Molecular identification and phylogenetic analysis of economically important acaroid mites (Acari: Astigmata: Acaroidea) in Korea

Molecular diagnosis is highly valuable for the species identification of microscopic mites. Here, we collected some economically important mites of the superfamily Acaroidea from various stored products in Korea. Those nucleotide sequences of ribosomal second internal transcribed spacer (ITS2) and the mitochondrial cytochrome oxidase subunit I (COI) regions were determined by PCR using universial primers. In nucleotide sequence comparison at GenBank database, seven species including Rhizoglyphus robini, R. echinopus, Sancassania sp. Acarus siro, Tyrophagus putrescentiae, T. similis in Acaridae and Suidasia medanensis in Suidasiidae were identified. Particularly, COI sequences of R. robini, R. echinopus, Sancassania sp. and T. similis were firstly determined. Our results suggest that the phylogenetic relationships inferred from the ITS2 region, rather than COI region, were similar to those derived based on their morphological classification. Our study provides molecular information for the identification and phylogenetic relationship of acaroid mites in Korea.     

Detection of honeybee tracheal mites (Acarapis woodi) by simple staining techniques

A total of 12 staining techniques, including five anionic and five cationic stains, and two mordant stains, were tested as possible histopathological methods for the detection of the honeybee tracheal mite, Acarapis woodi. The cationic stains stained the parasitic mites intensively and the ensheathing tracheae weakly positive in thin thoracic sections. The improved clarity and contrast of the stained mites within the tracheae in the thin thoracic sections facilitated the detection process. Even at very low levels of infestation, stained mites were detected easily and accurately under a dissecting microscope at a magnification as low as 10 ×. Consequently, examination of dissected trachae under a phase compound microscope, currently used for diagnosis of the mites, is no longer necessary. The stained specimen can also be mounted permanently on microslides.     

番茄黄化曲叶病毒的快速分子检测

番茄黄化曲叶病毒是当前世界范围内危害番茄生产的毁灭性病害。文章针对番茄黄化曲叶病毒全基因组序列的特异区段自主设计了1对特异性PCR引物(上游引物TYLCV-F:5′-ACGCATGCCTCTAATCCAGTGTA-3′,下游引物TYLCV-R:5′-CCAATAAGGCGTAAGCGTGTAGAC-3′),依据PCR扩增特异片段543 bp的有无可以快速、准确、高效、特异地检测出是否感染了TYLCV病毒,这项技术可以方便地应用到工厂化育苗的带毒性检测、蔬菜大规模生产中植株发病情况的快速检测以及抗病毒育种,从而为蔬菜安全可持续生产提供科技支撑。     

青海省寄生螨类的区系分布

根据建国以来的大量研究调查资料,对青海地区已记载的寄生螨类（主要包括革螨、恙螨）计10科33属100余种进行了初步的区系分布、数量与宿主关系的探讨。（1）河湟谷地小区[1]：计有45种,主要有：赛氏血革螨、秉氏血革螨、旱獭青厉螨、毒厉螨、鼠兔赫刺螨、褪色巨螯螨、似田鼠新恙螨、旱獭新恙螨等;（2）柴达木盆地小区：计有15种,具代表性种类为乌兰纤恙螨;（3）祁连青南小区：计有85种,具代表性种类为久治真棒恙螨、玉树羽叶恙螨和朱雀禽棒恙螨;（4）羌塘高原小区：计有3种,皆为血厉螨属种类。     

Biosynthesis of the widely distributed hydrocarbon (Z,Z)-6,9-heptadecadiene in astigmatid mites

ABSTRACT

Using a crude enzyme solution prepared from astigmatid mites, the conversion reaction to (Z,Z)-6,9-heptadecadiene (6,9-C17) using linoleyl aldehyde (LAld) as a substrate was successful. The mass spectrum of the reaction product using ¹³C-labeled LAld as a substrate could be assigned as ¹³C-labeled 6,9-C17. Unlike the findings in other species, the decarbonylase derived from mites did not require a coenzyme.     

