From east to west across the Palearctic: Phylogeography of the invasive lime leaf miner Phyllonorycter issikii (Lepidoptera: Gracillariidae) and discovery of a putative new cryptic species in East Asia

The checklist of leaf-mining moths Phyllonorycter Hbner (Lepidoptera: Gracillariidae) of Korea with description of two new species and nine newly recorded species

In the present study, a total of 30 species of Phyllonorycter Hbner, 1822 (Lepidoptera: Gracillariidae: Lithocolletinae) in Korea are recognized and enumerated. Among them, two species (Phyllonorycter phallustenuis sp. nov. and P. daehana sp. nov.) are newly described to science. In addition, nine species are reported for the first time for the country: P. ginnalae (Ermolaev, 1981), P. jezoniella (Matsumura, 1931), P. lonicerae (Kumata, 1963), P. nigristella (Kumata, 1957), P. ostryae (Kumata, 1963), P. reduncata (Ermolaev, 1986), P. sorbicola (Kumata, 1963), P. tritorrhecta (Meyrick, 1935), and P. zelkovae (Kumata, 1963). Detailed descriptions and illustrations of both adults and genitalia of the new species are provided.

Leaf-mining moths of the genus Phyllonorycter Hübner<br>(Lepidoptera: Gracillariidae: Lithocolletinae) associated with Malvaceae in China, with descriptions of one new species

Until recently, only one species of Phyllonorycter Hübner, 1822 has been known to feed on Malvaceae in China, i. e. the lime leaf miner P. issikii (Kumata, 1963) associated with Tilia spp. Here we describe a new species, Phyllonorycter bilobae T. Liu sp. n., found in Shaanxi and Shandong provinces in China feeding on Grewia biloba var. biloba G. Don and G. biloba var. parviflora (Bunge) Hand.—Mazz. (Malvaceae). Images of the adult, male and female genitalia, host plant, and the leaf mines of the new species are provided. Additionally, detailed distribution data of P. issikii in Shandong province (China) is given.  

Invasive Insect Pests of Forests and Urban Trees in Russia: Origin, Pathways, Damage, and Management

Invasive alien insects cause serious ecological and economical losses around the world. Here, we review the bionomics, modern ranges (and their dynamics), distribution pathways, monitoring, and control measures of 14 insect species known to be important invasive and emerging tree pests in forest and urban ecosystems of Russia: Leptoglossus occidentalis (Hemiptera: Heteroptera: Coreidae), Halyomorpha halys (Hemiptera: Heteroptera: Pentatomidae), Corythucha arcuata (Hemiptera: Heteroptera: Tingidae), Agrilus fleischeri, A. mali, A. planipennis, Lamprodila (Palmar) festiva (Coleoptera: Buprestidae), Ips amitinus, Polygraphus proximus (Coleoptera: Curculionidae: Scolytinae), Cydalima perspectalis (Lepidoptera: Crambidae), Acrocercops brongniardella, Cameraria ohridella, Phyllonorycter issikii, and P. populifoliella (Lepidoptera: Gracillariidae). We identified three major scenarios of tree pest invasions in the country and beyond: (1) a naturally conditioned range expansion, which results in the arrival of a pest to a new territory and its further naturalization in a recipient region; (2) a human-mediated, long-distance transfer of a pest to a new territory and its further naturalization; and (3) a widening of the pest’s trophic niche and shift to new host plant(s) (commonly human-introduced) within the native pest’s range frequently followed by invasion to new regions.

