The First Annual Frontiers in Life Sciences Conference IRIDESCENCE More than Meets the Eye

February 6 - 9, 2008 Arizona State University - School Of Life Sciences Old Main, Carson Ballroom, Tempe Campus

photo credit: Melissa Meadows TABLE OF CONTENTS

Overview...... 2-3

Acknowledgements...... 4-5

Daily Events ...... 6-7

Fashion Show...... 8-11

Guest Speaker Biographies ...... 12-15

Conference organizers...... 16

Oral Presentation Abstracts...... 16-35

Poster Abstracts...... 35-43

Subject Index ...... 44-45 photo credit: Tomatito26 | Dreamstime Stock Photos CONFERENCE OVERVIEW

2 A unique, integrative 4–day conference on iridescent colors in nature, Iridescence: More than Meets the Eye is a graduate student proposed and organized conference supported by the Frontiers in Life Sciences program in Arizona State University’s School of Life Sciences . This conference intends to connect diverse groups of researchers to catalyze synthetic cross– disciplinary discussions regarding iridescent coloration in nature, identify new avenues of research, and explore the potential for these stunning natural phenomena to provide novel insights in fields as divergent as materials science, sexual selection and primary science education . We invite you to join us for this exciting event February 6 – 9, 2008 at Old Main, Carson Ballroom, Tempe Campus .

Each day of the conference will be dedicated to a specific area of study . We have invited twelve main speakers from all over the world and from disciplines ranging from biology to nanotechnology . The day will begin with a series of plenary–style talks by invited speakers, followed by shorter talks by other participants as time allows . Afternoon break–out sessions centered on the day’s topic will give interested participants a chance to discuss and share ideas, leading to new collaborations and several publications . We will also have an evening poster session on Thursday February 7 . On the final evening, we will host a banquet and iridescent art event in collaboration with ASU’s Herberger College of the Arts and the Phoenix Art Museum . Please see the links below for more information about our invited speakers, daily themes and activities, and the final banquet .

3 IRIDESCENCE ACKNOWLEDGEMENTS

“Iridescence: More Than Meets the Eye” would not already written letters of support for our grant proposal, have been possible without the generous grant provided allowed us to use their well-known faces and impressive by the School of Life Sciences Research and Training biographies as advertisement on our website, and Initiatives Committee as part of the new Frontiers in have worked closely with us throughout the planning Life Sciences program . This innovative program, to our of this conference . Additionally, they are each giving a knowledge unique to Arizona State University, provides 30 minute talk, helping to lead discussion sessions in an annual award of $30,000 to a group of graduate the afternoons, and serving as judges for the student students at the School of Life Sciences to initiate and poster and talk competitions during the conference . organize a conference or workshop . Frontiers in Life We truly appreciate the support and enthusiasm that Sciences (FiLS) seeks to “highlight cutting-edge issues you have put towards this event . and discoveries in the life sciences” and “call attention to the excellent life science research going on in We would like to say a special thank you to the SoLS, publicizing our work both within and beyond artists and performers who have volunteered their ASU .” Proposals are accepted annually by the RTI time, resources, and talents to make our final banquet committee, and are evaluated based on many criteria, a memorable and unique event . Thanks to Galina including the intellectual scope and novelty of the Mihaleva, Jacqueline Benard, Dennita Sewell, meeting theme, an interdisciplinary emphasis, and a Zak Jones, and to our models and other artists solid logistical and financial plan . As the first group for your role in making this a truly interdisciplinary at ASU awarded this grant, we hope that our attempt and entertaining conference . to call together some of the best minds in the world to explore the phenomenon of iridescence from a variety of viewpoints will make the RTI committee proud, and will be a great beginning for the Frontiers in Life Sciences program . For their valuable comments on our proposal, their help with advertising the event, and of course for trusting our group to be the FiLS “guinea pigs,” we would like to extend our deepest gratitude to the 2006-2007 RTI committee: James Elser, Andrew Hamilton, Yung Chang, Stan Faeth, Shelley Haydel, Josie Clark-Curtiss, Pierre Deviche, Rebecca Clark, Russ LaBrutto, and Peggy Coulombe .

We would like to thank our invited speakers, without whom we may not have received this grant or attracted so many other scientists from across the globe! Dr . Stephanie Doucet, Dr . Helen Ghiradella, Dr . Roger Hanlon, Dr . Darrell Kemp, Dr . Kevin McGraw, Dr . Daniel Osorio, Dr . Richard Prum, Dr . Ronald Rutowski, Dr . Matthew Shawkey, Dr . Mohan Srinivasarao, Dr . Doekele Stavenga, and Dr . Peter Vukusic have

4 ACKNOWLEDGEMENTS

5 DAI LY EVENTS

Day 1 Mechanisms and Measurement Iridescent colors present a special problem for spectral quantification, as even slight movements of the colored object, illuminating light source and/or light collector can have large effects on the perceived spectra of the object . Despite this, many if not most researchers, particularly in the fields of animal behavior and evolutionary biology, have continued to use quantification methods that do not acknowledge this feature of iridescent coloration . While it is difficult to assess how detrimental this has been to the integrity of the results reported, there is a clear need for well–reasoned methodological are feasible in both laboratory and field settings? How recommendations that take in to account the interests do these recommendations change for animals living and knowledge of both evolutionary biologists and under water? Can spectral characteristics help us to physicists . How do we best characterize iridescent infer underlying optical mechanisms? What behavioral colors using modern spectrophotometric methods? data are needed to decide on the best arrangement Can we suggest ways of measuring these colors that of object, light source and collector? These questions and more will be addressed by invited speakers and will be discussed in an afternoon break–out session .

Day 2 Development Animals produce iridescent colors using highly ordered arrays of nanostructures . Next to nothing is known about how these nanostructural arrays are developed in vivo . How are these precise arrays produced during development? What cellular and/or genetic processes are involved? How do they respond to environmental perturbations? Can we gain insights or suggest promising directions by looking at modern nanofabrication methods or known principles of material self–assembly? Would studies of biological “nanofabrication” inform the growing field of nanotechnology?

Day 3 Evolution Like sequins on a stage costume, iridescent colors seem ideally suited to highlighting behavioral movements or impressing potential mates . Indeed,

6 recent research efforts have provided support for the of the Arts and the Phoenix Art Museum . At this event, idea that iridescent colors may serve as indicators of student dancers choreographed by Shouze Ma will male quality and may accentuate specific behaviors wear iridescent costumes created by costume artists during courtship . However, the literature on this subject Galina Mihaleva and Jacqueline Benard in a fashion is still relatively shallow . Even less well studied is the show-type performance . Following this, Dennita Sewell, role of iridescent colors in other evolutionary contexts . Phoenix Art Museum curator of fashion design will give For example, iridescent colors may be used to produce a lecture on the use of iridescence in traditional and startling and confusing flashes to ward off predation modern day fashion and costume . We will also announce attempts, as efficient warning colors for aposematic the winner(s) of the student poster competition and species, or as a signal during aggressive interactions . make final remarks . Registration for the conference is In some intriguing cases, these colors may even function required to attend this event . The cost is $35, payable in animal crypsis . This perhaps unexpectedly wide range by check or cash at the conference registration table of biological function exhibited by iridescent colors makes on February 6 . Please see the Registration page for questions regarding how and why they have evolved all details about reservations . the more compelling .

Day 4 Education We suggest that iridescent colors can serve as engaging examples for teaching students about a diverse set of often cross–disciplinary subjects such as optics, nanofabrication, animal behavior and the evolution of complex traits . Can we identify specific examples of iridescence well suited to classroom instruction? How might we harness the eye–catching power of iridescent colors in the science classroom? Can we introduce students to the growing field of nanotechnology by using biological examples of nanostructures? We have invited education experts, science administrators, and local teachers from a variety of disciplines to join us in constructing classroom recommendations and curricular initiatives related to iridescent colors . We will request the input of all participants, especially invited speakers, as we brainstorm creative ways of using iridescence in public education .

Final Banquet As a final capstone event, we will host an evening banquet and art event on February 9 showcasing several local artists from ASU’s Herberger College

7 8 FASHION SHOW

9 10 11 GUEST SPEAKERS

Stephanie Doucet is an Assistant is a major feature of cephalopod Professor of Biological Sciences skin patterns used for communication at the University of Windsor studying and camouflage . The Hanlon lab avian behavioral and evolutionary has discovered physiologically active ecology . iridophores and we has recently used spectrometers to accurately quantify light reflection from intact skin, Dr. Helen Ghiradella was born, raised, and begun to relate light reflection and educated in New York City . to ultrastructure . She received her BA (biology major and languages minor) from City College of New York, MA with John Anderson Dr. Darrell Kemp completed his PhD in Invertebrate Zoology at Cornell in 2002 and is presently an Australian University, and PhD with James Case Research Council postdoctoral fellow, in Neurobiology at the University of situated at James Cook University California at Santa Barbara . After in tropical northern Australia . His is postdoctoral study with Kenneth David broadly interested in evolution and Roeder at Tufts University, she moved sexual selection, and his research to Albany . From initial studies in insect focuses on the evolution of male hearing and firefly flash control, her mating strategies and exaggerated research interests have gradually sexual traits . He uses field observation, migrated closer to questions of biological experimental manipulation and quantitative pattern formation and development and, genetics to test specific theoretical with the help of friends in engineering predictions using model biological and physics, biological materials . systems, particularly insects . His most recent research has sought to understand the adaptive signaling significance of Dr. Roger Hanlon holds B .S ., MSc exaggerated iridescent male coloration and PhD degrees in Biology and Marine in tropical butterflies . Sciences and did postdoctoral work at Cambridge University . He moved to the Marine Biological Laboratory Dr. Kevin McGraw’s research program at Woods Hole in 1995 after 20 years centers on the control and function of at the University of Texas Medical striking colors in birds, including both Branch (Professor and Division Chief pigmentary and structural forms . He and in the Marine Biomedical Institute) . his students conduct multi-disciplinary His research focuses on adaptive investigations of the honesty-reinforcing coloration and behavior in cephalopods mechanisms for avian color signals (i .e . (squid, cuttlefish, octopus) . Overall, diet, health, hormones) and the linked 130 peer–reviewed scientific papers sexual or social function served by such have been published on these and colors (i .e . mate choice, status signaling) . related subjects . Structural coloration Their work has concentrated mostly on

