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The taxonomic history of nominal subspecies of Danaus gilippus is reviewed. The historical record together with analysis of both morphological and molecular characters suggest that the current infraspecific nomenclature is in need of revision. The absence of DNA barcode differences and lack of consistent morphological differences in wing maculation in western and eastern populations in continental North America currently assigned to subspecies D. g. thersippus and D. g. berenice, respectively, raise the possibility that only a single subspecies, D. g. berenice, should be recognized. Recently published isotopic evidence for connectivity between eastern and western populations of D. gilippus, and potential ecological consequences of the relatively low numbers present in the spring and summer breeding range of the eastern migratory populations of the monarch, Danaus plexippus, are briefly discussed. [ABSTRACT FROM AUTHOR]

Nucleotide sequences from a segment of the mitochondrial cytochrome c oxidase subunit I (COI) gene were used to examine phylogeography, intraspecific relationships and taxonomy of the boll weevil Anthonomus grandis Boheman (Coleoptera: Curculionidae) collected from wild and cultivated cotton hosts in Mexico and USA. Phylogenetic trees and TCS haplotype networks showed that boll weevils partitioned into two clusters: 'western' and 'eastern'. In addition to infesting cultivated cotton, Gossypium hirsutum, both groups were found on several other species of the cotton tribe Gossypieae: wild Gossypium, Hampea, Cienfuegosia and Hibiscus pernambucensis (eastern group only). No evidence was found for host plant-associated genetic differentiation in either group. The level of genetic divergence and lack of shared COI haplotypes, combined with five apparent fixed nucleotide differences between the two groups and earlier evidence of reproductive isolation, together provide strong support for reinstating the subspecies name, Anthonomus grandis thurberiae Pierce, for the western lineage. Demographic tests suggested that both lineages have undergone population expansions dating to the Pleistocene. A possible vicariant role for the Trans-Mexican Volcanic Belt and the Sierra Madre Occidental in promoting genetic divergence, and a reassessment of dispersal scenarios during the postulated northward expansion of A. g. thurberiae are discussed. [ABSTRACT FROM AUTHOR]

Cladonia is one of the largest lichen-forming ascomycete genera. It was formerly divided into ten sections, three of which, Crustaceae (Cladina), Tenues, and Impexae, are called the reindeer lichens. While previous studies have elucidated the relationships between species and sections, they often examined only one or a few specimens of each species in the analysis. This study examined the monophyly of selected members of sections Crustaceae, Tenues, and Impexae and their relationships in the genus Cladonia using the internal transcribed spacer region of the nuclear ribosomal DNA (ITS rDNA) and the mitochondrial small subunit gene of the mitochondrial ribosomalDNA(mtSSU). The phylogenetic tree contained four clades, two representing species in section Impexae, one representing species that belong to sections Crustaceae and Tenues, and one clade with C. arbuscula and related species. Five of 22 species, C. pycnoclada, C. stellaris, C. evansii, C. ciliata and C. subtenuis, showed monophyly in the phylogenetic tree; some of these 5 species have been shown previously to be monophyletic. The thallus branching pattern was interpreted as an important heritable character using the mtSSU network. Three duplets of paraphyletic species were further examined using ITS rDNA haplotype networks and AMOVA analysis. The results for the species duplets showed some mixing of haplotypes but the AMOVA analysis provided support for species separation within the duplets. While the evidence supports distinct species, further study is needed to conclusively show separate species in these duplets. [ABSTRACT FROM AUTHOR]

Knowing the origin of invasive taxa, whether multiple introductions have occurred, and levels of genetic variation relative to the native range, is vital to conducting rigorous tests of hypotheses to explain biological invasions. We explore phylogeographical relationships of two Eurasian knapweed taxa that are invasive in North America, Centaurea diffusa and C. stoebe micranthos (Asteraceae), using chloroplast DNA intron sequences. We also gathered data from C. stoebe stoebe, hybrids between C. diffusa and C. stoebe stoebe ( C. x psammogena), and three other species in the genus. We sequenced 213 individuals from Eurasia and North America, and found 22 haplotypes. Centaurea diffusa has lower haplotype diversity and allelic richness in the introduced range relative to the native range. Even with reduced variation, the data suggest at least two introductions of C. diffusa. There is a trend towards reduced variation in C. stoebe micranthos, but it is not significant. One of the haplotypes found in North American C. stoebe micranthos matches a haplotype from a taxon other than C. stoebe micranthos in Europe. This suggests introgression of the chloroplast between taxa, or possibly the invasion of another Centaurea taxon into North America. Additionally, C. diffusa, C. stoebe micranthos, and C. stoebe stoebe share several haplotypes, including their most common haplotype. This suggests ongoing hybridization between the species or incomplete segregation. These data can guide further exploration for the origins of these species, and point out locations within the introduced range with unique and diverse genetic makeup. [ABSTRACT FROM AUTHOR]

Melting snowfields in polar and alpine regions often exhibit a red and orange colouration caused by microalgae. The diversity of these organisms is still poorly understood. We applied a polyphasic approach using three molecular markers and light and electron microscopy to investigate spherical cysts sampled from alpine mountains in Europe, North America and South America as well as from both polar regions. Molecular analyses revealed the presence of a single independent lineage within the Chlamydomonadales. The genus Sanguina is described, with Sanguina nivaloides as its type. It is distinguishable from other red cysts forming alga by the number of cell wall layers, cell size, cell surface morphology and habitat preference. Sanguina nivaloides is a diverse species containing a total of 18 haplotypes according to nuclear ribosomal DNA internal transcribed spacer 2, with low nucleotide divergence (≤3.5%). Based on molecular data we demonstrate that it has a cosmopolitan distribution with an absence of geographical structuring, indicating an effective dispersal strategy with the cysts being transported all around the globe, including trans-equatorially. Additionally, Sanguina aurantia is described, with small spherical orange cysts often clustered by means of mucilaginous sheaths, and causing orange blooms in snow in subarctic and Arctic regions., (© FEMS 2019.)