Displaying publications 81 - 100 of 131 in total

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  1. Uni S, Mat Udin AS, Agatsuma T, Junker K, Saijuntha W, Bunchom N, et al.
    Parasit Vectors, 2020 Feb 06;13(1):50.
    PMID: 32028994 DOI: 10.1186/s13071-020-3907-8
    BACKGROUND: The genus Onchocerca Diesing, 1841 includes species of medical importance, such as O. volvulus (Leuckart, 1893), which causes river blindness in the tropics. Recently, zoonotic onchocercosis has been reported in humans worldwide. In Japan, O. dewittei japonica Uni, Bain & Takaoka, 2001 from wild boars is a causative agent for this zoonosis. Many filarioid nematodes are infected with Wolbachia endosymbionts which exhibit various evolutionary relationships with their hosts. While investigating the filarial fauna of Borneo, we discovered an undescribed Onchocerca species in the bearded pig Sus barbatus Müller (Cetartiodactyla: Suidae).

    METHODS: We isolated Onchocerca specimens from bearded pigs and examined their morphology. For comparative material, we collected fresh specimens of O. d. dewittei Bain, Ramachandran, Petter & Mak, 1977 from banded pigs (S. scrofa vittatus Boie) in Peninsular Malaysia. Partial sequences of three different genes (two mitochondrial genes, cox1 and 12S rRNA, and one nuclear ITS region) of these filarioids were analysed. By multi-locus sequence analyses based on six genes (16S rDNA, ftsZ, dnaA, coxA, fbpA and gatB) of Wolbachia, we determined the supergroups in the specimens from bearded pigs and those of O. d. dewittei.

    RESULTS: Onchocerca borneensis Uni, Mat Udin & Takaoka n. sp. is described on the basis of morphological characteristics and its genetic divergence from congeners. Molecular characteristics of the new species revealed its close evolutionary relationship with O. d. dewittei. Calculated p-distance for the cox1 gene sequences between O. borneensis n. sp. and O. d. dewittei was 5.9%, while that between O. d. dewittei and O. d. japonica was 7.6%. No intraspecific genetic variation was found for the new species. Wolbachia strains identified in the new species and O. d. dewittei belonged to supergroup C and are closely related.

    CONCLUSIONS: Our molecular analyses of filarioids from Asian suids indicate that the new species is sister to O. d. dewittei. On the basis of its morphological and molecular characteristics, we propose to elevate O. d. japonica to species level as O. japonica Uni, Bain & Takaoka, 2001. Coevolutionary relationships exist between the Wolbachia strains and their filarial hosts in Borneo and Peninsular Malaysia.