12 photo credit: Ton Rulkens

color control and communication been interested in the properties of in songbirds (especially finches and structural colors in bird plumage, and sparrows), but they have recently their meaning as signals . These colors expanded their studies to parrots, penguins, range from simple hues to brilliant ducks, and hummingbirds to understand iridescence, but they have found that how the mechanisms and functions of optically feathers are quite simple; their diverse colors compare to those they behave as more or less directional of well-studied passerine ornaments . interference reflectors, and can be One of Kevin’s main objectives at this characterised by a small number of conference is to encourage thought spectral measurements taken with a and discussion about whether or not purpose–built goniometer . iridescent coloration is biologically “special” and the extent to which Dr. Richard Prum is the William we should make unique ecological, Robertson Coe Professor of Ornithology, evolutionary, molecular, and physiological Ecology and Evolutionary Biology at predictions about iridescent coloration Yale University . compared to other types of color signals . Kevin is the faculty advisor of conference organizers Mike Butler, Lisa Taylor, Dr. Ronald Rutowski has worked for Matthew Toomey, and Melissa Meadows . over 30 years on both proximate and evolutionary aspects of mating behavior, Dr. Daniel Osorio works at the University vision, and visual signals in butterflies . of Sussex where he studies vision and Recent work in his lab has focused visual behaviour of animals including most intensely on iridescent coloration primates, birds and cephalopods . His in butterflies, the mechanisms that earliest research work was with Mike produce such coloration, and the Land on the role of structural colour in consequences of iridescence for its butterfly tapeta . More recently he has use as a signal in intra– and interspecific

photo credit: Tony Hisgett 13 14 photo credit (right corner clockwise: User:maxo, Benjamint444, Bob Peterson, Tony Hisgett, Bob Peterson, Bob Peterson

interactions . He is a professor at Arizona Doekele Stavenga studies Experimental State University, and is the faculty Physics at the University of Groningen, advisor of Nathan Morehouse, one of the Netherlands, where he has been the conference organizers . a professor of Biophysics since 1991 . Most of his research concerns the optics Dr. Matthew Shawkey completed his and physiology of insect eyes, but he Ph .D . in Geoff Hill’s lab in 2005, is has specifically focused on the spectral currently a post-doc in Steve Beissinger’s properties of butterfly vision . Recently lab and will begin work as an assistant his research has expanded to the optics professor of integrative biology at the of insect wings, especially butterflies . University of Akron in Spring 2008 . This entails analysis of the structure and He is broadly interested in the mechanics, reflectance spectra of single butterfly development and evolution of structural scales as well as the effect of scale (both iridescent and non-iridescent) stacks on the wing . He is furthermore plumage color . Most of his work focuses interested in unraveling the interplay on the two- and three-dimensional between insect colors and their color morphological basis of intra-and vision systems . inter-specific variation in structural plumage color and the broad-scale Dr. Peter Vukusic is a physicist leading evolution of structurally colored tissues . the work on natural photonics at the University of Exeter . Dr. Mohan Srinivasarao works at the School of Polymer Textile and Fiber Engineering and School of Chemistry and Biochemistry, Georgia Institute of Technology .

15 CONFERENCE ORGANIZERS

Mike Butler the importance of nitrogen limitation and (mike .butler@asu edu). received his bachelor’s female mate choice to the evolution of degrees in biology and physics from sexually dimorphic wing coloration in the Bowdoin College and his master’s degree Cabbage White butterfly, Pieris rapae . in raptor biology from Boise State He is also interested in the diversity of University . He is now in his second year optical mechanisms employed by animals in a doctoral program at Arizona State to generate bright color patterns . University under Dr . Kevin McGraw . Currently, his research focuses on Lisa Taylor immune function, carotenoid allocation, (lisa a. .taylor@asu .edu) studies sexual and coloration of mallard ducks during selection and coloration in Habronattus post–natal development . jumping spiders . Males of this genus are often highly ornamented with bright Melissa Meadows (sometimes iridescent) colors which they (melissa meadows@asu. .edu) holds a B .S . display for females in elaborate courtship in Marine Biology from the University of dances . The goal of her research is to North Carolina at Wilmington, but has understand how variation in male color since turned her attention to iridescent affects female choice, and ultimately, bird coloration . She is studying iridescent what a male’s colors might tell a female coloration as an honest signal of quality about his quality as a mate . in aggressive interactions and mate–choice, and is particularly interested in the Matthew Toomey information content that such signals (matthew .toomey@asu .edu) is a graduate may convey . She is taking advantage of of the University of Vermont and is Arizona State University’s large population currently pursuing a Ph .D . at Arizona of Anna’s hummingbirds, whose gorget State University . His research is focused feathers are pictured above, for this on the role of carotenoids in color vision work . Melissa is beginning her third and the evolution of colorful plumage in year as a doctoral student at ASU, birds . Matt is beginning his third year and is advised by Dr . Kevin McGraw . with advisor Dr . Kevin McGraw .

Nathan Morehouse (nmorehouse@asu edu). received a B .S . in Biological Sciences from Cornell University and is currently a doctoral candidate working with Dr . Ron Rutowski . He is interested interested in the selective pressures and nutrient dynamics underlying the evolution of bright coloration in animals . His work currently focuses on

16 17 ORAL PRESENTATION ABSTRACTS

the result of greener individuals in mate choice independently of Age-Related Differences in the having lower survival and/or nest train morphology . I am addressing Iridescent Plumage of Male Tree site fidelity . Indeed, relatively dull, questions about the function of Swallows: Hue and Brightness greener birds had a lower probability eyespot colouration in several Signal Different Aspects of of being recaptured the subsequent ways . First, I am testing the Individual Quality ± year . In contrast, we found that if hypothesis that peahens assess Pierre-Paul Bitton and Russell birds captured in their first year eyespot colour using an experimental D . Dawson, University of Northern as breeding adults were relatively approach in which I modify the British Columbia, Prince George, bright, color did not seem to eyespot signal . Second, I am testing British Columbia, Canada, influence subsequent recapture the possible signal content of the bittonp@unbc .ca probability . These results suggest iridescent plumage . To this end, I am examining relationships between Age-related differences in that plumage attributes in male measures of individual condition plumage characteristics of birds tree swallows have the potential and eyespot colour to test the have been relatively well researched of being honest signals of quality . hypothesis that the iridescent colour in carotenoid- and melanin-based Furthermore, plumage brightness is an honest signal of genetic quality . coloration but not for structurally and plumage hue might signal I am also looking at the nanostructural colored feathers . In this study, different aspects of male quality basis of the eyespot colour to test we investigated age-class related in this species . whether individual differences in differences in plumage attributes nanostructure are responsible for of male tree swallows (Tachycineta the observed variation in colour bicolor) which possess metallic Iridescent Eyespots and Sexual and in degree of iridescence, green to metallic blue iridescent Signaling in Peacocks which would suggest that the ± plumage on their dorsal surface . Roslyn Dakin , Department of eyespots signal information about Our results showed that, at the Biology, Queen’s University, Kingston, the individual during the process population level, older males were Ontario, Canada, of feather growth . Finally, I describe dakinr@biology .queensu .ca brighter and reflected light maximally the ways that peacocks exploit the at shorter wavelengths (i .e . were directionality of their eyespot signals The glittering plumage of the peacock bluer) . Differences in plumage during display . My results so far is one of nature’s most dazzling brightness were most likely caused indicate that peacocks are able to displays . Previously, it has been by changes within individuals as shown that peahens prefer to mate optimize their signaling effort by males increased in brightness with males that have longer trains orienting their trains towards the between the first time they were with a greater number of iridescent sun, for maximum eyespot reflectance captured and the subsequent eyespots . More recent studies of towards female targets, and that year . Differences in hue, however, captive peafowl indicate that the peacocks may use their display were not due to within individual complex structural colouration of dances to manipulate females to changes, but rather appear to be these eyespots might be important view them from the best angle .

