Seasonal prevalence of mosquitoes collected from light traps in the Republic of Korea, 2007

Adult mosquito surveillance was conducted using New Jersey light traps from 1 May to 15 October during 2007 at 14 US Army and three Air Force installations and two US Army training sites located in six provinces in the Republic of Korea to determine threshold levels to initiate pesticide applications based on trap indices. A total of 24 013 adult mosquitoes (19 763 [82.3%] females and 4250 [17.1%] males) comprising 16 species (including five members of the Anopheles Hyrcanus Group) and belonging to seven genera were collected. Females of the most commonly collected species were members of the Anopheles Hyrcanus Group (52.1%), followed by, Culex tritaeniorhynchus Giles (20.6%), Culex pipiens Coquillett (13.8%), and Aedes vexans nipponii (Theobald) (11.6%). Trap indices varied widely for species over their range, due in part, to geographical distribution and degree of association with urban or rural communities.     

DNA barcoding for the identification of eight species members of the Thai Hyrcanus Group and investigation of their stenogamous behavior

Eight species members of the Thai Hyrcanus Group were identified based on the intact morphology and molecular analysis (COI barcoding, 658 bp) of F₁-progenies. Five iso-female lines of each species were pooled in order to establish stock colonies. A stenogamous colony of each species was investigated by making 200 and 300 newly emerged adult females and males co-habit in a 30 cm cubic cage for one week. After ovipositon, the spermathecae of females were examined for sperms. The results revealed that Anopheles argyropus, Anopheles crawfordi, Anopheles nitidus, Anopheles pursati, Anopheles sinensis, Anopheles nigerrimus, Anopheles paraliae and Anopheles peditaeniatus yielded insemination rates of 0%, 0%, 0%, 31%, 33%, 42%, 50% and 77%, respectively. Continuous selection to establish stenogamous colonies indicated that An. sinensis, An. pursati, An. nigerrimus, An. paraliae and An. peditaeniatus provided insemination rates of 33–34%, 27–31%, 42–58%, 43–57% and 61–86% in 1, 2, 5, 6 and 20 generations of passages, respectively.     

Molecular Variation in the Paragonimus heterotremus Complex in Thailand and Myanmar

Paragonimiasis is an important food-borne parasitic zoonosis caused by infection with lung flukes of the genus Paragonimus. Of the 7 members of the genus known in Thailand until recently, only P. heterotremus has been confirmed as causing human disease. An 8th species, P. pseudoheterotremus, has recently been proposed from Thailand, and has been found in humans. Molecular data place this species as a sister species to P. heterotremus, and it is likely that P. pseudoheterotremus is not specifically distinct from P. heterotremus. In this study, we collected metacercariae of both nominal species (identification based on metacercarial morphology) from freshwater crabs from Phetchabun Province in northern Thailand, Saraburi Province in central Thailand, and Surat Thani Province in southern Thailand. In addition, we purchased freshwater crabs imported from Myanmar at Myawaddy Province, western Thailand, close to the Myanmar-Thailand border. The DNAs extracted from excysted metacercariae were PCR-amplified and sequenced for ITS2 and cox1 genes. The ITS2 sequences were nearly identical among all samples (99-100%). Phylogenies inferred from all available partial cox1 sequences contained several clusters. Sequences from Indian P. heterotremus formed a sister group to sequences from P. pseudoheterotremus-type metacercariae. Sequences of P. heterotremus from Thailand, Vietnam, and China formed a separate distinct clade. One metacercaria from Phitsanulok Province was distinct from all others. There is clearly considerable genetic variation in the P. heterotremus complex in Thailand and the form referred to as P. pseudoheterotremus is widely distributed in Thailand and the Thai-Myanmar border region.     

A new crocodilianfrom the Jurassic of Thailand, Sunosuchus thailandicus n. sp. (Mesosuchia,Goniopholididae)), and the palaeogeographical history of South-East Asia in the Mesozoic

A crocodilian jaw fragment from the Jurassicof Thailand is referred to a new species of the genus SunosuchusYoung,, 1948, S. thailandicus.. The genus Sunosuchus,, which is interpreted here as belonging to the family Goniopholididae (Mesosuchia),, was previously known only from the continental Jurassic of north-central China. The occurrence of this freshwater crocodilian in the Khorat Group of Thailand provides evidence that, whatever its previous palaeogeographical history may have been, by Jurassic times South-East Asia was part of Laurasia.     

