) and one perennial grass species (Arizona cottontop [Digitaria californica]), which are used in dryland restoration projects, were found to be particularly sensitive to soil residual herbicide activity. Thus, if using these herbicides to control woody plants and restore herbaceous vegetation via active seeding or relying on the in situ seed bank, considerations should be given to what species are used in the seed mix, what species are already present in the soil seed bank, and other details of the circumstances of herbicide application.

Gypsiferous groundwater and its desalination brine concentrate: Biomass, water use, and salt “mining” of three Southwestern USA native halophytes

In drought affected regions, alternative water sources and salt tolerant crops have become increasingly important. Although there is extensive documentation describing the response of halophytes to NaCl laboratory solutions, limited data exist on their responses to natural brackish groundwater (BGW) and desalination brine concentrate that could be dominated by ions other than Na and Cl. This study investigated the biomass, evapotranspiration (ET), water productivity (WP), and ion uptake responses of three southwestern USA native halophyte species, Atriplex canescens (Pursh) Nutt. (fourwing saltbush), A. lentiformis (Torr.) S. Watson (big saltbush), and Lepidium alyssoides A. Gray var. alyssoides (mesa pepperwort). Six-week-old seedlings were irrigated with a nonsaline control treatment solution [electrical conductivity (EC) of 0.6 dS m-1], CaSO4-dominant BGW (EC ≈ 4 dS m-1), CaSO4-dominant reverse osmosis (RO) concentrate (EC ≈ 8 dS m-1), and counterpart NaCl-dominant solutions (EC ≈ 4 or 8 dS m-1). After 6 wk, BGW and low NaCl solutions increased shoot biomass of . A. lentiformis by ≈ 20% but did not stimulate top growth of A. canescens or L. alyssoides. Increasing salinity had no effect on WP of L. alyssoides, but it increased WP of the Atriplex spp. The combined shoot Na and Cl concentrations reached 7% of dry wt. in L. alyssoides and 9–10% in the Atriplex spp. with no characteristic signs of leaf burn. Conversely, roots were the main sinks for Ca and S, combining for 6–7% of dry wt. and showing the potential to put the main brine solutes to beneficial use. Markedly similar patterns in growth and water use with the NaCl-only solutions and the CaSO4-dominant solutions suggests a primary role of total salinity in these salinity responses, which in turn supports the use of diverse BGW typesnot just NaCl for halophyte production.

Bionic research of photothermal conversion performance based on butterfly wings

AbstractAs the demand for sustainable construction practices increases, innovative ideas are being explored for the construction of insulated wall panels in contemporary buildings. The butterfly is a remarkable organism that uses a thermostatic mechanism to regulate its body temperature. The microstructure on the surface of its wing scales is responsible for reflecting incident light multiple times, extending the optical path, and increasing the light absorption, thus ensuring that its body temperature remains stable. This microstructure, also known as the light capture structure, has been simulated and analyzed using ANSYS software. The results indicate that this structure can improve the light‐thermal conversion efficiency in the illuminated region, thus increasing the local heat using light radiation. Additionally, due to the unique arrangement of units in the light capture structure, the heat exchange rate with air is significantly reduced, resulting in a low heat flux. Therefore, if this butterfly‐like trapped light structure is applied to the insulated wall panels, the requirements of modern architectural concepts can be realized.

Two sides of the same wing: ventral scales enhance dorsal wing color in the butterfly Speyeria mormonia.

Biological visual signals are often produced by complex interactions between light-absorbing and light-scattering structures, but for many signals potential interactions between different light-interacting components have yet to be tested. Butterfly wings, for example, are thin enough that their two sides may not be optically isolated. We tested if ventral wing scales of the Mormon fritillary Speyeria mormonia impact the appearances of dorsal orange patches, which are thought to be involved in sexual signaling. Using reflectance spectroscopy, we found ventral scales, either silvered or non-silvered, make dorsal orange patches significantly brighter, with the silvered scales having the greater effect. Computational modeling indicates both types of ventral scales enhance the chromatic perceptual signal of dorsal orange patches, with only the silvered scales also enhancing their achromatic perceptual signal. A lack of optical independence between the two sides of the wings of S. mormonia implies the wing surfaces of butterflies have intertwined signaling functions and evolutionary histories.

