Wing Pattern Research Articles

New integrated evidences reveal male polymorphism and species delimitation in stalk‐eyed fruit flies

AbstractSpecies of stalk‐eyed fruit flies, in the genera Pelmatops Enderlein and Pseudopelmatops Shiraki, have a distinct head structure with eyes located at the ends of stalks, setting them apart from other tephritids. Despite their unique morphology, the intraspecific variation of morphological and behavioural traits in these flies is still not well‐studied, leaving some questions about species definition unresolved. To address this, we conducted a study combining morphological evidence, behavioural studies, and molecular analyses. Our findings revealed male polymorphism in stalk‐eyed fruit flies for the first time, with four morphotypes observed in Pe. fukienensis and three in Pe. ichneumoneus and Ps. angustifasciatus. These morphotypes differ in eyestalk length, wing pattern, and the presence of projections or spikes at the ends of the compound eye. We also propose phylogenetic and phylogeographic implications for the group based on new molecular evidence, along with our observations of courtship and mating behaviours between previously recognized different species. Our study examined four nominal species (Pe. ichneumoneus and Pe. tangliangi, Ps. angustifasciatus and Ps. continentalis) and revealed rich evolutionary interactions within this group. Based on the results, we propose the synonymy of Pe. tangliangi Chen with Pe. ichneumoneus (Westwood) and Ps. continentalis Zia & Chen with Ps. angustifasciatus Zia & Chen.

Is Drosophila Dpp/BMP morphogen spreading required for wing patterning and growth?

Secreted signaling molecules act as morphogens to control patterning and growth in many developing tissues. Since locally produced morphogens spread to form a concentration gradient in the surrounding tissue, spreading is generally thought to be the key step in the non-autonomous actions. Here, we review recent advances in tool development to investigate morphogen function using the role of decapentaplegic (Dpp)/bone morphogenetic protein (BMP)-type ligandin the Drosophila wing disc as an example. By applying protein binder tools to distinguish between the roles of Dpp spreading and local Dpp signaling, we found that Dpp signaling in the source cells is important for wing patterning and growth but Dpp spreading from this source cells is not as strictly required as previously thought. Given recent studies showing unexpected requirements of long-range action of different morphogens, manipulating endogenous morphogen gradients by synthetic protein binder tools could shed more light on how morphogens act in developing tissues.

Subtle Introgression Footprints at the End of the Speciation Continuum in a Clade of Heliconius Butterflies.

Quantifying gene flow between lineages at different stages of the speciation continuum is central to understanding speciation. Heliconius butterflies have undergone an adaptive radiation in wing color patterns driven partly by natural selection for local mimicry. Color patterns are also known to be used as assortative mating cues. Therefore, wing pattern divergence is considered to play a role in speciation. A corollary is that mimicry between closely related species may be associated with hybridization and interfere with reproductive isolation. Here, we take a multifaceted approach to explore speciation history, species boundaries, and traits involved in species differentiation between the two closely related species, Heliconius hecale and Heliconius ismenius. We focus on geographic regions where the two species mimic each other and contrast this with geographic regions where they do not mimic each other. To examine population history and patterns of gene flow, we tested and compared a four-population model accounting for linked selection. This model suggests that the two species have remained isolated for a large part of their history, yet with a small amount of gene exchange. Accordingly, signatures of genomic introgression were small except at a major wing pattern allele and chemosensing genes and stronger in the mimetic populations compared with nonmimetic populations. Behavioral assays confirm that visual confusion exists but that short-range cues determine strong sexual isolation. Tests for chemical differentiation between species identified major differences in putative pheromones which likely mediate mate choice and the maintenance of species differences.

Taxonomic and diagnostic notes on the Catopta kendevanensis Daniel, 1937 species group (Lepidoptera: Cossidae) in the Middle East

We describe for the first time the male genitalia of four little studied taxa of carpenter moths of the genus Catopta in the Middle East, namely C. kendevanensis Daniel, 1937, C. anjumanica Daniel, 1964, C. rocharva Sheljuzhko, 1943 and C. eberti Daniel, 1964, as well as the female genitalia of C. kendevanensis. Catopta anjumanica stat. n. is upgraded from subspecies of C. kendevanensis to the species level. The wing pattern of holotypes C. kendevanensis, C. anjumanica and C. eberti are illustrated. A distribution map is provided for all species. http://www.zoobank.org/urn:lsid:zoobank.org:pub:FAB42D8C-646E-46AF-8AD4-3BCE178B4BF3

New records of Lasiocampidae (Lepidoptera) from Zanzibar Island with taxonomic notes and description of one new species of Odontopacha Aurivillius, 1909.

