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The Ornate Moth, Utetheisa ornatrix, has served as a model species in chemical ecology studies for decades. Like in the widely publicized stories of the Monarch and other milkweed butterflies, the Ornate Moth and its relatives are tropical insects colonizing whole continents assisted by their chemical defenses. With the recent advances in genomic techniques and evo-devo research, it is becoming a model for studies in other areas, from wing pattern development to phylogeography, from toxicology to epigenetics. We used a genomic approach to learn about Utetheisa's evolution, detoxification, dispersal abilities, and wing pattern diversity. We present an evolutionary genomic analysis of the worldwide genus Utetheisa, then focusing on U. ornatrix. Our reference genome of U. ornatrix reveals gene duplications in the regions possibly associated with detoxification abilities, which allows them to feed on toxic food plants. Finally, comparative genomic analysis of over 100 U. ornatrix specimens from the museum with apparent differences in wing patterns suggest the potential roles of cortex and lim3 genes in wing pattern formation of Lepidoptera and the utility of museum-preserved collection specimens for wing pattern research.
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Mariposas Diurnas , Mariposas Nocturnas , Animales , Mariposas Nocturnas/genética , Mariposas Diurnas/genética , Genómica , Alas de AnimalesRESUMEN
Long-distance migrations of insects contribute to ecosystem functioning but also have important economic impacts when the migrants are pests or provide ecosystem services. We combined radar monitoring, aerial sampling, and searchlight trapping, to quantify the annual pattern of nocturnal insect migration above the densely populated agricultural lands of East China. A total of ~9.3 trillion nocturnal insect migrants (15,000 t of biomass), predominantly Lepidoptera, Hemiptera, and Diptera, including many crop pests and disease vectors, fly at heights up to 1 km above this 600 km-wide region every year. Larger migrants (>10 mg) exhibited seasonal reversal of movement directions, comprising northward expansion during spring and summer, followed by southward movements during fall. This north-south transfer was not balanced, however, with southward movement in fall 0.66× that of northward movement in spring and summer. Spring and summer migrations were strongest when the wind had a northward component, while in fall, stronger movements occurred on winds that allowed movement with a southward component; heading directions of larger insects were generally close to the track direction. These findings indicate adaptations leading to movement in seasonally favorable directions. We compare our results from China with similar studies in Europe and North America and conclude that ecological patterns and behavioral adaptations are similar across the Northern Hemisphere. The predominance of pests among these nocturnal migrants has severe implications for food security and grower prosperity throughout this heavily populated region, and knowledge of their migrations is potentially valuable for forecasting pest impacts and planning timely management actions.
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Altitud , Migración Animal , Estaciones del Año , Animales , China , Migración Animal/fisiología , Agricultura/métodos , Ecosistema , Insectos/fisiología , Viento , Vuelo Animal/fisiologíaRESUMEN
Two robust rules have been discovered about animal hybrids: Heterogametic hybrids are more unfit (Haldane's rule), and sex chromosomes are disproportionately involved in hybrid incompatibility (the large-X/Z effect). The exact mechanisms causing these rules in female heterogametic taxa such as butterflies are unknown but are suggested by theory to involve dominance on the sex chromosome. We investigate hybrid incompatibilities adhering to both rules in Papilio and Heliconius butterflies and show that dominance theory cannot explain our data. Instead, many defects coincide with unbalanced multilocus introgression between the Z chromosome and all autosomes. Our polygenic explanation predicts both rules because the imbalance is likely greater in heterogametic females, and the proportion of introgressed ancestry is more variable on the Z chromosome. We also show that mapping traits polygenic on a single chromosome in backcrosses can generate spurious large-effect QTLs. This mirage is caused by statistical linkage among polygenes that inflates estimated effect sizes. By controlling for statistical linkage, most incompatibility QTLs in our hybrid crosses are consistent with a polygenic basis. Since the two genera are very distantly related, polygenic hybrid incompatibilities are likely common in butterflies.