Hierarchical morphogenesis of swallowtail butterfly wing scale nanostructures

The study of color patterns in the animal integument is a fundamental question in biology, with many lepidopteran species being exemplary models in this endeavor due to their relative simplicity and elegance. While significant advances have been made in unraveling the cellular and molecular basis of lepidopteran pigmentary coloration, the morphogenesis of wing scale nanostructures involved in structural color production is not well understood. Contemporary research on this topic largely focuses on a few nymphalid model taxa (e.g., Bicyclus, Heliconius), despite an overwhelming diversity in the hierarchical nanostructural organization of lepidopteran wing scales. Here, we present a time-resolved, comparative developmental study of hierarchical scale nanostructures in Parides eurimedes and five other papilionid species. Our results uphold the putative conserved role of F-actin bundles in acting as spacers between developing ridges, as previously documented in several nymphalid species. Interestingly, while ridges are developing in P. eurimedes, plasma membrane manifests irregular mesh-like crossribs characteristic of Papilionidae, which delineate the accretion of cuticle into rows of planar disks in between ridges. Once the ridges have grown, disintegrating F-actin bundles appear to reorganize into a network that supports the invagination of plasma membrane underlying the disks, subsequently forming an extruded honeycomb lattice. Our results uncover a previously undocumented role for F-actin in the morphogenesis of complex wing scale nanostructures, likely specific to Papilionidae.

Hierarchical morphogenesis of swallowtail butterfly wing scale nanostructures.

The study of color patterns in the animal integument is a fundamental question in biology, with many lepidopteran species being exemplary models in this endeavor due to their relative simplicity and elegance. While significant advances have been made in unraveling the cellular and molecular basis of lepidopteran pigmentary coloration, the morphogenesis of wing scale nanostructures involved in structural color production is not well understood. Contemporary research on this topic largely focuses on a few nymphalid model taxa (e.g., Bicyclus, Heliconius), despite an overwhelming diversity in the hierarchical nanostructural organization of lepidopteran wing scales. Here, we present a time-resolved, comparative developmental study of hierarchical scale nanostructures in Parides eurimedes and five other papilionid species. Our results uphold the putative conserved role of F-actin bundles in acting as spacers between developing ridges, as previously documented in several nymphalid species. Interestingly, while ridges are developing in P. eurimedes, plasma membrane manifests irregular mesh-like crossribs characteristic of Papilionidae, which delineate the accretion of cuticle into rows of planar disks in between ridges. Once the ridges have grown, disintegrating F-actin bundles appear to reorganize into a network that supports the invagination of plasma membrane underlying the disks, subsequently forming an extruded honeycomb lattice. Our results uncover a previously undocumented role for F-actin in the morphogenesis of complex wing scale nanostructures, likely specific to Papilionidae.

The Influence of Sodium Salt on Growth, Photosynthesis, Na+/K+ Homeostasis and Osmotic Adjustment of Atriplex canescens under Drought Stress

Atriplex canescens is widely cultivated as drought and salt-tolerant fodder in arid regions of Northwest China, which is used for photoremediation of degraded land and soil and water conservation. To explore the growth performance of A. canescens when exposed to drought and salt stress, seedlings were treated with a range of drought stress (WC1: 75 ± 3.6%, WC2: 49 ± 2.9% and WC3: 27 ± 2.5% of soil water content) and the corresponding drought stress with additional sodium salt supplementation (NaCl:Na2SO4 = 1:1 with the total concentration of Na+ set to 150 mM). The findings of this paper indicated that moderate sodium salt could stimulate the growth of A. canescens and effectively alleviate the deleterious impact of drought stress by increasing the turgor potential (ψt) and relative water content (RWC) and decreasing the leaf water osmotic potential (ψs). Furthermore, the photosynthetic capacity was improved and the negative effects of drought stress on photosystem II (PSII) were mitigated. The extra 150 mM sodium salt also markedly increased the contribution of Na+ to ψs and the contribution of betaine to ψs. In summary, these results indicate that A. canescens can adapt to drought stress by accumulating enough Na+ for osmotic adjustment (OA). Additionally, this paper is aimed to provide a fundamental basis for the utilization and cultivation of A. canescens as a favored pasture crop in the Qaidam basin, thus increasing the ecological and environmental benefits for arid regions worldwide.

Uniform and graded bio-inspired gyroid lattice: Effects of post-curing and print orientation on mechanical property

Additive manufacturing is spreading rapidly because it offers great design freedom in creating intricate lightweight shapes using lattice structures that offer numerous possibilities, including applications in aerospace, automotive, and electronics where mechanical properties are paramount. In this paper, inspired by the wing scale of the C. Rubi butterfly, unique uniform and density-graded gyroid lattice structures were proposed. This research designed the uniform gyroid lattice structure with two design configurations of unit cell sizes (4, 6, and 8) and solidity percentages (20, 30, 40, and 50) and density-graded gyroid with a solidity range of 20–80% in a constant volume of 30*30*30 mm. The designs have been modeled in nTopology software and manufactured using the Vat polymerization additive manufacturing technique with two printing orientations (0° and 25°). Two sets of the samples were printed, and one group was given postcuring treatment at 80°C for 2 hours. Quasi-static compression testing was performed to investigate the improvement in mechanical characteristics due to postcuring treatment and print orientation. The results indicate significant relationships between design parameters and mechanical performance. The density-graded gyroid lattice exhibits four times higher compressive strength than higher solidity uniform gyroid samples (UC-8-solidity-40 and 50%) when subjected to the same or less mass. In addition, debonding of connecting surfaces due to higher postcuring temperature, and better performance of horizontally printed samples have been addressed. Moreover, simulation and experimental deformation patterns for uniform and graded gyroid lattice structures have been displayed.