Seven genera and seven species of Lasiocampidae are newly recorded from the Zanzibar Island (Unguja): Bombycopsis C. & R. Felder, 1874 with Bombycopsis nigrovittata Aurivillius, 1927; Pallastica Zolotuhin & Gurkovich, 2009 with an unidentified species; Dollmania Tams, 1930 with an unidentified species; Mallocampa Aurivillius, 1902 with Mallocampa leighi Aurivillius, 1922; Eucraera Tams, 1930 with Eucraera witti Prozorov, 2016; Philotherma Möschler, 1887 with Philotherma montibia Strand, 1912; and Odontopacha Aurivillius, 1909 with Odontopacha fenestrata Aurivillius, 1909. The species are followed with taxonomic notes updating the status and distribution of the taxa. Bombycopsis nigrovittata is shown to have the maximum p-distance of 0.3% in cytochrome c oxidase I from Bombycopsis pallida Joannou & Krüger, 2009. Two specimens of Pallastica sp. from Zanzibar are different in wing coloration but identical genetically, both are 0.8-1.2% far from sequenced specimens collected in southern Malawi and eastern Zimbabwe and altogether 3.0-3.8% far from the Zambian and Malawian populations considered to be Pallastica pallens (Bethune-Baker, 1908). The barcoding revealed two distinct lineages of Dollmania in Tanzania with a p-distance of 3.5-3.7% between them, neither can be attributed to either Dollmania marwitzi (Strand, 1913) or Dollmania reussi (Strand, 1913) until the primary types or fresh topotypes are sequenced. The species Ph. montibia is taken out from the synonymy to Philotherma rosa (Druce, 1887) and is stated to be a bona species because of the difference in wing pattern and p-distance of 5.7-5.9%. A new species of the genus Odontopacha - Odontopacha dargei sp. n. - is described from southern Kenya and northern Tanzania where it occurs sympatrically with O. fenestrata. It differs from O. fenestrata by the paler coloration with the spotted external fascia on both wings and a p-distance of 3.04-3.65%. Lectotypes for D. marwitzi and Ph. montibia are established. Mallocampa leighi is recorded from Tanzania for the first time. Females of Chrysopsyche lutulenta Tams, 1923 earlier recorded from Zanzibar Island are figured and the species is recorded from DRC for the first time.

The Nemourinae (Insecta, Nemouridae) of the eastern Nearctic.

Morphology-based concepts of the 26 eastern Nearctic species of the subfamily Nemourinae (Insecta, Nemouridae) Billberg, 1820 are reviewed. Nemourinae is represented in this region by Nemoura Latrielle, 1796, Ostrocerca Ricker, 1952, Paranemoura Needham & Claassen, 1925, Podmosta Ricker, 1952, Prostoia Ricker, 1952, Shipsa Ricker, 1952, Soyedina Ricker, 1952, and Zapada Ricker, 1952. Wing venation and patterns of mottling are depicted with standard light microscopy. Diagnostic external reproductive structures are emphasized with line drawings, scanning electron microscopy, and standard light microscopy. A genus-level key to male and female adults is included. Species-level keys for Ostrocerca, Paranemoura, Prostoia, Soyedina, and Zapada are also provided.