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Mariposas Diurnas , Animales , Femenino , Mariposas Diurnas/genética , Hibridación Genética , Modelos Genéticos , Cromosomas SexualesRESUMEN
Species frequently differ in the number and structure of chromosomes they harbor, but individuals that are heterozygous for chromosomal rearrangements may suffer from reduced fitness. Chromosomal rearrangements like fissions and fusions can hence serve as a mechanism for speciation between incipient lineages, but their evolution poses a paradox. How can rearrangements get fixed between populations if heterozygotes have reduced fitness? One solution is that this process predominantly occurs in small and isolated populations, where genetic drift can override natural selection. However, fixation is also more likely if a novel rearrangement is favored by a transmission bias, such as meiotic drive. Here, we investigate chromosomal transmission distortion in hybrids between two wood white (Leptidea sinapis) butterfly populations with extensive karyotype differences. Using data from two different crossing experiments, we uncover that there is a transmission bias favoring the ancestral chromosomal state for derived fusions, a result that shows that chromosome fusions actually can fix in populations despite being counteracted by meiotic drive. This means that meiotic drive not only can promote runaway chromosome number evolution and speciation, but also that it can be a conservative force acting against karyotypic change and the evolution of reproductive isolation. Based on our results, we suggest a mechanistic model for why chromosome fusion mutations may be opposed by meiotic drive and discuss factors contributing to karyotype evolution in Lepidoptera.
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Mariposas Diurnas , Meiosis , Animales , Mariposas Diurnas/genética , Meiosis/genética , Hibridación Genética , Cariotipo , Cromosomas de Insectos/genética , Femenino , MasculinoRESUMEN
SignificanceGenes on sex chromosomes (i.e. human chX) are regulated differently in males and females to balance gene expression levels between sexes (XY vs. XX). This sex-specific regulation is called dosage compensation (DC). DC is achieved by altering the shape and compaction of sex chromosomes specifically in one sex. In this study, we use Oligopaints to examine DC in silkworms. This study visualizes this phenomenon in a species with ZW sex chromosomes, which evolved independently of XY. Our data support a long-standing model for how DC mechanisms evolved across species, and we show potential similarity between DC in silkworms and nematodes, suggesting that this type of DC may have emerged multiple independent times throughout evolution.
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Bombyx/genética , Cromosomas de Insectos/genética , Compensación de Dosificación (Genética) , Cromosomas Sexuales/genética , AnimalesRESUMEN
Muga silkworm (Antheraea assamensis), one of the economically important wild silkmoths, is unique among saturniid silkmoths. It is confined to the North-eastern part of India. Muga silk has the highest value among the other silks. Unlike other silkmoths, A. assamensis has a low chromosome number (n = 15), and ZZ/ZO sex chromosome system. Here, we report the first high-quality draft genome of A. assamensis, assembled by employing the Illumina and PacBio sequencing platforms. The assembled genome of A. assamensis is 501.18 Mb long, with 2697 scaffolds and an N50 of 683.23 Kb. The genome encompasses 18,385 protein-coding genes, 86.29% of which were functionally annotated. Phylogenetic analysis of A. assamensis revealed its divergence from other Antheraea species approximately 28.7 million years ago. Moreover, an investigation into detoxification-related gene families, CYP450, GST, and ABC-transporter, revealed a significant expansion in A. assamensis as compared to the Bombyx mori. This expansion is comparable to Spodoptera litura, suggesting adaptive responses linked to the polyphagous behavior observed in these insects. This study provides valuable insights into the molecular basis of evolutionary divergence and adaptations in muga silkmoth. The genome assembly reported in this study will significantly help in the functional genomics studies on A. assamensis and other Antheraea species along with comparative genomics analyses of Bombycoidea insects.
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Genoma de los Insectos , Mariposas Nocturnas , Filogenia , Animales , Mariposas Nocturnas/genética , Mariposas Nocturnas/clasificación , Secuenciación Completa del Genoma , Anotación de Secuencia MolecularRESUMEN
Research over the past 30 years has led to a widespread acceptance that insects establish widespread and diverse associations with microorganisms. More recently, microbiome research has been accelerating in lepidopteran systems, leading to a greater understanding of both endosymbiont and gut microorganisms and how they contribute to integral aspects of the host. Lepidoptera are associated with a robust assemblage of microorganisms, some of which may be stable and routinely detected in larval and adult hosts, while others are ephemeral and transient. Certain microorganisms that populate Lepidoptera can contribute significantly to the hosts' performance and fitness, while others are inconsequential. We emphasize the context-dependent nature of the interactions between players. While our review discusses the contemporary literature, there are major avenues yet to be explored to determine both the fundamental aspects of host-microbe interactions and potential applications for the lepidopteran microbiome; we describe these avenues after our synthesis.
