Taxonomic Revision of the Nearctic Genus Drepanaphis Del Guercio (Hemiptera, Aphididae: Drepanosiphinae).

The Nearctic aphid genus Drepanaphis Del Guercio, 1909, the largest within the subfamily Drepanosiphinae (Hemiptera: Aphididae), is characterised by distinctive dorsal abdominal tubercles. This study presents a comprehensive taxonomic revision of the genus, expanding the recognised species to 18, including the newly described Drepanaphis robinsoni Malik sp. nov. Detailed descriptions and figures for 44 morphs, encompassing alate viviparous females, oviparous females and males, are provided, with new identification keys for all known species and morphs. The sexual morphs of 15 species, particularly oviparous females, are documented for the first time. Morphometric and principal component analyses (PCA) are employed to distinguish the studied taxa. This study identifies and corrects numerous misidentifications in museum collections, previously labelled as D. acerifoliae, D. choanotricha, D. kanzensis, D. knowltoni, D. parva, D. sabrinae or D. tissoti. Furthermore, it revalidates the distinct status of D. nigricans and D. tissoti, which had been synonymised in earlier works. Current range maps for all species and images of key morphological features obtained through light and scanning electron microscopy are also presented, providing a more complete understanding of this understudied genus.

Aphidomorpha (Insecta: Hemiptera) in the entomological collection of the Zoology Research Group, University of Silesia in Katowice (DZUS), Poland.

The digitisation of the entomology resources of the Department of Zoology, University of Silesia DZUS (presently the Zoology Research Group, Katowice, Poland) allow presenting a substantial collection of aphids, adelgids and phylloxerids (Hemiptera: Aphidomorpha). The collection preserves more than 12 500 curated specimens stored as over 9 500 slides representing 683 taxa (645 identified to the species level and 38 identified only to the genus level), 160 genera, three families and 15 subfamilies. Thirty species represent type material. The geographical analysis of the Aphidomorpha collected shows mainly Eurasian areas, with particularly good representation from Central Europe (especially Poland). The highest diversity is represented by species of Aphididae (98.6%), with the richest in samples subfamily Aphidinae (65.2%). Four hundred twelve genera (972 taxa) of host plants from 99 families were identified among the slide-mounted specimens. A new nameAphis (Aphis) jaroslavholmani nom. nov. is proposed for Aphis (Aphis) holmani Kanturski Bezdk, 2019.

Structure of the reproductive system of the sexual generation of the endemic Arctic species Acyrthosiphon svalbardicum and its temperate counterpart Acyrthosiphon pisum (Hemiptera, Aphididae).

The Arctic aphids live briefly and must breed quickly to survive. Shortened life cycle, with only two generations: the stem mother and sexuales-oviparous females and males is an adaptation for optimal use of the short breeding period, which lasts from late July to the end of August. Using Acyrthosiphon svalbardicum, an endemic High Arctic aphid species, we describe the structure of the reproductive system of sexual morphs and compare with its temperate counterparts, in particular the model organism the pea aphid Acyrthosiphon pisum. Generally, the histological composition and ultrastructure of reproductive system of sexuales of A. svalbardicum is broadly similar to the reproductive systems described already in other species of aphids. The unique characters include in both oviparous females and males an enormous layer of the fat body, adhering to the structures of the internal reproductive system. The greatly enlarged accessory glands of males accumulate a heterogenous secretion composed of irregularly organized bunches of spicule-like structures of high electron density embedded in fine and coarse granular material. This material, unknown among temperate counterparts of A. svalbardicum, during mating is transported from the accessory glands of the male to its ejaculatory duct, where it is mixed with the ejaculate, and then is transferred to the spermatheca of the oviparous female.

Description of the previously unknown morphs of Periphyllus koelreuteriae (Takahashi) (Hemiptera, Aphididae: Chaitophorinae).

The previously unknown morphs of the autumn generations of Periphyllus koelreuteriae (Takahashi, 1919) (Hemiptera, Aphididae: Chaitophorinae)-the viviparous apterous female, the oviparous female and the alate male-are described and illustrated in detail based on specimens that were collected in China. Because P. koelreuteriae is a significant pest species that damages the ornamental and medicinal plants of the genus Koelreuteria, notes on its biology, host plants and distribution are presented.

