The seasonal abundance of horse and deer flies (family Tabanidae) was analyzed using Mosquito Magnet(R) traps at 5 sites located near/in the demilitarized zone, northern Gyeonggi-do, Republic of Korea from late April to early October for 4 consecutive years (2010-2013). A total of 2,999 horse and deer flies (tabanids) belonging to 5 genera and 20 species were collected. Chrysops mlokosiewiczi (90.9%) was the most frequently collected, followed by Haematopota koryoensis (4.8%) and C. suavis (1.0%). The remaining 17 species comprised only of 3.3% of all species collected. C. mlokosiewiczi demonstrated bimodal peak populations during mid-June and early August, while H. koryoensis demonstrated a unimodal peak during mid-July. Overall numbers of tabanids collected were influenced by the previous year's winter temperatures and precipitation. Population abundance was influenced by habitat with most of tabanids collected from habitats near forested areas, followed by rice paddies, and a beef farm.
Animals ; Diptera/*classification/*growth & development ; Ecosystem ; Female ; Male ; Population Dynamics ; Republic of Korea ; Seasons

Two-point mutations (V419L and L925I) on the voltage-sensitive sodium channel of bed bugs (Cimex lectularius) are known to confer pyrethroid resistance. To determine the status of pyrethroid resistance in bed bugs in Korea, resistance allele frequencies of bed bug strains collected from several US military installations in Korea and Mokpo, Jeollanamdo, from 2009-2019 were monitored using a quantitative sequencing. Most bed bugs were determined to have both of the point mutations except a few specimens, collected in 2009, 2012 and 2014, having only a single point mutation (L925I). No susceptible allele was observed in any of the bed bugs examined, suggesting that pyrethroid resistance in bed bug populations in Korea has reached a serious level. Large scale monitoring is required to increase our knowledge on the distribution and prevalence of pyrethroid resistance in bed bug populations in Korea. Based on present study, it is urgent to restrict the use of pyrethroids and to introduce effective alternative insecticides. A nation-wide monitoring program to determine the pyrethroid resistance level in bed bugs and to select alternative insecticides should be implemented.

When free-ranging birds are accidentally killed or die, there may be greater potential for their associated ticks to detach, seek alternate hosts, and become established. We examined 711 carcasses of 95 avian species for ticks at a stopover island of migratory birds in the Republic of Korea where only Ixodes nipponensis and I. persulcatus were previously reported from local mammals and vegetation. A total of 16 ticks, I. turdus and Haemaphysalis flava, were collected from 8 fresh carcasses belonging to 5 avian species. Despite their known abundance on migratory birds and mainland Korea, these species had not colonized the isolated insular ecosystem possibly due to the low abundance and diversity of local hosts. The results imply that increasing human impact, such as the anthropogenic mortality of migratory birds and the introduction of non-native mammalian hosts, will increase the potential invasion and colonization risk of ticks. This finding also suggests that tick surveillance consisting of fresh carcasses of dead migratory birds may provide additional information, often ignored in surveillance of ticks on live birds, for the potential introduction of non-native ticks and associated pathogens affecting animal and human health.

Leptospirosis has been one of important epidemic diseases in Korea since 1984. Wild rodents, mostly Apodemus agrarius, served the important source of infection especially in harvest season in rural areas of Korea. Prevalence of Leptospira spp. infection in field rodents were investigated by detecting leptospiral DNA from rodent kidney. Among 108 rodents collected from various areas in 1998, leptospiral DNA were detected from 7 rodents (6.48%). Among 104 rodents, Apodemus agrarius, captured from Yeonchon and Paju area in 2001 and 2002, leptospiral DNA were detected from 6 rodents (5.76%). No leptospiral DNA was detected from 23 rodonts (Apodemus peninsulae 16, Apodemus agrarius 2 and Eothenomys regulus 5) captured in Odae mountain area in 1998.
Animals ; DNA* ; Kidney ; Korea ; Leptospira ; Leptospirosis ; Murinae ; Polymerase Chain Reaction* ; Prevalence ; Rodentia* ; Seasons

