The longhorned tick, Haemaphysalis longicornis, is one of the vectors of severe fever with thrombocytopenia syndrome virus (SFTSV) in human. The use of pyrethroid insecticides induced pest resistance and environmental residual toxicity. Here in this work, our interest was given to the selection of highly virulent fungi against longhorned tick. A total of 101 fungal pathogens were assayed by dipping the nymph stage of ticks into a conidial suspension. Interestingly of the several species, one species showed high virulence and mycosis were observed in 7-15 days. Highly virulent strains were selected, and semi-field experiments were conducted. As a result, the control efficacy of the isolate was over 80% at 30 days of treatment. This work suggests that entomopathogenic fungi could be used to effectively control longhorend ticks.

Ticks are obligatory hematophagous ectoparasites, which can transmit various pathogens including bacteria, protozoa, and viruses via salivary secretion during feeding. Understanding salivation in ticks is crucial for the development of novel methods to prevent tick-borne disease transmission. The central nervous system (synganglion) of ticks controls salivary glands via several neuropeptidergic innervation: myoinhibitory peptide (MIP), SIFamide, and elevenin. These neuropeptides are thought to be modulators of dopamine’s action controlling the salivary glands including inward fluid transport into the lumen of salivary glands acini and emptying lumen solute into salivary duct by pumping and gating. These actions are via two distinct dopamine receptors, dopamine receptor (D1) and invertebrate D1-like dopamine receptor (InvD1L), respectively.

Longhorned tick, Haemaphysalis longicornis (Ixodida: Ixodidae) is one of the vectors of severe fever with thrombocytopenia syndrome virus (SFTSV) in human. The tick occurs in mostly grass fields, and the use of pyrethroid insecticides induced pest resistance and environmental residual toxicity. Particularly the use of chemicals near residential areas where persons live become a big issue, so environmentally safe control agents need to be considered. Here in this work, our interest was given to the selection of highly virulent fungi against H. longicornis. A total of 101 fungal pathogens collected from mountainous areas were assayed by a dipping the nymph stage of ticks into a conidial suspension (1×107conidia/ml). Interestingly among several species, one species showed high virulence and mycosis were observed in 7-15 days. Most of the selected isolates produced a large amount of conidia in Italian millet, rice and millet with thermotolerance at 40-45°C. Based on these results, we selected a couple of isolates with high virulence against H. longicornis and they could be used for the control of the ticks after the set-up of a practical application strategy in fields by optimizing fungal colonization in soil and phyllosphere.

The hard tick, Haemaphysalis longicornis (Ixodida: Ixodidae) is one of the vectors of severe fever with thrombocytopenia syndrome virus (SFTSV) causing in humans, however little consideration was given to the biological control of the pest. Therefore, this study provides a screening method to select entomopathogenic fungi, having high virulence against H. longicornis. The virulence test was conducted by dipping method with a conidial suspension (1×107 conidia/ml). As a result, cadavers of H. longicornis infected with entomopathogenic fungi were obtained by this method. Based on this results, we selected several isolates having high virulence to H. longicornis. We suggest that, selected isolates in this study can be used for the control of H. longicornis.

The hard tick, Haemaphysalis longicornis (Ixodida: Ixodidae) is one of the vectors of severe fever with thrombocytopeniasyndrome virus (SFTSV) causing in humans, however little consideration was given to the biological control of the pest.We evaluated three bioassay methods, such as spray, dipping and dropping. As a result, the dipping method was themost efficient way to measure the fungal virulence. Finally, we constructed a Haemaphysalis longicornis pathogenic fungallibrary to further facilitate the resources to be used as potential biological control agents. A conidial suspension of 1×107conidia/ml was exposed to the ticks by dipping. We confirmed that some isolates were highly virulent to the ticks. Thisresults indicated that some fungi could be used to effectively control the Haemaphysalis longicornis.

