Simulium (Asiosimulium) khongchiamense sp. nov. is described based on females, males, pupae, and mature larvae collected from Khong Chiam District, Ubon Ratchathani Province, northeastern Thailand. It is characterized in the female by the medium-long sensory vesicle, scutum with 3 dark longitudinal vittae and elongate cercus; in the male by the number of upper-eye (large) facets in 17 or 18 vertical rows and 18 or 19 horizontal rows, hind basitarsus moderately enlarged and ventral plate with the posterior margin moderately concave medially; in the pupa by the head and thoracic integument sparsely covered with tubercles and gill of arborescent type with 32 or 33 filaments; and in the larva by the postgenal cleft deep, reaching the posterior margin of the hypostoma and sheath of the subesophageal ganglion dark pigmented. DNA analysis based on COI gene of all known species of the subgenus Asiosimulium, except for S. shanense and S. suchitrae, indicated that this new species can be clearly differentiated from all other related species (S. phurueaense, S. oblongum, S. saeungae, S. furvum, and S. wanchaii) with interspecific genetic distances ranging between 4.79% and 19.18%. This is the eighth species of the subgenus Asiosimulium. Taxonomic notes are given to distinguish this new species from the 7 known species members in its same subgenus. Additionally, keys to species of all members in the subgenus Asiosimulium are provided.
Simulium (Gomphostilbia) okinawense Takaoka and S. (G.) tokarense Takaoka, both from the Nansei Islands, Japan, were morphologically reexamined and genetically analysed by using the COI gene sequences. The female, male, pupa and mature larva of the two species are redescribed. Morphological reexamination shows that both species are more similar to species in the S. asakoae species-group than to those in the S. ceylonicum species-group, by having a medium-long female sensory vesicle, yellow tuft hairs (S. (G.) okinawense) or yellow tuft hairs mixed with a few to several dark hairs (S. (G.) tokarense) at the base of the radial vein in the female and male, and medium-long larval postgenal cleft. However, the body of the male ventral plate (viewed ventrally) is parallel-sided (S. (G.) okinawense) or parallelsided or slightly narrowed (S. (G.) tokarense) and not emarginated basally, differing from those of most species in the S. asakoae species-group. Our genetic analysis shows that S. (G.) tokarense is in the S. asakoae species-group, and S. (G.) okinawense formed a separate sister clade with other members of the S. asakoae species-group with high bootstrap support. From the results of morphological and genetic analysis combined, S. (G.) okinawense and S. (G.) tokarense are transferred from the S. ceylonicum species-group to the S. asakoae species-group.
In recent decades, the numbers of cryptic taxa have increased significantly with current progress in DNA barcoding, yet, most of these cryptic taxa have not been formally named and recognized as valid species. To address this issue, we provide a guide for applying the procedure of describing new cryptic species in the family Simuliidae. Simulium (Simulium) vanluni from Pahang, Peninsular Malaysia, previously treated as S. nobile De Meijere, is described as a new species by using an integrated morpho-taxonomical and genetic approach. This new species is morphologically identical to S. nobile from Java and S. kiuliense Smart & Clifford from Borneo, but their distinctiveness is supported by an expanded multigene phylogeny analysis.
Five new species of black flies, Simulium (Gomphostilbia) chiangraiense, S. (G.) huaikaeoense, S. (G.) khaokhoense, S. (G.) maeklangense, and S. (G.) pamiangense, are described based on adults, pupae and mature larvae from Thailand. These five species are similar to one another and are placed in the S. decuplum subgroup of the S. batoense species-group by having the male fore coxae darkened, ventral plate flat and transverse; pupal gill with 10 short filaments; and larval postgenal cleft deep approaching or reaching the posterior margin of the hypostoma. Simulium (G.) chiangraiense sp. nov. and S. (G.) pamiangense sp. nov. differ from the three other new species by the much longer pupal gill filaments and darkened dorsal surface of abdominal segments 1 and 2. Taxonomic notes are provided to distinguish these five new species from five other related species. The phylogenetic positions of these new species in the S. decuplum subgroup are presented based on the mitochondrial COI gene. Simulium (G.) pamiangense sp. nov. and S. (G.) huaikaeoense sp. nov. are highly similar to each other genetically, showing a sister relationship, though they are clearly different morphologically. On the contrary, S. (G.) khaokhoense sp. nov. is distantly positioned from S. (G.) huaikaeoense nov., though it is almost indistinguishable morphologically from the latter.