Live Detection of Intracellular Chitin in Butterfly Wing Epithelial Cells In Vivo Using Fluorescent Brightener 28: Implications for the Development of Scales and Color Patterns.

Chitin is the major component of the extracellular cuticle and plays multiple roles in insects. In butterflies, chitin builds wing scales for structural colors. Here, we show that intracellular chitin in live cells can be detected in vivo with fluorescent brightener 28 (FB28), focusing on wing epithelial cells of the small lycaenid butterfly Zizeeria maha immediately after pupation. A relatively small number of cells at the apical surface of the epithelium were strongly FB28-positive in the cytosol and seemed to have extensive ER-Golgi networks, which may be specialized chitin-secreting cells. Some cells had FB28-positive tadpole-tail-like or rod-like structures relative to the nucleus. We detected FB28-positive hexagonal intracellular objects and their associated structures extending toward the apical end of the cell, which may be developing scale bases and shafts. We also observed FB28-positive fibrous intracellular structures extending toward the basal end. Many cells were FB28-negative in the cytosol, which contained FB28-positive dots or discs. The present data are crucial to understanding the differentiation of the butterfly wing epithelium, including scale formation and color pattern determination. The use of FB28 in probing intracellular chitin in live cells may be applicable to other insect systems.

Breeding Polyommatus icarus Serves as a Large-Scale and Environmentally Friendly Source of Precisely Tuned Photonic Nanoarchitectures.

The colour of the butterfly wing serves as an important sexual and species-specific signal. Some species produce structural colouration by developing wing scales with photonic nanoarchitectures. These nanostructures are highly conservative, allowing only a ±10 nm peak wavelength deviation in the reflectance spectra of the blue structural colour in natural Common Blue (Polyommatus icarus) populations. They are promising templates of future artificial photonic materials and can be used in potential applications, too. In this work, we present methodology and infrastructure for breeding laboratory populations of Common Blue as a cost-effective and environmentally friendly source of nanostructures. Our technology enables the production of approximately 7500 wing samples, equivalent to 0.5-1 m2 of photonic nanoarchitecture surface within a year in a single custom-made insectarium. To ascertain the reliability of this method, we compared reflectance properties between different populations from distant geographic locations. We also provide genetic background of these populations using microsatellite genotyping. The laboratory population showed genetic erosion, but even after four generations of inbreeding, only minimal shifts in the structural colouration were observed, indicating that wild Common Blue populations may be a reliable source of raw material for photonic surfaces.

Potential Large-area Imaging of Butterfly Wing Scales with Transmission Electron Microscopy.

Potential Large-area Imaging of Butterfly Wing Scales with Transmission Electron Microscopy.

Genetics of yellow-orange color variation in a pair of sympatric sulphur butterflies

Continuous color polymorphisms can serve as a tractable model for the genetic and developmental architecture of traits. Here we investigated continuous color variation in Colias eurytheme and Colias philodice, two species of sulphur butterflies that hybridize in sympatry. Using quantitative trait locus (QTL) analysis and high-throughput color quantification, we found two interacting large-effect loci affecting orange-to-yellow chromaticity. Knockouts of red Malpighian tubules (red), likely involved in endosomal maturation, result in depigmented wing scales. Additionally, the transcription factor bric-a-brac can act as a modulator of orange pigmentation. We also describe the QTL architecture of other continuously varying traits, together supporting a large-X effect model where the genetic control of species-defining traits is enriched on sex chromosomes. This study sheds light on the range of possible genetic architectures that can underpin a continuously varying trait and illustrates the power of using automated measurement to score phenotypes that are not always conspicuous to the human eye.

Butterfly blues and greens caused by subtractive colour mixing of carotenoids and bile pigments

Butterflies often have conspicuously patterned wings, due to pigmentary and/or structurally wing scales that cover the wing membrane. The wing membrane of several butterfly species is also pigmentary coloured, notably by the bile pigments pterobilin, pharcobilin and sarpedobilin. The absorption spectra of the bilins have bands in the ultraviolet and red wavelength range, resulting in blue-cyan colours. Here, a survey of papilionoid and nymphalid butterflies reveals that several species with wings containing bile pigments combine them with carotenoids and other short-wavelength absorbing pigments, e.g., papiliochrome II, ommochromes and flavonoids, which creates green-coloured patterns. Various uncharacterized, long-wavelength absorbing wing pigments were encountered, particularly in heliconiines. The wings thus exhibit quite variable reflectance spectra, extending the enormous pigmentary and structural colouration richness of butterflies.