Tick Abundance Research Articles

Dynamics of Ixodes ricinus and associated bacterial pathogens in the forest and agricultural ecosystems of northeastern France.

Ixodes ricinus ticks evolve mainly in forest ecosystems, which can be affected by human activities in different ways. The present study aimed to analyze the relationship between different landscapes, tick populations, and the circulation of bacterial agents in three French departments, i.e., Ardennes, Marne, and Meuse. A total of eight sites were selected in wetlands, agricultural areas, forest areas, and a hunting park. All these sites host populations of forest rodents, European badger, red fox, and roe deer; some also host wild boar. Ticks were collected during the period of peak activity from March to June over the course of 3 years. Ixodes ricinus nymphs were then analyzed by PCR for the presence of the following bacteria: Borrelia burgdorferi sensu lato, Neoehrlichia mikurensis, Anaplasma phagocytophilum, and Borrelia miyamotoi. The highest tick density, 145.7 nymphs/100 m2 was observed in the hunting park; specifically, in a specific double-fenced enclosure where the vegetation was particularly abundant with large deciduous trees. The presence of various hosts (rodents, badgers, foxes, and roe deer) was recorded. N. mikurensis and B. burgdorferi s.l., with a prevalence of 11.2% and 9.8%, respectively, were the most detected microorganisms in nymphs. Overall, 25.7% of the tested ticks were positive, and 3.3% carried at least two microorganisms. Forested areas surrounded either by agricultural areas or sites characterized by their host diversity and dense herbaceous vegetation appear suitable for the proliferation of ticks and associated pathogens.IMPORTANCEThe distribution and abundance of Ixodes ricinus ticks and associated pathogens vary according to the ecosystem. Forest areas, characterized by dense vegetation, many large trees, abundant leaf litter, and certain vertebrate hosts, have the highest tick densities. The impact of anthropization on these factors has not been sufficiently studied. In this study, we measured tick abundance in relation to the presence of wild animals (ungulates and rodents) and vegetation data, which are important factors influencing tick proliferation. In addition, we interviewed forestry workers, hunters, and farmers in the study area to identify natural and anthropogenic factors likely to affect tick populations. Overall, we conclude that ecosystem changes, in particular afforestation and deer population expansion, need to be thoroughly assessed in order to develop effective control measures while ensuring climate change mitigation.

Prediction of the incidence of lyme disease using mathematical modeling methods (using the example of the Kirov region)

Introduction. The Kirov region is an endemic region for Lyme disease (ixodic tick-borne borreliosis), which is caused by climatic conditions, an abundance of ticks and their feeders. The economic damage caused by Lyme disease includes the cost of treating patients and eliminating natural foci. Morbidity forecasting is necessary for planning preventive measures (acaricide treatments, awareness-raising activities with the population) and entomological monitoring. The effectiveness of such measures exceeds the above costs, which underlines the relevance of the study. The aim of the study is to analyze the influence of various factors on the incidence of Lyme disease using mathematical modeling methods for further epidemiological forecasting using the example of the Kirov region. Materials and methods. The data of the state reports «On the state of sanitary and epidemiological welfare of the population in the Kirov region» for 2006–2023 on the incidence of Lyme disease, the first and last reported cases of tick attachment to humans and the volume of acaricide treatments were studied. Hydrometeorological data: monthly and annual averages of air temperature, humidity, and precipitation. Spearman correlation analysis and multiple regression analysis were performed using the «Excel MS Office-2021» and «Statistica Advanced 12 for Windows RU» software. The level of p 0.05 was chosen as a criterion of statistical significance. Results. The interval forecast of incidence is up to 18.67 by 2024, 16.51 by 2025, and 14.36 per 100,000 population by 2026. Correlations between climatic factors and morbidity have been identified. A negative reliable correlation of moderate density was revealed between the incidence of Lyme disease in the Kirov region and the volume of acaricide treatments. Two forecasting models have been developed: based on the timing of the first and last reported cases of tick bites; based on hydrometeorological factors and the volume of acaricide treatment. Conclusion. The incidence of Lyme disease in the Kirov region is characterized by a downward trend. Mathematical models for predicting morbidity in the Kirov region are proposed.

Spring fever: early spring predicts Ixodes pacificus (Acari: Ixodidae) activity in northwestern California.