  2. Takaoka H, Srisuka W, Saeung A
    Trop Biomed, 2018 Dec 01;35(4):975-980.
    PMID: 33601845
    Simulium chayamaritae Takaoka and Srisuka from Thailand belongs to the Simulium darjeelingense species-group of Simulium (Simulium) (Diptera: Simuliidae). The female of this species is described for the first time based on a female reared from a pupa collected from Chiang Mai, Thailand. It is characterized by the sensory vesicle elongate and the inner margins of the arms of the genital fork divergent, then convergent apically. It is similar to the female of S. eshimai Takaoka and Adler of the same speciesgroup from Vietnam. Taxonomic notes are given to separate it from two other species of the S. darjeelingense species-group from India and Malaysia, and 28 of 31 other species of the subgenus Gomphostilbia recorded from Thailand.
  3. Ya'cob Z, Takaoka H, Low VL, Tan TK, Sofian-Azirun M
    Acta Trop, 2019 May;193:66-70.
    PMID: 30807749 DOI: 10.1016/j.actatropica.2019.02.023
    Simulium (Gomphostilbia) aziruni Takaoka, Hashim & Chen was described initially based only on a pupa and a mature larva collected from Peninsular Malaysia. Herein, we describe the morphological characters of the female of S. aziruni for the first time. It resembles those of the other members of the Simulium gombakense species-group by the genital fork with a distinct projection directed medioposteriorly from each arm and claw with a large basal tooth. Cytochrome c oxidase I (COI) barcoding analysis indicates that S. aziruni is the sister species of S. maleewongae, but both are distantly separated by a genetic distance of 4.9%.
  4. Srisuka W, Takaoka H, Saeung A
    Trop Biomed, 2015 Sep;32(3):504-10.
    PMID: 26695212 MyJurnal
    The male, pupa and mature larva of Simulium (Asiosimulium) wanchaii Takaoka & Choochote, one of the four species of the small Oriental black fly subgenus Asiosimulium, are described for the first time based on samples collected from Thailand. The male S. (A.) wanchaii is characterized based on the enlarged hind basitarsus and the ventral plate which is much wider than long. The pupa and larva are characterized by the gill with 19 filaments and the deep postgenal cleft, respectively. Keys are provided to identify all the four species of the subgenus Asiosimulium for females, males, pupae and mature larvae.
  5. Takaoka H, Sofian-Azirun M, Hashim R
    J Med Entomol, 2013 Nov;50(6):1179-89.
    PMID: 24843921 DOI: 10.1603/me13036
    Simulium (Comphostilbia) izuae sp. nov. is described from female, male, pupal, and larval specimens collected from Cameron's Highlands, Peninsular Malaysia. This new species is placed in the asakoae species-group of the subgenus Gomphostilbia. The pupa of this new species is characterized by the gill with eight long filaments arranged as (3 + 3) + 2 filaments, of which the ventral pair of filaments is borne on a stalk that is always shorter than the common basal stalk. Taxonomic notes to distinguish this new species from five other Malaysian species and 12 other species of the asakoae species-group from other countries are given. Keys to identify all 18 species of the asakoae species-group are also provided for females, males, pupae, and mature larvae.
  6. Urabe M, Nor Hashim NE, Uni S, Iwaki T, Abdullah Halim MR, Marzuki ME, et al.
    Parasitol Int, 2020 Jun;76:102074.
    PMID: 32057926 DOI: 10.1016/j.parint.2020.102074
    We describe Morishitium polonicum malayense n. subsp. from Asian glossy starlings (Aplonis panayensis strigata) (Horsfield, 1821) (Passeriformis: Sturnidae) caught in Malaysia. The trematodes had parasitized the air sacs and the thoracic and body cavities of 40 out of 67 (59.7%) birds examined. The specimens each had an oral sucker, a postpharyngeal genital pore, and tandem testes, but lacked a ventral sucker. The morphological characteristics of our specimens were similar to those of M. polonicum polonicum (Machalska, 1980) from Poland. However, the anterior extremity of vitelline follicles of the present specimens sometimes extended to the level of pharynx. The oral sucker width, oral sucker width/pharynx width ratio, and intertesticular space metrics differed from those of M. p. polonicum. The maximum-likelihood trees based on the cytochrome c oxidase subunit I (COI) and the internal transcribed spacer 2 (ITS2) sequences indicated that the species from the present study formed a sister group with M. p. polonicum from the Czech Republic. The p-distances of COI and ITS2 sequences between the present specimens and M. p. polonicum from the Czech Republic were 6.9-7.5% and 0.6%, respectively. These genetic divergences indicate the border for intra- or interspecific variation of digeneans. The definitive host species and geographical distribution of the current specimens were distinct from those of M. p. polonicum from Europe. We thus concluded that the present specimens are ranked as a new subspecies of M. polonicum, namely M. polonicum malayense n. subsp.
  7. Uni S, Mat Udin AS, Tan PE, Rodrigues J, Martin C, Junker K, et al.
    PMID: 36589876 DOI: 10.1016/j.crpvbd.2022.100078
    Species of the genus Pelecitus Railliet & Henry, 1910 the most widely distributed avian filariae in Africa and South America. Zoonotic cases in humans were reported in South America. While investigating the filarial fauna of wild animals in Malaysia, we discovered an undescribed filaria from the swollen footpad of the left leg of Copsychus malabaricus (Scopoli) in Pahang, Peninsular Malaysia. Adults of both sexes have a corkscrew-shaped body. Based on comparison of their morphological characteristics (i.e. pre-oesophageal cuticular ring distinct, oesophagus divided, vulva protuberant and situated at the level of anterior half of oesophagus, spicules strongly sclerotized and left spicule with broad blade) with other Pelecitus species, they are here described as Pelecitus copsychi Uni, Mat Udin & Martin n. sp. Multi-locus sequence analyses based on seven genes (12S rDNA, cox1, 18S rDNA, 28S rDNA, MyoHC, rbp1 and hsp70) were performed to determine the phylogenetic position of the new species. The calculated p-distance between the cox1 gene sequences for P. copsychi n. sp. and Pelecitus fulicaeatrae (Diesing, 1861) was 14.1%. Intraspecific genetic variation between two individuals of the new species was 0.4%. In both the Bayesian inference and maximum-likelihood trees, P. copsychi n. sp. was positioned in the second clade of ONC5, containing three genera of the subfamily Dirofilariinae (Foleyella Seurat, 1917, Pelecitus and Loa Stiles, 1905). Immunostaining and molecular analyses remained negative for the presence of Wolbachia endosymbionts. Our findings corroborate the division of the subfamily Dirofilariinae into ONC3 with Dirofilaria Railliet & Henry, 1911 and ONC5 with Pelecitus.
  8. Low VL, Takaoka H, Pramual P, Adler PH, Ya'cob Z, Huang YT, et al.
    Sci Rep, 2016 Feb 03;6:20346.
    PMID: 26839292 DOI: 10.1038/srep20346
    Perspicuous assessments of taxonomic boundaries and discovery of cryptic taxa are of paramount importance in interpreting ecological and evolutionary phenomena among black flies (Simuliidae) and combating associated vector-borne diseases. Simulium tani Takaoka & Davies is the largest and perhaps the most taxonomically challenging species complex of black flies in the Oriental Region. We use a DNA sequence-based method to delineate currently recognized chromosomal and morphological taxa in the S. tani complex on the Southeast Asian mainland and Taiwan, while elucidating their phylogenetic relationships. A molecular approach using multiple genes, coupled with morphological and chromosomal data, supported recognition of cytoform K and morphoform 'b' as valid species; indicated that S. xuandei, cytoform L, and morphoform 'a' contain possible cryptic species; and suggested that cytoform B is in the early stages of reproductive isolation whereas lineage sorting is incomplete in cytoforms A, C, and G.
  9. Hew YX, Ya'cob Z, Adler PH, Chen CD, Lau KW, Sofian-Azirun M, et al.
    Parasit Vectors, 2023 Jul 22;16(1):248.
    PMID: 37480109 DOI: 10.1186/s13071-023-05875-1
    BACKGROUND: DNA barcoding is a valuable taxonomic tool for rapid and accurate species identification and cryptic species discovery in black flies. Indonesia has 143 nominal species of black flies, but information on their biological aspects, including vectorial capacity and biting habits, remains underreported, in part because of identification problems. The current study represents the first comprehensive DNA barcoding of Indonesian black flies using mitochondrial cytochrome c oxidase subunit I (COI) gene sequences.

