Convergent, modular expression of ebony and tan in the mimetic wing patterns of Heliconius butterflies

The evolution of pigmentation in vertebrates and flies has involved repeated divergence at a small number of genes related to melanin synthesis. Here, we study insect melanin synthesis genes in Heliconius butterflies, a group characterised by its diversity of wing patterns consisting of black (melanin), and yellow and red (ommochrome) pigmented scales. Consistent with their respective biochemical roles in Drosophila melanogaster, ebony is upregulated in non-melanic wing regions destined to be pigmented red whilst tan is upregulated in melanic regions. Wing regions destined to be pigmented yellow, however, are downregulated for both genes. This pattern is conserved across multiple divergent and convergent phenotypes within the Heliconii, suggesting a conserved mechanism for the development of black, red and yellow pattern elements across the genus. Linkage mapping of five melanin biosynthesis genes showed that, in contrast to other organisms, these genes do not control pattern polymorphism. Thus, the pigmentation genes themselves are not the locus of evolutionary change but lie downstream of a wing pattern regulatory factor. The results suggest a modular system in which particular combinations of genes are switched on whenever red, yellow or black pattern elements are favoured by natural selection for diverse and mimetic wing patterns.     

Butterfly wing pattern mutants: developmental heterochrony and co-ordinately regulated phenotypes

Butterfly wings are colored late in development, when pigments are synthesized in specialized wing scale cells in a fixed developmental succession. In this succession, colored pigments are deposited first and the remaining areas are later melanized black or brown. Here we studied the developmental changes underlying two wing pattern mutants, firstly melanic mutants of the swallowtail Papilio glaucus, in which the yellow background is turned black, and secondly a Spotty mutant of the satyrid Bicyclus anynana, which carries two additional eyespots. Despite the very different pattern changes in these two mutants, they are both associated with changes in rates of scale development and correspondingly, the final color pattern. In the melanic swallowtail, background scales originally destined to become yellow (normally developing early and synthesizing papiliochrome) show delayed development, fail to make papiliochrome, and subsequently melanize at the same time as scales in the wild-type black pattern. In the B. anynana eyespot, scale maturation begins with the central white focus, then progresses to the surrounding gold ring and later finishes with melanization of the black center. Mutants showing additional eyespots display accelerated rates of scale development (corresponding to new eyespots) in wing cells not normally occupied by eyespots. Thus by either delaying or accelerating rates of scale development, the final color, or position, of a wing pattern element can be changed. We propose that this heterochrony of scale development is a basic mechanism of color pattern formation on which developmental mutants act to change lepidopteran color patterns. Received: 20 April 2000 / Accepted: 19 July 2000     

The Genetic,Morphological, and Physiological Characterization of a Dark Larval Cuticle Mutation in the Butterfly,Bicyclus anynana

Studies on insect melanism have greatly contributed to our understanding of natural selection and the ultimate factors influencing the evolution of darkly pigmented phenotypes. Research on several species of melanic lepidopteran larvae have found that low levels of circulating juvenile hormone (JH) titers are associated with a melanic phenotype, suggesting that genetic changes in the JH biosynthetic pathway give rise to increased deposition of melanin granules in the cuticle in this group. But does melanism arise through different molecular mechanisms in different species? The present study reports on a Bicyclus anynana (Lepidoptera: Nymphalidae) dark larvae single locus mutation, in which larvae exhibit a darker cuticle relative to wild type. Unlike other lepidopteran melanic larvae mutations, this one is autosomal recessive and does not appear to involve a deficiency in JH titers. Unlike JH deficiency mutants, dark larvae mutants display similar growth rates and sexual behaviors as wild type, and topical application of a JH analogue failed to rescue the wild type cuticular coloration. Finally, transmission electron microscopy showed that sclerotization or deposition of diffuse melanin, rather than deposition of melanin granules, produces the dark coloration found in the cuticle of this species. We conclude that different molecular mechanisms underlie larval melanism in different species of Lepidoptera.     