In the far western United States, the bacterial agent of Lyme disease, Borrelia burgdorferi sensu lato, is primarily transmitted to humans by the nymphal stage of the western black-legged tick, Ixodes pacificus. Predicting nymphal tick abundance would benefit public health but is complicated by the tick's complex multi-year life cycle and data limitations. To address this, we used readily available climate data, a long-term dataset from northwestern California, and time lags based on the tick's life cycle. Our model showed that warmer early spring temperatures during non-drought conditions the year prior predicted higher nymphal tick densities, while hot, dry springs the year prior were linked to earlier peaks in their abundance. Incorporating human-induced climate change projections, we predicted earlier peaks of nymphal tick activity over the next century, with the potential for an initial doubling in questing nymph numbers. This approach provides a valuable tool for public health and offers insights into the changing dynamics of Lyme disease ecology in the far-western US.

Ecologic Risk Factors for Infestation of Rhipicephalus sanguineus s.l. in a Rocky Mountain Spotted Fever-Endemic Area of Eastern Arizona.

Rocky Mountain spotted fever (RMSF) is a deadly tick-borne disease caused by the bacterium Rickettsia rickettsii. An ongoing epidemic of RMSF is affecting tribal communities in Arizona, with nearly 500 cases and 28 deaths since 2003. The San Carlos Apache Tribe has been consistently working to prevent RMSF using tick collars on dogs, pesticide treatments around homes, and increasing education for nearly a decade. Besides monitoring human disease levels and tick burden on dogs, we have little understanding of the long-term impact of prevention practices on tick abundance and infection rates in the peridomestic environment. We evaluated risk factors associated for tick infestation at home sites across the San Carlos Indian Reservation as well as R. rickettsii and Rickettsia massiliae prevalence in off-host ticks. Although the presence of fencing appears protective, the number of nearby structures is the most important risk factor associated with increased adult and nymphal tick abundance, highlighting the impact of a free-roaming dog population.

Linked empirical studies reveal the cumulative impact of acquired tick resistance across the tick life cycle.

Linked empirical studies reveal the cumulative impact of acquired tick resistance across the tick life cycle.

Micro- and Macroenvironment and Habitat Influences on Tick Abundance in Oklahoma City Urban Parks.

Most studies on tick-borne diseases in the United States have focused on suburban and rural areas, leaving a gap in understanding risks in cities, where environmental conditions and human-tick interactions differ. Recent research has examined microhabitat effects on tick abundance but are limited in spatial and temporal scope. Tick behavior, such as host seeking, is shaped by local environmental factors and remains underexplored in urban landscapes. Integrating Earth observations of macroenvironmental and habitat conditions may improve our understanding of urban tick ecology. We hypothesize that a combination of micro- and macroenvironmental and habitat conditions predicts tick abundance in urban parks. Specifically, we expect microclimate factors (humidity and leaf litter depth) and macroconditions (habitat type and spatial arrangement) to influence questing tick abundance. In summer 2023, we collected ticks from 13 parks in the Oklahoma City metropolitan area using carbon dioxide traps and flagging techniques. Over 97% of ticks were Amblyomma americanum, a species known for aggressive host-seeking behavior. Our analysis of tick abundance in relation to microenvironmental (temperature, humidity, wind, and vegetation) and macroenvironmental (land-cover and landscape metrics) factors showed that solar radiation negatively affected tick abundance, whereas soil pH, woody vegetation, and forest cover were positive predictors. For adults, leaf litter depth and solar radiation were negative predictors, whereas woody vegetation and forest cover had positive impacts. Amblyomma americanum nymph abundance increased with humidity and soil pH. These findings underscore the complex interactions between environmental factors and tick distributions, with implications for urban health and park management.

