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Aphis gossypii Glover is cosmopolitan pest aphid, known to be represented by host-associated lineages. Although it is widespread in the Pacific Basin, there has been no assessment of this species in this region. We examined patterns of morphological variation within and among populations collected across hosts and islands using multivariate morphometric analyses. Genetic variation was determined using microsatellite flanking region sequences and mitochondrial cytochrome oxidase subunit 1. This study confirmed the existence of genetically distinct host-associated lineages. We found that host plant affects morphological expression and therefore morphological criteria cannot be used to identify lineages. Comments are provided on the origin and maintenance of these host lineages and implications for management of this important pest aphid species. [ABSTRACT FROM AUTHOR]

The Canadian Hemiptera (Sternorrhyncha, Auchenorrhyncha, and Heteroptera) fauna is reviewed, which currently comprises 4011 species, including 405 non-native species. DNA barcodes available for Canadian specimens are represented by 3275 BINs. The analysis was based on the most recent checklist of Hemiptera in Canada (Maw et al. 2000) and subsequent collection records, literature records and compilation of DNA barcode data. It is estimated that almost 600 additional species remain to be discovered among Canadian Hemiptera. [ABSTRACT FROM AUTHOR]

DNA barcode reference libraries linked to voucher specimens create new opportunities for high-throughput identification and taxonomic re-evaluations. This study provides a DNA barcode library for about 45% of the recognized species of Canadian Hemiptera, and the publically available R workflow used for its generation. The current library is based on the analysis of 20,851 specimens including 1849 species belonging to 628 genera and 64 families. These individuals were assigned to 1867 Barcode Index Numbers (BINs), sequence clusters that often coincide with species recognized through prior taxonomy. Museum collections were a key source for identified specimens, but we also employed high-throughput collection methods that generated large numbers of unidentified specimens. Many of these specimens represented novel BINs that were subsequently identified by taxonomists, adding barcode coverage for additional species. Our analyses based on both approaches includes 94 species not listed in the most recent Canadian checklist, representing a potential 3% increase in the fauna. We discuss the development of our workflow in the context of prior DNA barcode library construction projects, emphasizing the importance of delineating a set of reference specimens to aid investigations in cases of nomenclatural and DNA barcode discordance. The identification for each specimen in the reference set can be annotated on the Barcode of Life Data System (BOLD), allowing experts to highlight questionable identifications; annotations can be added by any registered user of BOLD, and instructions for this are provided. [ABSTRACT FROM AUTHOR]

Aphis intybi Koch is recorded for the first time in North and South America. Measurements for the identification of this species in comparison with Aphis craccivora Koch are given. Aphis cytisorum Hartig is recorded for the third time in Argentina. Data on morphological variation, geographical distribution, and host plants of these species in Argentina are provided. Their morphological identification is supported by comparison of DNA sequences of the mitochondrial cytochrome oxidase subunit 1 (DNA barcode) and subunit 2. [ABSTRACT FROM AUTHOR]

Background: DNA barcoding, the analysis of sequence variation in the 59 region of the mitochondrial cytochrome c oxidase I (COI) gene, has been shown to provide an efficient method for the identification of species in a wide range of animal taxa. In order to assess the effectiveness of barcodes in the discrimination of Heteroptera, we examined 344 species belonging to 178 genera, drawn from specimens in the Canadian National Collection of Insects. Methodology/Principal Findings: Analysis of the COI gene revealed less than 2% intra-specific divergence in 90% of the taxa examined, while minimum interspecific distances exceeded 3% in 77% of congeneric species pairs. Instances where barcodes fail to distinguish species represented clusters of morphologically similar species, except one case of barcode identity between species in different genera. Several instances of deep intraspecific divergence were detected suggesting possible cryptic species. Conclusions/Significance: Although this analysis encompasses 0.8% of the described global fauna, our results indicate that DNA barcodes will aid the identification of Heteroptera. This advance will be useful in pest management, regulatory and environmental applications and will also reveal species that require further taxonomic research. [ABSTRACT FROM AUTHOR]

The taxonomic status of several Australian populations within the aphid genus Sitobion has been uncertain for many years. Morphometric investigations using principal component analysis and canonical discriminant analysis have allowed us to clarify the relationships of these entities. A form on grasses, referred to in the literature as Sitobion near fragariae, is shown not to separate morphometrically from S. fragariae (Walker) collected in Europe and North America. In contrast, Sitobion miscanthi (Takahashi) Clones 61 (2n = 20) and 34 (2n = 17) separate unequivocally from each other and from Clone 4 (2n = 18), the supposed ancestral karyotype. We argue against describing these as separate species. Sexual forms of S. miscanthi and Australian S. fragariae reared in the laboratory were compared with the sexual forms of European Sitobion avenae (Fabricius) and S. fragariae, respectively. Australian specimens from Smilax glyciphylla and Smilax australis (Smilacaceae) are not Sitobion smilacifoliae (Takahashi). [ABSTRACT FROM AUTHOR]

