title: Higher sika deer density is associated with higher local abundance of Haemaphysalis longicornis nymphs and adults but not larvae in central Japan.
abstract: Haemaphysalis longicornis (Acari: Ixodidae) is one of the most common and important arthropod disease vectors in Japan, carrying Japanese spotted fever and bovine theileriosis. The recent expansion of sika deer (Cervus nippon, Artiodactyla: Cervidae) populations, the most common wild host of H. longicornis, has also caused concern about increasing the risk of vector-borne diseases in Japan. We used generalized linear mixed model analysis to determine the relative contribution of deer density and other biological and abiotic factors on the abundance of H. longicornis ticks questing at each developmental stage. A total of 6223 H. longicornis adults, nymphs, and larvae were collected from 70 sites in three regions of central Japan. The abundance of questing adult and nymphal ticks was associated with deer density and other biotic and abiotic factors. However, the abundance of questing larvae showed no association with deer density but did show an association with other biotic and abiotic factors. These findings show that a high density of deer along with other biotic and abiotic factors is associated with increased risk of vector-borne diseases through amplified local abundance of questing nymphal and adult H. longicornis. Further, questing larvae abundance is likely regulated by environmental conditions and is likely correlated with survival potential or the distribution of other host species.
authors.affiliation: NARO Institute of Livestock and Grassland Science, Shiono, Miyota, Nagano 389-0201, Japan.
authors.forename: Hideharu
authors.initials: H
authors.lastname: Tsukada
authors.affiliation: NARO Institute of Animal Health, Kannondai, Tsukuba, Ibaraki 305-0856, Japan.
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Nakamura
authors.affiliation: Kyushu Research Station, NARO Institute of Animal Health, Chuzan, Kagoshima 891-0105, Japan.
authors.forename: Tsugihiko
authors.initials: T
authors.lastname: Kamio
authors.affiliation: Department of Clinical Veterinary Medicine, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido 080-8555, Japan.
authors.forename: Hisashi
authors.initials: H
authors.lastname: Inokuma
authors.affiliation: NARO Institute of Animal Health, Kannondai, Tsukuba, Ibaraki 305-0856, Japan.
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Hanafusa
authors.affiliation: Tochigi Prefectural Citizen's Park Management Office, Nagai, Yaita, Tochigi 329-2514, Japan.
authors.forename: Naoko
authors.initials: N
authors.lastname: Matsuda
authors.affiliation: Department of Environment and Forestry, Tochigi Prefectural Office, Tochigi 320-8501, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Maruyama
authors.affiliation: Shizuoka Prefecture Forestry and Forest Products Research Institute, Hamamatsu 434-0016, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Ohba
authors.affiliation: Kanagawa Prefecture Natural Environment Conservation Center, Nanasawa, Atsugi-shi, Kanagawa 243-0121, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Nagata
mesh_terms: D000818:Animals; D001179:Arthropod Vectors / Q000254:growth & development*; D002980:Climate; D003670:Deer / Q000469:parasitology* / Q000502:physiology; D005843:Geography; D026863:Ixodidae / Q000254:growth & development*; D007564:Japan; D008018:Life Cycle Stages / Q000502:physiology*; D016014:Linear Models; D011156:Population Density; D011157:Population Dynamics