Tracing the invasion of a leaf-mining moth in the Palearctic through DNA barcoding of historical herbaria

The lime leaf-miner, Phyllonorycter issikii is an invasive micromoth with an unusually higher number of haplotypes in the invaded area (Europe, Western Siberia) compared to its putative native region (East Asia). The origin of the genetic diversity in the neocolonized region remains unclear. We surveyed over 15 thousand herbarium specimens of lime trees (Tilia spp.) collected across the Palearctic over a period of 252 years (1764-2016) looking for preserved larvae within the archival leaf mines. We found 203 herbarium specimens with leaf mines of Ph. issikii collected in East Asia, one of them dating back to 1830, i.e. 133 years before the description of the species. In contrast, only 22 herbarium specimens collected in the West Palearctic in the last three decades (1987-2015) carried leaf mines. DNA barcoding of archival specimens revealed 32 haplotypes out of which 23 were novel (not known from modern populations) and found exclusively in East Asia. Six haplotypes are shared between both native and invaded areas and only two were responsible for the recent invasion of the Western Palearctic. The remarkable number of newly discovered haplotypes in archival populations supports East Asia as the native region and the source area of invasion.

Longer mtDNA Fragments Provide a Better Insight into the Genetic Diversity of the Sycamore Lace Bug, Corythucha ciliata (Say, 1832) (Tingidae, Hemiptera), Both in Its Native and Invaded Areas

Simple Summary

The sycamore lace bug (Corythucha ciliata Say, 1832) is one of the most abundant and widespread pests on plane trees (Platanus spp.) across the globe. The native range of the species is in North America, but it has been introduced to Europe (1964), South America (1985), Asia (1995), Australia (2006), and Africa (2014). To understand the genetic background behind this successful colonisation, we analysed a fragment (1356 bp) of the mitochondrial DNA. The 327 individuals revealed 17 haplotypes forming two separated groups. One group includes North American and Japanese individuals, while the other group comprises North American, European, and Asian individuals. We found a much higher genetic diversity in the native area (North America, 12 haplotypes) than in the invaded areas (Europe, five and Asia, four). The longer DNA fragment provided detailed information about the genetic structure of the species both in its native range and in the invaded areas, but the shorter DNA fragment could not provide a clear link between the genetic variation and the geographic origin.

Abstract

The sycamore lace bug (Corythucha ciliata Say, 1832) is of North American origin, but after its introduction to Europe (1964), South America (1985), Asia (1995), Australia (2006), and Africa (2014), it became an abundant and widespread pest on plane (Platanus spp.) trees. We analysed a 1356 bp long fragment of the mtDNA (COI gene) of 327 sycamore lace bug individuals from 38 geographic locations from Europe, Asia, and North America. Seventeen haplotypes (17 HTs) were detected. C. ciliata populations from North America exhibited higher haplotype diversity (12 HTs) than populations from Europe (6 HTs), Asia (4 HTs), or Japan (2 HTs). The haplotypes formed two haplogroups separated by at least seven mutation steps. One of these mutation steps includes HTs from North America and Japan. Another includes HTs from North America, Europe, and Asia. Haplotypes from Asia Minor, the Caucasus, and Central Asia are linked to haplotypes from Europe, while haplotypes found in Japan are linked to haplotypes found in North America only. The incorporation of published data from the GenBank into our dataset (altogether 517 individuals from 57 locations, but only 546 bp long fragment of the mtDNA) did not show any structure according to the geographic origin of the individuals.

Evaluating DNA Barcoding for Species Identification and Discovery in European Gracillariid Moths

Gracillariidae is the most species-rich leaf-mining moth family with over 2,000 described species worldwide. In Europe, there are 263 valid named species recognized, many of which are difficult to identify using morphology only. Here we explore the use of DNA barcodes as a tool for identification and species discovery in European gracillariids. We present a barcode library including 6,791 COI sequences representing 242 of the 263 (92%) resident species. Our results indicate high congruence between morphology and barcodes with 91.3% (221/242) of European species forming monophyletic clades that can be identified accurately using barcodes alone. The remaining 8.7% represent cases of non-monophyly making their identification uncertain using barcodes. Species discrimination based on the Barcode Index Number system (BIN) was successful for 93% of species with 7% of species sharing BINs. We discovered as many as 21 undescribed candidate species, of which six were confirmed from an integrative approach; the other 15 require additional material and study to confirm preliminary evidence. Most of these new candidate species are found in mountainous regions of Mediterranean countries, the South-Eastern Alps and the Balkans, with nine candidate species found only on islands. In addition, 13 species were classified as deep conspecific lineages, comprising a total of 27 BINs with no intraspecific morphological differences found, and no known ecological differentiation. Double-digest restriction-site associated DNA sequencing (ddRAD) analysis showed strong mitonuclear discrepancy in four out of five species studied. This discordance is not explained by Wolbachia-mediated genetic sweeps. Finally, 26 species were classified as “unassessed species splits” containing 71 BINs and some involving geographical isolation or ecological specialization that will require further study to test whether they represent new cryptic species.