보건위생 및 농업 환경에서 진드기는 우리에게 중요한 질병매개체이자 경쟁자이다. 지구온난화 및 야외 활동인구의 증가와 더불어 진드기에 의한 감염 환자수 및 사망자수가 증가하였고, 닭진드기나 꿀벌응애와 같은 축산외부기생자들에 의한 동물들의 피해도 급증하고 있는 추세이다. 이들 진드기를 인위적으로 제어하기 위해 화학합성 살비제들의 활용에 주로 의존해 왔다. 이에 따라 이들 약제들에 대한 안전성 우려 및 저항성 발생으로 식물체의 활용에많은 연구자들이 관심을 갖게 되어 산업적으로 활용 가능한 일부 소재들도 개발되었다. 비록 국내에서는 아직까지진드기와 관련된 다양한 연구가 이뤄지지 못한 실정이지만, 지금까지 국내에서 이뤄진 식물체 또는 그 유래물질들의연구를 위한 실내 방법론적인 접근법들, 이를 통해 도출된 활용 가능한 식물 소재들 그리고 상업화의 현실적인어려운 점 등에 관해 논의하고자 한다.

The Ixodid ticks has been suspected to be the vector of severe fever with thrombocytopenia syndrome virus (SFTSV) in Korea. In order to confirm transovarial transmission of Ixodid ticks, a total of blood fed 284 ticks were collected from six host animals. They were identified as 3 genera and 4 species, Haemaphysalis longicornis (97.2%), H. flava (0.7%), Ixodes nipponensis (1.8%) and Amblyomma testudinarium (0.4%). Among them, 192 female adults hatched their eggs successfully. Our results showed a high prevalence of SFTSV among collected ticks (3.1%, 6/192 ticks), and we detected SFTSV from their larvae. This result suggests that the parent generation of H. longicornis can transmit SFTSV transovarially into their F1 progeny and H. longicornis might be one of major vectors of SFTSV in Korea.

Mosquitoes and hard ticks are vectors of serious diseases, but factors affecting the abundance and distribution of vector species are not well-understood. Therefore, we monitored mosquito populations from three potential mosquito habitats using black light traps and BG-Sentinel traps in Gyeonggi-do, 2016. Also, we surveyed ticks using CO2-based traps at one location in Gyeonggi-do, 2016. From the traps, we collected a total of 4,818 mosquitoes in three potential mosquito habitats, and 3,207 ticks in Gyeonggi-do. Among the collected samples, the highest density of mosquitoes were observed in August, and tick density was highest in August either. In the samples, dominant mosquitoes were Aedes vexans nipponii (Species Ratio 49%), and Culex pipens pallens (SR 25%) in mosquito habitats and dominant ticks were Haemaphysalis longicornis (SR 56%) in Gyeonggi-do. This monitoring program for vector species can help develop effective management strategy, especially under the global climate change.

Ixodid ticks are notorious as the vector of severe fever with thrombocytopenia syndrome virus (SFTSV) in Korea. To confirm the transovarial transmission of SFTSV, we collected blood-fed adult ticks from animals in SFTS case reported area of Jeju island in 2015. A total of 476 ticks were collected from four host animal species, horse (81.3%), dog (9.0%), roe deer (7.1%) and wild boar (2.5%). They were identified as 1 genus and 2 species, Haemaphysalis longicornis (87.8%) and H. flava (12.2%). Among them, 131 adults hatched their eggs successfully. The body weight of females was highly correlated with the number of egg masses laid (P < 0.05). We confirmed that one adult H. flava was infected with SFTSV and its infection rate was 0.77%. The eggs of the SFTSV-infected adults also were infected with SFTSV and its transovarial transmission was confirmed. This result suggests that the parent generation of H. flava could transmit SFTSV transovarially into their F1 progeny and H. flava might be one of major vectors of SFTSV in Korea.