Effects of altered catecholamine metabolism on pigmentation and physical properties of sclerotized regions in the silkworm melanism mutant

Catecholamine metabolism plays an important role in the determination of insect body color and cuticle sclerotization. To date, limited research has focused on these processes in silkworm. In the current study, we analyzed the interactions between catecholamines and melanin genes and their effects on the pigmentation patterns and physical properties of sclerotized regions in silkworm, using the melanic mutant melanism (mln) silkworm strain as a model. Injection of β-alanine into mln mutant silkworm induced a change in catecholamine metabolism and turned its body color yellow. Further investigation of the catecholamine content and expression levels of the corresponding melanin genes from different developmental stages of Dazao-mln (mutant) and Dazao (wild-type) silkworm revealed that at the larval and adult stages, the expression patterns of melanin genes precipitated dopamine accumulation corresponding to functional loss of Bm-iAANAT, a repressive effect of excess NBAD on ebony, and upregulation of tan in the Dazao-mln strain. During the early pupal stage, dopamine did not accumulate in Dazao-mln, since upregulation of ebony and black genes led to conversion of high amounts of dopamine into NBAD, resulting in deep yellow cuticles. Scanning electron microscope analysis of a cross-section of adult dorsal plates from both wild-type and mutant silkworm disclosed the formation of different layers in Dazao-mln owing to lack of NADA, compared to even and dense layers in Dazao. Analysis of the mechanical properties of the anterior wings revealed higher storage modulus and lower loss tangent in Dazao-mln, which was closely associated with the altered catecholamine metabolism in the mutant strain. Based on these findings, we conclude that catecholamine metabolism is crucial for the color pattern and physical properties of cuticles in silkworm. Our results should provide a significant contribution to Lepidoptera cuticle tanning research.     

Abnormalities of wing pattern in the Eastern Tiger Swallowtail butterfly, Papilio glaucus

Abstract In much of its range Papilio glaucus L. has two forms of female, black and yellow, and the gene controlling the colour pattern is on the Y chromosome. Thus black mothers produce only black daughters and yellow mothers produce yellow daughters. Reasons are given to explain the occasional exceptions to this rule. The black female form mimics Battus philenor (L.), and an autosomal mutant is described in P.glaucus which is paralleled by a similar aberration in the model - a possible example of a model 'escaping' from a mimic and the mimic 'catching up' at one step.
Sex mosaics are readily seen in the black form of glaucus females and a numberare described from the Strecker collection. The probable cytogenetic constitution of these aberrations is discussed.
Hybrids are described between glaucus and its near relatives, P.rutulus Lucas, P.eurymedon Lucas and P.multicaudatus Kirby. These crosses produce mainly males but, by the use of ecdysterone, females have been obtained in the cross between the black female form of glaucus and the male of rutulus .     

Relative fitness of near isogenic lines for melanic and typical forms of the oriental armyworm, Mythimna separata (Walker)

Melanism in the oriental armyworm Mythimna separata (Walker) is characterized by a black color in adults instead of the normal body color of off-white. Because inheritance of melanism in this moth follows Mendel's law, with the melanic allele (t) recessive to the normal allele (T) at a single autosomal locus, a backcrossing procedure was used to develop near isogenic lines (NILs) for melanic (NILs-tt) and typical forms (NILs-TT) of this moth. Melanic males (tt) and typical females (TT) were crossed in the laboratory, their progeny (F(1)) were interbred, and F(2) melanic males were backcrossed to typical female offspring of the parallel line. This cycle was repeated five times to create NILs for melanic and typical forms of this moth. The effects of the melanic allele on relative fitness were evaluated in terms of developmental and reproductive characteristics. Life tables of the NILs were constructed to determine net reproductive rate (R(0)). Results indicated that NILs-tt possessed apparent developmental and reproductive advantages, including shorter immature development time, higher larval and pupal survival, a shorter adult preoviposition period, and more eggs laid per female compared with the NILs-TT.     

No association between mitochondrial DNA haplotypes and a female-limited mimicry phenotype in Papilio glaucus

Abstract Alternative alleles at a locus on the W chromosome of Papilio glaucus (causing dark or yellow wing colors, respectively) underlie a female-limited mimicry polymorphism thought to be maintained by balancing selection. In species with heterogametic females (i.e., the ZZ-male/ZW-female sex chromosome system), the mitochondrial DNA and the W chromosome are genetically linked because they are both maternally transmitted. We investigate the association of COI and COII mitochondrial DNA haplotypes with alternative W-linked phenotypes. Surprisingly, we find no congruence between mitochondrial DNA genealogies and inferred W-linked color alleles in P. glaucus. Using a maximum-likelihood phylogenetic approach, we reject the hypothesis of monophyly for darkmorph mitochondrial DNA lineages, even in the presence of putative low-frequency mimicry suppressor alleles or alternative melanizing factors. The most likely genealogical tree topologies assume more than one exchange event between mitochondrial DNA cytotype and the W-linked color morph. These results suggest that there is either paternal leakage of mitochondrial DNA or that more than two W-linked alleles underlie the alternative color morphs. Using data from an additional mitochondrial DNA locus, ND5, we show that pairwise linkage disequilibrium decays with physical distance between polymorphic sites. This finding suggests that genetic exchanges between maternal and paternal mitochondrial DNAs may have contributed to the lack of association we observe between phenotype and genotype.     