Cryptic Diversity in the Monotypic Neotropical Micromoth Genus Angelabella (Lepidoptera: Gracillariidae) in the Peru-Chile Desert

Simple Summary

The Neotropical Region harbors a highly diverse and poorly known fauna of leaf miners of the micromoth family Gracillariidae (Lepidoptera). Angelabella is a genus of Gracillariidae whose geographic range is restricted to a few valleys of the arid environments of the Peru-Chile desert. Only one species is currently included in this genus. The aims of this study were to explore the geographic range, determine the spatial distribution of mitochondrial lineages, and test lineage conspecificity hypotheses in Angelabella. The spatial distribution of genetic diversity indicated four spatial clusters, three of which are north of the previously known geographic range. These groups were defined as different species by four species delimitation methods. These results suggest that Angelabella harbors at least four morphologically cryptic species with restricted, not overlapping geographic ranges. This study shows that adequate single locus sequence analysis can be useful to discover surprising biodiversity patterns in underexplored environments, providing the base to plan further studies involving little-known organisms.

Abstract

Angelabella (Lepidoptera: Gracillariidae: Oecophyllembiinae) is considered a monotypic Neotropical genus of leaf miner micromoths known only from a few valleys of the arid environments of the Peru-Chile desert, particularly the southernmost part of Peru and northernmost part of Chile (type locality), where natural populations of its primary host plant occur. The geographic distribution of potential host plants provides a scenario for a wider range for this micromoth genus. The aims of this study were to explore the geographic range of Angelabella, determine the spatial distribution of mitochondrial lineages, and test lineage conspecificity hypotheses. The spatial distribution of genetic diversity indicated the presence of four spatial clusters, three of which are north of the previously known geographic range. Genetic distances were 0.2–0.8% and 3.6–8.3% (K2P) between haplotypes of the same and different spatial clusters, respectively. Phylogenetic relationships indicated reciprocal monophyly among the four spatial clusters, suggesting that allopatric differentiation processes have governed the recent history of Angelabella in these arid environments. These groups were defined as different species by four species delimitation methods, suggesting that Angelabella is not a monotypic genus, but harbors at least four morphologically cryptic allopatric species with restricted geographic ranges, including the type species and three candidate species.

Phylogeographic pattern of the plane leaf miner, Phyllonorycter platani (STAUDINGER, 1870) (Lepidoptera: Gracillariidae) in Europe

Background

The plane leaf miner, Phyllonorycter platani is a widely distributed insect species on plane trees and has a well-documented colonisation history in Europe over the last century. However, phylogeographic data of the species are lacking.

Results

We analysed 284 individuals from 38 populations across Europe, Asia, and North America. A 1242 bp fragment of the mitochondrial COI gene and an 893 bp fragment of the 28S rDNA has been Sanger sequenced. Twenty-four haplotypes were detected on the COI gene, and two alleles were identified on the 28S rDNA. We revealed two distinct clades for both markers reflecting the geographic origins, Asia and Europe. The genetic distance between the two main clades is 2.08% on the COI gene and 0.10% on the nuclear DNA.