18 predators . These field investigations corresponding economy of The Function of Iridescent and experimental manipulations information, for it seems that the Coloration in Birds: Insights involving satin bowerbirds, same developmental processes From Multiple Species wild turkeys, royal flycatchers, may get reworked to support Stephanie Doucet*, Department of and mallards demonstrate the vastly different functions in different Biological Sciences, University of importance of iridescent signaling places and in different organisms . Windsor, Windsor, Ontario, Canada, across distantly-related taxa . To illustrate this I will begin with sdoucet@uwindsor .ca Together with other studies, these a brief overview of what is known data suggest that multiple selective about development of unspecialized To date, research on the function forces have favored the evolution and of iridescent lepidopteran scales . of iridescence in birds has focused of iridescent plumage coloration I will then consider whether homologs on its potential role in mate choice . in birds . of this “developmental architecture” In particular, several studies have may form the underpinnings of other assessed the hypothesis that systems as diverse as the insect iridescent plumage coloration might tracheal system, the auditory sensilla serve as an honest indicator of Development of Iridescent of noctuids and other moths, the male quality . While this hypothesis Butterfly Scales: How to Make machinery that coordinates the is gaining increasing support, a Photonic Crystal...Or Two contraction of skeletal muscle fibrils further research is needed before Helen Ghiradella*, Department in response to the motor nerve any generalizations can be made . of Biology, State University of New impulse, and the bioluminescent Moreover, other possible hypotheses York, Albany, New York, “crystalloids” in the scales of for the function of iridescent plumage hghff@albany .edu polynoid scaleworms . If so, we remain virtually unexplored . may hope that understanding of Biological organisms use a limited Here, I use data from four species any of these will yield insights into to evaluate the possible role of set of materials to produce an the structure and development of iridescence in honest signaling, astonishing variety of complex the others . and. more . species recognition, mutual mate non-living structures . Moreover, choice, and defense against they may be doing this with a

19 Far Field Scattering Pattern Dynamic Iridescence and Nanostructural and Fourier of Differently Structured Single Passive White Reflection: Analysis of Dermal Iridophores Butterfly Scales Their Uses in Signaling and in Sceloporus Lizards with ± Marco A. Giraldo 1, Shinya Camouflage in Cephalopods Evolutionary Variation in Blue 2 Yoshioka , and Doekele G . Stavenga1, Roger T. Hanlon*, Lydia Mathger, Signaling Patches 1 2 1Department of Neorobiophysics, and Justin Marshall, Marine Diana K Hews , A . D . Leache , 3,2 1 University of Groningen, The Biological Laboratory, Woods Hole, M . D . Shawkey , D . J . Barnes , Netherlands, 2Graduate School Massachusetts, rhanlon@mbl .edu Indiana State University, Terre 2 of Frontier Biosciences, Osaka Haute, Indiana; University of University, Japan, m .a .giraldo@rug .nl Cephalopods mollusks possess California, Berkeley, California; extravagant, changeable skin 3University of Akron, Akron, Ohio, The wing scales of pierid butterflies that is used in a wide variety of dhews@isugw .indstate edu. are studded with beads, whose role behavioral functions . Speed of in the generation of color is twofold . change of skin patterns is on the We examined blue color production in Sceloporus lizard species that First, they scatter light incoherently, order of <1 second for pigmented vary in occurrence of blue abdominal proportionally to the density of beads chromatophore organs, and 1-5 skin patches, an ancestral trait for and, second, they store pigment seconds for iridophores (structural the genus used in social signaling . that absorbs light in a restricted reflectors) in vivo . Squids and Histological work (Quinn & Hews wavelength range . We studied six cuttlefish produce conspicuous 2003) supports the hypothesis that species of butterflies . The angular iridescence and bright whiteness white skin results when melanin reflectances of single scales were during agonistic displays, some underlying an iridophore layer is aspects of courtship, mate guarding, measured and compared with their reduced; wavelengths not initially and predator escape . These will anatomy . Light scattered by beaded scattered by the iridophore layer be explained and illustrated with scales of Pierids follows Lambert’s are reflected by an underlying underwater video . Whiteness is cosine law . Multilayered scales of reflective collagen layer . Here, produced by physiologically Morphos, however, scatter light we assessed other potential passive leucophore cells lying anisotropically . They show a mechanisms contributing to subjacent to chromatophores characteristic linear pattern that species differences in abdominal and iridophores, and is only visible is perpendicular to the ridges . color, evaluating nanostructure when overlying chromatophores are Scales of the silverspot butterfly, of iridophores in TEMs in males retracted . White spots and other Dione juno, have an almost featureless of blue- and of white-bellied species . signaling markings can be dynamically upper surface . The windows, spaces We tested the hypotheses that the enhanced by expansion of adjacent limited by ridges and crossribs, species differed in guanine platelet: dark chromatophores . Dynamic are closed by unpigmented chitin 1) thickness; 2) spacing (interplatelet camouflage is also produced with gap); 3) orientation; or 4) number of layers that work as a mirror to the aid of multi-colored iridescence layers (c .f . Morrison 1995) . Only incident light . A very interesting and whiteness, both of which mean platelet gap differed, and case is the purple tip butterfly, complement the short-wavelength was significantly greater (P < 0 .047) Colotis regina . The purple areas chromatophores . Sophisticated in the white species . Individual at the tip of the dorsal wings are camouflage on a wide variety variance in mean values (as composed by cover and ground of visual backgrounds will be assessed in 10 TEM transects scales . Ground scales have beads illustrated . Polarized light reflected per male) also did not differ that selectively absorb light of from iridophores can be passed significantly . Strengths of trait short and medium wavelengths, through the chromatophores, thus correlations differed between causing the scattered light to be enabling the possible use of a species; the white-bellied species red . Cover scales are multilayered hidden communication channel, (with evolutionary loss of blue and beaded resulting in both because cephalopods can perceive color) had a larger number of weak diffuser- and morpho-like effects . polarized light . correlations (r < 0 .5), consistent

20 with relaxed selection on iridphore objects are perfect tools for features . Fourier analysis of TEMs Seeing Is Believing: Using capturing the imagination of revealed that iridophore platelets Color to Capture the Imagination students and provide natural of both species were sufficiently of Students in the Classroom entry into many scientific topics . and Online organized and at the correct scale Two award winning web sites will Charles Kazilek, School of Life be presented as examples of how to produce color by coherent light Sciences, Arizona State University color can be introduced online and scattering alone . Subsequent into the classroom . Ask-a-Biologist radial analyses incorporating Reaching students and educators and the Paper Project both have estimated refractive indices of in the classroom has never been content on color designed for guanine and cytoplasm created more important for the sciences . students and teachers in grades predicted reflectance spectra One of the best ways to engage K-12 . Both sites are long-running that matched actual spectra in students and teachers is visually and award winning examples the blue species but not in the and in particularly using color . of how to take basic science white, suggesting that melanin The amazing color images and imbed it into colorful is essential for color production . from iridescence and florescent classroom activities .

21 females, theory predicts greater sex differences in the absolute degree of trait expression (i .e ,. greater levels of sexual dimorphism) . In this talk I discuss these factors refractive mediums and their The Evolution of Structural in relation to structural coloration, nanostructural anatomy and Coloration in Butterflies: Sexual drawing upon recent empirical organization, thin film modeling Selection, Sexual Dimorphism behavioral and quantitative genetic may be used to predict the light and Condition-Dependence research in two model butterfly behavior and thus infer on what Darrell J. Kemp*, School of Marine species, Colias eurytheme and characteristics are important for and Tropical Biology, James Cook Eurema hecabe . color production, revealing the University, Australia, email: darrell . proximate mechanisms of visual kemp@jcu .edu .au signaling . We conducted transmission electron microscopy on the feather Mechanisms of Iridescent Models for the evolution of signals barbules of 10 male blue-black Structural Color Production as honest indicators of mate quality grassquits (Volatinia jacarina), in Blue-Black Grassquit predict that the expression of such which exhibit a UV-reflecting Feather Barbs signals should be costly and depend ± iridescent plumage, in order to Rafael Maia , João Victor O . Caetano, upon the condition of the bearer . characterize the nanostructural Sônia Nair Báo, and Regina H . F . Such condition-dependence is components involved in color Macedo, Universidade de Brasília, thought to evolve as a form of production . From each barbule, Brazil, rafaelmaia@unb .br phenotypic plasticity, whereby we measured keratin cortex individuals respond to their Structural colors are produced and outer melanin layer thickness, environment (e .g ., the amount through interference of differentially number of melanin granules in of available resources) in order the melanin layer, and diameter reflected wavelengths, and are to optimize the trade-off between of these granules (melanin layer a component of the visual viability and reproduction . Because thickness divided by the number communication system of many male sexual traits are more closely of granules) . We found that blue-black animal taxa . Bird plumage may linked to reproductive success grassquit barbules display a 138 .9 produce iridescent colors due to than non-sexual traits, they ± 19 9. nm thick melanin cortex, the superposition of layers with are predicted to display stronger followed by a 407 7. ± 119 .6 nm different refractive index, such as condition-dependence . Furthermore, melanin layer formed by 2 .4 ± 0 .3 keratin and melanin layers . Given where analogous traits are seen in melanin granules 172 .2 ± 37 .1nm in the optical properties of these

22 diameter (all mean ± sd) . The model act as filters to the underlying decades, but, compared to mechanistic that best predicted the reflectance reflector cells . Iridophores act and functional lines of investigation, spectra considers only air/keratin as multilayer reflectors, whereas macroevolutionary comparative and keratin/melanin interfaces, and leucophores appear to be perfect studies are lacking . Here I review the thickness of the keratin layer . diffusers, appearing equally bright taxonomic variation in the production These results are in accordance from all angles of view . Recent and display of iridescent coloration with the growing knowledge of advances in technology have in birds . First, I use published structural color production by enabled us to take the spectrometer literature and meta-analytical avian feathers, and indicate that equipment underwater, enabling us techniques to test the prediction the nanostructural characteristics to take measurements of cephalopods that avian iridescent colors are of male blue-black grassquit (Sepia apama, South Australia) dependent upon the condition of barbules can account for its in their natural habitats . We show individuals and thus could serve coloration characteristics . that while the colors of certain as honest advertisements . Second, body parts are well suited to match I will track phylogenetic variability the colors of their surroundings, in iridescent coloration and other body parts are conspicuous, examine dietary, life-history, and Mechanisms of Cephalopod suggesting involvement in morphological (i .e . body location) Structural Coloration: Field visual signaling . predictors of interspecific variation and Laboratory Data in avian iridescence . These data Lydia Mathger, Justin Marshall, will be compared to similar, and Roger Hanlon, Marine recent studies of pigment-based Biological Laboratory, Woods Interspecific Variation in (i .e . carotenoid, melanin) color Hole, Massachusetts, Avian Iridescent Coloration: ornaments in birds to evaluate lmathger@mbl .edu Ecological, Morphological, the likelihood with which different Phylogenetic, and Quality- selective pressures have acted Color change in cephalopods Signaling Predictors on feather iridescence . (squid, cuttlefish and octopus) is Kevin J. McGraw*, School of Life unrivaled in the animal kingdom . Sciences, Arizona State University, Their sophisticated skin containing Kevin .McGraw@asu .edu pigmented chromatophore organs, structurally reflecting iridophores Our understanding of both proximate and light scattering leucophores and ultimate causes of variation in gives these animals an ability to iridescent coloration in animals almost instantaneously change has improved dramatically in recent body patterns for camouflage and signaling, despite their apparent color-blindness . Here we present data on the structures that are involved in cephalopod color change: chromatophores, iridophores and leucophores . In the laboratory, we can measure the spectral reflectance of each of these structures and by varying the angle of observation and angle of incident illumination, we can make inferences regarding their optical mechanisms . Chromatophores do not produce color by structural coloration; they are pigmented organs that