The colouration toolkit of the Pipevine Swallowtail butterfly,Battus philenor: thin films,papiliochromes, and melanin

The ventral hindwings of Pipevine Swallowtail butterflies, Battus philenor, display a colourful pattern, created by variously coloured wing scales. Reflectance and transmittance measurements of single scales indicate that the cream and orange scales contain papiliochrome pigments, while brown, black and blue scales contain melanin. Microspectrophotometry and scatterometry of both sides of the wing scales show that the lower lamina acts as a thin film, with reflection properties dependent on the scale’s pigmentation. Notably in the orange scales, the reflectance spectrum of the lower lamina is tuned to the pigment’s absorbance spectrum. The dorsal hindwings of the male (but not the female) B. philenor are blue-green iridescent. At oblique illumination, the light reflected by the male’s dorsal hindwings can be highly polarised, which may have a function in intersexual signalling.     

Assessing ecological and physiological costs of melanism in North American Papilio glaucus females: two decades of dark morph frequency declines

Polymorphisms for melanic form of insects may provide various selective advantages. However, melanic alleles may have significant/subtle pleiotrophic “costs.” Several potential pleiotrophic effects of the W (=Y)‐linked melanism gene in Papilio glaucus L. (Lepidoptera) showed no costs for melanic versus yellow in adult size, oviposition preferences, fecundity, egg viability, larval survival/growth rates, cold stress tolerance, or postdiapause emergence times. Sexual selection (males choosing yellow rather than mimetic dark females) had been suggested to provide a balanced polymorphism in P. glaucus, but spermatophore counts in wild females and direct field tethering studies of size‐matched pairs of virgin females (dark and yellow), show that male preferences are random or frequency‐dependent from Florida to Michigan, providing no yellow counter‐advantages. Recent frequency declines of dark (melanic/mimetic) females in P. glaucus populations are shown in several major populations from Florida (27.3°N latitude) to Ohio (38.5° N). Summer temperatures have increased significantly at all these locations during this time (1999–2018), but whether dark morphs may be more vulnerable (in any stage) to such climate warming remains to be determined. Additional potential reasons for the frequency declines in mimetic females are discussed: (i) genetic introgression of Z‐linked melanism suppressor genes from P. canadensis (R & J) and the hybrid species, P. appalachiensis (Pavulaan & Wright), (ii) differential developmental incompatibilities, or Haldane effects, known to occur in hybrids, (iii) selection against intermediately melanic (“dusty”) females (with the W‐linked melanic gene, b+) which higher temperatures can cause.     

The molecular basis of an avian plumage polymorphism in the wild: a melanocortin-1-receptor point mutation is perfectly associated with the melanic plumage morph of the bananaquit, Coereba flaveola

BACKGROUND: Evolution depends on natural selection acting on phenotypic variation, but the genes responsible for phenotypic variation in natural populations of vertebrates are rarely known. The molecular genetic basis for plumage color variation has not been described in any wild bird. Bananaquits (Coereba flaveola) are small passerine birds that occur as two main plumage variants, a widespread yellow morph with dark back and yellow breast and a virtually all black melanic morph. A candidate gene for this color difference is the melanocortin-1 receptor (MC1R), a key regulator of melanin synthesis in feather melanocytes. RESULTS: We sequenced the MC1R gene from four Caribbean populations of the bananaquit; two populations of the yellow morph and two populations containing both the yellow morph and the melanic morph. A point mutation resulting in the replacement of glutamate with lysine was present in at least one allele of the MC1R gene in all melanic birds and was absent in all yellow morph birds. This substitution probably causes the color variation, as the same substitution is responsible for melanism in domestic chickens and mice. The evolutionary relationships among the MC1R haplotypes show that the melanic alleles on Grenada and St. Vincent had a single origin. The low prevalence of nonsynonymous substitutions among yellow haplotypes suggests that they have been under stabilizing selection, whereas strong selective constraint on melanic haplotypes is absent. CONCLUSIONS: We conclude that a mutation in the MC1R is responsible for the plumage polymorphism in a wild bird population and that the melanic MC1R alleles in Grenada and St. Vincent bananaquit populations have a single evolutionary origin from a yellow allele.     