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Lepidópteros , Microbiota , Animales , LarvaRESUMEN
BACKGROUND: The order Lepidoptera has an abundance of species, including both agriculturally beneficial and detrimental insects. Molecular data has been used to investigate the phylogenetic relationships of major subdivisions in Lepidoptera, which has enhanced our understanding of the evolutionary relationships at the family and superfamily levels. However, the phylogenetic placement of many superfamilies and/or families in this order is still unknown. In this study, we determine the systematic status of the family Argyresthiidae within Lepidoptera and explore its phylogenetic affinities and implications for the evolution of the order. We describe the first mitochondrial (mt) genome from a member of Argyresthiidae, the apple fruit moth Argyresthia conjugella. The insect is an important pest on apples in Fennoscandia, as it switches hosts when the main host fails to produce crops. RESULTS: The mt genome of A. conjugella contains 16,044 bp and encodes all 37 genes commonly found in insect mt genomes, including 13 protein-coding genes (PCGs), two ribosomal RNAs, 22 transfer RNAs, and a large control region (1101 bp). The nucleotide composition was extremely AT-rich (82%). All detected PCGs (13) began with an ATN codon and terminated with a TAA stop codon, except the start codon in cox1 is ATT. All 22 tRNAs had cloverleaf secondary structures, except trnS1, where one of the dihydrouridine (DHU) arms is missing, reflecting potential differences in gene expression. When compared to the mt genomes of 507 other Lepidoptera representing 18 superfamilies and 42 families, phylogenomic analyses found that A. conjugella had the closest relationship with the Plutellidae family (Yponomeutoidea-super family). We also detected a sister relationship between Yponomeutoidea and the superfamily Tineidae. CONCLUSIONS: Our results underline the potential importance of mt genomes in comparative genomic analyses of Lepidoptera species and provide valuable evolutionary insight across the tree of Lepidoptera species.
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Genoma Mitocondrial , Lepidópteros , Malus , Mariposas Nocturnas , Humanos , Animales , Mariposas Nocturnas/genética , Malus/genética , Filogenia , Frutas , Lepidópteros/genética , ARN de Transferencia/genética , Codón de TerminaciónRESUMEN
Color vision in insects is determined by signaling cascades, central to which are opsin proteins, resulting in sensitivity to light at different wavelengths. In certain insect groups, lineage-specific evolution of opsin genes, in terms of copy number, shifts in expression patterns, and functional amino acid substitutions, has resulted in changes in color vision with subsequent behavioral and niche adaptations. Lepidoptera are a fascinating model to address whether evolutionary change in opsin content and sequence evolution are associated with changes in vision phenotype. Until recently, the lack of high-quality genome data representing broad sampling across the lepidopteran phylogeny has greatly limited our ability to accurately address this question. Here, we annotate opsin genes in 219 lepidopteran genomes representing 33 families, reconstruct their evolutionary history, and analyze shifts in selective pressures and expression between genes and species. We discover 44 duplication events in opsin genes across â¼300 million years of lepidopteran evolution. While many duplication events are species or family specific, we find retention of an ancient long-wavelength-sensitive (LW) opsin duplication derived by retrotransposition within the speciose superfamily Noctuoidea (in the families Nolidae, Erebidae, and Noctuidae). This conserved LW retrogene shows life stage-specific expression suggesting visual sensitivities or other sensory functions specific to the early larval stage. This study provides a comprehensive order-wide view of opsin evolution across Lepidoptera, showcasing high rates of opsin duplications and changes in expression patterns.