    METHODS: Genomic DNA of Indonesian black fly samples were extracted and sequenced, producing 86 COI sequences in total. Two hundred four COI sequences, including 118 GenBank sequences, were analysed. Maximum likelihood (ML) and Bayesian inference (BI) trees were constructed and species delimitation analyses, including ASAP, GMYC and single PTP, were performed to determine whether the species of Indonesian black flies could be delineated. Intra- and interspecific genetic distances were also calculated and the efficacy of COI sequences for species identification was tested.

    RESULTS: The DNA barcodes successfully distinguished most morphologically distinct species (> 80% of sampled taxa). Nonetheless, high maximum intraspecific distances (3.32-13.94%) in 11 species suggested cryptic diversity. Notably, populations of the common taxa Simulium (Gomphostilbia) cheongi, S. (Gomphostilbia) sheilae, S. (Nevermannia) feuerborni and S. (Simulium) tani in the islands of Indonesia were genetically distinct from those on the Southeast Asian mainland (Malaysia and Thailand). Integrated morphological, cytogenetic and nuclear DNA studies are warranted to clarify the taxonomic status of these more complex taxa.

    CONCLUSIONS: The findings showed that COI barcoding is a promising taxonomic tool for Indonesian black flies. The DNA barcodes will aid in correct identification and genetic study of Indonesian black flies, which will be helpful in the control and management of potential vector species.