Drosophila wing melanin patterns form by vein-dependent elaboration of enzymatic prepatterns

BACKGROUND: Animal melanin patterns are involved in diverse aspects of their ecology, from thermoregulation to mimicry. Many theoretical models have simulated pigment patterning, but little is known about the developmental mechanisms of color pattern formation. In Drosophila melanogaster, several genes are known to be necessary for cuticular melanization, but the involvement of these genes in melanin pattern evolution is unknown. We have taken a genetic approach to elucidate the developmental mechanisms underlying melanin pattern formation in various drosophilids. RESULTS: We show that, in D. melanogaster, tyrosine hydroxylase (TH) and dopa decarboxylase (DDC) are required for melanin synthesis. Ectopic expression of TH, but not DDC, alone was sufficient to cause ectopic melanin patterns in the wing. Thus, changes in the level of expression of a single gene can result in a new level of melanization. The ontogeny of this ectopic melanization resembled that found in Drosophila species bearing wing melanin patterns and in D. melanogaster ebony mutants. Importantly, we discovered that in D. melanogaster and three other Drosophila species these wing melanin patterns are dependent upon and shaped by the circulation patterns of hemolymph in the wing veins. CONCLUSIONS: Complex wing melanin patterns are determined by two distinct developmental mechanisms. Spatial prepatterns of enzymatic activity are established late in wing development. Then, in newly eclosed adults, melanin precursors gradually diffuse out from wing veins and are oxidized into dark brown or black melanin. Both the prepatterning and hemolymph-supplied components of this system can change during evolution to produce color pattern diversity.     

Genetic basis of stage-specific melanism: a putative role for a cysteine sulfinic acid decarboxylase in insect pigmentation

Melanism, the overall darkening of the body, is a widespread form of animal adaptation to particular environments, and includes bookcase examples of evolution by natural selection, such as industrial melanism in the peppered moth. The major components of the melanin biosynthesis pathway have been characterized in model insects, but little is known about the genetic basis of life-stage specific melanism such as cases described in some lepidopteran species. Here, we investigate two melanic mutations of Bicyclus anynana butterflies, called Chocolate and melanine, that exclusively affect pigmentation of the larval and adult stages, respectively. Our analysis of Mendelian segregation patterns reveals that the larval and adult melanic phenotypes are due to alleles at different, independently segregating loci. Our linkage mapping analysis excludes the pigmentation candidate gene black as the melanine locus, and implicates a gene encoding a putative pyridoxal phosphate-dependant cysteine sulfinic acid decarboxylase as the Chocolate locus. We show variation in coding sequence and in expression levels for this candidate larval melanism locus. This is the first study that suggests a biological function for this gene in insects. Our findings open up exciting opportunities to study the role of this locus in the evolution of adaptive variation in pigmentation, and the uncoupling of regulation of pigment biosynthesis across developmental stages with different ecologies and pressures on body coloration.     

Mitochondrial DNA diversity in an apomictic Daphnia complex from the Canadian High Arctic

Cyclic parthenogenesis is the ancestral mode of reproduction in the cladoceran crustacean, Daphnia pulex, but some populations have made the transition to obligate parthenogenesis and this is the only mode of reproduction known to occur in arctic populations. Melanism and polyploidy are also common in arctic populations of this species. Prior allozyme studies of arctic D. pulex revealed substantial levels of clonal diversity on a regional scale. Clonal groupings based on cluster analysis of allozyme genotypes do not conform to groupings based on the presence/absence of melanin or on ploidy level. In order to further elucidate genetic relationships among arctic D. pulex clones, mitochondrial DNA (mtDNA) variation was examined in 31 populations from two Canadian high-arctic sites. The data were also compared to a previous study of mtDNA variation in populations from a Canadian low-arctic site. Cladistic analysis of restriction site variation of the entire mitochondrial genome and nucleotide sequence variation of the mitochondrial control region was used to construct genetic relationships among mitochondrial genotypes. Three distinct mitochondrial lineages were detected. One lineage was associated with diploid, nonmelanic clones and is the same as the lineage that is found in temperate populations of D. pulex. The other two lineages (A & B) were associated with polyploid, melanic clones. Sequence divergence between the A and B lineages was 2.4%. Sequence divergence between D. pulex and either of these two lineages exceeded 3%. It is suggested that the melanic, polyploid clones are hybrids between males of D. pulex (and/or a closely related congener, D. pulicaria) and females of either of two ancestral melanic species that have mitochondrial lineages A and B. Geographic patterns of mitochondrial diversity in ‘melanic’ lineage B support the hypothesis of an high-arctic refuge for the ancestral species during the last glacial period.     