Assessment of wing geometric morphometrics of urban Culex quinquefasciatus (Diptera: Culicidae) populations

Culex quinquefasciatus is a cosmopolitan species distributed throughout tropical and subtropical areas of the world. The species is of great epidemiological importance as it is responsible for vectoring the causative agent of lymphatic filariasis and several arboviruses, including West Nile virus. Wing geometric morphometrics has been widely used to assess phenotypic variations in mosquito species. Here, we hypothesize that Cx. quinquefasciatus populations in urban parks in the city of São Paulo, Brazil, have been subjected to anthropogenic selective pressures that are responsible for driving their ecology and behavior. Mosquitoes were collected by CDC traps in five municipal parks in the city of São Paulo. Eighteen anatomical landmark coordinates on each female right wing were digitized. Canonical variate analysis, wireframe graphs, cross-validated reclassification tests and the neighbor-joining method were used to assess phenotypical dissimilarity in wing shape between populations. Centroid size was calculated to assess differences in wing size between populations, which can result from different environmental conditions during immature mosquito development. Moderately heterogeneous wing shape and wing size patterns were found in the populations analyzed, indicating that selective pressures in the urban environment are affecting the wing patterns of Cx. quinquefasciatus populations in the city of São Paulo, Brazil.

Issue Information

Molecular EcologyVolume 32, Issue 12 p. i-ii ISSUE INFORMATIONFree Access Issue Information First published: 05 June 2023 https://doi.org/10.1111/mec.16518AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Graphical Abstract Cover Illustrations: Male (left) and female (right) squinting bush brown Bicyclus anynana butterflies learn mate preferences for each other's wing patterns. However, they learn preferences for different traits, and exhibit sexually dimorphic brain and sensory gene expression during this learning process. Photo Credit: Sushant Potdar. Volume32, Issue12June 2023Pages i-ii RelatedInformation

Aristaless1 has a dual role in appendage formation and wing color specification during butterfly development

BackgroundHighly diverse butterfly wing patterns have emerged as a powerful system for understanding the genetic basis of phenotypic variation. While the genetic basis of this pattern variation is being clarified, the precise developmental pathways linking genotype to phenotype are not well understood. The gene aristaless, which plays a role in appendage patterning and extension, has been duplicated in Lepidoptera. One copy, aristaless1, has been shown to control a white/yellow color switch in the butterfly Heliconius cydno, suggesting a novel function associated with color patterning and pigmentation. Here we investigate the developmental basis of al1 in embryos, larvae, and pupae using new antibodies, CRISPR/Cas9, RNAi, qPCR assays of downstream targets, and pharmacological manipulation of an upstream activator.ResultsWe find that Al1 is expressed at the distal tips of developing embryonic appendages consistent with its ancestral role. In developing wings, we observe Al1 accumulation within developing scale cells of white H. cydno during early pupation while yellow scale cells exhibit little Al1 at this time point. Reduced Al1 expression is also associated with yellow scale development in al1 knockouts and knockdowns. We propose that Al1 expression in future white scales might be related to an observed downregulation of the enzyme Cinnabar and other genes that synthesize and transport the yellow pigment, 3–hydroxykynurenine (3-OHK). Finally, we provide evidence that Al1 activation is under the control of Wnt signaling.ConclusionsWe propose a model in which high levels of Al1 during early pupation, which are mediated by Wnt, are important for melanic pigmentation and specifying white portions of the wing while reduced levels of Al1 during early pupation promote upregulation of proteins needed to move and synthesize 3-OHK, promoting yellow pigmentation. In addition, we discuss how the ancestral role of aristaless in appendage extension may be relevant in understanding the cellular mechanism behind color patterning in the context of the heterochrony hypothesis.

MicroRNA miR-252-5p regulates the Notch signaling pathway by targeting Rab6 in Drosophila wing development.

The Notch signaling pathway plays a central role in the development of various organisms. However, dysregulation of microRNAs (miRNAs), which are crucial regulators of gene expression, can disrupt signaling pathways at all stages of development. Although Notch signaling is involved in wing development in Drosophila, the mechanism underlying miRNA-based regulation of the Notch signaling pathway is unclear. Here, we report that loss of Drosophila miR-252 increases the size of adult wings, whereas the overexpression of miR-252 in specific compartments of larval wing discs leads to patterning defects in the adult wings. The miR-252 overexpression-induced wing phenotypes were caused by aberrant Notch signaling with intracellular accumulation of the full-length Notch receptor during development, which could be due to defects in intracellular Notch trafficking associated with its recycling to the plasma membrane and autophagy-mediated degradation. Moreover, we identified Rab6 as a direct target of miR-252-5p; Rab6 encodes a small Ras-like GTPase that regulates endosomal trafficking pathways. Consistent with this finding, RNAi-mediated downregulation of Rab6 led to similar defects in both wing patterning and Notch signaling. Notably, co-overexpression of Rab6 completely rescued the wing phenotype associated with miR-252 overexpression, further supporting that Rab6 is a biologically relevant target of miR-252-5p in the context of wing development. Thus, our data indicate that the miR-252-5p-Rab6 regulatory axis is involved in Drosophila wing development by controlling the Notch signaling pathway.

