• Parasites, Hosts and Diseases
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• v.58 no.4
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• pp.445-450
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• 2020

Trombiculid "chigger" mites (Acari) are ectoparasites that feed blood on rodents and another animals. A crosssectional survey was conducted in 7 ecosystems of southern Vietnam from 2015 to 2016. Chigger mites were identified with morphological characteristics and assayed by polymerase chain reaction for detection of rickettsiaceae. Overall chigger infestation among rodents was 23.38%. The chigger index among infested rodents was 19.37 and a mean abundance of 4.61. A total of 2,770 chigger mites were identified belonging to 6 species, 3 genera, and 1 family, and pooled into 141 pools (10-20 chiggers per pool). Two pools (1.4%) of the chiggers were positive for Orientia tsutsugamushi. Ricketsia spp. was not detected in any pools of chiggers. Further studies are needed including a larger number and diverse hosts, and environmental factors to assess scrub typhus.

• Journal of Microbiology and Biotechnology
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• v.33 no.11
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• pp.1495-1505
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• 2023

The western honeybee Apis mellifera L., a vital crop pollinator and producer of honey and royal jelly, faces numerous threats including diseases, chemicals, and mite infestations, causing widespread concern. While extensive research has explored the link between gut microbiota and their hosts. However, the impact of Varroa destructor infestation remains understudied. In this study, we employed massive parallel amplicon sequencing assays to examine the diversity and structure of gut microbial communities in adult bee groups, comparing healthy (NG) and Varroa-infested (VG) samples. Additionally, we analyzed Varroa-infested hives to assess the whole body of larvae. Our results indicated a notable prevalence of the genus Bombella in larvae and the genera Gillamella, unidentified Lactobacillaceae, and Snodgrassella in adult bees. However, no statistically significant difference was observed between NG and VG. Furthermore, our PICRUSt analysis demonstrated distinct KEGG classification patterns between larval and adult bee groups, with larvae displaying a higher abundance of genes involved in cofactor and vitamin production. Notably, despite the complex nature of the honeybee bacterial community, methanogens were found to be present in low abundance in the honeybee microbiota.

• The Korean Journal of Ecology
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• v.12 no.2
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• pp.123-132
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• 1989

The parasitic mites were collected from a total of 2,691 house rats in four areas of Seoul, Seongnam, Incheon and Yangsuri of Korea from January, 1983 to December, 1986, Infestation rates, the species composition of the mites. species diversity, evenness, dominance, similarity of the mites among the areas and monthly abundance were studied as follows: Among twenty-one species of mites identified from two species of house rats in the areas, 12 species belonged to Mesostigmata, 8 species to prostigmata and 1 species to Metastigmata. Out of twenty-one species, ten including Androlaelaps casalis were commonly found only on Rattus norvegicus, however, two including Haemogamsus serdjukovae only on Rattus rattus, and all the trombiculid mites were found in particular on R norvegicus. The highest infestation rates of the mites on the rats ranged from June to August in all the areas throughout the year. The species diversity of the mites was the highest (0.6280) in Yangsuri with the highest evenness value (0.5770) observed in Incheon. The seasonal species diversities in Seoul, Seongnam and Yangsuri were higher in April, October and March respectively than the other time of the year. The highest similarity value was calculated between Yangsuri and Seoul areas, compared with the lowest combination in Seoul and Seongnam areas. The seasonal indices of mites showed that the most abundant number of mites was observed in spring and summer in Seoul and Seongnam, in summer and autumn in Incheon and in the winter season in Yangsuri. The mesostigmatid and metastigmatid mites were collected abundantly in July and September from R. norvegicus and R rattus in Seoul with the highest number of the above mites found from R. norvegicus in June in Seongnam. Particularly in Yangsuri, a large number of the mites were collected all the year round.

• Parasites, Hosts and Diseases
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• v.58 no.3
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• pp.315-319
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• 2020

In November 2019 a 5-month-old mixed-breed rabbit presented to Chungbuk National University Veterinary Teaching Hospital, Cheongju-si, Chungbuk, Republic of Korea (Korea) with symptoms comprising pruritus, crusts on skin, poor appetite and reduced defecation. The rabbit was purchased 2 months prior from a pet shop located in a big market, and that the symptoms were first observed about 2 weeks prior to the hospital visit. Physical examination revealed that the patient had crust formation and alopecia on the nose together with lesions on the digits. A skin scraping test was performed using mineral oil and a high density of mites was observed by microscopy. Each mite showed a round, tortoiselike body with 4 comparatively short pairs of legs. The anus was located at the terminal unlike with suspected pathogen, Notoedres cati. Based on morphological characteristics, we identified the mite as Sarcoptes sp. Ivermectin was administered weekly by subcutaneous injection at a dosage of 0.4 mg/kg, and 4 weeks of follow-up study revealed the patient was fully recovered. And no more mites were detected from the case. This is the first case report of sarcoptic mange in a pet rabbit in Korea.