Immune defence,a possible nonvisual selective factor behind the industrial melanism of moths (Lepidoptera)

It is generally believed that industrial melanism in Lepidoptera is mainly caused by differential predation by birds. In polluted areas, melanic individuals are favoured by natural selection because they are better camouflaged than pale moths on lichen‐free and sooty tree trunks. In this article, we show that, in the black arches moth (Lymantria monacha), melanic morphs have a stronger encapsulation response than pale morphs against nylon monofilament implants. This indicates that the melanic and pale morphs differ in the strength of their immune defence. The same chemical precursors and their end product, melanin pigment, are involved in the encapsulation response and in the external coloration. Thus, it seems that there may be two possible, not mutually exclusive, explanations for the frequency changes observed in the industrial melanism of moths. The dominant gene causes an increase in the amount of melanin pigment and its precursors. This increase causes two changes: an intensified immune defence as a form of improved encapsulation ability of foreign objects, and the well‐known protective dark coloration (a case of relational pleiotropy). It seems possible that industrial melanism is a by‐product of selection on the strength of immunity. In the field, these pleiotropic aspects are exceedingly difficult to distinguish from each other, and the factors may even be compensatory. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 99 , 831–838.     

Greater cuticular melanism is not associated with greater immunogenic response in adults of the polymorphic mountain stone weta, Hemideina maori

Abstract.  1. Greater immune function is associated with the high-density melanic phase of polyphenic insects, appearing to compensate for density-dependent increases in susceptibility to parasites and/or pathogens. Other types of discrete variation in cuticular colour occur in insects (which may or may not be associated with melanin pigmentation), but whether this variation is predictive of immune ability has not been investigated.
2. In the mountain stone weta Hemideina maori , a black morph and yellow banded morph occur. These morphs are not seasonally polyphenic and have discrete haplotype genetic markers. Black individuals are typically found at lower local densities than yellow individuals, contrary to relations between cuticular melanism and density seen in polyphenic insects.
3. Yellow males and females had greater melanotic encapsulation responses upon immune challenge than did black males and females, but these differences were not associated with differences in temperature selection between morphs. Morph differences in melanotic encapsulation responses were somewhat related to differences between morphs in haemocyte concentrations.
4. These results indicate that a common form of immune expression is not heightened with dark coloration in the mountain stone weta. Thus, earlier findings of greater immunity associated with darker cuticles in phase polyphenic insects cannot be extended to insects with other forms of discrete colour variation. These findings will help in elucidating causes and consequences of such colour polymorphism, which is widespread in several insect orders.     

Temporal and spatial expression of the yellow gene in correlation with cuticle formation and dopa decarboxylase activity in Drosophila development

The yellow (y) gene of Drosophila is required for the formation of black melanin and its deposition in the cuticle. We have studied by immunohistochemical methods the temporal and spatial distribution of the protein product of the y gene during embryonic and pupal development and have correlated its expression with events of cuticle synthesis by the epidermal cells and with cuticle sclerotization. Except for expression in early embryos, the y protein is only found in the epidermal cells and may be secreted into the cuticle as it is being deposited. The amount of y protein in various regions of the embryo and pupa correlates directly with the intensity of melanization over any section of the epidermis. Expression of the y gene begins in the epidermal cells at 48 hr after pupariation and is well correlated with the beginning deposition of the adult cuticle. At this stage the adult cuticle is unsclerotized and unpigmented and dopa decarboxylase levels, a key enzyme in catecholamine metabolism which provides the crosslinking agents as well as the precursors for melanin, is low. As a separate event 26 hr after the onset of y gene expression, the first melanin deposition occurs in the head bristles and pigmentation continues in an anterior to posterior progression until eclosion. This melanization wave is correlated with elevated dopa decarboxylase activity. Crosslinking of the adult cuticle also occurs in a similar anterior to posterior progression at about the same time. We have shown by imaginal disc transplantation that timing of cuticle sclerotization depends on the position of the tissue along the anterior-posterior axis and that it is not an inherent feature of the discs themselves. We suggest that actual melanization and sclerotization of the cuticle by crosslinking are initiated at this time in pupal development by the availability of the catecholamine substrates which diffuse into the cuticle. Intensity of melanization and position of melanin pigment is determined by the presence or absence of the y protein in the cuticle, thus converting the y protein prepattern into the melanization pattern.     