A new subspecies of Philiris diana Waterhouse & Lyell, 1914 (Lepidoptera: Lycaenidae) from the Wet Tropics of northern Australia

Philiris diana Waterhouse & Lyell, 1914 from the Wet Tropics of northeastern Queensland was previously thought to be monotypic, being most closely related to Philiris papuanus Wind & Clench, 1947 from Cape York Peninsula, Australia, and mainland New Guinea. However, a new subspecies was recently discovered on the Atherton Tableland, which we illustrate, diagnose and describe as Philiris diana fortuna ssp. nov. It appears to be a narrow-range endemic, restricted to montane forest (750–1,090 m asl) and allopatric or parapatric from the nominotypical subspecies Philiris diana diana Waterhouse & Lyell, 1914, which is largely restricted to low to mid-altitude forests in the coastal escarpment in the Cairns-Kuranda district. Despite being separated by a minimum distance of only 20–25 km, the two taxa show substantial phenotypic differences in wing pattern elements, but negligeable differences according to the mitochondrial COI barcode region (mean p-distance = 0.28%). The habitat and biology of the new taxon are summarized, and likely historical processes driving divergence between upland and lowland populations of this species hypothesized.

The genetic basis of wing spots in Pieris canidia butterflies

Spots in pierid butterflies and eyespots in nymphalid butterflies are likely non-homologous wing colour pattern elements, yet they share a few features in common. Both develop black scales that depend on the function of the gene spalt, and both might have central signalling cells. This suggests that both pattern elements may be sharing common genetic circuitry. Hundreds of genes have already been associated with the development of nymphalid butterfly eyespot patterns, but the genetic basis of the simpler spot patterns on the wings of pierid butterflies has not been investigated. To facilitate studies of pierid wing patterns, we report a high-quality draft genome assembly for Pieris canidia, the Indian cabbage white. We then conducted transcriptomic analyses of pupal wing tissues sampled from the spot and non-spot regions of P. canidia at 3-6 h post-pupation. A total of 1352 genes were differentially regulated between wing tissues with and without the black spot, including spalt, Krüppel-like factor 10, genes from the Toll, Notch, TGF-β, and FGFR signalling pathways, and several genes involved in the melanin biosynthetic pathway. We identified 14 genes that are up-regulated in both pierid spots and nymphalid eyespots and propose that spots and eyespots share regulatory modules despite their likely independent origins.

RNAi screen in the Drosophila wing of genes encoding proteins related to cytoskeleton organization and cell division

Cell division and cytoskeleton organization are fundamental processes participating in the development of Drosophila imaginal discs. In this manuscript we describe the phenotypes in the adult fly wing generated by knockdowns of 85% of Drosophila genes encoding proteins likely related to the regulation of cell division and cytoskeleton organization. We also compile a molecular classification of these proteins into classes that describe their expected or known main biochemical characteristics, as well as mRNA expression in the wing disc and likely protein subcellular localization for a subset of these genes. Finally, we analyze in more detail one protein family of cytoskeleton genes (Arp2/3 complex), and define the consequences of interfering with cell division for wing growth and patterning.

A learning experience elicits sex-dependent neurogenomic responses in Bicyclus anynana butterflies.

