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Adler P.H.,Clemson University | Belqat B.,Abdelmalek Essaadi University | Gonzalez J.G.,University of Vigo | Perez A.J.,University of Vigo | Seitz G.,District Government of Lower Bavaria
Zootaxa | Year: 2016

The banding sequence of the polytene chromosomes of Simulium armoricanum Doby & David from England, Portugal, and Spain was resolved relative to the standard map for the S. vernum group. The species is characterized by 11 fixed inversions, one nearly fixed inversion, and three common polymorphisms. The sister species of S. armoricanum is proposed as a formally undescribed species discovered in samples from Portugal. It shares one unique inversion with S. armoricanum, but otherwise differs by eight fixed or nearly fixed rearrangements. Simulium armoricanum and its newly discovered sister species, informally referred to as Simulium 'IL-8', are members of a larger clade of Palearctic species defined by a small pericentric inversion in chromosome III. Among the simuliid species occupying the same streams with S. armoricanum was the first record, chromosomally confirmed, of S. aureum Fries sensu stricto in Portugal. Successful chromosomal analysis of samples of S. armoricanum 17 years after initial fixation demonstrates the importance of storing cytologically fixed larvae at subzero temperatures. Copyright © 2016 Magnolia Press.

Seitz G.,District Government of Lower Bavaria | Adler P.H.,Clemson University | Forster M.,Water Management Office
Zootaxa | Year: 2015

Simulium (Nevermannia) berchtesgadense nov. spec. is described from the Alps of southeastern Germany. The morphology and diagnostic characters for all life stages except the egg are given, and the polytene chromosomes are compared with those of other members of the Simulium (Nevermannia) vernum group. The species is chromosomally similar to Simulium (Nevermannia) cryophilum cytoform 'A' but differs morphologically in each life stage. Bionomic information and the associated simuliid fauna are presented. Copyright © 2015 Magnolia Press.

Adler P.H.,Clemson University | Inci A.,Erciyes University | Yildirim A.,Erciyes University | Duzlu O.,Erciyes University | And 8 more authors.
Biological Journal of the Linnean Society | Year: 2015

Organisms with vast distributions often represent geographical mosaics of cryptic species. The black fly Simulium (Wilhelmia) lineatum is among the most widely distributed members of the family Simuliidae, ranging from the British Isles to eastern China. Rather than viewing S.lineatum as a possible aggregate of multiple species, taxonomists have suggested a more inclusive taxon with additional synonyms. Accordingly, S.lineatum is an ideal candidate for testing the hypothesis that a wide geographical distribution signals the presence of more than one species. A cytogenetic approach was used to probe the macrogenome of S.lineatum and other taxa proposed by taxonomists as conspecific. The banding patterns in the polytene chromosomes of 480 larvae from 15 countries across the Palearctic Region revealed 128 rearrangements of the complement. All rearrangements were autosomal and 89% were inversions nonrandomly distributed among species and among chromosome arms. The analyses clarify long-standing confusion over previously proposed names and reveal a longitudinal succession of four species sequentially replacing one another from west to east: Simulium lineatum s.s., Simulium balcanicum, Simulium turgaicum, and Simulium takahasii. Thus, S.turgaicum is recalled from synonymy and the other three species are validated. Within the most-represented species, S.balcanicum, the frequency of inversions follows a longitudinal gradient with a north-south bias; as the distance between the sites increases along this north-west-south-east axis, the similarity of inversion frequencies between sites decreases. Validation of the concept that broadly distributed black flies are composites of structurally similar species provides a framework for guiding discovery of additional biodiversity. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 114, 163-183. © 2014 The Linnean Society of London.

Adler P.H.,Clemson University | Seitz G.,District Government of Lower Bavaria
European Journal of Entomology | Year: 2014

The giant, polytene chromosomes of Simulium carthusiense Grenier & Dorier, 1959 were mapped, and all rearrangements were resolved relative to the standard banding sequence for the S. vernum group. The species is chromosomally cohesive from Austria to Spain, and is characterized by a chromocenter, two unique fixed inversions, 10 unique autosomal polymorphisms, and undifferentiated sex chromosomes. Rare individuals (3%) have two types of supernumerary chromosomes, representing the third example of a simuliid species that carries two different supernumeraries in the same individuals. Band-sequence comparisons with chromosomal outgroups indicate that S. carthusiense is the sister species of a clade that includes S. beltukovae (Rubtsov, 1956), the S. cryophilum complex, and S. urbanum Davies, 1966.

Adler P.H.,Clemson University | Kudelova T.,Comenius University | Kudela M.,Comenius University | Seitz G.,District Government of Lower Bavaria | Ignjatovic-Cupina A.,University of Novi Sad
PLoS ONE | Year: 2016

The European black fly Simulium (Simulium) colombaschense (Scopoli), once responsible for as many as 22,000 livestock deaths per year, is chromosomally mapped, permitting its evolutionary relationships and pest drivers to be inferred. The species is 12 fixed inversions removed from the standard sequence of the subgenus Simulium. Three of these fixed inversions, 38 autosomal polymorphisms, and a complex set of 12 X and 6 Y chromosomes in 29 zygotic combinations uniquely characterize S. colombaschense and reveal 5 cytoforms: 'A' in the Danube watershed, 'B' in Italy's Adige River, 'C' in the Aliakmonas River of Greece, 'D' in the Aoös drainage in Greece, and 'E' in the Belá River of Slovakia. 'C' and 'D' are reproductively isolated from one another, and 'B' is considered a cytotype of 'A,' the probable name bearer of colombaschense. The species status of 'E' cannot be determined without additional collections. Three derived polytene sequences, based on outgroup comparisons, place S. colombaschense in a clade of species composed of the S. jenningsi, S. malyschevi, and S. reptans species groups. Only cytoforms 'A' and 'B' are pests. Within the Simuliidae, pest status is reached through one of two principal pathways, both of which promote the production of large populations of blood-seeking flies: (1) colonization of the world's largest rivers (habitat specialization) or (2) colonization of multiple habitat types (habitat generalization). Evolutionary acquisition of the ability to colonize large rivers by an ancestor of the S. jenningsi-malyschevi-reptans clade set the scene for the pest status of S. colombaschense and other big-river members of the clade. In an ironic twist, the macrogenome of S. colombaschense reveals that the name associated with history's worst simuliid pest represents a complex of species, two or more of which are nonpests potentially vulnerable to loss of their limited habitat. © 2016 Adler et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

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