The reproductive system of the male and oviparous female of a model organism-the pea aphid, Acyrthosiphon pisum (Hemiptera, Aphididae).

The structure of the reproductive system of the sexual generation-males and oviparous females-of the pea aphid Acyrthosiphon pisum (Harris) (Hemiptera, Aphididae), a serious pest of cultivated plants of Fabaceae, was investigated. For the first time we describe the morphology, histology and ultrastructure of the reproductive system in both morphs of the sexual generation of aphids within one species, using light and fluorescent microscopy, as well as transmission and scanning electron microscopy. The results revealed that males have testes composed of three follicles fused by the upper ends of the vasa efferentia, the vasa deferentia run independently, the accessory glands are asymmetric and the ejaculatory duct shortened. Oviparous females have ovaries composed of seven ovarioles each. The lateral oviducts join to a short common oviduct connected with the unpaired spermatheca and paired accessory glands. Yolky eggs with an aggregation of symbiotic bacteria at the posterior pole are produced. Histologically, the components of genital tracts are broadly similar: the epithelial cells of the walls of the vasa deferentia and accessory glands of the male and oviparous female have secretory functions which correlate with the age of the studied morphs. We also found symbiotic bacteria within the vasa deferentia epithelial cells in males and within the cells of the lateral oviducts of females. Because the pea aphid is listed among the 14 species that are of the greatest economic importance, our results will be useful for managing aphid populations, protecting plants and ensuring global food security.

The composition of the aphid fauna (Insecta, Hemiptera) of the Royal Botanic Gardens, Kew.

At least a dozen species of aphids (Insecta, Hemiptera) of non-native origin have expanded their range in Europe, however the importance of botanic gardens in this phenomenon has not been studied previously in detail. As a case study, investigations on the species composition and host range of Aphidomorpha in the Royal Botanic Gardens, Kew, London, United Kingdom, were conducted over a period of twelve days, in June 2017. The inventory study was carried out in the collection of living plants, both in the gardens and the glasshouses and nurseries. In total, 94 taxa of Aphidomorpha are identified (one phylloxerid, one adelgid and 92 species of aphids). 20 species are regarded as alien to the European aphid fauna and among them nine are believed to be the first published records for Kew. 20 species are regarded as serious pests, capable of virus transmission. The list of host plants includes 155 taxa from 89 genera and 49 families. Ericolophium holsti (Takahashi), species of Asiatic origin associated with Rhododendron spp., was found for the first time in the field in the UK. Changes in the species composition of the aphid fauna in reference to the Eastop's studies in 1960s were discussed.

A comparative morphological revision of the aphid genus Myzaphis van der Goot, 1913 (Insecta: Hemiptera: Aphididae) revealed a new genus and three new species.

The aphid genus Myzaphis van der Goot, 1913 from the tribe Macrosiphini is revised to include eight species. Apterous and alate viviparous females, known fundatrices and known sexual morphs (oviparous females and males) of Myzaphis bucktoni, M. juchnevitschae, M. rosarum, M. tianshanica and M. turanica are re-described and illustrated. Lectotype and paralectotypes of Myzaphis bucktoni and M. turanica are designated. The status of M. komatsubarae nomen dubium is discussed. Myzaphis avariolosa is regarded as a species belonging to the genus Ericaphis. Three new species: M. oezdemirae Kanturski & Barjadze sp. nov., M. tuatayae Kanturski & Barjadze sp. nov. from Turkey and M. rezwanii Kanturski & Barjadze sp. nov. from Iran are described and illustrated. Myzaphis bucktoni is recorded from Portugal for the first time. Diagnosis of the genus Myzaphis van der Goot, 1913 is redefined and a new genus Richardsaphis Kanturski & Barjadze gen. nov. is erected with the type species R. canadensis (Richards) comb. nov. Richardsaphis is for the first time recorded from the USA and hitherto unknown oviparous female and alate male are described and illustrated. Original keys to species of the genus Myzaphis and aphid genera of the tribe Macrosiphini with 2-2-2 first tarsal chaetotaxy are also provided.