Sexually dimorphic behaviour is pervasive across animals, with males and females exhibiting different mate selection, parental care, foraging, dispersal, and territorial strategies. However, the genetic underpinnings of sexually dimorphic behaviours are poorly understood. Here we investigate gene networks and expression patterns associated with sexually dimorphic imprinting-like learning in the butterfly Bicyclus anynana. In this species, both males and females learn visual preferences, but learn preferences for different traits and use different signals as salient, unconditioned cues. To identify genes and gene networks associated with this behaviour, we examined gene expression profiles of the brains and eyes of male and female butterflies immediately post training and compared them to the same tissues of naïve individuals. We found more differentially expressed genes and a greater number of associated gene networks in the eyes, indicating a role of the peripheral nervous system in visual imprinting-like learning. Females had higher chemoreceptor expression levels than males, supporting the hypothesized sexual dimorphic use of chemical cues during the learning process. In addition, genes that influence B. anynana wing patterns (sexual ornaments), such as invected, spalt, and apterous, were also differentially expressed in the brain and eye, suggesting that these genes may influence both sexual ornaments and the preferences for these ornaments. Our results indicate dynamic and sex-specific responses to social scenario in both the peripheral and central nervous systems and highlight the potential role of wing patterning genes in mate preference and learning across the Lepidoptera.

High level of novelty under the hood of convergent evolution.

Little is known about the extent to which species use homologous regulatory architectures to achieve phenotypic convergence. By characterizing chromatin accessibility and gene expression in developing wing tissues, we compared the regulatory architecture of convergence between a pair of mimetic butterfly species. Although a handful of color pattern genes are known to be involved in their convergence, our data suggest that different mutational paths underlie the integration of these genes into wing pattern development. This is supported by a large fraction of accessible chromatin being exclusive to each species, including the de novo lineage-specific evolution of a modular optix enhancer. These findings may be explained by a high level of developmental drift and evolutionary contingency that occurs during the independent evolution of mimicry.

Description of Culicoides truuskae sp. n. (Diptera: Ceratopogonidae) from southern Africa

Culicoides truuskaeLabuschagne and Meiswinkel sp. n. is described and illustrated in both sexes from material collected in South Africa and Namibia. It is restricted to the xeric western margin of the subcontinent, occurring in Fynbos, Nama-Karoo and Succulent Karoo ecoregions in South Africa and Desert and Savanna ecoregions in Namibia experiencing 600 mm of rainfall annually.Culicoides truuskaesp. n. is part of the Afrotropical 'plain-wing'Culicoidesin which the wing lacks a distinguishing pattern of light and dark spots; the diagnostic dark smudge that traverses wing cell r3 may result inC. truuskaesp. n. being misidentified as the sympatric but phyletically unrelatedCulicoides herero(Enderlein) - (of the Similis group, subgenus Oecacta Poey). Additionally, this study is the first description of the male ofC. herero. C. truuskaesp. n. andCulicoides coarctatusClastrier and Wirth share similar characters in the male genitalia, although the two species are separable on wing pattern and female flagellum sensilla coeloconica (SCo) distribution. The breeding habitat and adult female blood-feeding preferences of C.truuskaesp. n. are not known. A maximum likelihood phylogenetic tree, using mitochondrialcytochrome c oxidaseI (COI) sequence data, is provided to further clarify the relationship betweenC. truuskaesp. n.,C. coarctatusandC. herero. Extensive light trap data, collected over 30 years, are used to map the distribution ranges ofC. truuskaesp. n.,C. coarctatusandC. hereroin Southern Africa.Contribution:The description of this new species and the description of the male ofC. hereroincreases our understanding of the diversity and distribution ofCulicoidesspecies in southern Africa.

Developmental, Reproduction, and Feeding Preferences of the Sitobion avenae Mediated by Soil Silicon Application.