番茄黄化曲叶病毒的快速分子检测

番茄黄化曲叶病毒是当前世界范围内危害番茄生产的毁灭性病害。文章针对番茄黄化曲叶病毒全基因组序列的特异区段自主设计了1对特异性PCR引物(上游引物TYLCV-F：5′-ACGCATGCCTCTAATCCAGTGTA-3′, 下游引物TYLCV-R：5′-CCAATAAGGCGTAAGCGTGTAGAC-3′), 依据PCR扩增特异片段543 bp的有无可以快速、准确、高效、特异地检测出是否感染了TYLCV病毒, 这项技术可以方便地应用到工厂化育苗的带毒性检测、蔬菜大规模生产中植株发病情况的快速检测以及抗病毒育种, 从而为蔬菜安全可持续生产提供科技支撑。     

Molecular ecology of some Cecidophyopsis mites (Acari: Eriophyidae) on Ribes species and evidence for their natural cross colonisation of blackcurrant (R. nigrum)

Ribosomal DNA from Cecidophyopsis mites from different Ribes species was amplified using the polymerase chain reaction and the products digested using restriction enzymes. After separating the DNA fragments on gels, it was possible to identify specimens of mites obtained from field samples by comparing the profiles of their DNA banding patterns with those of known Cecidophyopsis species. Using this analysis, a non-gall forming mite found infesting blackcurrant buds in New Zealand was identified as the gooseberry mite (C. grossulariae). On wild red currant (Ribes spicatum) from Finland showing two sizes of galled buds, the red currant gall mite (C. selachodon) was identified in the larger galls located at the tips of branches and a distinct mite in the smaller galls located on the lower parts of the branches. A mite with a DNA banding profile indistinguishable from this latter mite from R. spicatum was also identified in galled buds of blackcurrant genotypes growing in Finland, including those containing the blackcurrant gall mite (C. n'ftw)-resistance genes P or Ce. The DNA banding profile of this mite resembled most closely that of C. ribis , but was distinct from it. The occurrence of C. grossulariae and this distinct Cecidophyopsis mite on blackcurrant has implications for the genetic control of Cecidophyopsis mites and possibly for the spread of the reversion disease agent in this crop.     

Molecular detection of Rickettsia aeschlimannii in Hyalomma spp. ticks from camels (Camelus dromedarius) in Nigeria,West Africa

Several species of the spotted fever group rickettsiae have been identified as emerging pathogens throughout the world, including in Africa. In this study, 197 Hyalomma ticks (Ixodida: Ixodidae) collected from 51 camels (Camelus dromedarius) in Kano, northern Nigeria, were screened by amplification and sequencing of the citrate synthase (gltA), outer membrane protein A (ompA) and 17‐kDa antigen gene fragments. Rickettsia sp. gltA fragments were detected in 43.3% (42/97) of the tick pools tested. Rickettsial ompA gene fragments (189 bp and 630 bp) were detected in 64.3% (n = 27) and 23.8% (n = 10) of the gltA‐positive tick pools by real‐time and conventional polymerase chain reaction (PCR), respectively. The amplicons were 99–100% identical to Rickettsia aeschlimannii TR/Orkun‐H and R. aeschlimannii strain EgyRickHimp‐El‐Arish in GenBank. Furthermore, 17‐kDa antigen gene fragments of 214 bp and 265 bp were detected in 59.5% (n = 25) and 38.1% (n = 16), respectively, of tick pools, and sequences were identical to one another and 99–100% identical to those of the R. aeschlimannii strain Ibadan A1 in GenBank. None of the Hyalomma impressum ticks collected were positive for Rickettsia sp. DNA. Rickettsia sp. gltA fragments (133 bp) were detected in 18.8% of camel blood samples, but all samples were negative for the other genes targeted. This is the first report to describe the molecular detection of R. aeschlimannii in Hyalomma spp. ticks from camels in Nigeria.     

