What one genus of showy moths can say about migration, adaptation, and wing pattern.

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.

Causes of endemic radiation in the Caribbean: evidence from the historical biogeography and diversification of the butterfly genus Calisto (Nymphalidae: Satyrinae: Satyrini).

BACKGROUND: Calisto is the largest butterfly genus in the West Indies but its systematics, historical biogeography and the causes of its diversification have not been previously rigorously evaluated. Several studies attempting to explain the wide-ranging diversity of Calisto gave different weights to vicariance, dispersal and adaptive radiation. We utilized molecular phylogenetic approaches and secondary calibrations points to estimate lineage ages. In addition, we used the dispersal-extinction-cladogenesis model and Caribbean paleogeographical information to reconstruct ancestral geographical distributions. We also evaluated different models of diversification to estimate the dynamics of lineage radiation within Calisto. By understanding the evolution of Calisto butterflies, we attempt to identify the main processes acting on insular insect diversity and the causes of its origin and its maintenance. RESULTS: The crown age of Calisto was estimated to the early Oligocene (31 ± 5 Ma), and a single shift in diversification rate following a diversity-dependent speciation process was the best explanation for the present-day diversity found within the genus. A major increase in diversification rate was recovered at 14 Ma, following geological arrangements that favoured the availability of empty niches. Inferred ancestral distributional ranges suggested that the origin of extant Calisto is in agreement with a vicariant model and the origin of the Cuban lineage was likely the result of vicariance caused by the Cuba-Hispaniola split. A long-distance dispersal was the best explanation for the colonization of Jamaica and the Bahamas. CONCLUSIONS: The ancestral geographical distribution of Calisto is in line with the paleogeographical model of Caribbean colonization, which favours island-to-island vicariance. Because the sister lineage of Calisto remains ambiguous, its arrival to the West Indies remains to be explained, although, given its age and historical biogeography, the hypothesized GAARlandia land bridge might have been a plausible introduction route from continental America. Intra-island radiation caused by ecological innovation and the abiotic creation of niche spaces was found to be the main force shaping Calisto diversity and island endemism in Hispaniola and Cuba.

A near chromosome-level genome assembly of a ghost moth (Lepidoptera, Hepialidae).

Ghost moths are an unusual family of primitive moths (Lepidoptera: Hepialidae) known for their large body size and crepuscular adult activity. These moths represent an ancient lineage, frequently have soil dwelling larvae, and are adapted to high elevations, deserts, and other extreme environments. Despite being rather speciose with more than 700 species, there is a dearth of genomic resources for the family. Here, we present the first high quality, publicly available hepialid genome, generated from an Andean species of ghost moth, Druceiella hillmani. Our genome assembly has a length of 2,586 Mbp with contig N50 of 28.1 Mb and N50 of 29, and BUSCO completeness of 97.1%, making it one of the largest genomes in the order Lepidoptera. Our assembly is a vital resource for future research on ghost moth genomics.

Erythrina stem borer moth in California - New taxonomic status and implications for control of this emerging pest.

During the last 10 years, the Erythrina stem borer moth, Terastia meticulosalis, emerged as a pest of cultivated coral trees (Erythrina spp.) in California. Erythrina trees are valued for their moderate drought resistance and beautiful flame-like flowers. They are beloved enough to be considered Los Angeles's official "City Tree." Thus, they are a valuable horticultural crop and are grown by many nurseries and occur throughout the landscape in coastal southern California. Coral trees have been heavily affected by T. meticulosalis recently. Using whole genome sequencing techniques, we analysed the origins of this and other infestations of Erythrina in coastal areas and found that they have likely originated from the repeated expansions of the native range of the species in Arizona, a process possibly driven by climatic factors and/or movement of plants by humans. We also found sufficient genetic differences between the western population of the moth and the rest of the New World populations to describe a new western subspecies, T. meticulosalis occidentalis Sourakov & Grishin ssp. n. (type locality USA: CA, San Diego Co., La Jolla). These findings are of economic importance for future attempts to control the moth's impact on activities surrounding the horticultural use of Erythrina spp. by the Californian landscape and nursery industries.

A high-throughput multispectral imaging system for museum specimens.