Mosquito species distribution and larval breeding habitats with taxonomic identification of Anopheline mosquitoes in Korea

In 2005, adult and larval mosquito surveillance was conducted at selected sites in Korea to associate larval habitats with species distribution of mosquitoes of the Anopheles Hyrcanus Group (An. sinensis, An. lesteri, An. pullus, An. belenrae and An. kleini) and other mosquito species. Anopheles specimens belonging to the Anopheles Hyrcanus Group were identified to species level by molecular confirmation using the internal transcribed spacer (ITS)‐2 within nuclear ribosomal (r)DNA. A total of 6644 mosquitoes from resting and light trap collections (4451; 67.0%) and larval collections (2193; 33.0%) comprising 32 species and nine genera (Culex [11], Anopheles [8], Ochlerotatus [5], Aedes [3], Armigeres [1], Coquillettidia [1], Mansonia [1], Tripteroides [1] and Lutzia [1]) were collected. Larval habitats were characterized into 14 categories. Of a total of 4534 Anopheles spp. collected (3766 resting and light trap collections and 768 larval collections), Anopheles sinensis (3194; 70.4%) was the most frequently captured, followed by An. kleini (813; 17.9%), An. pullus (299; 6.6%) and An. belenrae (129; 2.8%). Four species of Anopheles (An. lesteri, An. sineroides, An. koreicus and An. lindesayi) were infrequently collected (<3.0%) at all sites surveyed by all methods of collection. Anopheles kleini, An. pullus and An. belenrae were collected in greater proportions in malaria high‐risk areas north of Seoul, and were infrequently collected in other parts of Korea, where An. sinensis was the predominant Anopheles spp. captured. A total of 2110 culicine mosquitoes (685 adult collections and 1425 larval collections) comprising 24 species and eight genera were collected.     

Seasonal prevalence of mosquitoes collected from light traps with notes on malaria in the Republic of Korea, 2004

Adult mosquito surveillance was conducted during 2004 at 29 US military installations and training sites located in six provinces in the Republic of Korea. Adult mosquitoes were collected in New Jersey light traps and Magnet traps from 1 May through 15 October to determine threshold levels to initiate pesticide applications and to identify malaria infection rates at selected army installations and training sites. A total of 89 206 adults (78 454 [87.9%] females and 10 752 [12.1%] males) comprising 20 species (including five members of the Anopheles Hyrcanus Group) and belonging to seven genera were collected. The most common species collected were members of Culex tritaeniorhynchus Giles (49.4%) and Anopheles sinensis Wiedemann complex (39.1%), followed by Culex pipiens Coquillett (6.1%) and Aedes vexans nipponii (Theobald) (4.2%). Trap indices varied widely for species over their range, due in part to geographical distribution and degree of association with urban communities.     

The semi-aquatic freshwater earthworms of the genus Glyphidrilus Horst, 1889 from Thailand (Oligochaeta,Almidae) with re-descriptions of several species

The semi-aquatic freshwater earthworm genus Glyphidrilus Horst, 1889 from Thailand was investigated based on extensive recent collecting. The species in this genus were characterized by their external and internal morphological characters of the location of wings, genital openings, genital organ structures and their locations, as well as the dimensions of body length and number of segments. Several type specimens were compared with both previous and newly collected materials. Ten new species are described from several river systems in Thailand; as Glyphidrilus borealis sp. n., Glyphidrilus chaophraya sp. n., Glyphidrilus chiensis sp. n., Glyphidrilus huailuangensis sp. n., Glyphidrilus kratuensis sp. n., Glyphidrilus quadratus sp. n., Glyphidrilus trangensis sp. n., Glyphidrilus wararamensis sp. n., Glyphidrilus vangthongensis sp. n. and Glyphidrilus vesper sp. n. Each species is endemic to a single river system. All 26 previously described species are re-described, and eight lectotypes have been designated. An identification key and a morphological comparison summary are provided.     

Six new species of the Anopheles leucosphyrus group, reinterpretation of An. elegans and vector implications