European species of the aphid genus Eulachnus Del Guercio, 1909 (Hemiptera: Aphididae: Lachninae): revision and molecular phylogeny.

The aphid genus Eulachnus in Europe is revised to include 12 species, using an integrative taxonomy approach, based on morphometric, molecular and biological traits. Fundatrix, apterous and alate viviparous female of a new species-Eulachnus stekolshchikovi Kanturski sp. nov. are described. Neotypes are designated for E. agilis, E. brevipilosus and E. nigricola. Lectotypes are designated for E. alticola, E. cembrae, E. rileyi and E. tuberculostemmatus. New synonyms are proposed: E. abameleki syn. nov. (= Cinara pini), E. cretaceus syn. nov. (= E. agilis), E. tauricus syn. nov. (= E. rileyi), E. pallidus syn. nov. (= E. tuberculostemmatus). Eulachnus mingazzinii (near Cinara piniphila) and E. nigrofasciatus (near C. brauni) are regarded as incertae sedis. Full species status is given for E. garganicus stat. nov. and E. ibericus stat. nov. Apterous viviparous female of E. cembrae; apterous and alate viviparous females of remaining species are redescribed. Sexual morphs of E. agilis, E. alticola, E. cembrae, E. intermedius, E. nigricola, E. rileyi and oviparous female of E. tuberculostemmatus are fully redescribed and figured for the first time. Fundatrices of E. agilis, E. brevipilosus, E. cembrae, E. rileyi and E. tuberculostemmatus, sexuales of E. brevipilosus and the alate male of E. tuberculostemmatus are described and figured. A new host plant-Pinus cembra for E. brevipilosus is reported, and this species is recorded for the first time from Czech Republic. Eulachnus tuberculostemmatus is reported for the first time from Croatia. Phylogenetic studies, based on the COI and ITS2 molecular markers, are provided to visualize and discuss the relationships within the European species. COI barcodes are provided for seven species.

Geographical variation in morphology of Chaetosiphella stipae stipae Hille Ris Lambers, 1947 (Hemiptera: Aphididae: Chaitophorinae).

Chaetosiphella stipae stipae is a xerothermophilous aphid, associated with Palaearctic temperate steppe zones or dry mountain valleys, where there are grasses from the genus Stipa. Its geographical distribution shows several populations that are spread from Spain, across Europe and Asia Minor, to Mongolia and China. Geographical variation in chaetotaxy and other morphological features were the basis to consider whether individuals from different populations are still the same species. Moreover, using Ch. stipae stipae and Stipa species occurrences, as well as climatic variables, we predict potential geographical distributions of the aphid and its steppe habitat. Additionally, for Stipa species we projected current climatic conditions under four climate change scenarios for 2050 and 2070. While highly variable, our results of morphometric analysis demonstrates that all Ch. stipae stipae populations are one very variable subspecies. And in view of predicted climate change, we expect reduction of Stipa grasslands. The disappearance of these ecosystems could result in stronger separation of the East-European and Asian steppes as well as European 'warm-stage' refuges. Therefore, the geographic morphological variability that we see today in the aphid subspecies Ch. stipae stipae may in the future lead to speciation and creation of separate subspecies or species.

The relationships within the Chaitophorinae and Drepanosiphinae (Hemiptera, Aphididae) inferred from molecular-based phylogeny and comprehensive morphological data.