The phenomenon of phylogenetic synhospitality in acariform mites (acari: acariformes)--the permanent parasites of vertebrates

The term synhospitality means the association of two or more closely related parasite species with one host species (Eichler, 1966). The cases of two or three synhospitalic species are known from the same host species, and especially ones where parasites were recorded from different parts of the host range, are quite common. The most ordinary reason causing synhospitality in permanent parasites is the host switching. Nevertheless, there are a number of synhospitality cases, where the parasite complex is monophyletic because evolved on a single host species. The special term--"phylogenetic synhospitality" (FS) is proposed for these cases of synhospitality. Most known cases of FS in acariform mites, permanent parasites of vertebrates, are analysed. It is found out that both astigmatan and prostigmatan parasite mites demonstrate a numbers of FS. The majority of these examples represent parasitism of two or three synhospitalic parasite species. Impressive examples of FS involving a number of synhospitalic species is shown by only astigmatan mites inhabiting the fur of mammals or plumage of birds. Most known examples involving four or more mite species are discussed: 51 mite species of the genus Schizocarpus (Chirodiscidae) parasitizing Castor fiber and C. canadensis (Castoridae); 6 species of Listrophorus spp. (Listrophoridae) from Ondatra zibethicus (Cricetidae); 23 species of Listrophoroides s. 1. (Atopomelidae) from Maxomys surifer (Muridae); 21 species of Cytostethum (Atomelidae) from Potorous tridactylus (Potoridae); 4 species of Listrophoroides (Afrolistrophoroides) from Malacomys longipes (Muridae); 7 species of Fainalges (Xolalgidae) from Aratinga holochlora (Psittacidae); 4 species of Zygepigynia (Pteronyssidae) from Chrysocolaptes lucidus (Picidae). The main reason of FS is that, in spite of the Fahrenholz's rule, the speciation of many parasites proceeds much more intensively than in their hosts because of the more rapid replacement of the parasitic generations. The first factor causing FS is the mite speciation it temporary segregated populations of the host (allopatric speciation). In this case, the "multispecies complexes" appeared after the subsequent reintegration of the host populations formerly isolated. The second factor is the speciation due to the specialization of mites to local microhabitats in the fur or plumage of host (sympatric or synxenic speciation). The second way of speciation is most characteristic for mites with highly specialized attaching structures. The phenomenon of FS more resides in ectoparasites of mammals rather than in feather mites in spite of much more structural complicacy of plumage rather than the fur. The high mobility of birds and wide dispersion of their new generations probably embarrass the process of sympatric speciation in their parasites. As a rule, only really significant geographical barriers play role for population isolation in birds. Thus, it could be concluded that two independent factors or their combination lead to FS. (i) The complex and/or disjunctive host range giving a possibility for allopatric speciation in parasites. (ii) The deep mite specialization to local microhabitats on the host body causing sympatric (synxenic) speciation. Fur of mammals and plumage of birds are very complicated in structure and microconditions and provide a considerable number of different microhabitats for mites inhabiting them. The prevalence of one of these two factors depends on the biological peculiarities of both parasites and their hosts. In mites with lesser specialized attaching organs, for example in atopomelids, allopatric speciation dominates. In mites with strongly specialized attaching organs, for example in listrophorids or chirodiscids, both pathways of speciation may take place. In feather mites, sympatric speciation should be more probable due to quite complicate and various structure of feathers in avian hosts. In fur mites, sympatric speciation is more likely in mites parasitizing hosts with peculiar ecology, for example in semiaquatic rodents possessing quite different fur structure in different parts of the body.     

Multiplex PCR assay for identifying five species of chigger mites in the Republic of Korea

Chigger mites (Trombiculidae), which are known vectors of Orientia tsutsugamushi, have significantly fewer molecular data available than other known species, with a focus on morphological species identification rather than molecular species identification. However, chigger mites are easily damaged because of small size. In addition, natural variation and adult similarity would interrupt accurate classification and identification. Therefore, in this study, a multiple polymerase chain reaction (PCR) method using the internal transcribed spacer (ITS) region of five frequently occurring species (Euschoengastia koreaensis, Leptotrombidium orientale, Leptotrombidium pallidum, Leptotrombidium palpale, and Leptotrombidium scutellare) among eight species known to mediate the spread of is presented. This is the first report using molecular species identification for the classification method of chigger mites, which was only possible with morphological species identification, and is expected to be used as basic data for vector surveillance.     