• Korean Journal of Clinical Laboratory Science
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• v.48 no.3
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• pp.242-246
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• 2016

The distribution and population density of rodents and chigger mites were investigated between April 2013 and November 2013 in the Gokseong-gun of Jeollanam-do, Korea. A total of 79 rodents were collected using Sherman collapsible traps, and among them, 73 were Apodemus agrarius (92.4%), 4 were Crocidura lasiura (5.0%), and 2 were Microtus fortis (2.5%). Sixty-eight out of the 79 rodents were parasitized by chiggers, showing an infestation rate of 86.0% and a chigger index of 74.5; the chigger index of A. agrarius was 75.4. From the trapped field rodents, 5,063 chigger mites were collected and identified with 6 species of 2 genera. Leptotrombidium scutellare was the dominant species with 3,535 chiggers (69.8%), followed by L. pallidum with 777 chiggers (15.3%). This results showed that the distribution of chigger mites differ in dominant species according to seasons. L. pallidum was the predominant chigger collected in April (34.3%), May (70.0%), and June (55.1%); whereas L. scutellare was the predominant chigger collected in September (75.5%), October (71.8%), and November (74.2%).

• Parasites, Hosts and Diseases
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• v.27 no.2
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• pp.141-144
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• 1989

During October-December 1987, chigger mites infested on the striped field mice (Apodemus agrarius cereae) collected at Pochun-gun, Gyeonggi Province and Chinhae city, Kyongnam Province were identified. . 1. Of 171 back-striped mice collected, chigger mites wire found from 58 mice, showing 33.9% of infestation rate. 2. Total 865 chigger mites collected were classified into seven species; Leptotrombidium pallidum (4.3%), L. palpate(23.0%), L. orienpalis(20.2%), L. xetum(19.0%), Neotrombicula tamiyai(32.9%), JV. japonica(0.25%) and Euschongastia koreaensis(0.3%). Though the most dominant species in number was N. tamiyai(32.9% of the total), this species was collected at very limited locality and for a short period. Therefore, most common species in Korea seems to be L. palpale which was found at all localities throughout the whole survey period. L. pallidum which is known as the vector species of tsutsugamushi disease in Korea was collected in a very low number(4.3% of the total chiggers collected). 3. The number of chigger mites infested on a host animal showed great variations from one chigger up to 207 chiggers. The present study has shown that there may be other Leptotrombidium species mite(s) for the vector and host of tsutsugamushi disease in Korea.

• Parasites, Hosts and Diseases
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• v.59 no.6
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• pp.625-634
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• 2021

Based on the field investigations in 91 investigation sites (counties) in southwest China between 2001 and 2019, the present paper reported the chigger mites on A. agrarius mice in southwest China for the first time by using a series of statistical methods. From 715 striped field mice captured in 28 of 91 investigated sites, only 255 chiggers were collected, and they were identified as 14 species, 6 genera in 3 subfamilies under 2 families. Of 715 A. agrarius mice, only 24 of them were infested with chigger mites with low overall prevalence (P_M=3.4%), overall mean abundance (M_A=0.36 mites/host) and overall mean intensity (M_I=10.63 mites/host). The species diversity and infestation of chiggers on A. agrarius were much lower than those previously reported on some other rodents in southwest China. On a certain species of rodent, A. agrarius mouse in southwest China seems to have a very low susceptibility to chigger infestations than in other geographical regions. Of 14 chigger species, there were 3 dominant species, Leptotrombidium sialkotense, L. rupestre and Schoengastiella novoconfuciana, which were of aggregated distribution among different individuals of A. agrarius hosts. L. sialkotense, one of 6 main vectors of scrub typhus in China, was the first dominant on A. agrarius. The species similarity of chigger mites on male and female hosts was low with C_SS=0.25, and this reflects the sex-bias of different genders of A. agrarius mice in harboring different chigger species.