23 of red ommochrome pigments and iridescent blue coloration in this Diverse Color Production black melanin pigments within the mimicry complex belies a striking Mechanisms are Responsible wing scales . Here, we present a diversity of underlying color for Convergent Blue Structural mimicry complex where one part production mechanisms . Coloration in a Butterfly of the aposematic color pattern Mimicry Complex is an iridescent blue produced via 1 Nathan I. Morehouse , Marco structural mechanisms: the Batesian 2 1 Measurement and Meaning of A . Giraldo , Ron L . Rutowski and mimicry complex surrounding the 2 1 Iridescence in Bird Plumage Doekele G . Stavenga , School of Pipevine Swallowtail, Battus philenor . Daniel Osorio*, School of Life Life Sciences, Arizona State University, While diffusely-reflecting color 2 Sciences, University of Sussex, Department of Neurobiophysics, elements of this aposematic Brighton, United Kingdom, University of Groningen, pattern are likely to be produced d .osorio@sussex .ac uk. The Netherlands by pigments common to all species in the mimetic complex Examples of convergent evolution As colours flash from black to brilliant (e .g . melanins, ommochromes), of animal coloration are commonplace, but changing hues, iridescence catches the mechanisms producing blue the eye by breaking the rules that particularly in the study of mimicry, coloration in models and mimics govern commonplace materials, where visual cues have played a are uncertain given the diversity of and this is why birds have iridescent central role in our understanding known mechanisms that generate courtship displays . Biologists ask of how and why mimicry evolves . iridescent blue within the represented if the purpose is simply to attract attention, or if iridescent plumage can transmit information about the qualities of a potential mate . To answer these questions we need measurements to describe the brilliance of a hummingbird or bird of paradise: how colours change as they move and how they may be seen in display . Iridescent plumage is remarkable for the purity of the colours, its blackness, and its directionality, but we can capture these properties with a few simple geometrical measurements of reflected light . Measurements imply near crystalline order in the nanostructure of black pigment and air embedded in feather protein, but they show that However, in many of the species butterfly taxa . Using transmission and scanning electron microscopy, feathers work as tuned mirrors seems, studied thus far, the underlying spectrophotometry of intact which lack the 3-dimensional color-producing mechanisms wings and single wing scales, complexity of insect cuticles . involved in color mimicry traits and mathematical modeling, we To conclude I will compare the are similar if not identical . For reveal at least three distinct iridescence plumage of individuals instance, the color patterns of the optical mechanisms from five within a species - the magnificent classic Müllerian mimics the Monarch species in this mimicry complex frigate bird - and ask how iridescent (Danaus plexippus) and the Viceroy that generate the blue component plumage might complement the (Limenitis archippus) are produced of the color signal . Our work thus colour, sounds and movement in in both species by the deposition reveals that the convergence in their courtship .

24 complex fluids. Although, the specifics bandgap analysis on a variety of Optimality of Triply Periodic of the developmental mechanisms these iridescent structures and Iridescent Structures remain to be determined it is fruitful compare the degree of global Leon Poladian, Maryanne C .J . to explore to types of structures and local iridescence and how it Large, and Michelle Rigozzi, that minimise interfacial energy . might vary with numerical aperture . University of Sydney, Australia, Thus we used the Landau theory We also explore the optimality leonp@maths .usyd .edu au. of phase transitions, to investigate of these structures as we vary the diversity of such structures . the volume fraction of the solid At least five species of butterfly Phenomenological free energy and air phases . are now known to possess functions and their corresponding three dimensional periodic phase diagrams are derived for microstructures, however the transitions between structural Evolutionary Photonics: The Interface of Optics, specific geometry and topology phases previously unexplored of the microstructure remains Phylogenetics, Biochemistry, with his method . This study is ambiguous . Two of the several Development, and Behavior then complemented by an optical proposed structures are: the Richard O. Prum*, Department analys is of the stable structures diamond (D) which is a four-fold of Ecology and Evolutionary found in the phase transition coordinated structure on a face- Biology, Yale University, New analysis . We perform a photonic centred cubic lattice; and the gyroid Haven, Connecticut, Richard . (G) which is a three-fold coordinated prum@yale edu. structure on a body-centred cubic lattice . In other organisms, a six-fold Photonic structures are classified coordinated P structure on a simple according to whether they exhibit cubic lattice has also been observed . 1D, 2D, or 3D periodicity . These Is it a coincidence that these three classifications have not considered structures are the three most common whether nanoorder is on the scale and simplest triply periodic minimal of many scatterers or limited to surfaces (TPMS)? These structures local scales . Local order produces and their lower dimensional coun- quasi-ordered materials that are terparts show a striking resemblance common in biological systems to structural phases that appear in and present new challenges for

25 physical analysis . Traditionally, we still know relatively little about the evolution of structurally colored biologists have accepted the the development of color producing anatomical systems should be standard optical classifications nanostructures . There are two informed by these systems are self of the mechanism of color production, alternative mechanisms– self assembled or cellularly assembled . But these optical concepts are assembly and “cellular” assembly . effected by the intellectual history Self assembly includes physical of physics and the mathematics and biochemical processes in Photo-Real Rendering of Iridescence From Thin Films of analysis . The traditional optical which the nanostructure results in Insects classification creates problems from the ordered interactions of Mark J. Prusten, Silicon Arts, Tucson, for evolutionary analysis by the materials themselves . Cellular Arizona, photondyn@silicon-art .com obfuscating the fundamental assembly include more complex physical commonalities shared physiological mechanisms of Iridescence is found in terrestrial among different coherently scattering living cells . Examples of cellular animals, and is most highly developed anatomies . Comparative work mechanisms include butterfly wing in two groups, insects and birds . on the evolution of structural colors scales, beetle cuticles, and likely Perhaps not coincidentally, these in birds and butterflies document keratin/melanosome arrays in classes also exhibit well developed that many color producing iridescent feather barbules . TEM visual systems, and protean nanostructures have evolved images of the development of the body coverings . In insects, such across the boundaries within the spongy medullary β-keratin in blue colors are often considered as traditional optics tool box, defying macaw bird feathers indicate that anti-predator adaptations, either the traditional notions of optical this material is a self assembled crypsis or aposematism, or a mechanism . With few exceptions, nanostructure . Future discussion of means of thermoregulation . This paper presents the modeling and development on High Dynamic Range Images, HDRI, Photo-real shaders for simulating the optical characteristics of the surfaces of both winged insects like butterflies and moths and non-winged insects such as beetles . The shader will simulate the thin film structure of the scales on butterflies . These Iridescent scales are visually stunning structures that reflect highly saturated color . They also create an array of non-chromatic optical phenomena, such as polarization, polarization mixing and highly directional flashes .

26 The influence of sub-surface directional properties and the signals? What aspects of sender scattering, global illumination, therefore restrictive set of geometries behavior and the reflecting structures final gathering and spectral of light source, sender and receiver enhance signal perception by rendering and the influence of that allow for maximal transmission, receivers? These and other issues motion blur or movement created iridescent colors present a special will be discussed to provide a flashes will be presented for a challenge when used as communicatory framework for thinking about how variety of these insects . The signals . Poulton (1890) was one iridescent signals are described simulation of the polarized light of the first to point out this issue and measured in behaviorally and and the interaction of the insects and proposed that iridescent ecologically relevant ways . with classic lighting setup will signalers should behave in ways be reviewed were the illumination that enhance signal transmission . varies greatly in spectrum In particular, the expectation is A Physically Based and intensity . that the behavior of the senders Anisotropic Iridescence of iridescent signals will have Model for Rendering Morpho evolved to enhance the perception Butterflies Photo-Realistically of the signal in those behavioral Measurement of Iridescent Iman Sadeghi, University of Signals Informed by Behavior and ecological circumstances in California- San Diego, La Jolla, and Ecology which it is typically or most likely California, sadeghi@gmail .com Ronald Rutowski*, School of Life to be displayed . There have been Sciences, Arizona State University, few efforts to test this expectation, Rendering the brilliant iridescent r .rutowski@asu edu. but these considerations have colors of the Morpho butterflies important implications for how we has been a challenge in computer A recurrent hypothesis about animal measure and describe iridescent graphics . The cause of vivid blue communication is that communicatory signals and their production and color of the wings of these species behavior and signals should be for inferring what might be the is not as the result of the pigments adapted to enhance reception of salient features of such signals . of the wing . They are caused by the signal by intended receivers . What are the relevant features of the physical microscopic structures Because of their often highly the ambient lighting for iridescent on the scales of the wing . These