Silicon occupies an important position in the nutrient requirements of wheat. It has been reported that silicon enhances plant resistance to phytophagous insects. However, only limited research has been carried out on the effects of silicon application to wheat and Sitobion avenae populations. In this study, three silicon fertilizer concentrations were treated for potted wheat seedlings, including 0 g/L, 1 g/L, and 2 g/L of water-soluble silicon fertilizer solution. The effect of silicon application on the developmental period, longevity, reproduction, wing pattern differentiation, and other vital life table parameters of the S. avenae were determined. The cage method and the Petri dish isolated leaf method were used to determine the effect of silicon application on the feeding preference of the winged and wingless aphid. The results showed silicon application had no significant effect on the aphid instar of 1-4; although, 2 g/L silicon fertilizer prolonged the nymph stage and 1 and 2 g/L of silicon application all shortened the adult stage and reduced the longevity and fertility of the aphid. Two instances of silicon application reduced the net reproductive rate (R0), intrinsic rate of increase (rm), and finite rate of increase (λ) of the aphid. A 2 g/L silicon application prolonged the population doubling time (td), significantly reduced the mean generation time (T), and increased the proportion of winged aphids. The results also demonstrated that the selection ratio of winged aphids in wheat leaves treated with 1 g/L and 2 g/L silicon was reduced by 8.61% and 17.88%, respectively. The number of aphids on leaves treated with 2 g/L silicon was significantly reduced at 48 and 72 h of aphids released, and the application of silicon to wheat was detrimental to the feeding preference of S. avenae. Therefore, the application of silicon at 2 g/L to wheat has an inhibitory effect on the life parameters and feeding preference of S. avenae.

The Genetic Mechanisms Underlying the Concerted Expression of the yellow and tan Genes in Complex Patterns on the Abdomen and Wings of Drosophila guttifera.

How complex morphological patterns form is an intriguing question in developmental biology. However, the mechanisms that generate complex patterns remain largely unknown. Here, we sought to identify the genetic mechanisms that regulate the tan (t) gene in a multi-spotted pigmentation pattern on the abdomen and wings of Drosophila guttifera. Previously, we showed that yellow (y) gene expression completely prefigures the abdominal and wing pigment patterns of this species. In the current study, we demonstrate that the t gene is co-expressed with the y gene in nearly identical patterns, both transcripts foreshadowing the adult abdominal and wing melanin spot patterns. We identified cis-regulatory modules (CRMs) of t, one of which drives reporter expression in six longitudinal rows of spots on the developing pupal abdomen, while the second CRM activates the reporter gene in a spotted wing pattern. Comparing the abdominal spot CRMs of y and t, we found a similar composition of putative transcription factor binding sites that are thought to regulate the complex expression patterns of both terminal pigmentation genes y and t. In contrast, the y and t wing spots appear to be regulated by distinct upstream factors. Our results suggest that the D. guttifera abdominal and wing melanin spot patterns have been established through the co-regulation of y and t, shedding light on how complex morphological traits may be regulated through the parallel coordination of downstream target genes.

Dominance mechanisms in supergene alleles controlling butterfly wing pattern variation: insights from gene expression in Heliconius numata.

Loci under balancing selection, where multiple alleles are maintained, offer a relevant opportunity to investigate the role of natural selection in shaping genetic dominance: the high frequency of heterozygotes at these loci has been shown to enable the evolution of dominance among alleles. In the butterfly Heliconius numata, mimetic wing color variations are controlled by an inversion polymorphism of a circa 2 Mb genomic region (supergene P), with strong dominance between sympatric alleles. To test how differences in dominance observed on wing patterns correlate with variations in expression levels throughout the supergene region, we sequenced the complete transcriptome of heterozygotes at the prepupal stage and compared it to corresponding homozygotes. By defining dominance based on non-overlapping ranges of transcript expression between genotypes, we found contrasting patterns of dominance between the supergene and the rest of the genome; the patterns of transcript expression in the heterozygotes were more similar to the expression observed in the dominant homozygotes in the supergene region. Dominance also differed among the three subinversions of the supergene, suggesting possible epistatic interactions among their gene contents underlying dominance evolution. We found the expression pattern of the melanization gene cortex located in the P-region to predict wing pattern phenotype in the heterozygote. We also identify new candidate genes that are potentially involved in mimetic color pattern variations highlighting the relevance of transcriptomic analyses in heterozygotes to pinpoint candidate genes in non-recombining regions.

Temnolopha paucusinota Muadsub & Pinkaew (Lepidoptera: Tortricidae: Olethreutinae), a new species from Thailand

Temnolopha paucusinota sp. nov. from Thailand is described as new to science. Two specimens, a male and a female were collected in Phu Kheio Wildlife Sanctuary, northeastern Thailand. Due to more complete wing pattern, the female specimen is selected as the holotype. Illustrations of adults and genitalia are provided. An identification key of Thai Temnolopha species is also provided. This new species increases the number of described Temnolopha species to five worldwide.