Abstract. Among Oriental anopheline mosquitoes (Diptera: Culicidae), several major vectors of forest malaria belong to the group of Anopheles (Cellia) leucosphyrus Dönitz. We have morphologically examined representative material (> 8000 specimens from seven countries) for taxonomic revision of the Leucosphyrus Group. Six new species are here described from adult, pupal and larval stages (with illustrations of immature stages) and formally named as follows: An. latens n. sp. (= An. leucosphyrus species A of Baimai et al., 1988b), An. cracens n. sp., An. scanloni n. sp., An. baimaii n. sp. (formerly An. dirus species B, C, D, respectively), An. mirans n. sp. and An. recens n. sp. Additionally, An. elegans (James) is redescribed and placed in the complex of An. dirus Peyton & Harrison (comprising An. baimaii, An. cracens, An. dirus, An. elegans, An. nemophilous Peyton & Ramalingam, An. scanloni and An. takasagoensis Morishita) of the Leucosphyrus Subgroup, together with An. baisasi Colless and the An. leucosphyrus complex (comprising An. balabacensis Baisas, An. introlatus Baisas, An. latens and An. leucosphyrus). Hence, the former Elegans Subgroup is renamed the Hackeri Subgroup (comprising An. hackeri Edwards, An. pujutensis Colless, An. recens and An. sulawesi Waktoedi). Distribution data and bionomics of the newly defined species are given, based on new material and published records, with discussion of morphological characters for species distinction and implications for ecology and vector roles of such species. Now these and other members of the Leucosphyrus Group are identifiable, it should be possible to clarify the medical importance and distribution of each species. Those already regarded as vectors of human malaria are: An. baimaii[Bangladesh, China (Yunnan), India (Andamans, Assam, Meghalaya, West Bengal), Myanmar, Thailand]; An. latens[Borneo (where it also transmits Bancroftian filariasis), peninsular Malaysia, Thailand]; probably An. cracens (Sumatra, peninsular Malaysia, Thailand); presumably An. scanloni (Thailand); perhaps An. elegans (the Western Ghat form of An. dirus, restricted to peninsular India); but apparently not An. recens (Sumatra) nor An. mirans[Sri Lanka and south-west India (Karnataka, Kerala, Tamil Nadu)], which is a natural vector of simian malarias. Together with typical An. balabacensis, An. dirus and An. leucosphyrus, therefore, the Leucosphyrus Group includes about seven important vectors of forest malaria, plus at least a dozen species of no known medical importance, with differential specific distributions collectively spanning > 5000 km from India to the Philippines.     

Middle Permian Ostracods from Tak Fa Limestone, Phetchabun Province, Central Thailand

This paper presents the first Permian ostracod fauna discovered in Thailand. The ostracods are recovered from the Tak Fa Limestone (Middle Permian) in Phetchabun province, central Thailand. The ostracods belong to eight genera and 15 species. Four species are newly described: Sargentina phetchabunensis nov. sp., Geffenina bungsamphanensis nov. sp., Reviya subsompongensis nov. sp. and Bairdia takfaensis nov. sp. The ostracod assemblages characterize a shallow marine, near shore environment at the time of deposition. Except for one species, which shows palaeobiogeographical links between Central Thailand and South China, all the other species are endemic.     

A molecular phylogeny of mosquitoes in the Anopheles barbirostris Subgroup reveals cryptic species: Implications for identification of disease vectors

The Barbirostris Subgroup of the genus Anopheles includes six mosquito species that are almost identical in adult morphology, but differ in their roles in the transmission of malaria and filariasis within Southeast Asia. The lack of robust, diagnostic morphological characters in adults has contributed to extensive misidentification of the species. Mosquitoes were collected from localities in Thailand and Indonesia, with an emphasis on specimens identified in the field as An. barbirostris and An. campestris. A 754 bp COI mitochondrial gene fragment was sequenced from 136 specimens and the rDNA ITS2 region (c.1600–1800 bp) from 51 specimens. Phylogenetic analyzes based on Bayesian methods, distance measures and Maximum-parsimony produced five clades (I–V) that are congruent between the nuclear and mitochondrial data sets. Based on adult female morphology, it is deduced that three of these clades, I–III, are members of the Barbirostris Complex whereas Clade V is An. campestris. The identity of Clade IV is as yet unknown. Using a haplotype network analysis, Clade III was found to have a star-like genealogy, suggesting population expansion. There were no shared haplotypes between clades. In Afrotropical anopheline mosquitoes, speciation has been linked to the expansion of human populations and the development of agriculture. We postulate that the radiation of species within the Barbirostris Subgroup in Southeast Asia may similarly be linked to human population expansion and the agrarian revolution. The development of a propensity for feeding on the blood of humans in some species of the Subgroup would have led to the transmission of malaria protozoa and filarial nematodes.     

Paragonimus paishuihoensis Metacercariae in Freshwater Crabs,Potamon lipkei,in Vientiane Province,Lao PDR

Among Paragonimus species, P. paishuihoensis is one of the most mysterious and poorly understood species. Metacercariae are characterized by having a unique dendritically branched excretory bladder. However, the morphology of the adult worm remains unknown. To date, metacercariae of this species have been reported only in China and Thailand. In this study, we first found P. paishuihoensis metacercariae in freshwater crabs, Potamon lipkei, in Hinheub District, Vientiane, Lao PDR, with a prevalence of 77.7% and the average intensity of 10.3 (range 1-28) metacercariae per crab. The molecular data based on ITS2 and CO1 markers indicated that P. paishuihoensis from Laos and Thailand were almost completely identical and were close to members of the Paragonimus bangkokensis/Paragonimus harinasutai complex. Attempts to infect experimental animals (cats, dogs, and rats) with P. paishuihoensis were unsuccessful, suggesting that these animals might be unsuitable definitive hosts for the species. Further studies are necessary to elucidate the taxonomic status and life cycle of P. paishuihoensis.     