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Visión de Colores , Lepidópteros , Humanos , Animales , Opsinas/genética , Duplicación de Gen , Lepidópteros/genética , Evolución Molecular , Opsinas de Bastones/química , Opsinas de Bastones/genética , Insectos/genética , Filogenia , Expresión GénicaRESUMEN
Butterflies, like many insects, use gustatory and olfactory cues innately to assess the suitability of an oviposition site and are able to associate colours and leaf shapes with an oviposition reward. Studies on other insects have demonstrated that the quality of the reward is a crucial factor in forming associative memory. We set out to investigate whether the large cabbage white Pieris brassicae (Linnaeus) has the ability to associate an oviposition experience with a neutral olfactory cue. In addition, we tested whether the strength of this association is dependent on the gustatory response to the glucosinolate sinigrin, which is a known oviposition stimulus for P. brassicae. Female butterflies were able to associate a neutral odour with an oviposition experience after a single oviposition experience, both in a greenhouse and in a semi-natural outdoor setting. Moreover, butterflies performed best when trained with concentrations of sinigrin that showed the strongest response by specific gustatory neurons on the forelegs. Our study provides novel insight into the role of both gustatory and olfactory cues during oviposition learning in lepidopterans and contributes to a better understanding of how these insects might be able to adapt to a rapidly changing environment.
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Mariposas Diurnas , Señales (Psicología) , Aprendizaje , Oviposición , Animales , Mariposas Diurnas/fisiología , Femenino , Glucosinolatos/metabolismo , Olfato , Odorantes/análisisRESUMEN
Temporal ecological niche partitioning is an underappreciated driver of speciation. While insects have long been models for circadian biology, the genes and circuits that allow adaptive changes in diel-niches remain poorly understood. We compared gene expression in closely related day- and night-active non-model wild silk moths, with otherwise similar ecologies. Using an ortholog-based pipeline to compare RNA-Seq patterns across two moth species, we find over 25 pairs of gene orthologs showing differential expression. Notably, the gene disco, involved in circadian control, optic lobe and clock neuron development in Drosophila, shows robust adult circadian mRNA cycling in moth heads. Disco is highly conserved in moths and has additional zinc-finger domains with specific nocturnal and diurnal mutations. We propose disco as a candidate gene for the diversification of temporal diel-niche in moths.
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Ritmo Circadiano , Mariposas Nocturnas , Animales , Mariposas Nocturnas/genética , Mariposas Nocturnas/crecimiento & desarrollo , Mariposas Nocturnas/fisiología , Proteínas de Insectos/genética , Proteínas de Insectos/metabolismo , Evolución Biológica , Expresión GénicaRESUMEN
Organisms inhabiting highly seasonal environments must cope with a wide range of environmentally induced challenges. Many seasonal challenges require extensive physiological modification to survive. In winter, to survive extreme cold and limited resources, insects commonly enter diapause, which is an endogenously derived dormant state associated with minimized cellular processes and low energetic expenditure. Due to the high degree of complexity involved in diapause, substantial cellular regulation is required, of which our understanding primarily derives from the transcriptome via messenger RNA expression dynamics. Here we aim to advance our understanding of diapause by investigating microRNA (miRNA) expression in diapausing and direct developing pupae of the butterfly Pieris napi. We identified coordinated patterns of miRNA expression throughout diapause in both head and abdomen tissues of pupae, and via miRNA target identification, found several expression patterns to be enriched for relevant diapause-related physiological processes. We also identified two candidate miRNAs, miR-14-5p and miR-2a-3p, that are likely involved in diapause progression through their activity in the ecdysone pathway, a critical regulator of diapause termination. miR-14-5p targets phantom, a gene in the ecdysone synthesis pathway, and is upregulated early in diapause. miR-2a-3p has been found to be expressed in response to ecdysone, and is upregulated during diapause termination. Together, the expression patterns of these two miRNAs match our current understanding of the timing of hormonal regulation of diapause in P. napi and provide interesting candidates to further explore the mechanistic role of microRNAs in diapause regulation.