Geographical Distribution and Molecular Identification of Larval. Trombiculid Mites in Korea (2005∼2007)

A surveillance of trombiculid mites was conducted by collecting wild small mammals twice a year (spring and autumn seasons) at 24 localities in Korea from 2005 to 2007 to clarify the nationwide distribution of scrub typhus vectors. Among 783 trapped rodents, Apodemus agrarius accounted for 87.4% and the trapping rate at riverside was recorded the highest. A total of 67,325 mites representing 4 genera and 14 species were collected and their chigger index (C. I.) was 86.0. The predominant species were Leptotrombidium pallidum (52.6%), L. scutellare (27.1%), L. palpale (8.2%), L. orientale (5.6%), and Neotrombicula tamiyai (1.7%). However, the portion of L. scutellare in southern area including endemic provinces such as Jeollabuk‐Do (34.3%), Jeollanam‐Do (49.0%), and Gyeongsangnam‐Do (88%) were relatively higher than middle areas where L. pallidum was predominant in. Additionally, in autumn season, the density of L. scutellare was increased up to 42.0% while that of L. pallidum was decrease to 37.6%. Now we are performing a periodic surveillance again (2011～2013) and trying to develop a method to identify these trombiculid mites using molecular markers.     

Biology, ecology, and management of the bulb mites of the genus Rhizoglyphus (Acari: Acaridae)

Bulb mites of the genus Rhizoglyphus (Claparède) (Acari: Acaridae) have been identified as pests of many crops and ornamentals in storage, in the greenhouse, and in the field. The most importanthosts are species in the family Liliaceae (e.g. Allium spp.), but bulb mites will often attack otherimportant crops such as potatoes (Solanum sp.) and carrots (Daucus carota). Despite their economicimportance and broad distribution, the systematics of the genus remains in a state of confusion and is inneed of a comprehensive revision. In addition, the field biology and ecology of these mites is not wellunderstood, and methods for sampling, monitoring, and loss assessment are limited. Management of bulbmites is complicated by their short generation time, high reproductive potential, broad food niche,interactions with other pests and pathogens, and unique adaptations for dispersal. Historically, control ofthese acarine pests has relied on the use of synthetic miticides and insecticides, but this option is nowlimited due to documented resistance and withdrawal of registration of some products. Alternativecontrol strategies, including cultural and biological control, have shown limited success, but need to befurther developed and implemented.     

Abundances and host relationships of chigger mites in Yunnan Province,China

This paper reports on ectoparasitic chigger mites found on small mammals in Yunnan Province, southwest China. Data were accumulated from 19 investigation sites (counties) between 2001 and 2009. A total of 10 222 small mammal hosts were captured and identified; these represented 62 species, 34 genera and 11 families in five orders. From the body surfaces of these 10 222 hosts, a total of 92 990 chigger mites were collected and identified microscopically. These represented 224 species, 22 genera and three subfamilies in the family Trombiculidae (Trombidiformes). Small mammals were commonly found to be infested by chigger mites and most host species harboured several species of mite. The species diversity of chigger mites in Yunnan was much higher than diversities reported previously in other provinces of China and in other countries. A single species of rodent, Eothenomys miletus (Rodentia: Cricetidae), carried 111 species of chigger mite, thus demonstrating the highest species diversity and heaviest mite infestation of all recorded hosts. This diversity is exceptional compared with that of other ectoparasites. Of the total 224 mite species, 21 species accounted for 82.2% of all mites counted. Two species acting as major vectors for scrub typhus (tsutsugamushi disease), Leptotrombidium scutellare and Leptotrombidium deliense, were identified as the dominant mite species in this sample. In addition to these two major vectors, 12 potential or suspected vector species were found. Most species of chigger mite had a wide range of hosts and low host specificity. For example, L. scutellare parasitized 30 species of host. The low host specificity of chigger mites may increase their probability of encountering humans, as well as their transmission of scrub typhus among different hosts. Hierarchical clustering analysis showed that similarities between different chigger mite communities on the 18 main species of small mammal host did not accord with the taxonomic affinity of the hosts. This suggests that the distribution of chigger mites may be strongly influenced by the environment in which hosts live.     