Preliminary study of the genetic diversity of eastern Assamese macaques (Macaca assamensis assamensis) in Thailand based on mitochondrial DNA and microsatellite markers

Human overpopulation, deforestation, invasion of agricultural areas, and livestock are the primary causes for population fragmentation of wildlife. The distribution range of species of the genus Macaca is constantly decreasing and becoming increasingly fragmented due to forest deterioration. Assamese macaques (M. assamensis) are classified as near threatened in the International Union for Conservation of Nature (IUCN) Red List of Threatened Animals (2008) and have been declared a protected wildlife animal according to Wildlife Preservation and Protection Act, B.E.2535 (1992) of Thailand. As studies of the population history and genetic diversity of Assamese macaques in Thailand are currently lacking, we aimed at a first investigation of their genetic diversity based on mitochondrial DNA [hypervariable regions 1 and 2 (HV1, HV2) and cytochrome B (CYTB) regions], as well as 15 microsatellite markers of five sampling sites distributed across Thailand. Our results indicate that Assamese macaques in Thailand are diverse, with eight maternal haplotypes and a low inbreeding coefficient in the Phu Khieo Wildlife Sanctuary (PKWS) population. Moreover, our phylogenetic and median-joining network analysis based on mitochondrial (mt)DNA suggests a population distribution in accordance with the evolutionary scenario proposed for M. sinica. Today, the population of Assamese macaques is fragmented, and conservation strategies are needed to ensure the maintenance of genetic diversity of this primate species.     

Characterization of Variability in Some Pathogenic Species of Alternaria Based on the Nucleotide Sequence of Ribosomal DNA

The internal transcribed spacer (ITS) sequences within the ribosomal DNA (rDNA) region were targeted to delineate genetic variability among eight Alternaria species that cause economically important diseases in crops. The rDNA regions of Alternaria species comprising of rRNA genes and the ITS regions were cloned and sequenced. Phylogenetic relationship based on the rDNA sequences and PCR-RFLP of amplified rDNA sequences clustered eight species of Alternaria into three major groups. A. macrospora and A. helianthi accumulated wide genetic variations and are distantly related to rest of the six species which formed two major groups. Group I comprised of three species viz., A. dianthicola, A. brassicae and A. citri, while group II had A. longipes, A. porri and A. alternata. Incorporation of unique stretches of nucleotides and single nucleotide substitutions within relatively conserved ITS1 and ITS2 regions led to clustering of the members of Alternaria species in each group. The divergent sequences within the ITS regions can be employed to design species-specific PCR primer for use in molecular diagnostics.     

Freshwater fishes of thailand as experimental intermediate hosts for Capillaria philippinensis

Bhaibulaya M., Indra-Ngarm S. and Ananthapruti M. 1979. Freshwater fishes of Thailand as experimental intermediate hosts for Capillaria philippinensis. The International Journal for Parasitology9: 105–108. Nine species of freshwater fishes from Thailand have been exposed to infection with embryonated eggs of Capillaria philippinensis. The eggs were fed to fishes with food or through a polyethylene tube. After 10–30 days larvae capable of establishing intestinal capillariasis in Mongolian gerbils were recovered from six fish species: Cyprinus carpio, Puntius gonionotus, Aplocheilus panchax, Gambusia holbrookii, Rasbora borapelensis, and Trichopsis vittatus. Larvae were not recovered from Tilapia nilotica, Osteochilus hasseltii and Trichogaster trichopterus. Five human cases of intestinal capillariasis have been reported from widely scattered areas of Thailand and the natural intermediate and definitive hosts remain to be determined.     

Records of Hedotettix and Teredorus in Thailand with the description of three new species (Orthoptera,Tetrigidae)

We are studying the fungi associated with insects in northern Thailand and as a result several rarely collected insect species have been uncovered. The genera Hedotettix with one new species and Teredorus with two new species are reported from Thailand. Hedotettix triangularis Zha & Hyde, sp. n., Teredorus chiangraiensis Zha & Hyde, sp. n. and Teredorus combfemorus Zha & Hyde, sp. n. are introduced, described and photographed and compared with other species. Keys to species of Hedotettix and Teredorus from Thailand are provided.     