  10. Low VL, Srisuka W, Saeung A, Tan TK, Ya'cob Z, Yeong YS, et al.
    J Med Entomol, 2020 09 07;57(5):1675-1678.
    PMID: 32333022 DOI: 10.1093/jme/tjaa081
    Previous studies suggested the presence of species complex in the so-called Simulium asakoae Takaoka & Davies (Diptera: Simuliidae) in Thailand due to its high morphological variability and genetic divergence. To investigate whether the true S. asakoae is present in Thailand, we performed a detailed morphological identification of S. asakoae and compared its DNA barcodes with the morphospecies S. asakoae from Myanmar and the typical S. asakoae from Malaysia. Phylogenetic analysis revealed the Thai materials analyzed in this study were indeed genetically similar with those from Myanmar and Malaysia, though genetic distances 0-2.27% were observed. We tentatively regard this divergence as intraspecific variation, and the automatic barcode gap discovery analysis further supports them as a single species.
  11. Pramual P, Thaijarern J, Sofian-Azirun M, Ya'cob Z, Hadi UK, Takaoka H
    J Med Entomol, 2015 Sep;52(5):829-36.
    PMID: 26336220 DOI: 10.1093/jme/tjv080
    Simulium feuerborni Edwards is geographically widespread in Southeast Asia. Previous cytogenetic study in Thailand revealed that this species is a species complex composed of two cytoforms (A and B). In this study, we cytologically examined specimens obtained from the Cameron Highlands, Malaysia, and Puncak, Java, Indonesia. The results revealed two additional cytoforms (C and D) of S. feuerborni. Specimens from Malaysia represent cytoform C, differentiated from other cytoforms by a fixed chromosome inversion on the long arm of chromosome III (IIIL-5). High frequencies of the B chromosome (33-83%) were also observed in this cytoform. Specimens from Indonesia represent the cytoform D. This cytoform is differentiated from others by a fixed chromosome inversion difference on the long arm of chromosome II (IIL-4). Mitochondrial DNA sequences support genetic differentiation among cytoforms A, B, and C. The pairwise F(ST) values among these cytoforms were highly significantly consistent with the divergent lineages of the cytoforms in a median-joining haplotype network. However, a lack of the sympatric populations prevented us from testing the species status of the cytoforms.
  12. Lee HY, Loong SK, Ya'cob Z, Low VL, Teoh BT, Ahmad-Nasrah SN, et al.
    Acta Trop, 2021 Jul;219:105923.
    PMID: 33878305 DOI: 10.1016/j.actatropica.2021.105923
    Although the microbiome of blood-feeding insects serves an integral role in host physiology, both beneficial and pathogenic, little is known of the microbial community of black flies. An investigation, therefore, was undertaken to identify culturable bacteria from one of Malaysia's most common black flies, Simulium tani Takaoka and Davies, using 16S rDNA sequencing, and then evaluate the isolates for antibiotic resistance and virulence genes. A total of 20 isolates representing 11 bacterial species in four genera were found. Five isolates showed β-hemolysis on Columbia agar, and virulence genes were found in three of these isolates. Some degree of resistance to six of the 12 tested antibiotics was found among the isolates. The baseline data from this study suggest rich opportunities for comparative studies exploring the diversity and roles of the microbiome of S. tani and other Southeast Asian black flies.
  13. Srisuka W, Sulin C, Aupalee K, Phankaen T, Taai K, Thongsahuan S, et al.
    Insects, 2021 May 31;12(6).
    PMID: 34072677 DOI: 10.3390/insects12060504
    Black flies form a group of small blood-sucking insects of medical and veterinary importance. This study aimed to investigate the community structure, biodiversity and spatial and temporal distribution of adult black flies in tropical rain forests, by using malaise traps in Doi Inthanon National Park, northern Thailand. Malaise traps were placed along six elevational gradients (400 m to 2500 m, above sea level) at Doi Inthanon National Park, Chiang Mai province, from December 2013 to November 2014. A total of 9406 adult female black flies belonging to five subgenera-Daviesellum (2%), Gomphostilbia (23%), Montisimulium (11%), Nevermannia (16%) and Simulium (48%)-were collected. Among 44 taxa found, S. tenebrosum complex had the highest relative abundance (11.1%), followed by the S. asakoae species-group (9.6%), the S. striatum species-group (7.7%), S. inthanonense (6.6%), S. doipuiense complex (6.4%), S. chomthongense complex (5.3%), S. chumpornense (5.1%) and S. nigrogilvum (4.1%). Two human-biting species-S. nigrogilvum and species in the S. asakoae species-group-were found in all of the collection sites with 100% species occurrence. Species richness was highest at mid elevation (1400 m), which is represented by 19 black fly species. The peak and lowest seasonal abundance was observed in the rainy and hot season, respectively. Seasonal species richness was highest in the cold season, except for that from elevation sites at 700 m, 1700 m and 2500 m. This study revealed that the malaise trap is effective in providing important data for further monitoring of the effects of environmental changes and conservation planning on the biodiversity of black flies in Doi Inthanon National Park.
