• Parasites, Hosts and Diseases
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• v.42 no.4
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• pp.195-200
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• 2004

We investigated the induction of resistance to Haemaphysalis longicornis infestation in rabbits that had been immunized with recombinant H. longicornis P27/30 protein. The success of immunological control methods is dependent upon the use of potential key antigens as tick vaccine candidates. Previously, we cloned a gene encoding 27 kDa and 30 kDa proteins (P27/30) of H. longicornis, and identified P27/30 as a troponin I-like protein. In this study, rabbits that were immunized with recombinant P27/30 expressed in Escherichia coli showed the statistically significant longer feeding duration for larval and adult ticks (P<0.05), low engorgement rates in larval ticks (64.4%), and an apparent reduction in egg weights, which suggest that H. longicornis P27/30 protein is a potential candidate antigen for a tick vaccine. These results demonstrated that the recombinant P27/30 protein might be a useful vaccine candidate antigen for biological control of H. longicornis.

• Korean Journal of Veterinary Research
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• v.43 no.1
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• pp.145-150
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• 2003

To determine effectively the chitinolytic activity of rCHT1 from the hard tick H. longicornis expressed in baculovirus-mediated Spodoptera frugtperda (Sf) 9 cells, a simple and sensitive assay system was established in solid phase using agarose gel containing ethylene glycol chitin as substrate. The various factors affecting the efficacy of the assay were also investigated. The effects of various temperature, dosages of proteins, pH of media and time courses of reaction were examined to verify the sensitivity of assay for chitinolytic activity of rCHT1 protein. It was found that the optimal reactive conditions were $37^{\circ}C$ of temperature, 12 to 15 hours of reactive times, $0.1{\mu}g$ of protein concentration and pH 5 to 7 of media. Using the assay system designed, the functional activities of H. longicornis rCHT1l protein could be evaluated simply and sensitively.

• Korean Journal of Veterinary Service
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• v.39 no.2
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• pp.75-80
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• 2016

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging disease characterized by fever and thrombocytopenia. Haemaphysalis longicornis ticks comprise the major population of ticks in the environment and have been considered as the main vector for SFTS virus (SFTSV). Here we investigated the distribution of ticks carrying SFTSV collected from the environment using the dragging or sweeping methods during April~October 2015 in Jeollanam-do, Korea. Sampling was taken from Songjeong, Omi, Bangkwang, Sandong areas in Jiri walking trails. Among the total 3,869 ticks collected, 3,823 ticks (98.8%) were H. longicornis, 41 (1.1%) were Amblyomma testudinarium, and 5 (0.1%) were Ixodes nipponensis. Classification results by regional groups of H. longicornis indicated that 1,613 ticks were collected in Sandong, 1,190 ticks in Omi, 603 ticks in Bangkwang, and 417 ticks in Songjeong. In monthly distributional studies of H. longicornis based on the developmental stages, nymph (325 ticks) was collected from May to October, 94% of larvae from April to June, and 94% of adult from June to August. These results showed the different dominant stage of ticks according to seasons. However, no SFTSV-specific gene was detected in 3,823 ticks of H. longicornis, 41 of A. testudinarium and 5 of I. nipponensis.

• Korean Journal of Veterinary Research
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• v.54 no.2
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• pp.117-120
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• 2014

Chemotherapeutic treatment is still the foundation of tick control programs. This study investigated the acaricidal efficacy of cypermethrin alone and in combination with chlorpyrifos against Haemaphysalis (H.) longicornis. Unfed larval ticks were exposed to 0.1, 1.0, and 10 mg/mL cypermethrin for 60 min, after which the acaricidal efficacy was examined based on tick mortality. All compounds showed similar suppression curves, with the best control being achieved by cypermethrin and chlorpyrifos (1 : 1 ratio) at 10 mg/mL. Effective cypermethrin concentrations for tick control were two to seven times higher than the recommended doses, indicating resistance by H. longicornis.

• Parasites, Hosts and Diseases
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• v.59 no.5
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• pp.481-487
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• 2021

The objective of this study was to evaluate the efficacy of an imidacloprid 10% and flumethrin 4.5% polymer matrix collar against the developmental stages of Haemaphysalis longicornis infesting dogs using the hair from treated dogs in a semi-in-vitro assay set. When incubated with 0.5 g of the hair collected from the dogs installed with the drug-embedded collar after 10 days, average death rate of the larval, nymphal, and adult H. longicornis was 21.5%, 77.9%, and 100% at 30 min, 1 hr, and 2 hr, respectively. This study showed the larval stages as well as the nymphal and adult stages of H. longicornis ticks are killed upon contact with the hair from dogs treated with the collar within 2 hr.