The costs of colour: plasticity of melanin pigmentation in an outbreaking polymorphic forest moth

Outside the context of industrial melanism, little is known about the physiological and ecological importance of genetic melanic polymorphisms in moths. Melanin pigments are synthesized from amino acid precursors and should therefore be costly to produce in nitrogen‐limited insects. A genetic melanic polymorphism is present in adult Malacosoma disstria Hübner (Lepidoptera: Lasiocampidae), a widespread forest moth with outbreaking population dynamics. We test the hypotheses that melanin‐based colouration is physiologically costly in M. disstria, that expression of melanin‐based colouration is a plastic trait which varies with population density and nutrition, and that the genetically based melanic phenotype is disadvantaged under nutritionally poor conditions. Two experiments were used to test these hypotheses. A field study compared pigmentation and phenotypic frequencies in moths collected from high‐ and low‐density populations. A laboratory experiment investigated the effects of larval nitrogen availability on adult pigmentation and phenotypic frequencies. High population density and nitrogen limitation reduced pigmentation and size of all moths, but phenotypic frequencies were not affected in either experiment. The effects of diet on both pigmentation and size were stronger for melanic moths than for typical moths. Our results show that adult melanism in M. disstria is physiologically costly, that colour expression is plastic despite its genetic component, and that the melanic phenotype may be disadvantaged under poor conditions but favoured under good conditions. We suggest that temporal variation in selection and trait plasticity help maintain polymorphism stability.     

Ultrastructure and morphogenesis of the wing scales in Heliconius erato phyllis (Lepidoptera: Nymphalidae): What silvery/brownish surfaces can tell us about the development of color patterning?

Usually the literature on Heliconius show three types of scales, classified based on the correlation between color and ultrastructure: type I – white and yellow, type II – black, and type III – orange and red. The ultrastructure of the scales located at the silvery/brownish surfaces of males/females is for the first time described in this paper. Besides, we describe the ontogeny of pigmentation, the scale morphogenesis and the maturation timing of scales fated to different colors in Heliconius erato phyllis. The silvery/brownish surfaces showed ultrastructurally similar scales to the type I, II and III. The ontogeny of pigmentation follows the sequence red, black, silvery/brownish and yellow. The maturation of yellow-fated scales, however, occurred simultaneously with the red-fated scales, before the pigmentation becomes visible. In spite of the scales at the silvery/brownish surfaces being ultrastructurally similar to the yellow, red and black scales, they mature after them; this suggests that the maturation timing does not show a relationship with the scale ultrastructure, with the deposition timing of the yellow pigment. The analysis of H. erato phyllis scale morphogenesis, as well as the scales ultrastructure and maturation timing, provided new findings into the developmental architecture of color pattern in Heliconius.     

Resource-mediated condition dependence in sexually dichromatic butterfly wing coloration

Theory predicts that traits subject to strong sexual selection should evolve to be more exaggerated and developmentally integrated than nonsexual traits, thus leading to heightened condition dependence. Until recently, however, efforts to evaluate this prediction have suffered from either a purely correlational (nonmanipulative) approach, or from using manipulations of doubtful ecological relevance. Here I address these issues by integrating observation and manipulation to study condition- and sex-related color variation in a butterfly. The focal species, Eurema hecabe (Pieridae), possesses three sexually homologous and morphogenetically discrete dorsal wing color elements-coherently scattered ultraviolet (UV), pteridine yellow, and melaninic black. The UV is most strongly sexually selected, and is also the only color element with restricted distribution across female wings. Condition dependence and sexual dichromatism were pervasive, characterizing all color traits except the melanic black, and acting such that low condition males resembled high condition females. Although female coloration tended to exhibit greater phenotypic variation, size-scaled UV was more variable and condition dependent in males. Importantly, manipulation of larval resources was sufficient to closely reconstruct the extent and patterns of field-observed phenotypic variation in condition, and color trait expression, which implicates larval resource acquisition as a primary driver of condition dependence. These results support theories regarding phenotypic variation in sexually selected traits.