Phytoseiid mites (Acari: Mesostigmata) associated with tea gardens in north of Iran

Predator mites of Phytoseiidae family are among the most important biocontrol agents in the world. These beneficial mites are considered as natural enemies of many pests and herbivore mites, and can feed on different growth stages of pests (egg, larva or nymph). Five species of Phytoseiidae mites were found during a survey conducted on tea plants, Camellia sinensis (Theaceae), in the Mazandaran and Guilan Provinces in the north of Iran, on the coast of the Caspian Sea, the major tea-growing region of Iran. Some of these species are recorded for the first time in tea gardens of Iran.     

Phylogenetic analysis of spotted fever group rickettsiae based on gltA, 17-kDa, and rOmpA genes amplified by nested PCR from ticks in Japan

In order to understand the natural situation of rickettsiae in the ticks in Japan, the rickettsial genes, gltA gene, rOmpA gene, and 17-kDa gene, were amplified from the ticks by nested PCR. The prevalences of rickettsial gltA genes among Haemaphysalis formosensis, H. longicornis, H. megaspinosa, Ixodes ovatus, H. flava, H. kitaokai, and I. persulcatus were 62, 57, 24, 24, 19, 13, and 10%, respectively; 26% (186/722) being the average. The gltA genes amplified from the ticks were classified into 9 genotypes (I to IX) by the difference in nucleotide sequences. Genotype I was detected from 7 species of ticks. Genotype II mainly was detected from H. longicornis and H. formosensis. Genotypes III and VII mainly were detected from H. flava and I. ovatus. The polarization in the distribution of genotypes among regions where the ticks were collected was not clear. Based on the phylogenetic analysis of the three genes presented here, genotypes I, III, and IV (detected from H. formosensis, H. hystricia, and I. ovatus ) are genetically close with each other, but rickettsiae of the same property still have not been isolated from ticks anywhere in the world. These genotypes should be considered as new species among SFG rickettsiae. Genotype II was identical with strain FUJ-98, genetically close to R. japonica which has been isolated from ticks in China. Genotype V was identical with R. felis and strain California 2 isolated from the cat flea. This is the first report on the detection of R. felis from ticks. Genotype VI detected from Ixodes sp. did not seem to belong to genus Rickettsia. Based on the previous antigenic data and the phylogenetic analysis presented here, Genotype VII should be considered a variant of R. helvetica and genotype VIII detected from I. ovatus and I. persulcatus were identical with R. helvetica. Genotype IX detected from I. nipponensis was genetically close to the strains IRS3, IRS4, and IrR/Munich isolated from I. ricinus in Slovakia and German.     

Molecular Prevalence of Acarapis Mite Infestations in Honey Bees in Korea

Acarapis mites, including Acarapis woodi, Acarapis externus, and Acarapis dorsalis, are parasites of bees which can cause severe damage to the bee industry by destroying colonies and decreasing honey production. All 3 species are prevalent throughout many countries including UK, USA, Iran, Turkey, China, and Japan. Based on previous reports of Acarapis mites occurring in northeast Asia, including China and Japan, we investigated a survey of Acarapis mite infestations in honey bees in Korean apiaries. A total of 99 colonies of Apis mellifera were sampled from 5 provinces. The head and thorax of 20 bees from each colony were removed for DNA extraction. PCR assays were performed with 3 primer sets, including T, A, and K primers. Results indicated that 42.4% (42/99) of samples were Acarapis-positive by PCR assay which were sequenced to identify species. Each sequence showed 92.6-99.3% homology with reference sequences. Based on the homology, the number of colonies infected with A. dorsalis was 32 which showed the highest infection rate among the 3 species, while the number of colonies infected with A. externus and A. woodi was 9 and 1, respectively. However, none of the Acarapis mites were morphologically detected. This result could be explained that all apiaries in the survey used acaricides against bee mites such as Varroa destructor and Tropilaelaps clareae which also affect against Acarapis mites. Based on this study, it is highly probable that Acarapis mites as well as Varroa and Tropilaelaps could be prevalent in Korean apiaries.     