  14. Hew YX, Ya'cob Z, Chen CD, Lau KW, Sofian-Azirun M, Muhammad-Rasul AH, et al.
    Acta Trop, 2024 Feb;250:107097.
    PMID: 38097150 DOI: 10.1016/j.actatropica.2023.107097
    Mitochondrial cytochrome c oxidase subunit I (COI) sequences were utilized to infer the population genetic structure of Simulium (Gomphostilbia) atratum De Meijere, an endemic simulid species to Indonesia. Both median-joining haplotype network and maximum-likelihood tree revealed two genetic lineages (A and B) within the species, with an overlap distribution in Lombok, which is situated along Wallace's line. Genetic differentiation and gene flow with varying frequencies (FST = 0.02-0.967; Nm = 0.01-10.58) were observed between populations of S. (G.) atratum, of which population pairs of different lineages showed high genetic differentiation. Notably, the high genetic distance of up to 5.92 % observed within S. (G.) atratum in Lombok was attributed to the existence of two genetically distinct lineages. The co-occurrence of distinct lineages in Lombok indicated that Wallace's line did not act as faunistic border for S. (G.) atratum in the present study. Moreover, both lineages also exhibited unimodal distributions and negative values of neutrality tests, suggesting a pattern of population expansion. The expansion and divergence time estimation suggested that the two lineages of S. (G.) atratum diverged and expanded during the Pleistocene era in Indonesia.
  15. Takaoka H, Ya'cob Z, Sofian-Azirun M
    Zootaxa, 2018 Oct 12;4498(1):1-65.
    PMID: 30486086 DOI: 10.11646/zootaxa.4498.1.1
    The classification, annotated list and keys for the black fly species from Peninsular Malaysia are updated. The number of black fly species increased from 38 in 1995 to 62 (including a new species herein described) in 2018. The 62 species are classified in four subgenera of the genus Simulium: one species in Daviesellum, 35 species in Gomphostilbia, five species in Nevermannia and 21 species in Simulium. Species in the latter three subgenera are further placed in species-groups or subgroups. Keys are provided for females, males, pupae and mature larvae. Simulium (S.) perakense sp. nov. is described and placed in the S. striatum species-group. The males of S. (G.) decuplum, S. (G.) tahanense, S. (S.) malayense, the female of S. (G.) adleri, and the female and larva of S. (G.) varicorne are described for the first time. The female, male, pupa and larva of S. (G.) trangense, the male and pupa of S. (G.) varicorne and the pupa of S. (G.) adleri are redescribed. Simulium (G.) sp. A is identified as S. (G.) pegalanense. Brief notes for each species are given on morphological characteristics, aquatic habitats and geographical distributions.
  16. Ya'cob Z, Takaoka H, Low VL, Sofian-Azirun M
    Acta Trop, 2018 Sep;185:110-114.
    PMID: 29709632 DOI: 10.1016/j.actatropica.2018.04.029
    Simulium (Simulium) hackeri Edwards, 1928 of the Simulium variegatum species-group from Malaysia was described initially based on the female specimen from Cameron Highlands, Pahang. In the present study, the pupa and larva of this species are described for the first time. Their morphological characters resemble those of the Simulium variegatum species-group by having six gill filaments per side, abdomen with dorsal spine-combs at least on segments 7 and 8, cocoon with wall-pocket shaped and with or without an anterodorsal projection. Postgenal cleft of the larva medium-sized, rarely small, ventral papillae small or absent. The DNA barcode of this species is also reported herein.
  17. Hempolchom C, Sookrung N, Srisuka W, Reamtong O, Sakolvaree Y, Chaicumpa W, et al.
    Parasitol Res, 2019 Aug;118(8):2353-2359.
    PMID: 31263951 DOI: 10.1007/s00436-019-06383-x
    Simulium dermatitis is an IgE-mediated skin reaction in animals and humans caused by the bites of black flies. Although Simulium nigrogilvum has been incriminated as the main human-biting black fly species in Thailand, information on its salivary allergens is lacking. Salivary gland extract of S. nigrogilvum females was subjected to sodium dodecylsulfate-polyacrylamide gel electrophoresis, and the separated components were applied onto nitrocellulose membranes for immunoblotting, which was performed by probing the protein blots with sera from 17 individuals who were allergic to the bites of S. nigrogilvum. IgE-reactive protein bands were characterized further by liquid chromatography-mass spectrometry (LC-MS/MS) analysis. Nine protein bands (79, 42, 32, 25, 24, 22, 15, 13, and 11 kDa) were recognized in the serum of the subjects. Four of the nine protein bands (32, 24, 15, and 11 kDa) showed IgE reactivity in all (100%) of the tested sera, and they were identified as salivary secreted antigen 5-related protein, salivary serine protease, erythema protein, and hypothetical secreted protein, respectively. Three other proteins, salivary serine protease (25 kDa), salivary D7 secreted protein (22 kDa), and hypothetical protein (13 kDa), reacted with > 50% of the sera. The relevance of the identified protein bands as allergens needs to be confirmed by using pure recombinant proteins, either in the in vivo skin prick test or in vitro detection of the specific IgE in the serum samples of allergic subjects. This will be useful for the rational design of component-resolved diagnosis and allergen immunotherapy for the allergy mediated by the bites of black flies.