Functional connectivity for white-tailed deer drives the distribution of tick-borne pathogens in a highly urbanized setting

ContextAs cities seek to provide more habitat for wildlife, there may be unintended consequences of increasing tick-borne disease hazards. In the United States, the Northeast is both highly urban and a hotspot for blacklegged ticks (Ixodes scapularis) and tick-borne disease emergence. Though tick-borne disease was once considered a suburban and rural problem, tick-borne hazards in urban landscapes are increasing.ObjectivesWe hypothesized that multi-scale ecological processes hierarchically contribute to tick-borne hazards across an urbanization gradient. Urban greenspaces with higher functional connectivity to deer movement would have higher deer occupancy at the ‘ecological neighborhood’ scale, resulting in increased blacklegged tick populations and pathogen infection at the scale of within greenspaces.MethodsTo evaluate our hypothesis, we used circuit theory methods to model the impact of functional connectivity on deer occupancy, blacklegged tick abundance, and pathogen infected ticks across an urbanization gradient. We sampled nymphal ticks during their peak activity and deployed wildlife cameras to detect deer at 38 greenspaces across New York City and Long Island, NY from 2022 to 2023.ResultsWe found that functional connectivity significantly predicted deer occupancy with cascading effects on abundance of blacklegged nymphal ticks and Borrelia burgdorferi infection. We novelly identified a threshold of functional connectivity in urban areas necessary for deer occupancy, tick populations, and tick infection with B. burgdorferi, to emerge in urban environments.ConclusionsWe recommend targeted tick-borne hazard mitigation along this functional connectivity threshold as part of urban greenspace management plans. Additionally, we highlight the importance of examining multi-scale landscape drivers of host, tick, and pathogen interactions.

Climate-driven variation in the phenology of juvenile Ixodes pacificus on lizard hosts

BackgroundEctothermic arthropods, like ticks, are sensitive indicators of environmental changes, and their seasonality plays a critical role in the dynamics of tick-borne disease in a warming world. Juvenile tick phenology, which influences pathogen transmission, may vary across climates, with longer tick seasons in cooler climates potentially amplifying transmission. However, assessing juvenile tick phenology is challenging in arid climates because ticks spend less time seeking for blood meals (i.e. questing) due to desiccation pressures. As a result, traditional collection methods like dragging or flagging are less effective. To improve our understanding of juvenile tick seasonality across a latitudinal gradient, we examined Ixodes pacificus phenology on lizards, the primary juvenile tick host in California, and explored how climate factors influence phenological patterns.MethodsBetween 2013 and 2022, ticks were removed from 1527 lizards at 45 locations during peak tick season (March–June). Tick counts were categorized by life stage (larvae and nymphs) and linked with remotely sensed climate data, including monthly maximum temperature, specific humidity and Palmer Drought Severity Index (PDSI). Juvenile phenology metrics, including tick abundances on lizards, Julian date of peak mean abundance and temporal overlap between larval and nymphal populations, were analyzed along a latitudinal gradient. Generalized additive models (GAMs) were applied to assess climate-associated variation in juvenile abundance on lizards.ResultsMean tick abundance per lizard ranged from 0.17 to 47.21 across locations, with the highest abundance in the San Francisco Bay Area and lowest in Los Angeles, where more lizards had zero ticks attached. In the San Francisco Bay Area, peak nymphal abundance occurred 25 days earlier than peak larval abundance. Temporal overlap between larval and nymphal stages at a given location varied regionally, with northern areas showing higher overlap, possibly due to the bimodal seasonality of nymphs. We found that locations with higher temperatures and increased drought stress were linked to lower tick abundances, although the magnitude of these effects depended on regional location.ConclusionsOur study, which compiled 10 years of data, reveals significant regional variation in juvenile I. pacificus phenology across California, including differences in abundance, peak timing, and temporal overlap. These findings highlight the influence of local climate on tick seasonality, with implications for tick-borne disease dynamics in a changing climate.Graphical

Season, Body Condition and Developmental Stage Influence the Gut Microbiota of the Sole Living Rhynchocephalian Reptile (Sphenodon punctatus).

Seasonality plays a crucial role for many species, especially reptiles. In multiple reptile species, seasonality has been linked to shifts in the gut microbiota, influenced by factors, such as ambient temperature, food availability and shifting host function across different seasons. We tested whether the tuatara, an endemic New Zealand reptile and the sole extant member of the order Rhynchocephalia, maintains a stable gut microbiota over 2 years of sampling across three seasons (summer, autumn, spring) or if the dominant bacterial community varies with season. We found that community diversity changed significantly seasonally, with the most diverse gut community found in the spring. We also found that season significantly influenced beta-diversity, as did tuatara developmental stage, tuatara body condition and tick abundance. However, there was little evidence for a recurring seasonal bacterial assemblage in 2024 compared with 2023. For tuatara where the same individual was resampled over multiple seasons, bacterial community composition appeared to be most correlated with the time of sampling, with closer temporal samples more similar to one another than samples taken further apart, which was also seen in the significance of the sampling period as a factor explaining variation across all tuatara. We identified bacterial genera that significantly increased or decreased in each season. Despite notable shifts among seasons, particularly in autumn, the tuatara gut microbiota exhibits remarkable persistence over time, including within individuals.