We present an economical imaging system with integrated hardware and software to capture multispectral images of Lepidoptera with high efficiency. This method facilitates the comparison of colors and shapes among species at fine and broad taxonomic scales and may be adapted for other insect orders with greater three-dimensionality. Our system can image both the dorsal and ventral sides of pinned specimens. Together with our processing pipeline, the descriptive data can be used to systematically investigate multispectral colors and shapes based on full-wing reconstruction and a universally applicable ground plan that objectively quantifies wing patterns for species with different wing shapes (including tails) and venation systems. Basic morphological measurements, such as body length, thorax width, and antenna size are automatically generated. This system can increase exponentially the amount and quality of trait data extracted from museum specimens.

Emperors, admirals and giants, zebras, tigers and woolly bears: casting a broader net in exploring heparin effects on Lepidoptera wing patterns.

Background: Studies of heparin effects on Lepidoptera wing patterns have been restricted to a small number of species. I report observations from experiments on a broader range of taxa, including first results from swallowtails, tiger moths and microlepidoptera. Methods: Heparin injections were made in prepupal and early pupal stages of the following species representing several Lepidoptera lineages: Junonia coenia, Agraulis vanillae, Asterocampa clyton (Nymphalidae); Heraclides cresphontes, Pterourus troilus, Eurytides marcellus (Papilionidae); Hypercompe scribonia, Estigmene acrea, Hyphantria cunea (Erebidae); and Glyphodes sibillalis (Crambidae). Heparin-induced changes in wing pattern are illustrated, and advantages of using prepupal vs. pupal stages for this type of pharmacological manipulation of wing patterns are discussed. Results: In buckeyes, heparin-induced changes consisted of loss of orange parafocal elements as marginal and submarginal bands shifted basally. In gulf fritillaries, changes in black and silver markings were similar to those found in wild aberrant individuals. In tawny emperor, intermediate and extreme levels of transformation were achieved, pointing to homology of this species' unusual eyespots to those of other nymphalids. In swallowtails, heparin-induced changes were much more restricted and proved harder to achieve, possibly indicating higher levels of stability and compartmentalization of wing patterns in this butterfly family. In tiger moths, elongation of black markings occurred so that normally distinct spots sometimes merged; in leopard moth, these changes were restricted to areas adjacent to discal spot. In pyraloid moth, changes were mostly restricted to expansion of wing marginal bands and hindwing border. Conclusions: Variation in wing pattern response to heparin found between different species and families in this study warrants further taxonomic widening of exploration of wing pattern formation mechanisms in Lepidoptera. While there are many similarities, there also seem to be very significant differences in the ways wing patterns are formed in different families of butterflies and moths.

Giving eyespots a shiner: Pharmacologic manipulation of the Io moth wing pattern.

Our knowledge of wing pattern formation in Lepidoptera has advanced significantly in recent years due to the careful examination of several groups of butterflies. The eyespot is a prominent feature of Lepidoptera wing pattern, especially in the family Saturniidae. The present study examined how sulfated polysaccharides, which are known to simulate cold shock effect in nymphalid butterflies, affected the wing pattern formation of the Io moth, Automeris io (Saturniidae).  Prepupae and pupae of this species were subjected to injections of heparin and cold shock. While the cold shock had little to no effect on wing pattern, the aberrations resulting from heparin injections consisted of moderate to profound increases in melanism around the eyespots. The resulting aberrations are dubbed 'Black Eye' and 'Comet Eye.' Most other known aberrations of Automeris io eyespots are summarized, illustrated and named.

"Darwin's butterflies"? DNA barcoding and the radiation of the endemic Caribbean butterfly genus Calisto (Lepidoptera, Nymphalidae, Satyrinae).