  18. Ya'cob Z, Takaoka H, Pramual P, Low VL, Sofian-Azirun M
    Acta Trop, 2016 Jan;153:57-63.
    PMID: 26476394 DOI: 10.1016/j.actatropica.2015.10.007
    To investigate the breeding habitat preference of black flies, a comprehensive black fly survey was conducted for the first time in Peninsular Malaysia. Preimaginal black flies (pupae and larvae) were collected manually from 180 stream points encompassing northern, southern, central and east coast of the Peninsular Malaysia. A total of 47 black fly species were recorded in this study. The predominant species were Simulium trangense (36.7%) and Simulium angulistylum (33.3%). Relatively common species were Simulium cheongi (29.4%), Simulium tani (25.6%), Simulium nobile (16.2%), Simulium sheilae (14.5%) and Simulium bishopi (10.6%). Principal Component Analysis (PCA) of all stream variables revealed four PCs that accounted for 69.3% of the total intersite variance. Regression analysis revealed that high species richness is associated with larger, deeper, faster and higher discharge streams with larger streambed particles, more riparian vegetation and low pH (F=22.7, d.f.=1, 173; P<0.001). Relationship between species occurrence of seven common species (present in >10% of the sampling sites) was assessed. Forward logistic regression analysis indicated that four species were significantly related to the stream variables. S. nobile and S. tani prefer large, fast flowing streams with higher pH, large streambed particles and riparian trees. S. bishopi was commonly found at high elevation with cooler stream, low conductivity, higher conductivity and more riparian trees. In contrast, S. sheilae was negatively correlated with PC-2, thus, this species commonly found at low elevation, warmer stream with low conductivity and less riparian trees. The results of this study are consistent with previous studies from other geographic regions, which indicated that both physical and chemical stream conditions are the key factors for black fly ecology.
  19. Takaoka H, Fukuda M, Otsuka Y, Aoki C, Uni S, Bain O
    Med Vet Entomol, 2012 Dec;26(4):372-8.
    PMID: 22827756 DOI: 10.1111/j.1365-2915.2012.01023.x
    Studies of blackfly vectors of Onchocerca dewittei japonica Uni, Bain & Takaoka (Spirurida: Onchocercidae), a parasite of wild boar implicated in the aetiology of zoonotic onchocerciasis in Japan, and six other zoonotic Onchocerca species of this country are reviewed. Molecular identification of infective larvae found in wild-caught female blackflies showed that Simulium bidentatum (Shiraki) (Diptera: Simuliidae) is a natural vector of O. dewittei japonica, and also Onchocerca sp. sensu Fukuda et al., another parasite of wild boar. Inoculation experiments demonstrated that Simulium arakawae Matsumura and four other Simulium species are putative vectors. Similarly, S. arakawae, S. bidentatum and Simulium oitanum (Shiraki) are putative vectors of Onchocerca eberhardi Uni & Bain and Onchocerca skrjabini Rukhlyadev, parasites of sika deer. Morphometric studies of infective larvae indicated that Onchocerca lienalis Stiles, a bovine species, is transmitted by S. arakawae, Simulium daisense (Takahasi) and Simulium kyushuense Takaoka, and that Onchocerca sp. sensu Takaoka & Bain, another bovine species, is transmitted by S. arakawae, S. bidentatum, S. daisense and S. oitanum. Prosimulium sp. (Diptera: Simuliidae) and Simulium japonicum Matsumura are suspected vectors of Onchocerca suzukii Yagi, Bain & Shoho and O. skrjabini [Twinnia japonensis Rubtsov (Diptera: Simuliidae) may also transmit the latter], parasites of Japanese serow, following detection of the parasites' DNA genes in wild-caught blackflies.
  20. Srisuka W, Takaoka H, Otsuka Y, Fukuda M, Thongsahuan S, Taai K, et al.
    Parasit Vectors, 2017 Nov 21;10(1):574.
    PMID: 29157269 DOI: 10.1186/s13071-017-2492-y
    BACKGROUND: Blackflies are an important medical and veterinary group of small blood-sucking insects. Ninety-three blackfly species have been reported in Thailand. However, information on their biodiversity and population dynamics in each region is lacking. The main aim of this study was to assess the regional biodiversity, seasonal abundance and distribution of blackflies in six eco-geographically different regions in the country.