Black light traps were used to measure the seasonal and geographical distribution of Culicoides spp. (biting midges or no-see-ums) at 9 cowsheds in the southern half of the Republic of Korea (ROK) from June through October 2010. A total of 25,242 Culicoides females (24,852; 98.5%) and males (390; 1.5%) comprising of 9 species were collected. The most commonly collected species was Culicoides punctatus (73.0%) followed by C. arakawae (25.7%), while the remaining 7 species accounted for <1.0% of all Culicoides spp. collected. The mean number of Culicoides spp. collected per trap night (Trap Index [TI]) was highest for C. punctatus (409.3), followed by C. arakawae (144.2), C. tainanus (4.1), C. oxystoma (1.2), C. circumscriptus (0.7), C. homotomus (0.6), C. erairai (0.4), C. kibunensis (0.3), and C. nipponensis (0.04). Peak TIs were observed for C. punctatus (1,188.7) and C. arakawae (539.0) during July and August, respectively. C. punctatus and C. arakawae have been implicated in the transmission of arboviruses and other pathogens of veterinary importance that adversely impact on animal and bird husbandry.
Animals ; Cattle ; Ceratopogonidae/classification/*growth & development ; Female ; *Housing, Animal ; Male ; Phylogeography ; Republic of Korea ; Seasons

A survey to determine the geographical distribution and relative abundance of potential vectors of scrub typhus was conducted from October to November 2006 at 13 localities throughout the Republic of Korea. Apodemus agrarius accounted for 97.6% (80/82) of all rodents, while only 2 Myodes regulus (2/82) were collected. A total of 10,860 chiggers were collected from A. agrarius belonging to 4 genera and 8 species, while only Walchia fragilis (40) was collected from Myodes regulus. Leptotrombidium pallidum (8,137; 74.9%), a vector of scrub typhus, was the predominant species collected from A. agrarius followed by Leptotrombidium scutellare (2,057, 18.9%), Leptotrombidium palpale (279; 2.7%), Leptotrombidium orientale (232; 2.1%), and Leptotrombidium zetum (79; 0.7%), Neotrombicula tamiyai (58; 0.5%), Euschoengastica koreaensis (16; 0.1%), and Cheladonta ikaoensis (2; < 0.1%). L. pallidum was the predominant chigger collected at collection sites in Gangwon (100%), Gyeonggi (87.2%), Chungnam (100%), Chungbuk (100%), Jeonbuk (73.9%), Jeonnam (77.0%), and Gyeongbuk (66.1%) provinces, whereas L. scutellare was the predominant chigger collected in Gyeongnam province (77.9%) and Jeju Island (62.3%). Data suggest a correlation between chigger population abundance and human cases of scrub typhus in Korea.
Animals ; Arvicolinae/*parasitology ; *Disease Vectors ; Geography ; Mites/*microbiology ; Murinae/*parasitology ; Orientia tsutsugamushi/*isolation & purification ; Republic of Korea ; Scrub Typhus/transmission

Biting midges (Culicoides: Ceratopogonidae) were collected by Mosquito Magnet(R) traps at the Neutral Nations Supervisory Commission (NNSC) camp and Daeseongdong village inside the demilitarized zone (DMZ) and near the military demarcation line (MDL) separating North and South Korea and at Warrior Base (US Army training site) and Tongilchon 3 km south of the DMZ in northern Gyeonggi Province, Republic of Korea (ROK), from May-October 2010-2012, to determine their seasonal distributions. A total of 18,647 Culicoides females (18,399; 98.7%) and males (248; 1.3%) comprising 16 species were collected. Overall, the most commonly collected species was Culicoides nipponensis (42.9%), followed by C. erairai (29.2%), C. punctatus (20.3%), C. arakawae (3.3%), C. pallidulus (1.8%), and C. circumscriptus (1.4%), while the remaining 10 species accounted for only 1.1% of all Culicoides spp. collected. The seasonal distribution of C. nipponensis was bimodal, with high numbers collected during May-June and again during September. C. erairai was more frequently collected during June-July, followed by sharply decreased populations from August-October. C. punctatus was collected in low numbers from May-September with high numbers collected during October. C. erairai was predominantly collected from the NNSC camp (85.1% of all C. erairai collected) located adjacent to the MDL at Panmunjeom in the northernmost part of Gyeonggi-do (Province), while other sites yielded low numbers of specimens.
Animals ; Ceratopogonidae/*classification/*growth & development ; Democratic People's Republic of Korea ; Female ; Male ; Republic of Korea ; *Seasons