Although the link between activity in the nuclei of galaxy and galactic mergers has been under scrutiny for several years, it is still unclear to what extent and for which populations of active galaxies merger- triggered activity is relevant. The environments of AGN allow an indirect probe of the past merger history and future merger probability of these systems, suffering less from sensitivity issues when extended to higher redshifts than traditional morphological studies of AGN host galaxies. Here we present results from our investigation of the environment of radio selected sources out to a redshift z=2. We employ the first data release J-band catalog of the new near-IR Infrared Medium-Deep Survey (IMS), 1.4 GHz radio data from the Faint Images of the Radio Sky at Twenty-cm (FIRST) survey and a deep dedicated VLA survey of the VIMOS field, covering a combined total of 20 sq. degrees. At a ux limit of the combined radio catalog of 0.1 mJy, we probe over 8 orders of magnitude of radio luminosity. Using the second closest neighbor density parameters, we test whether active galaxies inhabit denser environments. We find evidence for a sub-population of radio-selected AGN that reside in significantly overdense environments at small scales, although we do not find significant overdensities for the bulk of our sample. We show that radio-AGN in the most underdense environments have vigorous ongoing star formation. We interpret these results in terms of the triggering and fuelling mechanism of radio-AGN.

Ticks are obligatory ectoparasites of many vertebrates and transmit pathogens causing diseases such as Heartland virus and Ehrlichiosis. The lone star tick, Ambloyomma americanum L., is the primary vector of Ehrlichia chaffeensis, which causes human monocytic Ehrlichiosis. We aimed to investigate the genomic levels of gene regulation in the processes of acquiring the pathogen and of immune to pathogen. We designed six experimental groups: E. chaffeensis positive and negative groups of males and females, and pathogen free male and female ticks. Illumine HiSeq 2500 sequenced six libraries with 100-cycle single direction. Raw sequence reads (more than 209 million) were trimmed and filtered based on minimum quality score (Q-value >30) and size (> 40nt) for de novo assembly. Assembly using Trinity pipeline produced 140,574 contigs from trimmed and filtered sequence reads (about 117 million reads, 56% of raw data). For quality control of the de novo assembly of transcripts, we filtered out the sequences for mitochondrial, E. chaffeensis, and transposable elements sequences, and tested for contig redundancy and gap separations of the assembled sequences. RSEM and edgeR analyses of 61,802 contigs for identifying differentially expressed genes were followed by Blast2GO analyses for annotations of contigs and enriched-gene ontology (GO) term analyses in pairwise comparisons of the libraries. Further investigation of major groups of genes induced by pathogen would provide better understanding of pathogen-vector interaction, which will allow us to prevent of pathogen transmission by interrupting interaction between pathogen and ticks.

Tick salivary secretion during blood-feeding is crucial for successful tick feeding. Control of salivary secretion involves dopamine, which is the most potent inducer of tick salivation. Dopamine activates salivation by orchestrating two different physiological responses through two distinct dopamine receptors. In addition, the study demonstrated that two different types of cells in the salivary gland acini are responsible for each of the diverging physiological pathways: epithelial cells for inward fluid transport and myoepithelial cells for expelling fluid out through the acinar ducts. We were further interested in the downstream physiology of the dopamine receptors. A candidate gene (Na/K-ATPase), which is highly expressed in the salivary glands, was investigated. Immunoreactivity revealed that Na/K-ATPase is expressed in epithelial cells of acini. Ouabain, a Na/K-ATPase blocker, significantly suppressed both dopamine induced inward fluid transport and dopamine induced salivation in a dose-dependent manner. We measured the salivary contents to determine Na, K, and Cl ion, and protein concentrations. Treatment of ouabain at the low dose produced hyperosmolar saliva, but with same amount of protein as the control saliva. The results suggest that ouabain-sensitive Na/K-ATPase is the main downstream pathway for dopamine response in the epithelial cells of salivary gland for water transport, but not for protein secretion.