Spatial and temporal prevalence, abundance and infestation intensity of the ixodid tick population on small domestic ruminants (goat and sheep) in different agro-climatic regions of Tamil Nadu.

Spatial and temporal prevalence, abundance and infestation intensity of the ixodid tick population on small domestic ruminants (goat and sheep) in different agro-climatic regions of Tamil Nadu.

Modelling the small spatial scale questing abundance of Hyalomma lusitanicum Koch, 1844 (Acari: Ixodidae), vector of Crimean-Congo haemorrhagic fever virus.

Modelling the small spatial scale questing abundance of Hyalomma lusitanicum Koch, 1844 (Acari: Ixodidae), vector of Crimean-Congo haemorrhagic fever virus.

Assessing the Influence of Seasonal and Climatic Variations on Livestock Tick Incidence in Tehran Province, Iran: Cross-Sectional Study

Background Ticks are well-known ectoparasites of domestic animals, causing significant economic losses and playing a crucial role in the transmission of pathogens within the livestock industry worldwide, including in Iran. Understanding the distribution and diversity of ticks is essential for effective control strategies, especially in regions like Tehran province, where livestock plays a vital role in the economy. Objective This study aimed to determine the frequency and distribution of livestock ticks across different seasons and climatic zones in Tehran province. Methods In 2019, a total of 1623 domestic animals infested with ticks were examined, including chickens, sheep, camels, cows, pigeons, and dogs. A total of 806 ticks were collected, comprising 121 (15%) soft ticks and 685 (85%) hard ticks. Tick species were identified and categorized based on their occurrence in mountainous and plain climate regions. Results Out of the 806 collected ticks, 44.8% (n=361) were found in the mountainous region and 55.2% (n=445) were found in the plain region. The most abundant species was Rhipicephalus sanguineus (n=307, 38.1%), while Rhipicephalus (Boophilus) annulatus was the least common (n=3, 0.4%). Seasonal variation indicated peak infestation in the spring (n=486, 60.3%) and the lowest infestation in the winter (n=77, 9.6%). Conclusions The study highlights the significant diversity and abundance of both soft and hard ticks in livestock across various regions of Tehran province. These findings emphasize the need for targeted tick control measures, considering the differences in tick distribution between mountainous and plain climate regions.

Influence of elevation on Ixodes pacificus (Acari: Ixodidae) nymph seasonality, abundance, and Borrelia infection prevalence in the Sierra Nevada foothills.

The western blacklegged tick, Ixodes pacificus Cooley and Kohls, is a significant public health concern due to its capacity to vector Borrelia burgdorferi sensu stricto (Spirochaetales: Spirochaetaceae), the causative agent of Lyme disease. To determine the influence of elevation on the seasonality and abundance of Ixodes pacificus nymphs in the Sierra Nevada foothills of California, we used a standardized flagging procedure to sample nymphs from rocks and logs at 16 sites during 2018 to 2020. We sampled a total of 4,720 rocks and logs during 168 surveillance events and collected 1,469 I. pacificus nymphs. Nymphal abundance was similar on rock and log substrates. Tick abundance and seasonality varied by elevation, with lower elevation sites exhibiting higher nymphal abundance and earlier seasonal activity. Nymphal activity started later and persisted longer into the summer months at higher elevation sites. Nymphal abundance on rocks and logs was not predictive of adult abundance the following year, as estimated by drag sampling for adult ticks along hiking trails within the nymph sampling areas. Overall, 4.9% and 1.4% of the tested nymphs were infected with Borrelia burgdorferi s.l. and B. miyamotoi, respectively. We found no relationship between elevation and B. burgdorferi s.l. infection prevalence, although fewer nymphs were tested from higher elevation sites. These findings advanced our understanding of I. pacificus nymphal abundance and distribution and helped improve assessment of public health risks associated with tick exposure in the Sierra Nevada foothills.