The Adelgidae form a small clade of insects within the Aphidoidea (Hemiptera) that includes some of the most destructive introduced pest species threatening North American forest ecosystems. Despite their importance, little is known about their evolutionary history and their taxonomy remains unresolved. Adelgids are cyclically parthenogenetic and exhibit multigeneration complex life cycles. They can be holocyclic, with a sexual generation and host alternation, or anholocyclic, entirely asexual and without host alternation. We discuss adelgid behavior and ecology, emphasizing plant-insect interactions, and we explore ways that the biogeographic history of their host plants may have affected adelgid phylogeny and evolution of adelgid life cycles. Finally, we highlight several areas in which additional research into speciation, population genetics, multitrophic interactions, and life-history evolution would improve our understanding of adelgid biology and evolution. [ABSTRACT FROM AUTHOR]

Calaphidinae is the second‐largest subfamily in the family Aphididae. Despite their species diversity and some taxonomic controversy, no phylogenetic studies have been conducted on them thus far. Herein, we report the first molecular phylogeny of Calaphidinae and two related lineages, Phyllaphidinae and Saltusaphidinae, based on five genes (3418 bp) for 126 taxa. Maximum parsimony, maximum‐likelihood and Bayesian inference phylogenetic analyses were performed on the multilocus dataset. Divergence time estimation, biogeographical reconstruction, ancestral host plant reconstruction and PhyloType analyses were performed to identify evolutionary trends in Calaphidinae. Our phylogenetic results lead to several conclusions: Phyllaphidinae is a sister group to Calaphidinae s.l.; Calaphidinae is paraphyletic with respect to the former "Saltusaphidinae"; the ingroup clade was subdivided into nine newly recognized lineages; and three subtribes of Calaphidinae (Monaphidina, Calaphdina and Panaphidina) and many genera were not recovered as monophyletic. A new classification is proposed with eight tribal divisions that reflect our phylogenetic results, including three new tribes (Pterocallidini trib.n., Pseudochromaphidini trib.n. and Shivaphidini trib.n.) and three new statuses (Saltusaphidini stat.n., Therioaphidini stat.n. and Myzocallidini stat.n.). The ancestral reconstruction results imply that the ingroup taxa's common ancestor originated in the Eastern Palaearctic and might have fed on Fagaceae in the Late Cretaceous. Later, multiple host shifts and an expanding geographical distribution led to the current species diversity of Calaphidinae. Our reconstructions suggest that species diversification cannot solely be explained by speciation via host shifts and that geographical isolation probably also played a key role. Our results provide new insight into the natural classification and history of the host plant associations and biogeography of Calaphidinae s.l. [ABSTRACT FROM AUTHOR]

Adelges (Cholodkovskya) viridanus (Cholodkovsky 1896) (Hemiptera: Adelgidae) is found throughout Eurasia where it is understood to be anholocyclic, feeding on species of larch (Larix), without host alternation. For the first time, we report this species in North America, outside of its native range, from specimens collected in an arboretum in Ohio, USA. Molecular phylogenetic analysis was inconclusive as to whether it was introduced from Europe or Asia. In addition, specimens collected from Picea jezoensis in Japan were confirmed for the first time as A. (C.) viridanus by matching DNA sequences to specimens collected on Larix. Therefore, A. (C.) viridanus is either capable of completing a host‐alternating holocycle in Japan, or includes very recently diverged anholocyclic populations on Picea. Finally, we describe the adult fundatrix form, which was previously unknown. [ABSTRACT FROM AUTHOR]