A new genus of water mites (Acari,Hydrachnidia, Wettinidae) from bromeliad phytotelmata in the Brazilian Atlantic rainforest

Adults of Bromeliacaruscardosogen. n., sp. n. are described from phytotelmata of Quesneliaarvensis (Vellozo) Mez. (Bromeliaceae) in the subtropical area of the Atlantic rainforest, São Paulo State, Brazil. The new genus Bromeliacarus is proposed and diagnosed, based primarily on the autapomorphic presence of 7–9 pairs of acetabula flanking the gonopore. A possible relationship between Bromeliacarus and other Wettinidae are discussed.     

Host range of Neozygites floridana isolates (Zygomycetes: Entomophthorales) to spider mites

Neozygites floridana (Weiser & Muma) (Zygomycetes: Entomophthorales) has been reported infecting naturally at least 18 species of tetranychids worldwide. However, the host range of N. floridana is unknown. Epizootics caused by this pathogen to tetranychid populations indicate that N. floridana has the potential to be used as a biological control agent. However, the virulence and specificity of species and strains of Neozygites need to be assessed in the laboratory to reveal its potential as a biological control agent. N. floridana isolates are currently been investigated in Brazil as biological control agents against the tomato red mite, Tetranychus evansi Baker & Pritchard, and the two-spotted spider mite, Tetranychus urticae Koch. The pathogenicity of five strains of N. floridana obtained from T. urticae, T. evansi and T. ludeni Zacher was assessed against populations of Mononychellus tanajoa (Bondar), Schizotetranychus sacharum Flechtmann & Baker, Tetranychus abacae Baker & Pritchard and Tetranychus armipenis Flechtmann & Baker, in addition to the species from which the fungus was obtained. Mummified mites were placed on leaf discs of the host plant of each tetranychid to promote fungal sporulation, and after 24 h the mites were transferred to the leaf discs. Contamination, infection and mummification were evaluated daily for seven days after confinement. Each isolate was pathogenic to three or four out of the six spider mite species tested. However, except for isolate ESALQ1421, all isolates caused higher levels of infection and significant mummification only to the tetranychid species from which they were collected. None of the isolates was pathogenic to S. sacharum and only one isolate infected T. abacae. Alternative hosts may be important for N. floridana survival in tropical regions where resting spores are rarely found.     

Molecular detection of Leishmania (Sauroleishmania) tarentolae in human blood and Leishmania (Leishmania) infantum in Sergentomyia minuta: unexpected host-parasite contacts

The detection of atypical Kinetoplastida in vertebrate hosts and vectors might suggest unexpected host-parasite contacts. Aside to major vectors of Leishmania (Leishmania) infantum in Italy (e.g. Phlebotomus perniciosus and Phlebotomus perfiliewi), the sand fly fauna also includes Sergentomyia minuta, herpetophilic and proven vector of Leishmania (Sauroleishmania) tarentolae, in which records of blood meal on mammals and detection of L. infantum DNA are increasing. This study was conducted in Central Italy aiming to molecularly detect potential atypical Leishmania host-vector contacts. Detection of Leishmania spp. DNA was performed by polymerase chain reaction (SSU rRNA, ITS1 targets) on field-collected sand fly females (N = 344), blood samples from humans (N = 185) and dogs (N = 125). Blood meal identification was also performed on engorged sand flies. Leishmania spp. DNA was found in 13.1% sand flies, 3.7% humans and 14.4% dogs. Sequence analysis identified L. infantum in S. minuta (4.4%), P. perniciosus (9.1%), humans (2.2%) and dogs (14.4%). Leishmania tarentolae was detected in S. minuta (12.6%), P. perfiliewi (6.6%) and human (1.6%) samples. Of 28 S. minuta examined for blood meal, 3.6 and 21.4% scored positive for human and lizard DNA, respectively. These results indicate the importance of one-health approach to explore new potential routes of transmission of leishmaniasis involving S. minuta.