Bird–tick and human–tick encounters in the Rio Grande Valley (Texas, USA): ecological associations and pathogen detections

BackgroundThe tropical climate and diverse vector community allows the Rio Grande Valley (RGV) of South Texas to support many vector-borne pathogen transmission cycles. It is a key area for monitoring bird ticks, since most of the migratory birds fly through this corridor to move for south tropical latitudes. Some of the tick species that infest birds in Texas can also transmit tick-borne pathogens that concern public health.MethodsDuring bird banding activities in 2019–2024, ticks were collected opportunistically from local and migrant birds, as well as from outdoor recreationalists, to explore the presence of tick-borne pathogens. Applying a polymerase chain reaction (PCR)-DNA sequencing approach, ticks were tested for Ehrlichia and Rickettsia species.ResultsOf 375 ticks, eight tick species were identified, including species regarded as locally established (Amblyomma inornatum, Amblyomma maculatum, Amblyomma mixtum, Amblyomma tenellum, and Dermacentor variabilis), neotropical species imported by migratory birds (Amblyomma geayi and Amblyomma longirostre), and for the first time in Texas, Ixodes keiransi, formerly the North American lineage of Ixodes affinis. Amblyomma tenellum was the most abundant tick species (89.3%). All ticks were screened for Ehrlichia, resulting in Ehrlichia chaffeensis detection in three A. tenellum ticks (one nymph and two adults) found on humans, and one positive for Ehrlichia ewingii in an A. inornatum nymph collected from a Clay-colored Thrush (Turdus grayi). Both bacteria can cause human ehrlichiosis, which is infrequently reported in Texas. The Rickettsia screening of ticks resulted in detection of Rickettsia amblyommatis, a potentially pathogenic spotted fever group Rickettsia, in nine ticks: eight A. inornatum ticks (one larva, five nymphs and two adults), seven of which were collected from Long-billed Thrashers (Toxostoma longirostre); and an A. longirostre engorged nymph from an Acadian Flycatcher (Empidonax virescens).ConclusionsOur results highlight the importance of occupational exposure to ticks and the potential public health impact of the relatively neglected human-biting vector, A. tenellum.. There is also a critical need to investigate the fate of bird-imported A. inornatum and A. longirostre, and the pathogens they carry.Graphical

Focus on brown dog tick-transmitted Rocky Mountain spotted fever in dogs and people: shared threats and solutions.

Rocky Mountain spotted fever (RMSF) kills people and dogs in rural communities throughout the Americas and in urban epidemics in Brazil and Mexico. The companion Currents in One Health by Foley et al, AJVR , March 2025, addresses the urban ecology of this devastating disease across the Americas. Cases acquired from Dermacentor spp ticks are sylvatic and sporadic, in contrast with peridomestic cases from Rhipicephalus sanguineus sensu lato, which relies on dogs as hosts. Since the early 2000s, RMSF reemerged in northern Mexico with at least 9,152 human cases and case mortality up to 50%. These cases tend to occur where people are impoverished and have marginal access to medical care. Data on RMSF in dogs are sparse, although dogs are sentinels for human risk. The presence of roaming dogs in neighborhoods is associated with human cases, canine seroprevalence, and tick abundance. Dogs and people share hematological and clinical chemical findings and results of targeted diagnostic tests. Diagnosis requires PCR confirmation or rising convalescent titers, although seropositivity can be a cross-reaction with other rickettsial organisms. Suspect cases should be treated with doxycycline immediately. Coinfection with other R sanguineus -transmitted pathogens is common. Veterinarians in clinical practice can help families manage RMSF risk with client education and provide tick preventive medication, although the considerable cost is a barrier. Veterinarians can also advise how to manage tick infestations in a home, recognizing that eradicating R. sanguineus is very difficult. To reduce roaming and canine population sizes, veterinarians should promote canine spay, neuter, and restraint to the home.

Uneven temporal distribution of piroplasms (Piroplasmida: Babesiidae, Theileriidae) in Haemaphysalis concinna in an urban biotope of the Western Palearctic focus region of this tick species.