The Chaitophorinae is a bionomically diverse Holarctic subfamily of Aphididae. The current classification includes two tribes: the Chaitophorini associated with deciduous trees and shrubs, and Siphini that feed on monocotyledonous plants. We present the first phylogenetic hypothesis for the subfamily, based on molecular and morphological datasets. Molecular analyses were based on the mitochondrial gene cytochrome oxidase subunit I (COI) and the nuclear gene elongation factor-1α (EF-1α). Phylogenetic inferences were obtained individually on each of genes and joined alignments using Bayesian inference (BI) and Maximum likelihood (ML). In phylogenetic trees reconstructed on the basis of nuclear and mitochondrial genes as well as a morphological dataset, the monophyly of Siphini and the genus Chaitophorus was supported. Periphyllus forms independent lineages from Chaitophorus and Siphini. Within this genus two clades comprising European and Asiatic species, respectively, were indicated. Concerning relationships within the subfamily, EF-1α and joined COI and EF-1α genes analysis strongly supports the hypothesis that Chaitophorini do not form a monophyletic clade. Periphyllus is a sister group to a clade containing Chaitophorus and Siphini. The Asiatic unit of Periphyllus also includes Trichaitophorus koyaensis. The analysis of morphological dataset under equally weighted parsimony also supports the view that Chaitophorini is an artificial taxon, as Lambersaphis pruinosae and Pseudopterocomma hughi, both traditionally included in the Chaitophorini, formed independent lineages. COI analyses support consistent groups within the subfamily, but relationships between groups are poorly resolved. These analyses were extended to include the species of closely related and phylogenetically unstudied subfamily Drepanosiphinae, which produced congruent results. Genera Drepanosiphum and Depanaphis are monophyletic and sister. The position of Yamatocallis tokyoensis differs in the molecular and morphological analyses, i.e. it is either an independent lineage (EF-1α, COI, joined COI and EF-1α genes) or is nested inside this unit (morphology). Our data also support separation of Chaitophorinae from Drepanosiphinae.

Descriptions of little-known and unknown morphs of Periphyllus acerihabitans Zhang (Hemiptera: Aphididae: Chaitophorinae).

Periphyllus acerihabitans Zhang, 1982, associated with Acer buergerianum, is known only from the original description from China. Based on the type series and specimens collected in Japan, we re-describe apterous and alate viviparous females of P. acerihabitans and describe dimorph (aestivating nymph) and oviparous female in detail with illustrations. This is the first record of this species from Japan. The differences between P. acerihabitans and a related species P. viridis (Matsumura, 1919) are discussed. Keys to similar species: P. acerihabitans, P. viridis and P. californiensis (Shinji, 1917), associated with A. buergerianum or A. pictum subsp. mono, are provided.

Morphology of the European species of the aphid genus Eulachnus (Hemiptera: Aphididae: Lachninae) - A SEM comparative and integrative study.

Scanning electron microscopy (SEM) methods were used for the first time to elucidate the external morphology of the European species of the genus Eulachnus (Hemiptera: Aphididae: Lachninae), a representative genus of the conifer-feeding aphids tribe Eulachnini. We examined and compared the external morphology of apterous and alate viviparous females from the parthenogenetic generation as well as oviparous females and alate males belonging to the sexual generation. FE-SEM images based on HMDS and cryo-SEM preparation techniques revealed better image quality than the CPD technique in regard to surface tension and morphological signs of cell deteriorations (i.e., existence of depressions, drying artifacts and membrane blebs). Three morphologically different species groups "agilis", "brevipilosus" and "cembrae" were proposed due to the differences in head, antennae, legs and dorsal chaetotaxy as well as dorsal sclerotization. The most characteristic features and differences of representatives of these groups are presented and discussed.

A new species of the nearctic gall-forming genus Tamalia Baker (Hemiptera: Aphididae: Tamaliinae).

The apterous viviparous female and alate oviparous female of a new aphid species, Tamalia milleri sp. nov., a representative of a nearctic relict genus Tamalia and associated with Arctostaphylos columbiana, is described and figured in detail from specimens collected in California and Oregon (USA) and deposited in the Natural History Museum, London (UK). The differences between T. milleri and a related species, T. dicksoni Remaudière & Stroyan as well as other taxa of this genus are discussed. The distribution of Tamalia and a key to identification of the known species of the genus are provided.

Sexual morphs and biology of Aphis verbasci Schrank (Hemiptera: Aphididae).

The oviparous female and wingless male of Aphis verbasci from Poland and the United Kingdom are described and illustrated in detail for the first time, with notes on biology, distribution and host plants. 