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Fem is a W-linked gene that encodes a piRNA precursor, and its product, Fem piRNA, is a master factor of female determination in Bombyx mori. Fem has low similarity to any known sequences, and the origin of Fem remains unclear. So far, two hypotheses have been proposed for the origin of Fem: The first hypothesis is that Fem is an allele of Masc, which assumes that the W chromosome was originally a homologous chromosome of the Z chromosome. The second hypothesis is that Fem arose by the transposition of Masc to the W chromosome. To explore the origin of Fem, we determined the W chromosome sequences of B. mori and, as a comparison, a closely relative bombycid species of Trilocha varians with a Fem-independent sex determination system. To our surprise, although the sequences of W and Z chromosomes show no homology to each other, a few pairs of homologues are shared by W and Z chromosomes, indicating the W chromosome of both species originated from Z chromosome. In addition, the W chromosome of T. varians lacks Fem, while the W chromosome of B. mori has over 100 copies of Fem. The high-quality assembly of the W chromosome of B. mori arose the third hypothesis about the origin of Fem: Fem is a chimeric sequence of multiple transposons. More than half of one transcriptional unit of Fem shows a significant homology to RTE-BovB. Moreover, the Fem piRNA-producing region could correspond to the boundary of the two transposons, gypsy and satellite DNA.
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Bombyx , Cromosomas Sexuales , Animales , Cromosomas Sexuales/genética , Femenino , Bombyx/genética , Mariposas Nocturnas/genética , ARN Interferente Pequeño/genética , Evolución Molecular , Cromosomas de Insectos/genética , Análisis de Secuencia de ADN , Filogenia , Procesos de Determinación del Sexo/genética , MasculinoRESUMEN
The world's largest butterfly genus Delias, commonly known as Jezebels, comprises ca. 251 species found throughout Asia, Australia, and Melanesia. Most species are endemic to islands in the Indo-Australian Archipelago or to New Guinea and nearby islands in Melanesia, and many species are restricted to montane habitats over 1200 m. We inferred an extensively sampled and well-supported molecular phylogeny of the group to better understand the spatial and temporal dimensions of its diversification. The remarkable diversity of Delias evolved in just ca. 15-16 Myr (crown age). The most recent common ancestor of a clade with most of the species dispersed out of New Guinea ca. 14 Mya, but at least six subsequently diverging lineages dispersed back to the island. Diversification was associated with frequent dispersal of lineages among the islands of the Indo-Australian Archipelago, and the divergence of sister taxa on a single landmass was rare and occurred only on the largest islands, most notably on New Guinea. We conclude that frequent inter-island dispersal during the Neogene-likely facilitated by frequent sea level change-sparked much diversification during that period. Many extant New Guinea lineages started diversifying 5 Mya, suggesting that orogeny facilitated their diversification. Our results largely agree with the most recently proposed species group classification system, and we use our large taxon sample to extend this system to all described species. Finally, we summarize recent insights to speculate how wing pattern evolution, mimicry, and sexual selection might also contribute to these butterflies' rapid speciation and diversification.
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Mariposas Diurnas , Animales , Filogenia , Mariposas Diurnas/genética , Nueva Guinea , Australia , EcosistemaRESUMEN
A robust and stable phylogenetic framework is a fundamental goal of evolutionary biology. As the third largest insect order in the world following Coleoptera and Diptera, Lepidoptera (butterflies and moths) play a central role in almost every terrestrial ecosystem as indicators of environmental change and serve as important models for biologists exploring questions related to ecology and evolutionary biology. However, for such a charismatic insect group, the higher-level phylogenetic relationships among its superfamilies are still poorly resolved. Compared to earlier phylogenomic studies, we increased taxon sampling among Lepidoptera (37 superfamilies and 68 families containing 263 taxa) and acquired a series of large amino-acid datasets from 69,680 to 400,330 for phylogenomic reconstructions. Using these datasets, we explored the effect of different taxon sampling with significant increases in the number of included genes on tree topology by considering a series of systematic errors using maximum-likelihood (ML) and Bayesian inference (BI) methods. Moreover, we also tested the effectiveness in topology robustness among the three ML-based models. The results showed that taxon sampling is an important determinant in tree robustness of accurate lepidopteran phylogenetic estimation. Long-branch attraction (LBA) caused by site-wise heterogeneity is a significant source of bias giving rise to unstable positions of ditrysian groups in phylogenomic reconstruction. Phylogenetic inference showed the most comprehensive framework to reveal the relationships among lepidopteran superfamilies, and presented some newly relationships with strong supports (Papilionoidea was sister to Gelechioidea and Immoidea was sister to Galacticoidea, respectively), but limited by taxon sampling, the relationships within the species-rich and relatively rapid radiation Ditrysia and especially Apoditrysia remain poorly resolved, which need to increase taxon sampling for further phylogenomic reconstruction. The present study demonstrates that taxon sampling is an important determinant for an accurate lepidopteran tree of life and provides some essential insights for future lepidopteran phylogenomic studies.