27 micro-structures has been studied models; Multi-layer thin film extensively in various fields by model [Yinlong Sun . 2006] and Lack of Plumage Ultraviolet different expertise . Modeling these separate lamellae model Status Signaling in Blueblack micro-structures on a computer, [S KINOSHITA. et al . 2002] . Grassquits (Volatinia Jacarina) ± if not impossible, would require Both of those models fail to Eduardo S. A. Santos , Regina H . F . Macedo, Universidade de huge amount of data storage, describe the anisotropic nature Brasília, Brazil, e .salves@gmail .com computing power and complex of the light reflectance on these access mechanisms . Therefore, structures . The introduced model in Plumage patches that reflect rendering the appearance of these this paper produces an anisotropic ultraviolet (UV) coloration may be butterflies requires developing model with interpolating between important signals in mate choice . simplified, yet accurate, models those two isotropic models . The However, few studies have tested which demonstrate the behavior model is based on the physical if this function also occurs in of their micro-structures in different properties and analytical derivations male-male competition . In the lighting conditions . In this paper of the microscopic structures blue-black grassquit (Volatinia I have addressed the problem of of on the scales of the wings . jacarina), both the blue-black rendering the anisotropic iridescence Rendered images with this model and white plumage coloration of colors of the Morpho butterflies match the experimental description males reflect UV . Previous studies photorealistically . The developed [Fox 1976; Simon 1971] of have demonstrated that the blue- model is physically based and iridescence properties of the black coloration is associated with combines two previously presented Morpho butterflies . male body condition, and also, less

28 parasitized males present brighter toward a smaller role of UV coloration reflectance . We tested the possibility in intra-sexual as compared to From Flight to Bright – How that UV coloration of male plumage inter-sexual communication . Qualcomm’s Inspired by is associated with status signalling Nature Technology has Kept in competition for resources . Mobile Phones Powered Up We conducted experimental Cheryl Schwarzman, Iridescent and UV Wing Signals manipulations using an artificial Qualcomm, Inc . in a Tropical Helicopter food source to produce agonistic San Diego, California, Damselfly encounters among males, and took cschwarz@qualcomm com. Tom D. Schultz1 and Ola M . spectrophotometric measurements Fincke2, 1Department of Biology, of the blue-black rump and wing mirasol ™ displays are a technology Denison University, Granville, Ohio, coverts and white under-wing patch . breakthrough that promise 2Department of Zoology, University Four indices were calculated to substantial performance benefits of Oklahoma, Norman, Oklahoma, describe the variation in the over competing display technologies . schultz@denison .edu blue-black and white coloration: The reflective displays, based on brightness, as the sum of reflectance Interferometric Modulation (IMOD) The tropical damselfly Megaloprepus between 320 and 700 nm; hue, technology, require no backlighting caerulescens exhibits sexually as the wavelength of maximum dimorphic wing patterns that reflectance; intensity, as the maximum reflectance reached; are likely play a role in and UV chroma, as the sum of courtship and territorial reflectance between 320 and 400 nm, defense . Both sexes divided by the sum of reflectance exhibit white and between 320 and 700 nm . We found violet patches on no significant effect of the measured the tips of their indices of UV reflectance of the transparent wings, three color patches on the dominance but in reverse position . of male blue-black grassquits . To date, Translucent white there are very few studies reporting on the role of UV coloration in patches are pigmentary, signalling within the context of but the violet color of the photo credit Lisa Taylor male-male interactions . However, non-transmissive bands arises the first evidences seem to point from thin-layer interference and and can be viewed in bright sunlight a stack of 12-14 epicuticular and in a wide range of environments . layers on either side of the wing Moreover, these displays offer plane . Both patches reflect a significant reduction in power wavelengths between 325 and consumption as compared to other 400 nm when the viewing angle display technologies, while extending device battery life and enabling new is normal to the wing surface, features . mirasol ™ displays work however, the iridescence and by reflecting light so that specific UV reflectance of the dark patches wavelengths interfere with each are extinguished at angles of 45 other to create pure, vivid colors . degrees or less . With the changing The phenomenon that makes a wing angle during the stroke cycle butterfly’s wings shimmer is the these wing reflectors would provide same process that gives mirasol a flashing UV signal that may be displays their color . mirasol ™ used to distinguish male from displays will enable an optimum female damselflies . user experience for consumers who

29 demand more from their wireless similarities between many iridescent devices . Qualcomm MEMS taxa suggest that diffraction Technologies, Inc . currently has gratings fulfill one or more shared locations in San Diego, California, functions across multiple lineages San Jose, California, and of Coleoptera . Hsinchu, Taiwan .

Levels of Organization as a Spectral Iridescence in Framework for Examining the tissues while non-iridescent colors Coleoptera: The Evolution Mechanics and Evolution of can be created by both organized Bio-Optical Tissues and Function of Beetle and unorganized tissues . Evolutionary Diffraction Gratings Matthew Shawkey*, Department ± transitions between non-iridescent Ainsley E. Seago , University of of Biology, University of Akron, Akron, and iridescent colors in the grackles California, Berkeley, California, Ohio, mshawkey@nature .berkeley .edu and allies (Family Icteridae) and in seago@nature .berkeley .edu Structures are composed of materials hummingbirds (Family Trochilidae) Insect colors have long been organized in from zero to three occur when tissues shift between classified into two categories: dimensions . Organization imparts unorganized and organized forms . pigmentary and structural, with properties to materials that they However, the colors of these two the latter most commonly exemplified would not have otherwise; a groups are dramatically different . by “iridescent” colors arising from structure made of given materials These differences are probably multilayer thin-film reflectors . arranged in an unorganized way caused by phylogenetic and True spectral iridescence, which will have different properties than physiological constraints and the arises from diffraction gratings one made of the same materials functions that these colors serve . at the surface of the integument, arranged in an organized way . Grackles lack the elongated and has traditionally been considered Similarly, the consistency of sometimes hollow melanin granules a rarity among beetles . A survey that organization will affect the present in hummingbird feathers of U S. . collections indicates that structures’ properties; a one- that may create brighter and more this structural color mechanism dimensionally organized object saturated iridescent colors . Wild is in fact far more widespread will have different properties than turkeys Melleagris gallopavo and than previously suspected; recent a three dimensionally organized other species arrange similar hollow phylogenetic analyses of Coleoptera object . Colors of feathers can be melanin granules in two dimensions provide a conservative preliminary created either by unorganized or to create bright iridescent color . estimate of twelve independent origins organized tissues composed of Three dimensionally arranged of diffraction gratings in this order . keratin, air and pigments . Iridescent structures, by contrast, may Ecological and morphological colors are created solely by organized create non-iridescent color .

30 Electron tomography and three entertainment sources opportunities dimensional fourier data suggest Usefulness of Iridescence as a to foster student-based wonder is th at non-iridescent “spongy” Learning Progression Theme not readily accomplished . Moreover, structural tissue is organized at Through K-12 Science Education the need to link state standards with the same spatial scale in all three Jan Snyder, National Science every lesson means that educators dimensions . This consistency may Foundation GK-12 Program must balance studentinterest with explain why the colors created by Coordinator, Arizona State University state-determined policy . Color it, unlike those created by one provides a natural opportunity and two dimensionally organized An important factor that leads to to incorporate these two issues tissues, do not change with angle successful outcomes for science such that science lessons can of viewing . Interestingly, evolutionary education is the ability to instill tap student interest and personal transitions between 3D organized a sense of wonder in students . experience with state requirements tissues and other organized tissues Students of all ages, ethnicities, meant to meet regulations now in may be relatively rare . Levels of and both genders, can be more force due to the N .C .L .B . Act . Students organization thus provide an readily hooked on science if they have seen rainbows, but so have excellent framework for examining are able to develop a personal they witnessed the iridescence mechanisms and evolution of sense of wonder . With competition associated with bird feathers, bio-optical tissue . educators experience from ongoing some fish in an aquarium (thought

31 photo credit Nathan Morehouse

not as common as with terrestrial presence of “thin film structures” . qualities, are measured together, systems), wings of butterflies, flies Since then, much progress has among other things . In order to and beetles . The students’ familiarity been made and it is now recognized avoid such complications, one must with these phenomena can be readily that many of these brilliant perform the necessary optical associated with inquiry-based, and colors are due to various kinds of measurements on single individual standards aligned, K-12 science microstructures present on butterfly wing scales . There have been a lessons . Furthermore, the strands wing scale . In other words, the few measurements of the optical upon which these lessons can be colors are produced by periodic properties of individual wing based offer means for district or structures of cuticle-air that mimic scales; however, such studies are school-level curriculum designers photonic crystals . These structural quite sparse . Hence we have to incorporate learning progressions colors can include deep blacks, embarked on a systematic study throughout grade levels they serve . reds, oranges and greens, as well of the optics of individual wing With the involvement of learning as the more common blues, violets, scales . To characterize the angular progressions, as illustrated in ultraviolets, and whites . Typically dependence of the individual wing the AAAS, Project 2061, Atlas of these colors appear metallic due to scales we used a goniometer with Science Literacy (Volumes 1 and 2), the saturation or the purity of the the ability to rotate in all three teachers and curriculum planners colors produced . There have been directions . A single Morpho butterfly can more effectively promote a number of reports where the “color” scale was mounted at the tip and continued development of students’ of large areas of the butterfly of carefully centered with its long axis concept formation as they avoid interest has been studied . Such parallel or perpendicular to incoming use of redundant topics and lessons measurements are subject to a light . The illumination was a white from one year to the next . number of inconsistencies due to light source and the reflected light the fact that the precise a lignment of was collected via two reflective the scales for different measurements lenses, equipped with fiber optic may be difficult and that multiple leads, which was connected to Color on Wings: Optics scale types, with different optical a spectrophotometer providing the of Individual Wing Scales Mohan Srinivasarao*, School of Polymer, Textile and Fiber Engineering and School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, mohan@ptfe .gatech .edu

The beautiful iridescent colors found on the wings of butterflies have attracted the attention of brilliant minds over the past centuries starting with Newton, who understood that these colors must be due to the