Nature conservation in the Republic of Korea (ROK), in addition the effects of global warming has increasingly changed Korea’s weather to a subtropical climate has resulted in increased populations of wild animals in association with their ectoparasites. Increased numbers of animal and bird hosts and warmer climate has resulted in higher populations of members of the Family Ixodidae (hard ticks), in addition to habitat and geographical distributions resulting from reforestation. There are; 6 Genera (Amblyomma, Boophilus, Dermacentor, Haemaphysalis, Ixodes, Rhipcephalus) in the Family Ixodidae, and with 35 species. Studies in the ROK over the past 10 years has resulted in the recognition of 3 Genera of Ixodidae (Haemaphysalis, Ixodes, Amblyomma) and 14 species (H. longicornis, H. flava, H. japonica, H. phasiana, H. ornithophila, H. formosensis, Ixodes nipponensis, I. persulcatus, I. turdus, I. pomerantzevi, I. granulatus, I. vespertilionis, I. simplex, Amblyomma testudinarium). A number of tick-borne pathogens, including severe fever with thrombocytopenia (SFTS) virus, tick-borne encephalitis (TBE) virus, Borrelia, Anaplasma, Ehrlichia, Rickettsia, Bartonella, Theileria and Babesia species, have been detected in ticks collected from the ROK. In addition to detecting these pathogens in zoonotic hosts, they have also been detected from pets, domestic animals, and humans. These pathogens often demonstrate vector and host-specificity, while affecting veterinary and medical health. The analysis of vector and pathogen distributions is crucial for the development of diseased mitigation strategies, requiring additional studies to determine the distributions of animal and bird hosts and vectors and associated pathogens.

Vector-borne diseases, including those transmitted by ticks, pose serious public health threats to US military populations, as well as military and civilian populations in the Republic of Korea. (1) From 2004-2010, a total of 54,495 ticks belonging to three genera and eight species [Haemaphysalis longicornis (33,242; 61.0%), H. flava (18,525; 34.0%), Ixodes nipponensis (2,420; 4.4%), H. phasiana (216, 0.4%), H. japonica (33; <0.1%), Amblyomma testudinarium (26; <0.1%), I. turdus (17; <0.1%), and I. persulcatus(16; <0.1%)] were collected by tick drag. (2) As part of the rodent-borne disease surveillance program, a total of 6,773 ticks belonging to two genera and four species were collected from small mammals at US military installations and training sites in Korea from 2004-2009. (3) In collaboration with Seoul National University, a total of 920 ticks, belonging to two genera and six species were collected from small-large mammals. (4) In addition, a total of 250 ticks belonging to two genera and five species were collected from migratory birds. (5) I. simplex and I. vespertilionis also were collected from limited numbers of bats. Additional collections from small-large mammals, migratory birds, bats, and other animals are needed to identify the geographical and host range of ticks and the associated pathogens they harbor. Furthermore, these data can be used to provide predictive emergence and distributions of ticks and their associated pathogens.

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging disease, causing high fever, thromobocytopenia, leukopenia, gastrointestinal simptoms (vomiting, diarrhea), hemorrhage and multiorgan dysfunction. It was known that Haemaphysalis longicornis (H. longicornis), a major tick in Korea, is the principal vector for severe fever with thrombocytopenia syndrome virus (SFTSV). Firstly, to investigate the existence and prevalence of SFTSV in the country, we collected the ticks in 9 provinces in South Korea and detected SFTSV from H. longicornis ticks from 2011 to 2012. And we also investigated SFTSV infection in ticks collected from healthy humans without SFTS symptom and their residential areas. From the former study, we collected 13,053 ticks, and H. longicornis (90.8%, 11,856/13,053) was the most abundant among them. The minimum infection rate (MIR) of SFTSV in H. longicornis was 0.5% (59 pools). From the later study, totally 422 ticks of 8 species were collected from humans and at their neighborhood throughout the nation from May to October, 2013 and SFTSVs were detected from 12 pools (5.7% MIR) by RT-PCR. Finally, we diagnosed 35 patients by detecting SFTSV gene with their sera, and isolated 26 SFTSVs among them in 2013. These findings indicate that SFTSVs are prevalent and SFTS is probably endemic in Korea.

A four-year-old sexually intact male dog and a seven-year-old sexually intact female dog presenting with heavy tick infestation were tentatively diagnosed with tick paralysis. Both dogs died due to respiratory failure. A number of ticks were observed in the head, ears, neck, trunk, and limbs of each dog. In these cases, a presumptive diagnosis of tick paralysis could be based on the presence of a species of tick known to cause paralysis combined with the absence of any other disease previously. Most ticks were identified as Haemaphysalis longicornis according to morphological features. Tick paralysis in dogs has rarely been reported in Korea.