The Adelges (Dreyfusia) piceae (Ratzeburg) species complex is a taxonomically unstable group of six species. Three of the species are cyclically parthenogenetic [Ad. nordmannianae (Eckstein), Ad. prelli (Grossmann), and Ad. merkeri (Eichhorn)] and three are obligately asexual [Ad. piceae, Ad. schneideri (Börner), and Ad. nebrodensis (Binazzi & Covassi)]. Some species are high‐impact pests of fir (Abies) trees, so stable species names are needed to communicate effectively about management. Therefore, to refine species delimitation, guided by a reconstruction of their biogeographic history, we genotyped adelgids from Europe, North America, and the Caucasus Mountains region with 19 microsatellite loci, sequenced the COI DNA barcoding region, and compared morphology. Discriminant analysis of principal components of microsatellite genotypes revealed four distinct genetic clusters. Two clusters were morphologically consistent with Ad. nordmannianae. One of these clusters consisted of samples from the Caucasus Mountains and northern Turkey, and the other included samples from this region as well as from Europe and North America, where Ad. nordmannianae is invasive. A third cluster was morphologically consistent with Ad. piceae, and included individuals from Europe, where it is native, and North America, where it is invasive. In North America, the majority of Ad. piceae individuals were assigned to two geographically widespread clones, suggesting multiple introductions. The fourth cluster included individuals morphologically consistent with Ad. prelli or Ad. merkeri. However, based on genetic assignments, hybrid simulations, and approximate Bayesian computation, we find it likely that these are contemporary hybrids between Ad. nordmannianae and Ad. piceae that arose independently in Europe and North America, so we propose that Ad. prelli and Ad. merkeri are invalid. Finally, we synonymise Ad. schneideri(syn.n.) with Ad. nordmannianae and designate Ad. nebrodensis as subspecies Ad. piceae nebrodensis(stat.n.). Our revised taxonomy therefore recognises two species: Ad. nordmannianae and Ad. piceae, which we estimate to have diverged recently, during one of the last two interglacial periods. Finally, we comment on this species complex being in the midst of transition between sexual and asexual reproduction, a pattern that is probably common in Adelgidae. [ABSTRACT FROM AUTHOR]

Thirty-three species of aphids are now established in New Caledonia. All species appear to have been introduced accidentally by human activity in the last century. Here, 17 aphid species are recorded for the first time: Aphis eugeniae, Aphis glycines, Aphis odinae, Aulacorthum solani, Brachycaudus helichrysi, Cerataphis orchidearum, Greenidea psidii, Hyperomyzus carduellinus, Hysteroneura setariae, Lipaphis pseudobrassicae, Micromyzus katoi, Myzus ornatus, Pentalonia caladii, Rhopalosiphum nymphaeae, Rhopalosiphum rufiabdominale, Schizaphis rotundiventris, and Tetraneura fusiformis. Thirteen more species are also more or less regularly intercepted at the borders through biosecurity surveys, without further establishment. This demonstrates that aphids represent a major biosecurity threat, including a threat as potential plant virus vectors. The reinforcement of biosecurity is a priority for such biodiversity hotspots, from the perspectives of both agriculture and the native environment. Prioritisation and promotion of local development of vegetable and fruit production, rather than their risky importation from abroad, is desirable. Such an approach also should be promoted and extended to other Pacific islands, which all share the lack of native aphid fauna and their associated plant disease vector risks. [ABSTRACT FROM AUTHOR]

Aphids are a species rich group comprising many important pests. However, species identification can be very difficult for aphids due to their morphological ambiguity. DNA barcoding has been widely adopted for rapid and reliable species identification as well as cryptic species detection. In this study, we investigated cryptic diversity in the subfamily Calaphidinae (Hemiptera: Aphididae) based on 899 sequences of cytochrome c oxidase I (COI) for 115 morphospecies (78 species collected in this study and sequences of 73 species downloaded from Genbank). Among these 115 morphospecies, DNA barcoding results of 90 (78.3%) species were identical to results of morphological identification. However, 25 (21.7%) morphospecies showed discrepancies between DNA barcoding and traditional taxonomy. Among these 25 discordances, a total of 15 cryptic species were identified from 12 morphospecies. We also found three morphologically distinct species pairs that sharing DNA barcoding. Based on molecular operational taxonomic unit (MOTU) estimation, we discussed on species delimitation threshold value for these taxa. Our findings confirm that Calaphidinae has high cryptic diversity even though aphids are relatively well-studied. [ABSTRACT FROM AUTHOR]

Aphid species from 11 of the major islands of Micronesia ranging from Majuro, Republic of the Marshall Islands, in the east to Koror and Babeldaup, Republic of Palau, in the west, are documented based on 1,691 collections. Other islands sampled included Yap, Kosrae, and Chuuk in the Federated States of Micronesia; Saipan, Tinian, and Rota in the Commonwealth of the Northern Mariana Islands; and the Territory of Guam. Host-plant associations were documented at each collection site. Thirty-five aphid species were collected from 139 plant species in 43 different plant families. None of the aphids collected is indigenous to Micronesia. A key to the identification of the aphid species is provided. [ABSTRACT FROM AUTHOR]

Highlights: [•] We proposed and evaluated an alternative approach for generating an aphid phylogeny. [•] We reconstructed phylogenetic relationships within Aphididae based on 255 sequences derived from Buchnera symbionts. [•] We showed that symbiont derived DNA yields informative phylogenetic signal and is a useful source of data. [ABSTRACT FROM AUTHOR]