32 reflection/transmission as a function butterflies appears to be quite photonic-crystalperiod in the grain of wavelength . By rotating the scale different . The intense, short-wave (amorphous structure) . These in this setup we were able to study length iridescence of many blues various levels of disorder can be the reflectance and transmission is caused by multilayers with quantified by the grain size, the as a function of angle and compare variable-sized holes in the scale coherence length of the structure . those results to the measurements body . It is an interesting question The visual effect produced by in a microspectrometer connected whether the wing coloration of structures with different coherence to a microscope . In this talk we butterflies is related to the spectral lengths include iridescence, metallic will discuss the results of our characteristics of their visual system . colour lacking iridescence, dull measurements of individual wing colours and whites . Exemples of scale reflectance including the photo credit: Tony Hisgett polarization dependence . Dosing Disorder: A Classification of the Visual Effects Developed by Weevils Iridescence and the Coloration Jean Pol Vigneron, Victoria of Butterfly Wings Welch, and Marie Rassart, Doekele Stavenga*, Department University of Namur, Belgium, of Neurobiophysics, University jean-pol vigneron@fundp. .ac .be of Groningen, the Netherlands, d g. .stavenga@rug .nl Photonic structures which appear on living organisms are not perfect . Iridescence, mediated by However, contrasting the usual multilayer interference, is a engineer’s feeling, these imperfections widespread phenomenon among are not the result of unreliable insects encountered, for instance, in fabrication processes, but qualities the cuticle of beetles and damselflies, that are maintained throughout in the corneal facetlenses of horseflies, evolution at each generation in in the wing scales of butterflies, and the species population . These weevils which present this wide also in the tapetal reflectors of moth imperfections can then be considered range of coherence lengths and and butterfly eyes . In my presentation to be part of the optimized visual effects will be presented I will specifically focus on the various diffuse-reflection optical device . and commented . coloration principles that butterflies The family of weevils known as employ: incoherent scattering, Curculionidae provides good multilayer iridescence, and/or examples: many of the species in Bringing Microwaves to Natural photonic crystals . A comparative this family are coloured by scales Photonics: The Novel Use of survey of wing coloration of pierid which contain a three-dimensional Extra UV-VIS-IR Radiation in the butterflies, using UV photography photonic crystal . However, these Characterization of an Insect and reflectance spectrophotometry, photonic structures are usually Broadband Reflector reveals that many pierids display divided in domains, so that the Pete Vukusic* School of Physics, a distinct sexual dichromatism, which contents of the scale is better University of Exeter, Exeter, United can be related to the phylogeny . described as a photonic polycrystal Kingdom, P .Vukusic@exeter .ac .uk The optical basis of the wing colors than a monocrystal : each grain of pierids can be well explained in the polycrystal is cut from a The photonic function of animal from the structuring and stacking highly ordered photonic crystal ultrastructure is difficult to measure of the scales . While pigment granules (short-range order), but the orientation unambiguously . This is invariably cause a diffuse coloration, the of the different grains varies across due to the often significant variation directional iridescence of pierid the scale (long-range disorder) . in alignments of juxtaposed wing-borne scales is due to multilayered scale The size of the domains ranges or integument-based colour centres . ridges . The optics of the scales from the full size of the scale It is also complicated further by the and wing coloration of lycaenid (monocrystal) to the size of the presence of secondary ultrastructural

33 or pigmentary components which the optical interaction of original constituent pigmentary or light themselves exhibit elastic or inelastic nanoscale animal samples . By scattering material that is used . scattering . Experimental manipulation using appropriately fabricated In this sense, a strong connection and characterisation of individual models and centimetre wavelength between visual art and the natural colour centres, such as single radiation sources therefore, better world is unmistakable . Colour, lepidopteran scales, is possible in understanding of the photonic shade and pattern are created some cases and this improves the function of animal ultrastructure and controlled for a specific becomes accessible . The technique biological or aesthetic effect . For has been applied in this instance over a decade, the global cosmetics to the characterisation of a company L’Oreal have funded previously unstudied insect a dynamic interaction between broad-band reflector . When used science and art by awarding its concurrently with conventional International Art and Science of analysis techniques, it has provided Color Prize annually . It is given to much clearer evidence about the artists or scientists in recognition true nature of the way in which for their work and achievements light interacts with the insect’s on the theme of understanding ultra-structure . color and its fundamental link between art and science . It was recently awarded to Pete Vukusic, the plenary speaker, for his School of Life Sciences Seminar research into the field of animal and Plenary: From Morpho to colours, specifically the category Seurat: Insect Colour Reflections on a Entry to the L’oreal Art And of colour that is generated when Science of Colour Competition light interacts with microscopic Pete Vukusic*, School of Physics, structures on or in animal surfaces . University of Exeter, United Kingdom, This is referred to as structural P .Vukusic@exeter .ac .uk colour and has profound importance to many fields of science and to The living world is awash with color many different technologies . This, costumes that are arranged in the science of structural colour in innumerable shades, patterns and the living world, and its applicability hues . The vast majority have one and relevance to art, is the subject quality of optical data, but it fundamental objective in common; of this lecture . nonetheless has distinct limitations . namely, they dictate the quality To this end, we have developed a and quantity of light that enters Iridescence of Rock Dove’s technique with which it is possible the eye of the beholder . This ability Neck Feather to make much more highly precise to control light has been central Shinya Yoshioka, Eri Nakamura, and experimental measurements of to the evolution of many species, Shuichi Kinoshita, Graduate School of the photonic effect of isolated and studies of bright coloration Frontier Biosciences, Osaka University, nanoscale animal ultrastructure . have been critical in elucidating Japan, syoshi@fbs .osaka-u .ac .jp This comprises manufacture key evolutionary processes for of 3D models of animal many decades . Through history, art Iridescence is observed in various ultrastructure at appropriately and artists have also relied on the kinds of animals that utilize scaled-up dimensions and a ability to control colour, shade and optical interference phenomenon measurement of the way in which pattern . The varied representation of microstructures to produce these reconstructed models interact of objects and scenes in works of their brilliant colors . In general, the with microwave frequency radiation . art is underpinned by the optical iridescence appears owing to the This interaction is analogous to properties and signatures of each interference condition that relates

34 the wavelength of the reflected mechanism - thin-layer interference . have constructed a simple optical light with the angle of view or The peculiarity lies in the fact system, which can modulate the incidence . However, the neck that the higher-order interference spectrum of white light to have feather of rock dove has a very condition is satisfied . This causes an arbitrary spectral line shape, in peculiar iridescence: the color the sophisticated correspondence order to further investigate optical change is limited only in two colors, in the spectral line shape between and visual effects of thin-layer green and purple, and the change the reflectance and the visual interference . It is found that the occurs very suddenly by only color sensitivities of human eye, thickness of the thin layer found slightly shifting the viewing angle . and results in the two-color in the rock dove’s feather is very We have performed microscopic and nature of the iridescence . The optimized to cause the two-color optical measurements to clarify the correspondence can be also seen nature of the iridescence . origin of this peculiar iridescence . with the absorption maximum of It is found that it is produced by the visual pigments in the rock the surprisingly simple physical dove’s vision . In addition, we

35 photo credit: Dario Sanches Poster ABSTRACTS

of Chrysina gloriosa towards 4 made initial flights significantly Chrysina Gloriosa May different light stimuli: linearly more often towards controls Differentiate Between polarized, unpolarized, and right (linearly or unpolarized light) than Circularly, Linearly, and and left circularly polarized light . towards either of the two circularly Unpolarized Light We tested 27 individuals, placed in polarized stimuli (mean proportion ± Parrish Brady , John Abbott, and the center of a 20”x20”x13” choice flights towards control = 0 .58; mean Molly Cummings, University of Tex- chamber with 1 .5” x 1 .5” slits on proportion to left circularly polarized as at Austin, Austin, Texas, each of 3 sides for light presentation . = 0 .23; and right = 0 .18), suggesting scorpionjeger@hotmail com. For each trial, the initial flight that circular polarization provides direction estimate of the beetle a weaker stimulus than linearly or Iridescent cuticles of beetles from was recorded . We alternated filter unpolarized light . Cotrary to our the genus Chrysina are one of positions between trials and tested expectations, beetles displayed the few naturally occurring sources each beetle with two different little preference between right of left circularly polarized light . or left circularly polarized light . We hypothesize that Chrysina filter setups . We found significant Controlling for slight variations can perceive circularly polarized differences in flight orientation in differential flux and determining light differently from unpolarized (F = 23 .4, p <0 .0001) between light, possibly allowing beetles to circularly and linearly polarized the perceived light intensity of detect each other while remaining light, as well as between circularly the various polarizations are camouflaged from predators . We polarized and unpolarized light important next steps in tested differential flight orientation (F = 26 .3, p < 0 .0001 ). Beetles understanding this system .