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Teorema de Bayes , Mariposas Diurnas , Mariposas Nocturnas , Filogenia , Animales , Mariposas Nocturnas/genética , Mariposas Nocturnas/clasificación , Funciones de Verosimilitud , Mariposas Diurnas/genética , Mariposas Diurnas/clasificación , Modelos GenéticosRESUMEN
MicroRNAs (miRNAs) are post-transcriptional gene regulators. In the miRNA pathway's cytoplasmic part, the miRNA is processed from a hairpin-structured precursor to a double-stranded (ds) mature RNA and ultimately to a single-stranded mature miRNA. In insects, ingesting these two ds forms can regulate the target gene expression; this inspired the trophic miRNA's use as a functional genomics and pest management tool. However, systematic studies enabling comparisons of pre- and mature forms, dosages, administration times and instar-wise effects on target transcripts and phenotypes, which can help develop a miRNA administration method, are unavailable due to the different focuses of the previous investigations. We investigated the impact of trophically delivered Px-let-7 miRNA on the lepidopteran pest Plutella xylostella, to compare the efficacies of its pre- and ds-mature forms. Continuous feeding on the miRNA-supplemented diet suppressed expressions of FTZ-F1 and E74, the target ecdysone pathway genes. Both the pre-let-7 and mature let-7 miRNA forms similarly downregulated the target transcripts in all four larval instars. Pre-let-7 and let-7 ingestions decreased larval mass and instar duration and increased mortality in all instars, exhibiting adverse effects on larval growth and development. miRNA processing Dicer-1 and AGO-1's upregulations upon miRNA ingestion denoted the systemic miRNA spread in larval tissues. The scrambled sequence controls did not affect the target transcripts, suggesting the sequence-specific targeting by the mature miRNA and hairpin cassette's non-involvement in the target downregulation. This work provides a framework for miRNA and target gene function analyses and potentiates the trophic miRNA's utility in pest management.
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Transcriptomic data have been used to study sex chromosome dosage compensation (SCDC) in approximately 10 Lepidoptera ZW species, yielding a consensus compensation pattern of Z ≈ ZZ < AA . $$ \approx \mathrm{ZZ}<\mathrm{AA}. $$ It remains unclear whether this compensation pattern holds when examining more Lepidoptera ZW species and/or using proteomic data to analyse SCDC. Here we combined transcriptomic and proteomic data as well as transcriptional level of six individual Z genes to reveal the SCDC pattern in Helicoverpa armigera, a polyphagous lepidopteran pest of economic importance. Transcriptomic analysis showed that the Z chromosome expression of H. armigera was balanced between male and female but substantially reduced relative to autosome expression, exhibiting an SCDC pattern of Z ≈ ZZ < AA $$ \approx \mathrm{ZZ}<\mathrm{AA} $$ . When using H. amigera midgut proteomic data, the SCDC pattern of this species changed from Z ≈ ZZ < AA $$ \approx \mathrm{ZZ}<\mathrm{AA} $$ at transcriptomic level to Z = ZZ = AA at the proteomic level. RT-qPCR analysis of transcript abundance of six Z genes found that compensation for each Z gene could vary from no compensation to overcompensation, depending on the individual genes and tissues tested. These results demonstrate for the first time the existence of a translational compensation mechanism, which is operating in addition to a translational mechanism, such as has been reported in other lepidopteran species. And the transcriptional compensation mechanism functions to accomplish Z chromosome dosage balance between the sexes (M = F on the Z chromosome), whereas the translation compensation mechanism operates to achieve dosage compensation between Z chromosome and autosome (Z = AA).