Endosymbiotic microorganisms in Adelges (Sacchiphantes) viridis (Insecta, Hemiptera, Adelgoidea: Adelgidae): Molecular characterization, ultrastructure and transovarial transmission.

The aim of this paper was to identify endosymbiotic microorganisms living in the body cavity of a Polish population of an aphid, Adelges (Sacchiphantes) viridis, as well as to describe their ultrastructure and mode of transmission between generations. Molecular data (amplification and sequencing of 16S rRNA genes) indicated that endosymbionts of A. (S.) viridis are Betaproteobacteria of the species "Candidatus Vallotia virida". Endosymbiotic bacteria are rod-shaped and localized in the cytoplasm of specific cells, termed bacteriocytes, of host insects. Endosymbionts sharing the same bacteriocytes differ in the density of their cytoplasm. There are two morphotypes of endosymbiotic bacteria: with electron-dense cytoplasm and electron-translucent cytoplasm. Since only bacteria containing electron-dense cytoplasm were observed in the binary fusion stage, differences in density of the cytoplasm are probably due to changes in the cytoskeleton of bacteria during division. Endosymbionts of A. (S.) viridis are transovarially (i.e. via oocytes) transmitted from the mother to the offspring.

Shenahweum minutum (Hemiptera, Aphidoidea: Drepanosiphinae)-taxonomic position and description of sexuales.

The oviparous female and winged male of Shenahweum minutum (Davis) are described and illustrated in detail for the first time. Notes on distribution and host plants are presented as well as additional taxonomic data on the genus.

The sexuales of giant black bark aphid, Pterochloroides persicae (Hemiptera, Aphidoidea: Lachninae).

The oviparous female and male of the giant black bark aphid Pterochloroides persicae (Cholodkovsky) are described and illustrated for the first time. Notes on distribution, biology and host plants are presented.

The sexuales of Thelaxes suberi (Hemiptera, Aphidoidea: Thelaxinae).

The oviparous female and male of Thelaxes suberi (del Guercio) are described and illustrated in detail for the first time. Notes on distribution, biology and host plants are presented, and keys are provided to the known sexuales of European Thelaxes species.

A comparative morphology of the male genitalia of Aphididae (Insecta, Hemiptera): part 2.

The present study provides new data related to the morphology of the male genitalia of Aphididae. The structure of the male genitalia of 39 species from 23 genera of Aphididae was studied using light and scanning electron microscopy. In the species studied, the genitalia of males consist of a phallus composed of the sclerotized basal part with its articulation and a membranous apical part-an aedeagus as well as parameres. This state probably represents the hypothetical plesiomorphic condition of the external male genitalia of aphids. According to the results of the present study, the male genitalia vary among subfamilies (the most varied in Lachninae). Both the phallus and parameres show great variability in their form and the number of setae and may provide characters of taxonomic and diagnostic importance. The shape, size, and modification of parameres are considered in conjunction with the phylogenetic relationships among the studied taxa. Compared with Lachninae, Greenideinae, Aiceoninae, the external genitalia of Aphidinae are less specialized, having many features in common with those of drepanosiphine aphids and differing little from the hypothetical condition. In dwarfish males of Anoeciinae, Thelaxinae, Hormaphidinae, and Eriosomatinae, the miniaturization of the body size affects on the modification of genitalia, mostly parameres. However, the homology of non-modified and modified structures of parameres is not clear.

Comparative morphology of the male genitalia of Aphididae (Insecta, Hemiptera): part 1.

The present study provides new data concerning the morphology of the male genitalia of Aphididae and unifies their nomenclature. The structure of the male genitalia of 31 species from 26 genera of Aphididae was studied with light and scanning electron microscopy. In the studied species, the genitalia of males consist of a phallus composed of the sclerotized basal part with its articulation and a membranous apical part-an aedeagus. Laterally of the phallus, there is a pair of setose parameres. The shape of the aedeagus, the shape and length of the sclerotized basal part and its articulation as well as the variability of parameres in their form and the number of setae are recognized as important systematic signs of the genitalia. These characters are considered in conjunction with the phylogenetic relationships among the studied taxa.