Optics of Individual Wing Scales of a Blue Morpho: Angle Dependent Polarized Reflectance ± Matija Crne , Saroja Malladi, Vivek Sharma, Jung Ok Park, and Mohan Srinivasrao, Georgia Institute of Technology, Atlanta, Georgia, matija .crne@chemistry .gatech .edu

It is well known, that the color on butterfly scales can be generated in the absence of chromophores . Instead, the spectral characteristics of many butterfly wings are determined by the structure of the scales that comprise the wings . By looking at the butterfly wing of the Morpho butterflies and tilting them, an angular dependence of photo credit: Dick Daniels 36 photo credit: Amada44

reflectance is clearly observed . on the reflectance . The characteristic species examined were gold (silvery In our work we characterized this peak in the reflectance red-shifts yellow) and brown-red colored phenomenon using a single scale in comparison to a 90 degree C. aurigans and the silver (silver-pale mounted in a microspectrometer . back-reflectance measurement on blue) C. chrysargyrea . While all of To characterize the angular a microscope connected to the the beetles examined exhibit dependence of the individual wing microspectrophotometer . The both metallic and pale colors, we scales, we used a goniometer with polarized spectra show a pronounced examined only the pale coloration . the ability to rotate in all three difference at longer wavelengths . The epicuticle of the elytra was not directions . A single Morpho When the polarizer is oriented homogenous and could be separated butterfly scale was mounted at perpendicular to the scale axis, into three different layers: (1) superficial the tip and carefully centered . the reflectance is much higher than layer without any particular structure Perpendicular to this axis were when the polarizer is parallel to measuring several-hundred nm in two reflective lenses, equipped with the scale axis . In addition to that, thickness, (2) multilayer: several-dozen optic fiber leads . One was connected the spectra in polarized light had very thin (50-100 nm) layers exhibiting to a light source and the other to more pronounced peaks . We low electron density, and (3) multilayer: a spectrophotometer . By rotating will discuss the results of these several thick (100-300 nm) layers the scale in this setup we were and other measurements in exhibiting higher electron density . able to study the reflectance and this presentation . The pitch of multilayer (2) was transmission as a function of angle . observed to vary with distance from In addition, we added a polarizer the surface . For the convenience to study the effects of polarization of analysis, multilayer (2) could Relationship Between Pale Color hypothetically be divided into and Integument Structure in upper, middle, and lower parts . Chrysina Beetles Each part of multilayer (2) was Kiyoshi Miyamoto1, Motoki Hoshi2, thought to affect the color of the Sachi Miyamoto3, and Akinori beetle due to light interference, Kosaku1, 1Institute of Medical Science, procuring colors that ranged from Dokkyo Medical University, Tochigi, the visible to ultraviolet wavelengths . Japan; 2College of Agrobiological Conversely, the colors that arose Resources, University of Tsukuba, due to interference by the layers of Tsukuba, Japan; 3Sano Senior multilayer (3) ranged from red and High School, Tochigi, Japan, to ultrared . The colors produced by miyamoto@dokkyomed .ac .jp the upper, middle, lower parts of The fine structure responsible for multilayers (2) and (3) agree surface color in Chrysina beetles, well with those observed in living beetles . which inhabit tropical rain and cloud forests at altitudes of approximately 1,000 m in the highlands of Costa Rica, were investigated using electron microscopy (JEOL JEM-1011) . The

37 Effects of Rearing Condition and Adaptive Variation of Iridescent Age on Iridescent Coloration in Plumage Coloration in Magpies Battus Philenor (Pica Pica) ± ±1 Alexandra C. Nahm and Hyun-Young Nam , Chang-Yong Ronald L . Rutowski, Arizona Choi1, Jihoon Lee1, Sang-Im Lee1, State University, acnahm@asu .edu Jae Chun Choe2, 1Seoul National University, South Korea, 2Ewha Conventional wisdom holds that in Womans University, South Korea, butterflies the dorsal wing surface stern0223@lycos .co .kr coloration may be used in intersexual communication while the ventral Black-billed magpies (Pica pica) wing coloration is a warning signal have weak bluish/greenish iridescence intended for predators, especially on their black plumage of wing in distasteful species . The Pipevine and tail . Recent studies have Swallowtail butterfly, Battus philenor, showed that coloration by feather bears iridescent patches on the microstructure indicates good ventral and dorsal hindwing quality in sexual selection though surfaces . The ventral iridescence some species of them were previously is part of their aposematic coloration known as sexually monochromatic while the dorsal iridescence is birds, and elongated tail feathers believed to serve as an aid for of magpies are related with body selection of a mate . This permits an condition . Therefore we compared assessment of if and how function their quality indices with coloration might shape the properties of by age/sex/breeding status . We iridescent color signals . We collected investigated variation of iridescence spectra from both dorsal and color in feather whether 1) it indicates ventral wing surfaces of lab- sex and/or age status and 2) it can reared and field-caught individuals . be a conditiondependent character Brightness, intensity, hue and in the chosen sex of breeding chroma were extracted from the individuals and 3) it fluctuates spectra to describe and compare under variable climate conditions . the coloration of the two sexes Both bluish wing coloration ranged and the two the wing surfaces . UV-blue and greenish tail coloration The ventral hindwing iridescence ranged out of UV region were related differs little among the sexes with both age-sex status, however, as might be expected of an in contrast to our prediction that aposematic signal . The dorsal UV-directional coloration will act as hindwing iridescence is restricted an sexually selected characteristic, to males, again suggesting it is greenish tail coloration only had a sexual signal, and is much less relationship with body condition and much bright than that of the ventral reproductive success of breeding hindwing iridescence of both sexes, males . Tail coloration also had perhaps due to differences in the relationship with climate fluctuations . ecological circumstances in which In the area where climate is more the signals are displayed . Lastly, fluctuated, variation of tail color age affects the iridescence on the tend to higher than wing color or ventral hindwing surface more than other physical characters which do that of the dorsal hindwing surface . not indicate body condition . We

38 concluded from these results that tail coloration of male magpies may act as a quality indicator in context of sexual selection .

Spec(Tac)Ular Beacon Signaling of Iridescent Butterflies ± Primoz Pirih 1, Mojca Stojan-Dolar2, Bodo Wilts1,3 and Doekele G . Stavenga1, 1University of Groningen, Groningen, the Netherlands; 2 German Primate Center, Göttingen, Germany; 3University of Goettingen, Goettingen, Germany, p pirih@rug. .nl

Insects (e .g . beetles, damselflies, and most notably butterflies) build multilayer structures in order to produce iridescent colouration, reflecting in the UV-A to green spectral range (320 .550 . nm), but use pigments to produce long-wavelength colouration . While pigmentary colouration is usually diffuse-reflecting, iridescence represents more or less specular reflections . The most advertised showcase of blue iridescence is presented by the neotropical Morpho butterflies, whose lighthouse-like blue flashing may be appreciated both in relatively open spaces and in dense tropical forests . Here, we explore the hypothesis that specularity may be used as means of directing -and thus enhancing the visibility of the colour signal . We report on our field work in Peruvian Amazonia, where we observed behaviour of morphos and related their activity to environmental parameters (e .g . terrain openness, illumination conditions) . We describe basic activity patterns which indicate the employed strategy of signalling and develop a simple model for the distribution of the reflected signal into the environment . We discuss the general properties

39 40 photo credit: Brian Gratwicke of the beacon signalling strategy in species from different groups of butterflies (Morphinae, Lycaenidae, Pieridae) and the link between the beacon signalling and butterfly vision .

Evolution and Reuse of Iridescent Structures in Butterflies Shelley Wickham, Leon Poladian, Maryanne C .J . Large, and Lars S Jermiin, University of Sydney, Australia, leonp@maths .usyd .edu .au

The diversity of 2D optical microstructures found in butterfly wing scales exhibit modifications to the basic multi-layer structure with observable changes to the iridescence . Here, we optically characterise examples of three variations of multi-layer structure, as found in 10 species . The modifications involve, respectively, the elaboration of ridge-lamellae and microribs . A third modification uses tilted ridges . It appears that some modifications enhance iridescence (possibly for signaling) while others suppress the iridescence (possibly for camouflage). In addition, we consider the phylogeny of the butterflies, and are thus able to relate the optical properties of the structures to their evolutionary development from a common primitive version . Of particular interest has been the issue of why structures recur in the evolutionary tree . It is possible that the evolutionary ‘cost’ involved in losing a complex structure or modification is much less than in gaining it in the first place . This possibility can be assessed by using a ‘Dollo’ parsimony analysis . Both simple and Dollo parsimony analyses were used,

41 photo credit: Charlesjsharp three-dimensional, photonic crystal in the body of the scale fractured when indented, and scales with a multilayer stack in the body of the scale bent when indented . In addition, different parts of the scale respond in different ways to indentation, suggesting specific functions for each part .

Structural Colour and Thermoregulation in Butterflies Stephen G . Bosi, Jacqueline Hayes, Maryanne C .J . Large and Leon Poladian, University of Sydney, Australia, leonp@maths .usyd .edu .au

It has been hypothesized several times in the literature that the colour (including the presence or absence of structural colour) of butterfly wings imbues them with photothermal properties that allowing the mechanism of adaptation the elastic modulus and hardness assist in thermoregulation . It has also been suggested that loss to be addressed . Simple parsimony of butterfly scales for the first time of iridescent/structural colour suggests convergent evolution of through nanoindentation and increases solar absorptance and one structure, while Dollo parsimony correlate mechanical properties so may represent a selective implies that ‘latent’ structures can to the type of iridescent structure . advantage in cold, harsh climates . be reused . Butterfly scales are complex This paper refutes both aspects structures made from dry insect of this hypothesis . 64 species of cuticle . Because the scales were butterfly in the families Geometridae, highly compliant the residual depth Hardness and Elastic Properties Lycaenidae, Nymphalidae, Papilionidae, of penetration of the indenter tip of Iridescent Scales Pieridae, Sphingidae, Uraniidae and was accurately measured using Jacqueline Hayes, Maryanne C .J . Zygaenidae were obtained . The three-dimensional visualization of Large, Leon Poladian, and Mike specimens were divided into the impression . The mechanical Swain, University of Sydney, Australia, two groups; 36 iridescent and 28 leonp@maths .usyd .edu au. properties are largely dependent noniridescent specimens . The on the microstructure of the scale . solar absorptance of their wings was It is easy to assume that iridescent Scales with a multilayer stack measured spectrophotometrically structure might have evolved under in the ridges of the scale had from 250 nm to 2600 nm . For each selective pressures associated the highest elastic modulus and specimen, the long term 24 hr with their spectral appearance . hardness . Scales with an ordered mean temperature for the month However, this neglects the possibility three-dimensional crystal structure and location of capture was obtained . that the structures may have other had a lower elastic modulus and Contrary to the hypothesis, a roles, or perhaps that they have hardness . Moreover, there were plot of solar absorptance versus been “seconded” to serve an scales that did not respond normally habitat temperature did not show a optical function . Here, we study to indentation . Scales with an trend of decreasing absorptance