Genetic divergence in the snorkel snail,Rhiostoma housei,a species complex in Thailand (Caenogastropoda: Cyclophoridae)

Allozyme variation was examined in 292 samples of the snorkel snail, Rhiostoma housei, collected from 12 localities within four regions of Thailand. Ten allozyme loci were screened across all the samples using horizontal starch gel electrophoresis, and eight of these loci, from eight enzyme systems, were found to be polymorphic. Within these eight loci the expected heterozygosity (H_exp) was moderate to high ranging from 0.015 to 0.148 with an overall mean of 0.081 ± 0.041, whilst a high genetic heterogeneity among samples was found (F_st = 0.798). R. housei exhibited a weak pattern of isolation by distance over the entire tested species range in Thailand. The high F_st and moderate to high H_exp suggest gene flow amongst populations is partially restricted resulting in fragmentation into local gene pools. Based on allele frequencies and an allozyme dendrogram, six groups were identified, and these entities may represent separate biological species. The large values of genetic distances and fixed allelic differences obtained for each combination of allopatric samples imply the presence of cryptic species under the name R. housei.     

Distribution and larval habitats of Anopheles species in northern Gyeonggi Province,Republic of Korea

A total of 180 larval collection sites (e.g., rice paddies, marshes, ground pools, ponds, stream margins, and irrigation and drainage ditches) was surveyed within a 2 km radius from Warrior Base training area, 5 km south of Panmunjeom (Joint Security Area, demilitarized zone), Gyeonggi Province, Republic of Korea (ROK), from May through October, 2007 to characterize larval habitat distributions of members of the Anopheles Hyrcanus Group (An. sinensis, An. lesteri, An. pullus, An. belenrae, An. kleini, and An. sineroides). A total of 5,859 anopheline larvae was collected from 84.4% of the sites surveyed, of which 4,071 were identified to species by polymerase chain reaction (PCR) using the ribosomal DNA internal transcribed spacer 2 (rDNA ITS2). Anopheles sinensis (52.6%) was the most frequently collected, followed by An. kleini (29.4%), An. sineroides (9.8%), An. pullus (6.7%), An. belenrae (1.1%), and An. lesteri (0.5%). Anopheles pullus and An. kleini were collected in greater proportions in May and from May – July, respectively. Few An. sinensis were collected from May – June, but it was the predominant species collected by August, and accounted for >80% of all larvae from September – October. Anopheles kleini was found in all habitats sampled; however, it was collected most frequently in young growth rice paddies, while An. sinensis was collected more frequently in mature and post‐harvest paddies. Anopheles pullus was associated with pre‐cultivated rice paddies, including water‐filled tire ruts left from the previous fall's harvest.     

Cytogenetics of the South American DROSOPHILA MULLERI Complex: The MARTENSIS Cluster. More Interspecific Sharing of Inversions

Three Drosophila mulleri complex species have been found to be endemic to the cactus regions of northern South America. The three species are morphologically distinct, and no hybridization between species has been found in either the laboratory or nature. An analysis of their salivary gland chromosomes revealed that they evolved from a single cytological population, subspecies F of the ancestor of the D. mulleri complex, and comprise a cluster of sister species that are homozygous for inversions not found elsewhere. Within the martensis cluster are also found several inversions that are unique for these species, but have segregated out among the three species. Thus 2f² is found in martensis and starmeri, but not in uniseta, while 2t⁶, 3v and 3w are found in starmeri and uniseta, but not in martensis. This is analogous to the situation found within the remainder of the mulleri complex species, all the members of which share homozygosity for six other inversions. An interpretation of the cytological evolution of the martensis cluster is proposed.     

Middle Permian ostracod fauna from the Khao Khad Formation (Indochina Terrane), Central Thailand

Permian ostracods are reported for the first time from the Wordian (Middle Permian) Khao Khad Formation of Saraburi Group (Lopburi Province, Central Thailand). The ostracod fauna consists of 18 species belonging to 11 genera including Bairdia, Bohlenatia, Liuzhinia, Silenites, Acratia, Bairdiacypris, Basslerella, Aurigerites, Microcheilinella, Paraparchites and Shemonaella. The studied Khao Khad Limestone, which are rich in fusulinids, gastropods, ostracods, bivalves and brachiopods, was deposited in a shallow carbonate platform on the western margin of the Indochina Terrane. The ostracod assemblage is typically Palaeo-Tethyan and similar to faunas from the other Lower to Middle Permian limestones in central Thailand.