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Global climate change has been identified as a potential driver of observed insect declines, yet in many regions, there are critical data gaps that make it difficult to assess how communities are responding to climate change. Poleward regions are of particular interest because warming is most rapid while biodiversity data are most sparse. Building on recent advances in occupancy modeling of presence-only data, we reconstructed 50 years (1970-2019) of butterfly occupancy trends in response to rising minimum temperatures in one of the most under-sampled regions of North America. Among 90 modeled species, we found that cold-adapted species are far more often in decline compared with their warm-adapted, more southernly distributed counterparts. Furthermore, in a post hoc analysis using species' traits, we find that species' range-wide average annual temperature is the only consistent predictor of occupancy changes. Species with warmer ranges were most likely to be increasing in occupancy. This trend results in the majority of butterflies increasing in occupancy probability over the last 50 years. Our results provide the first look at macroscale butterfly biodiversity shifts in high-latitude North America. These results highlight the potential of leveraging the wealth of presence-only data, the most abundant source of biodiversity data, for inferring changes in species distributions.
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Mariposas Diurnas , Animales , Mariposas Diurnas/fisiología , Temperatura , Biodiversidad , Cambio Climático , Regiones Árticas , EcosistemaRESUMEN
Recent work has shown the decline of insect abundance, diversity and biomass, with potential implications for ecosystem services. These declines are especially pronounced in regions with high human activity, and urbanization is emerging as a significant contributing factor. However, the scale of these declines and the traits that determine variation in species-specific responses remain less well understood, especially in subtropical and tropical regions, where insect diversity is high and urban footprints are rapidly expanding. Here, we surveyed moths across an entire year in protected forested sites across an urbanization gradient to test how caterpillar and adult life stages of subtropical moths (Lepidoptera) are impacted by urbanization. Specifically, we assess how urban development affects the total biomass of caterpillars, abundance of adult moths and quantify how richness and phylogenetic diversity of macro-moths are impacted by urban development. Additionally, we explore how life-history traits condition species' responses to urban development. At the community level, we find that urban development decreases caterpillar biomass and adult moth abundance. We also find sharp declines of adult macro-moths in response to urban development across the phylogeny, leading to a decrease in species richness and phylogenetic diversity in more urban sites. Finally, our study found that smaller macro-moths are less impacted by urban development than larger macro-moths in subtropical environments, perhaps highlighting the tradeoffs of metabolic costs of urban heat favoring smaller moths over the relative benefits of dispersal for larger moths. In summary, our research underscores the far-reaching consequences of urbanization on moths and provides compelling evidence that urban forests alone may not be sufficient to safeguard biodiversity in cities.
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Ecosistema , Mariposas Nocturnas , Animales , Humanos , Urbanización , Larva , Filogenia , Biodiversidad , InsectosRESUMEN
Elevated temperature often has life stage-specific effects on ectotherms because thermal tolerance varies throughout ontogeny. Impacts of elevated temperature may extend beyond the exposed life stage if developmental plasticity causes early exposure to carry-over or if exposure at multiple life stages cumulatively produces effects. Reproductive traits may be sensitive to different thermal environments experienced during development, but such effects have not been comprehensively measured in Lepidoptera. In this study, we investigate how elevated temperature at different life stages alters reproduction in the European corn borer moth, Ostrinia nubilalis. We tested effects of exposure to elevated temperature (28 °C) separately or additively during larval, pupal, and adult life stages compared to control temperatures (23 °C). We found that exposure to elevated pupal and adult temperature decreased the number of egg clusters produced, but exposure limited to a single stage did not significantly impact reproductive output. Furthermore, elevated temperature during the pupal stage led to a faster transition to the adult stage and elevated larval temperature altered synchrony of adult eclosion, either by itself or combined with pupal temperature exposure. These results suggest that exposure to elevated temperature during development alters reproduction in corn borers in multiple ways, including through carry-over and additive effects. Additive effects of temperature across life stages are thought to be less common than stage-specific or carry-over effects, but our results suggest thermal environments experienced at all life stages need to be considered when predicting reproductive responses of insects to heatwaves.