Simulium (Gomphostilbia) maleewongae sp. nov. is described based on the adult males and females, their pupal exuviae, and larvae from Thailand. This new species is placed in the Simulium gombakense species-group of Simulium (Gomphostilbia). It is characterized by the female cibarium with a cup-like appendage, male ventral plate deeply depressed ventromedially, pupal gill composed of an inflated structure and eight slender filaments, cone-shaped pupal terminal hooks, and cocoon with an anterodorsal projection. Taxonomic notes are given to separate this new species from 10 other species of the same species-group known from China, India, Malaysia, Thailand, Nepal, and Vietnam. Keys to identify all 11 species of the S. gombakense species-group are provided for females, males, pupae, and larvae.
Spirochetes from the Borrelia genus are known to cause diseases in humans, namely Lyme disease and relapsing fever. These organisms are commonly transmitted to humans by arthropod vectors including ticks, mite, and lice. Here, we report the molecular detection of a Borrelia sp. from a Haemaphysalis hystricis Supino tick collected from wildlife in an Orang Asli settlement in Selangor, Malaysia. Phylogenetic analyses of partial 16s rRNA and flaB gene sequences revealed that the Borrelia sp. is closely related to the relapsing fever group borreliae, Borrelia lonestari, Borrelia miyamotoi, and Borrelia theileri, as well as a number of uncharacterized Borrelia sp. from ticks in Portugal and Japan. To our knowledge, this is the first report of a Borrelia sp. detected in H. hystricis, and in Malaysia. The zoonotic potential of this Borrelia sp. merits further investigation.
Two new species, Simulium (Gomphostilbia) sunapii and S. (G.) rangatense, are described based on adults, pupae, and mature larvae from Flores, in the eastern part of the Sunda Archipelago, Indonesia. Simulium (G.) sunapii sp. nov. is placed in the S. asakoae species-group, representing the easternmost geographical record for the group in this archipelago. It is characterized by a small number of male upper-eye large facets in eight or nine vertical columns and 12 horizontal rows. Simulium (G.) rangatense sp. nov. is placed in the S. ceylonicum species-group and is characterized by the pupal gill with six filaments. This new species, together with two related species of the S. ceylonicum species-group in Flores, suggests the species radiation of this species-group might have been accompanied by a reduction of the number of pupal gill filaments from eight to four through six. Taxonomic notes are provided to distinguish these two new species from related species.
Little information is available on human anaplasmosis and ehrlichiosis in Southeast Asia despite increasing reports of the detection of Anaplasma spp. and Ehrlichia spp. in the ticks. We report herein the serological findings against the tick-borne pathogens in a group of animal farm workers (n = 87) and indigenous people (n = 102) in Peninsular Malaysia. IgG antibodies against Ehrlichia chaffeensis were detected from 29.9% and 34.3% of farm workers and indigenous people, respectively, using commercial indirect immunofluorescence assays. Comparatively, only 6.9% of the indigenous people but none of the animal farm workers were seropositive to Anaplasma phagocytophilum. A polymerase chain reaction (PCR) assay targeting the 16S rRNA gene of Anaplasmataceae was used to identify Anaplastamataceae in ticks collected from various locations adjacent to the areas where the serological survey was conducted. In this study, a total of 61.5% of ticks infesting farm animals, 37.5% of ticks infesting peri-domestic animals in rural villages, 27.3% of ticks collected from wildlife animals, and 29.1% of questing ticks collected from forest vegetation were positive for Anaplasmataceae DNA. Sequence analyses of 16S rRNA gene region (238 bp) provide the identification for Anaplasma marginale, Anaplasma bovis, Anaplasma platys, A. phagocytophilum, and Anaplasma spp. closely related to Candidatus Cryptoplasma californiense in ticks. E. chaffeensis DNA was not detected from any ticks, instead, Ehrlichia sp. strain EBm52, Ehrlichia mineirensis and Candidatus Ehrlichia shimanensis are the only Ehrlichia sp. identified from cattle ticks in this study. Further investigation is required to ascertain the occurrence of zoonotic transmission of Ehrlichia and Anaplasma infections in Peninsular Malaysia.