An overlapping zone of the two clades was found across Eastern Europe and the Anatolian Peninsula. We detected heterozygote individuals of the 28S rDNA gene in Moldavia, Ukraine and in the southern part of Turkey. These suggest that the two clades can hybridise. Furthermore, the presence of European type homozygote individuals has been confirmed in the southern part of Turkey as well.

Conclusions

We have shown that both post-glacial recolonization and recent expansion events influenced the present genetic structure of P. platani. The genetic patterns revealed at least two refugia during the last ice age: one in the Balkan Peninsula and the other in the Caucasus region. Recent expansion was detected in some European and Central Asian populations. The two main clades (Europe/Asia) show definite genetic differences; however, several hybrid individuals were found in the overlapping zone as well (stretching over Eastern Europe and the Anatolian Peninsula). Discrepancies in mitochondrial and nuclear data indicate introgressions in the southern part of the Anatolian Peninsula.

Electronic supplementary material

The online version of this article (10.1186/s12862-018-1240-z) contains supplementary material, which is available to authorized users.

Phylogeographic structure in three North American tent caterpillar species (Lepidoptera: Lasiocampidae): Malacosoma americana, M. californica, and M. disstria

While phylogeographic structure has been examined in many North American vertebrate species, insects have received much less attention despite their central ecological roles. The moth genus Malacosoma (Hübner, 1820), is an important group of forestry pests responsible for large-scale defoliation across much of the Nearctic and Palearctic. The present study uses sequence variation in the mitochondrial cytochrome c oxidase 1 (COI) gene to examine the population genetic structure of the three widespread Malacosoma species (M. americana, M. californica, and M. disstria). Populations of all three species showed highest diversity in the south, suggesting that modern populations derived from southern refugia with loss of variation as these lineages dispersed northwards. However, despite similar life histories and dispersal abilities, the extent of regional variation varied among the taxa. M. americana, a species restricted to eastern North America, showed much less genetic structure than the western M. californica or the widespread M. disstria. The regional differentiation in the latter reflects the likely derivation of modern lineages from several refugia, as well as taxonomic uncertainty in M. californica. In these respects, the three species of Malacosoma share phylogeographic patterns similar to those detected in vertebrates which are characterised by greater phylogeographic breaks in the western half of the continent and limited structure in the east.

Genetic divergence of isolated populations of the native micromoth Bucculatrix mirnae (Lepidoptera: Bucculatricidae) in the arid environments of Northern Chile

Analysis of maternally inherited genes is especially helpful in population studies of host-specialized insects, as female dispersal is key to find an adequate host plant to ensure larval survival. Bucculatrix mirnae (Lepidoptera: Bucculatricidae) is a little-known Neotropical micromoth native to the arid environments of northern Chile whose hypermetamorphic larvae are miners and skeletonizers on leaves of two species of Baccharis (Asteraceae) shrubs. This micromoth has been detected in three isolated locations embracing a narrow geographic range: two from the coastal valleys of the Atacama Desert near sea level and one from the western slopes of the Andes at about 3000 m elevation. As the dispersal of B. mirnae is mostly restricted to the small adult stage, the altitudinal gradient and desert areas among the three localities could be effective barriers, triggering genetic differentiation among populations. Sequences of the DNA barcode fragment of the cytocrome oxidase subunit I mitochondrial gene were analyzed to assess for the first time the patterns of genetic variation of B. mirnae. Fifteen haplotypes, each exclusive to one locality, were found in the 71 specimens analyzed. Genetic divergence (K2P) between haplotypes of different localities was at least 2.0%. A Bayesian analysis with sequences of congeneric species grouped all the B. mirnae haplotypes in a clade, in which three well-supported locality-specific haplogroups were found. In concordance with this pattern, an analysis of molecular variance showed that the highest genetic variation was found among populations. Furthermore, all the population pairwise comparisons (F_ST) were significant. These results suggest that female migration between isolated populations of B. mirnae is absent. This pattern must be considered in the current scenario of habitat destruction and modification in the arid environments of northern Chile.