    METHODS: Blackfly larvae and pupae were sampled monthly from 58 sites between May 2011 and April 2013. Diversity parameters, seasonal abundance, regional distribution and frequency of species occurrence in stream sites were analyzed.

    RESULTS: A total of 19,456 mature larvae representing 57 species, and belonging to six subgenera in the genus Simulium Latreille (s.l.), were found. The five predominant taxa were S. fenestratum (8.6%), the S. asakoae complex (8.3%), S. nakhonense (7.5%), the S. siamense complex (7.4%) and the S. doipuiense complex (6.7%). The most frequent taxa at all sites were the S. asakoae complex (84.5%), followed by S. fenestratum (82.8%), the S. siamense complex (75.9%), S. decuplum (60.3%), S. nakhonense (58.6%) and the S. tani complex (48.3%). The richness of regional species was highest (40 species) in the north and predominated in the cold season. However, blackflies in the south predominated during the hot season. The highest numbers of blackflies collected from central, northeastern, eastern and western regions of the country were observed in the rainy season. Overall, the mean number of blackflies collected across the six regions during the rainy and cold season had no statistically significant difference, but it differed significantly in the hot season.

    CONCLUSIONS: Blackflies in Thailand were surveyed in all three seasons across six geographical regions. These findings demonstrated that blackfly communities at each stream site varied with seasonality, and the regional relative abundance of blackflies differed markedly in the hot season. It was also found that the occurrence and distribution of blackflies in each region were associated strongly with elevation.

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