42 with increasing temperature . non-iridescent colors, barbules feather coloration with high Moreover, it was found that the iridescent ones . In some animals, repeatability (hue: 0 92,. brightness: iridescent butterflies exhibited on iridescence is a result of fine 0 .65, red chroma: 0 95). and that average, significantly higher solar incised lines on a surface but in is biologically meaningful, taking absorptance (0 .68) than noniridescent birds (and many insects), they into account the potential for signal butterflies (0.43). result from the same multi-layer optimization and feather color refraction that gives rise to blue variation between feathers within and green . The influence of an individual .The apparatus will be sub-surface scattering, global present for demonstration during Photo-Real Rendering of illumination, final gathering and the poster session . Iridescence from Thin Films spectral rendering and the influence in Feathers on Birds of pockets of air inside the feathers Mark J. Prusten, Silicon that scatter all wavelengths of light Arts, Tucson, Arizona, Quantitative Analysis of Passive will be examined . The brightness photondyn@silicon-art com. Color Changes in Dynastes of the white for example depends Hercules (Coleoptera) on the number and distribution of The most highly developed examples Marie Rassart and Jean Pol Vigneron, those pockets . The simulation of iridescence found in terrestrial University of Namur, Belgium, of the polarized light and the interaction animals is birds and insects . The marie rassart@fundp. .ac .be of the insects with classic lighting two groups frequently interact; setup will be reviewed were birds are among the principal The large South-American beetle the illumination varies greatly in predators of insects . In this paper, Dynastes hercules lichyi undergoes spectrum and intensity . the mechanics of iridescence are passive colour transformations, described for the structures of changing from khaki-green to deep feathers in birds and models are black when the ambient humidity made for the development of High Quantifying Iridescent is increased . Such a darkening Dynamic Range Images, HDRI, Coloration: A New Apparatus probably improves the insects’ photo-real shaders . The simulation and Comparison of Techniques camouflage at night, when most of iridescent qualities of the hair Melissa Meadows Rader, Nathan of the light is lost and humidity is and feathers of birds is developed . Morehouse, Ronald Rutowski, getting high . This communication The modeling and rendering of Jonathan Douglas, and Kevin essentially reports on a study of the feather structures incorporate McGraw, Arizona State University, the physical aspects of this colour thin film multilayer optical stacks . Melissa Meadows@asu. .edu change, and on its possible Whether a color is iridescent depends implications for material sciences . on the part of the feather that Most animal colors are easily We first recorded the optical generates it: barbs produce quantifiable by a variety of well- reflection factor of the cuticle established techniques . However, of these Dynastes under various iridescent colors, with their shifts stabilized hygrometric conditions, in hue and brightness caused by providing a photometric description minute changes in viewing geometry, of the progressive coloration loss present a challenge . In order to near 80% humidity . In parallel, measure color in a repeatable, scanning electron microscope biologically-relevant way, we nano-morphology investigations developed a new apparatus that of the cuticle allowed to determine allows for continuous variation the structure of the hygro-adjustable of viewing geometry . We also coloring layers . The dry structure examined the efficacy of several is essentially a wide-period Bragg commonly-used color measurement multilayer which alternates chitin methods, and arrived on a method sheets and void layers . A two- for measuring iridescent hummingbird dimensional, disordered, array of photo credit: Surya Prakash

43 rods normal to the cuticle surface or low quality diets, and their coloration maintains the rigidity of the structure . Effects of Diet on Male was me sured after 45 days . In The khaki-green coloration is explained Coloration in a Jumping Experiment 1, male’s faces tended by the second-order multilayer Spider (Habronattus Pyrrithrix) to be redder in the high quality diet 1 1 photonic gap which opens near 500 nm Lisa A. Taylor , Kevin J . McGraw , group than the low quality group 2 1 and the black appearance is shown and David Clark , Arizona State suggesting that condition-dependence 2 to result from water infiltration through University, Alma College, Alma, of red coloration may be mediated cracks in a thick protecting transparent Michigan, Lisa .A Taylor@asu. .edu by juvenile diet . In Experiment 2, wax layer covering the photonic diet had no effect on red coloration structure . The color change is In many animals, conspicuous male suggesting that adult diet is unlikely explained by the attenuation of coloration is thought to function as to be important in maintaining this the refractive index contrast, which an honest indicator of mate quality . coloration . Green leg tuft and white permits the incident light to reach In Habronattus pyrrithrix, females pedipalp coloration were unaffected the deeper absorbing melanin are dull and inconspicuous, while by diet in either experiment, suggesting substrate . This mechanism was males have a brilliant red face, green that these colors may be less likely confirmed by 3D transfermatrices leg tufts, and white pedipalps that to signal aspects of nutrition . simulations . It is suggested that they display to females during these natural structures, in which courtship . Our previous work suggests the optical properties are controlled that the red coloration of males Effects of Food Stress on Iridescent Signaling by moving fluids, can be synthesized is condition-dependent in a wild population, and thus has the potential in Battus Philenor with already known mesoporous ± Kimberly Vann , Alexandra Nahm, materials . The resulting hygrochromic to function as a quality indicator . and Ronald Rutowski, Arizona surfaces could have a variety of uses When color is condition-dependent, State University, knvann@asu .edu in sensing or displaying applications . it may be an honest signal of the nutritional condition and foraging ability of its bearer . If so, we expect Male pipevine swallowtail butterflies, that enhancing the quality of a Battus philenor, have iridescent male’s diet would enhance his patches on the dorsal and ventral coloration . In Experiment 1, to hindwings, while females have iridescent patches only on the ventral surface . The ventral patches have apparent function as warning signals, and the dorsal patches as a signal of quality for mate choice . The condition dependence of these signals will give insight into their function . The condition dependence of the iridescent signals is expected to be greater for the dorsal surface than the ventral surface, because

understand how juvenile diet of the differences in the assumed affects development of adult male functions . Two treatment groups coloration, we reared juvenile of larvae were removed from host spiders on either high or low quality plant (Aristolochia watsonii) during diets, and measured their coloration the third and fourth day of the final at maturity . In Experiment 2, to larval instar, and a third treatment understand how adult diet affects group was allowed to feed through the maintenance of coloration, wild pupation . Adults resulting from caught adults were fed either high these larvae were measured, weighed, and the colors analyzed

44 photo credit: Kati Fleming through spectrophotometry . Food and orientations on the wing deprivation leads to smaller adult Multi-Scale Optical Response membrane, and the wing membrane body size as measured by forewing of Structured Surfaces in Living shape keeps some memory of its length and body mass . Organisms folding at the time of the exit from Jean Pol Vigneron and Marie Rassart, pupa . The visual effects determined University of Namur, Belgium, at all these length scales are important Multi-Physics Description jean-pol vigneron@fundp. .ac .be to biology and should be consiered, of the Day-Flying Moth even if approaching this from ab Cocytia D’urvillei Natural photonic structures are initio Maxwell’s equations is Jean Pol Vigneron and Marie Rassart, complex objects : their geometry unfeasible . We propose an hybrid University of Namur, Belgium, reveals several length scales, with approach for calculating the jean-pol .vigneron@fundp .ac be. different orders of magnitude . In reflectance spectra from such principle, a complete vector-wave complex surfaces, which combine In chapter 30 of his book on the description of the optical response Monte-Carlo ray tracing for exploration of the Malay Archipelago of structure should be applied, long-paths propagation and fully (1869), Alfred Russel Wallace but in many situations, the scattering vectorial multiple scattering of underlined the outstanding appearance surface is too large and too complex electromagnetic wave for local of a local day-flying moth, Cocytia to warrant any feasible approach . color filtering . The procedure has d’Urvillei . Exploration at the In a butterfly wing such as that of been applied to explain the light submicron scale showed that the Brazilian butterfly Cyanophrys scattering properties of several this moth has developed several remus, for instance, a single insect’s coloring structures photonic and hydrophobic structures: ventral scale contains a photonic exhibiting short-range order and (1) the clear wings show a dense polycrystal, made of highly long-range disorder, and the simple array of cylindrical protrusions structured grains with a distribution case of an hemispheric multilayer,as which is possibly an optimized showing long-range orientation found on the cuticle of the brightly trade-off between an antireflection disorder . The scales themselves colored African shield-backed bug coating and a water-repellent are implanted at various angles beetle Calidea panaethiopica. structure, (2) the black areas on the wing veins and magins are covered by absorbing scales, where the ridges and cross ribs are minimized, for the probable purpose of optimizing access to a granular broadband absorber on the scale’s ground membrane; (3) the dorsal side of the abdomen is spectacularly iridescent, selecting yellow to cyan reflections . Scanningelectron microscope examination of the long scales which produce this iridescence revealed a structure very similar to that found on the wings of the Morpho butterflies . This observation on organisms that appear to be so distant (geographically and phylogenetically) suggests that this type of photonic construct is very generic and highly constrained by bio-fabrication steps .

45 Abstract SUBJECT INDEX

photo credit: Charlesjsharp

46 Birds: Pages 18, 19, 22, 23, 24, 26, 28, 30, 34, 38, 41

Butterflies and moths: Pages 19, 20, 22, 24, 25, 27, 32, 33, 36, 38, 39, 40, 42

Color Measurement, color change, and color usefulness: 19, 20, 22, 24, 27, 28, 29, 34, 36, 38, 39, 40, 41, 42, 43

Education and Application: Pages 21, 26, 27, 29, 31,

Environment and conditions / Evolution: Pages 18, 19, 20, 22, 23, 24, 25, 26, 28, 30, 34, 36, 38, 39, 41, 42,

Insects / spiders: Pages 25, 26, 29, 30, 33, 36, 37, 42

Mechanisms and Measurement / scale and feather structure: Pages 18, 19, 20, 22, 23, 24, 25, 27, 29, 30, 32, 33, 34, 36, 37, 39, 40, 41, 43

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