Due to the growing public health and tourism awareness, Cimex hemipterus Fabricius (Hemiptera: Cimicidae) has gained a great interest in increasing reported infestation cases in tropical regions of the world, including Malaysia. Since the information on the molecular ecology and population biology of this species are tremendously lacking, the isolation and development of molecular markers can be used to determine its genetic structure. In this study, novel microsatellite primers isolated from enriched genomic libraries of C. hemipterus were developed using 454 Roche shotgun sequencing. Seven validated polymorphic microsatellite primers were consistently amplified and characterized from 70 tropical bed bugs collected from seven locations throughout Malaysia. The number of alleles per locus identified ranged from 6 to 14. Comparison of loci for overall and between population were done with mean observed and expected heterozygosity were determined at 0.320 and 0.814, 0.320 and 0.727, respectively. Polymorphic information criteria (PIC) valued the markers as highly informative as PIC >0.5. Overall population, they are possibly in Hardy-Weinberg equilibrium with loci Ch_09ttn, Ch_01dn, and Ch_13dn showing signs of a null allele. There were no scoring errors caused by stutter peaks, no large allele dropout was detected for all loci and showed no evidence of linkage disequilibrium. In conclusion, all seven molecular microsatellite markers identified can be beneficially used to gain more information on the population genetic structure and breeding patterns of C. hemipterus as well as the relationship of dispersal and infestation.
Simulium (Asiosimulium) saeungae sp. nov. (Diptera: Simuliidae) is described based on females, males, pupae, and mature larvae collected from Nan Province, Northern Thailand. It is characterized by the medium-long cerci in the female, enlarged hind basitarsus, and broad ventral plate with its posterior margin not deeply concave in the male, arborescent pupal gill with 42-56 filaments in the pupa and smaller number of primary rays of the labral fan (30-33) in the larva. This is the fifth species of the subgenus Asiosimulium, the second smallest among 10 subgenera in the Oriental Region. Taxonomic notes are given to distinguish this new species from the three known species from Thailand and one from Nepal.
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.
Prior to 1965, Singapore was part of the Malaya (now Malaysia) and was usually not mentioned when mosquito records were reported for Malaya. Consequently, many species that occurred in Singapore were not listed in the world mosquito catalog, and the available checklist for Singapore since 1986 is incomplete, with some imprecise species information. In updating this checklist, we examined and verified mosquito specimens collected from Singapore in various depositories, including a thorough review of past taxonomic literature. Here, we report a checklist of 182 mosquito species, 33 new distribution records, and a consolidated status list of vectors for Singapore. As Singapore is a travel hub and hosts one of the busiest container ports in the world, there is a risk of introducing mosquito species and their associated pathogens of human disease to the country. Hence, the distribution records are important to increase our knowledge on mosquito ecology as well as to understand the risk of newly introduced vectors and their associated pathogens.
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.
We report the presence of a male Haemaphysalis semermis collected from the domestic cat, Felis catus in an aboriginal village located in Pahang, Malaysia. This paper constitutes a new host record of this tick species, and also the first documentation of the infestation of companion animals other than domestic dogs (Canis lupus) by H. semermis in Malaysia. Additionally, we have included an updated host index of the tick species in Southeast Asia.
Ixodes granulatus Supino, 1897 (Acari: Ixodida) is one of Malaysia's most common hard ticks and is a potential vector for tick-borne diseases (TBDs). Despite its great public health importance, research on I. granulatus microbial communities remains largely unexplored. Therefore, this study aimed to investigate the bacterial communities of on-host I. granulatus collected from three different recreational areas on the East Coast of Peninsular Malaysia using high throughput Next Generation Sequencing (NGS). A total of 9 females on-host I. granulatus were subjected to metabarcoding analysis targeting V3-V4 regions of 16S ribosomal RNA (rRNA) using the Illumina MiSeq platform. This study identified 15 bacterial phyla corresponding to 19 classes, 54 orders, and 90 families from 435 amplicon sequence variants (ASVs), revealing a diverse bacterial community profile. Together with 130 genera assigned, local I. granulatus harbored 4 genera of pathogens, i.e., Rickettsia da Rocha Lima, 1916 (Rickettsiales: Rickettsiaceae) (58.6%), Borrelia Swellengrebel 1907 (Spirochaetales: Borreliaceae) (31.6%), Borreliella Adeolu and Gupta 2015 (Spirochaetales: Borreliaceae) (0.6%), and Ehrlichia Cowdria Moshkovski 1947 (Rickettsiales: Ehrlichiaceae) (39.9%). Some endosymbiont bacteria, such as Coxiella (Philip, 1943) (Legionellales: Coxiellaceae), Wolbachia Hertig 1936 (Rickettsiales: Ehrlichiaceae), and Rickettsiella Philip, 1956 (Legionellales: Coxiellaceae), were also detected at very low abundance. Interestingly, this study reported the co-infection of Borrelia and Ehrlichia for the first time, instilling potential health concerns in the context of co-transmission to humans, especially in areas with a high population of I. granulatus. This study successfully characterized the tick microbiome and provided the first baseline data of I. granulatus bacterial communities in Malaysia. These results support the need for way-forward research on tick-associated bacteria using NGS, focusing on medically important species toward TBD prevention.