We access the molecular diversity of the black fly Simulium nobile De Mejiere, using the universal cytochrome c oxidase subunit I (COI) barcoding gene, across its distributional range in Southeast Asia. Our phylogenetic analyses recovered three well-supported mitochondrial lineages of S. nobile, suggesting the presence of cryptic species. Lineage A is composed of a population from Sabah, East Malaysia (Borneo); lineage B represents the type population from Java, Indonesia; and lineage C includes populations from the mainland of Southeast Asia (Peninsular Malaysia and Thailand). The genetic variation of lineage C on the mainland is greater than that of lineages A and B on the islands of Borneo and Java. Our study highlights the value of a molecular approach in assessing species status of simuliids in geographically distinct regions.
The widespread nominal black fly Simulium (Simulium) rufibasis Brunetti was reexamined morphologically, chromosomally, and molecularly to determine the status of populations in Japan and Korea with respect to S. rufibasis from the type locality in India and to all other known species in the S. (S.) tuberosum species-group. Morphological comparisons established that the species previously known as S. rufibasis in Japan and Korea is distinct from all other species. Consequently, it was described and illustrated as a new species, Simulium (S.) yamatoense. Simulium yokotense Shiraki, formerly a synonym of S. rufibasis, was morphologically reevaluated and considered a species unplaced to species-group in the subgenus Simulium. Chromosomal analyses of S. yamatoense sp. nov. demonstrated that it is unique among all cytologically known species of the S. tuberosum group and is the sister species of the Taiwanese species tentatively known as S. (S.) arisanum Shiraki. Populations of S. yamatoense sp. nov. included two cytoforms, based on the sex chromosomes. Cytoform A, including topotypical representatives, was found in Kyushu, Japan, whereas cytoform B was found in Korea and Honshu, Japan. Molecular analysis based on the COI mitochondrial gene generally corroborated morphological and chromosomal data that S. yamatoense sp. nov. is a distinct species and, like the chromosomal data, indicate that it is most closely related to S. arisanum, with interspecific genetic distance of 2.92-4.63%.
Simulium (Simulium) phraense sp. nov. (Diptera: Simuliidae) is described from females, males, pupae, and larvae from Thailand. This new species is placed in the Simulium striatum species group and is most similar to Simulium (Simulium) nakhonense Takaoka & Suzuki (Diptera: Simuliidae) from Thailand among species of the same species group but is barely distinguished from the latter species by lacking annular ridges on the surface of the pupal gill filaments. The fast-evolving nuclear big zinc finger (BZF) gene has successfully differentiated this new species from its allies, S. (S.) nakhonense and Simulium (Simulium) chiangmaiense Takaoka & Suzuki (Diptera: Simuliidae) of the S. striatum species group. The BZF gene sequences show that this new species is more closely related to S. (S.) nakhonense than to S. (S.) chiangmaiense, further supporting its morphological classification.
A new black fly species, Simulium haiduanense Takaoka, Low & Huang (Diptera: Simuliidae), is described on the basis of females, males, pupae, and mature larvae from Taiwan. This new species is placed in the Simulium argentipes species-group of the subgenus Simulium (Diptera: Simuliidae) and is characterized by the yellowish female legs, ovipositor valves rounded apically and with its inner margin concave, claw with a small subbasal tooth, male style without a basal protuberance, pupal gill with eight filaments, corbicular cocoon, and larval abdomen lacking paired protuberances. It represents the first record of the S. argentipes species-group from Taiwan. Taxonomic notes are given to separate this new species from all eight species in the same species-group. The phylogenetic relationships of this new species with four related species are presented.