The genus Calisto Hübner, 1823 is the only member of the diverse, global subfamily Satyrinae found in the West Indies, and by far the richest endemic Caribbean butterfly radiation. Calisto species occupy an extremely diverse array of habitats, suggestive of adaptive radiation on the scale of other classic examples such as the Galápagos or Darwin's finches. However, a reliable species classification is a key requisite before further evolutionary or ecological research. An analysis of 111 DNA 'barcodes' (655 bp of the mitochondrial gene COI) from 29 putative Calisto species represented by 31 putative taxa was therefore conducted to elucidate taxonomic relationships among these often highly cryptic and confusing taxa. The sympatric, morphologically and ecologically similar taxa Calisto confusa Lathy, 1899 and Calisto confusa debarriera Clench, 1943 proved to be extremely divergent, and we therefore recognize Calisto debarriera stat. n. as a distinct species, with Calisto neiba Schwartz & Gali, 1984 as a junior synonym syn. n. Species status of certain allopatric, morphologically similar sister species has been confirmed: Calisto hysius (Godart, 1824) (including its subspecies Calisto hysius aleucosticha Correa et Schwartz, 1986, stat. n.), and its former subspecies Calisto batesi Michener, 1943 showed a high degree of divergence (above 6%) and should be considered separate species. Calisto lyceius Bates, 1935/Calisto crypta Gali, 1985/Calisto franciscoi Gali, 1985 complex, also showed a high degree of divergence (above 6%), confirming the species status of these taxa. In contrast, our data suggest that the Calisto grannus Bates, 1939 species complex (including Calisto grannus dilemma González, 1987, Calisto grannus amazona González, 1987, stat. n., Calisto grannus micrommata Schwartz & Gali, 1984, stat. n., Calisto grannus dystacta González, 1987, stat. n., Calisto grannus phoinix González, 1987, stat. n., Calisto grannus sommeri Schwartz & Gali, 1984, stat. n., and Calisto grannus micheneri Clench, 1944, stat. n.) should be treated as a single polytypic species, as genetic divergence among sampled populations representing these taxa is low (and stable morphological apomorphies are absent). A widely-distributed pest of sugar cane, Calisto pulchella Lathy, 1899 showed higher diversification among isolated populations (3.5%) than expected, hence supporting former separation of this species into two taxa (pulchella and darlingtoni Clench, 1943), of which the latter might prove to be a separate species rather than subspecies. The taxonomic revisions presented here result in Calisto now containing 34 species and 17 subspecies. Three species endemic to islands other than Hispaniola appear to be derived lineages of various Hispaniolan clades, indicating ancient dispersal events from Hispaniola to Puerto Rico, Cuba, and Jamaica. Overall, the degree of intrageneric and intraspecific divergence within Calisto suggests a long and continuous diversification period of 4-8 Myr. The maximum divergence within the genus (ca. 13.3%) is almost equivalent to the maximum divergence of Calisto from the distant pronophiline relative Auca Hayward, 1953 from the southern Andes (14.1%) and from the presumed closest relative Eretris Thieme, 1905 (14.4%), suggesting that the genus began to diversify soon after its split from its continental sister taxon. In general, this 'barcode' divergence corresponds to the high degree of morphological and ecological variation found among major lineages within the genus.

DNA barcoding Central Asian butterflies: increasing geographical dimension does not significantly reduce the success of species identification.

DNA barcoding employs short, standardized gene regions (5' segment of mitochondrial cytochrome oxidase subunit I for animals) as an internal tag to enable species identification. Prior studies have indicated that it performs this task well, because interspecific variation at cytochrome oxidase subunit I is typically much greater than intraspecific variation. However, most previous studies have focused on local faunas only, and critics have suggested two reasons why barcoding should be less effective in species identification when the geographical coverage is expanded. They suggested that many recently diverged taxa will be excluded from local analyses because they are allopatric. Second, intraspecific variation may be seriously underestimated by local studies, because geographical variation in the barcode region is not considered. In this paper, we analyse how adding a geographical dimension affects barcode resolution, examining 353 butterfly species from Central Asia. Despite predictions, we found that geographically separated and recently diverged allopatric species did not show, on average, less sequence differentiation than recently diverged sympatric taxa. Although expanded geographical coverage did substantially increase intraspecific variation reducing the barcoding gap between species, this did not decrease species identification using neighbour-joining clustering. The inclusion of additional populations increased the number of paraphyletic entities, but did not impede species-level identification, because paraphyletic species were separated from their monophyletic relatives by substantial sequence divergence. Thus, this study demonstrates that DNA barcoding remains an effective identification tool even when taxa are sampled from a large geographical area.