• Korean Journal of Clinical Laboratory Science
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• v.47 no.3
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• pp.147-152
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• 2015

The seasonal pattern of larvae, nymph and adult life stages for three tick species were studied for April-October, 2014. Haemaphysalis longicornis (610), Haemaphysalis flava (296) and Ixodes nipponensis (15) were collected from Pocheon by the dragging and flagging method. H.longicornis (254), H.flava (345) and I.nipponensis (15) were collected from Cheolwon in the same way. H.longicornis adults peaked in June while nymphs were more frequently collected from April through June. In contrast, H.longicornis larvae were collected only in September and October. H.flava adults were collected in April, September, and October while nymphs were collected from April through October. The nymphs peaked in April in Pocheon while May was the peak in Cheolwon. Larvae of H.longicornis and H.flava were collected only in September and October. I.nipponensis adults and nymphs were more frequently collected in April, while the larvae were not collected during that period. Collecting ticks by the dragging and flagging method provides estimates of population densities for life stages of the selected species and the associated disease risk. These results can be used to predict seasonal population densities of ticks and the prevalence of tick-borne pathogens.

• Journal of Applied Biological Chemistry
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• v.62 no.1
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• pp.19-23
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• 2019

The chemical compositions of the essential oil of Valeriana officinalis roots obtained by steam distillation method were analyzed by GC-MS. The 16 constituents were identified in the V. officinalis oil, and the most abundant compounds were patchouli alcohol (18.69%) and ${\beta}$-gurjunene (15.26%). Acaricidal effects of the V. officinalis oil were evaluated against Tyrophagus putrescentiae, Haemaphysalis longicornis larva and H. longicornis nymph by contact bioassay. The $LD_{50}$ values against T. putrescentiae, H. longicornis larva and H. longicornis nymph were 28.01, 178.26 and $207.98{\mu}g/cm^2$, respectively. Agar disc diffusion bioassay showed the antibacterial activity of the V. officinalis oil against foodborne pathogens, especially L. monocytogenes. These results showed that the essential oil of V. officinalis roots derived from USA has a potential for development as acaricide and antimicrobial.

• Korean journal of applied entomology
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• v.60 no.3
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• pp.323-329
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• 2021

This study investigated the seasonal distribution of ticks in Boeun, Chungbuk, South Korea, from 2016 to 2020. Over the five-year period, ticks were collected annually from four different sites. A total of 17,704 ticks belonging to three tick species (Haemaphysalis longicornis, Haemaphysalis flava, and Ixodes nipponensis) were collected. H. longicornis was the dominant species across all four sites with the highest density of 68.40% of the total collected specimens, followed by H. flava (3.53%) and I. nipponensis (0.06%). The larvae of unidentified species were also collected: 11.81 T.I. (28.01%). The H. longicornis population peaked during the spring season (May-June), whereas the larval population peaked during August and September. H. longicornis was collected the most from four sites (coniferous forest, broad-leaf forest, mountain path, and copse), with the exception of the larvae, which was collected the most in grassland and grave. H. flava was collected from all sites, but in a small proportion. The SFTS virus was not found in any of the 828 pools of ticks during 2016-2020. Based on the results of this study, the continuous surveillance of the tick population is recommended to mitigate the spread of diseases by these vectors.

• Korean journal of applied entomology
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• v.60 no.3
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• pp.315-322
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• 2021

This study investigated the acaricidal and repellent activities of various plant extracts and Cnidium officinale-derived materials against Haemaphysalis longicornis. Among the 24 methanolic plant extracts, C. officinale showed the highest acaricidal activity (93.3%) against H. longicornis. Platycodon grandiflorus, Phytolacca americana, Magnolia denudata, Houttuynia cordata, C. officinale, and Pueraria montana showed significant differences in their repellent activity. Consequently, the activity of solvent-fractionated materials and the derived material of the C. officinale, was investigated and a 90% acaricidal effect was observed three days after hexane fraction treatment, indicating that the repellent response was statistically significant. Butylidenephthalide, which is a C. officinale-derived compound, showed 90% acaricidal activity seven days after treatment. Additionally, all H. longicornis moved to the untreated area in the t-tube olfactometer experiment, confirming the repellent activity of butylidenephthalide. Therefore, the results of this study suggest the use of C. officinale crude extract and butylidenephthalide as potent acaricidals and repellents against H. longicornis, respectively.

• Parasites, Hosts and Diseases
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• v.51 no.3
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• pp.327-334
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• 2013

Vaccination is considered a promising alternative for controlling tick infestations. Haemaphysalis longicornis midgut proteins separated by SDS-PAGE and transferred to polyvinylidene difluoride (PVDF) membrane were screened for protective value against bites. The western blot demonstrated the immunogenicity of 92 kDa protein (P92). The analysis of the P92 amino acid sequence by LC-MS/MS indicated that it was a H. longicornis paramyosin (Hl-Pmy). The full lenghth cDNA of Hl-Pmy was obtained by rapid amplification of cDNA ends (RACE) which consisted of 2,783 bp with a 161 bp 3' untranslated region. Sequence alignment of tick paramyosin (Pmy) showed that Hl-Pmy shared a high level of conservation among ticks. Comparison with the protective epitope sequence of other invertebrate Pmy, it was calculated that the protective epitope of Hl-Pmy was a peptide (LEEAEGSSETVVEMNKKRDTE) named LEE, which was close to the N-terminal of Hl-Pmy protein. The secondary structure analysis suggested that LEE had non-helical segments within an ${\alpha}$-helical structure. These results provide the basis for developing a vaccine against biting H. longicornis ticks.