Ticks were collected from 35 animals from 5 provinces and 3 metropolitan cities during 2012. Ticks also were collected by tick drag from 4 sites in Gyeonggi-do (2) and Jeollabuk-do (2) Provinces. A total of 612 ticks belonging to 6 species and 3 genera were collected from mammals and a bird (n=573) and by tick drag (n=39). Haemaphyalis longicornis (n=434) was the most commonly collected tick, followed by H. flava (158), Ixodes nipponensis (11), Amblyomma testudinarium (7), H. japonica (1), and H. formosensis (1). H. longicornis and H. flava were collected from all animal hosts examined. For animal hosts (n>1), the highest Tick Index (TI) was observed for domestic dogs (29.6), followed by Siberian roe deer (17.4), water deer (14.4), and raccoon dogs (1.3). A total of 402 H. longicornis (adults 86, 21.4%; nymphs 160, 39.8%; larvae 156, 38.9%) were collected from wild and domestic animals. A total of 158 H. flava (n=158) were collected from wild and domestic animals and 1 ring-necked pheasant, with a higher proportion of adults (103, 65.2%), while nymphs and larvae only accounted for 12.7% (20) and 22.2% (35), respectively. Only 7 A. testudinarium were collected from the wild boar (6 adults) and Eurasian badger (1 nymph), while only 5 I. nipponensis were collected from the water deer (4 adults) and a raccoon dog (1 adult). One adult female H. formosensis was first collected from vegetation by tick drag from Mara Island, Seogwipo-si, Jeju-do Province.
Animals ; Animals, Domestic ; Animals, Wild ; Female ; Male ; Prevalence ; Republic of Korea ; Tick Infestations/epidemiology/parasitology/*veterinary ; Ticks/*classification

A total of 1,618 ticks [420 individual (adults) and pooled (larvae and nymphs) samples], 369 rodents (Apodemus arius, Rattus norvegicus, Tscherskia triton, Mus musculus, and Myodes regulus), and 34 shrews (Crocidura lasiura) that were collected in northern Gyeonggi-do near the Demilitarized Zone (DMZ) of Korea during 2004-2005, were assayed by PCR for selected zoonotic pathogens. From a total of 420 individual and pooled tick DNA samples, Anaplasma (A.) phagocytophilum (16), A. platys (16), Ehrlichia (E.) chaffeensis (63), Borrelia burgdorferi (16), and Rickettsia spp. (198) were detected using species-specific PCR assays. Out of 403 spleens from rodents and shrews, A. phagocytophilum (20), A. platys (34), E. chaffeensis (127), and Bartonella spp. (24) were detected with species-specific PCR assays. These results suggest that fevers of unknown causes in humans and animals in Korea should be evaluated for infections by these vector-borne microbial pathogens.
Anaplasma phagocytophilum/genetics/isolation & purification ; Animals ; Biological Warfare ; DNA, Bacterial/genetics/isolation & purification ; Ehrlichiosis/transmission/veterinary ; Humans ; Korea ; Mice/*microbiology ; Rats/*microbiology ; Seasons ; Shrews/*microbiology ; Ticks/*microbiology ; Zoonoses

This study describes the seasonal distribution of larvae, nymph, and adult life stages for 3 species of ixodid ticks collected by tick drag and sweep methods from various habitats in the Republic of Korea (ROK). Grasses less than 0.5 m in height, including herbaceous and crawling vegetation, and deciduous, conifer, and mixed forests with abundant leaf/needle litter were surveyed at United States (US) and ROK operated military training sites and privately owned lands near the demilitarized zone from April-October, 2004 and 2005. Haemaphysalis longicornis Neumann adults and nymphs were more frequently collected from April-August, while those of Haemaphysalis flava Neumann and Ixodes nipponensis Kitaoka and Saito were collected more frequently from April-July and again during October. H. longicornis was the most frequently collected tick in grass habitats (98.9%), while H. flava was more frequently collected in deciduous (60.2%) and conifer (57.4%) forest habitats. While more H. flava (54.1%) were collected in mixed forest habitats than H. longicornis (35.2%), the differences were not significant. I. nipponensis was more frequently collected from conifer (mean 8.8) compared to deciduous (3.2) and mixed (2.4) forests.
Animals ; Demography ; *Ecosystem ; Republic of Korea ; *Seasons ; Ticks/*classification/*physiology