Haemaphysalis concinna is a Palearctic tick species known as a potential or proven vector of several pathogens, including a broad spectrum of Babesia and Theileria species. The aim of this study was to examine the monthly presence of these piroplasms in H. concinna specimens collected from the vegetation of an urban habitat in Budapest, Hungary, in 2019 and 2020. The questing abundance of H. concinna was highest in June. By contrast, the occurrence of T. capreoli in unfed H. concinna peaked in April, and was significantly more common in the spring, than in the rest of the year. Among the detected eleven Babesia genotypes, two were present only in nymphs and adults of H. concinna. These were identical in the amplified part of their 18S rRNA gene to piroplasms reported from the Far East. Three further Babesia genotypes, however, showed genetic heterogeneity and were also carried by larvae. Babesia-infected nymphs and adults were most common in May and July. In conclusion, the results of this study show that in a questing population of H. concinna the highest monthly prevalence of Babesia and Theileria spp. may be different from each other and from the peak abundance of carrier ticks. Based on previous reports on the effect of tick-borne pathogens on other species of ticks, the factors that may influence this phenomenon in H. concinna may include changes in the metabolism and behavior (host finding and feeding success) as well as survival rate of infected ticks. Further studies will be necessary to clarify this.

Epidemiology of Ticks and Tick-Borne Hemopathogens of Cattle in Two Selected Districts of Northwest Ethiopia.

Ticks and tick-borne haemopathogens are major obstacles to cattle production causing significant economic losses in Ethiopia. The objective of this study was to determine the epidemiology of ticks and tick-borne haemopathogens in cattle in Northwest Ethiopia. Cross-sectional studies were conducted in dry and short rainy seasons. A stratified random sampling technique was employed. Accordingly, a total of 392 cattle were examined. During sampling parameters like; sex, age, breed, body condition score, district and production system were recorded for each animal. Ticks were collected from each animal and examined under stereomicroscope for species identification. The blood sample was taken from the ear vein by pricking with a lancet and then thin smear was made with a frosted microscopic slide and stained with Giemsa for the detection of haemopathogen infections with 100× oil immersion magnification. Of the 392 cattle examined, 87.8% and 17.1% were positive for tick infestation and tick-borne haemopathogens, respectively. The prevalence of tick and tick-borne haemopathogens was 93.9% and 27% in the short rainy season and 81.6% and 7.1% in the dry season, respectively. Amblyomma, Rhipicephalus, Hyalomma and Rhipicephalus (Boophilus) genera, and A. variegatum, A. lepidum, Rh. evertsi, Hy. rufipes and Rh. (B.) decoloratus species were identified. Rhipicephalus (B.) decoloratus was the most prevalent (66.1%) and abundant (38%) tick species. Season, district, age and sex showed significant (p < 0.05) associations with tick infestations. Babesia bigemina (10%), Anaplasma marginale (5.4%), Theileria species (3.1%) and Anaplasma centrale (1.3%) haemopopathogens were detected. Except, for Anaplasma central, they had a significant (p < 0.05) association with season. Ticks and tick-borne haemopathogens were found to be prevalent and had seasonal dynamics. Therefore, strategic and integrated control approaches against the vector and the parasite should be designed.

Environmental ticks in rural and peri urban areas of Ariquemes region, Rondonia, Western Amazon, Brazil

Rondonia state reports more spotted fever (SF) cases than any other state in the Brazilian Amazon. Ariquemes is the only municipality that has reported SF cases in this state, but no information has been obtained about the tick and Rickettsia spp. responsible. This study aimed to describe the free-living tick fauna and search for rickettsial DNA in ticks collected from a region where one specific infection was most likely acquired. Ticks were collected at four sites in Ariquemes municipality, and at one site in both Alto Paraíso and Rio Crespo municipalities. A total of 1082 ticks and eight larvae clusters were collected, comprising 12 species from the genus Amblyomma. The most abundant tick species found in this study were Amblyomma oblongoguttatum, A. scalpturatum and A. naponense. All ticks were tested for the presence of citrate synthase (gltA) and the outer membrane protein A (ompA) gene fragments to detect any Rickettsia. No rickettsiae amplification was observed; however, we did record the presence of A. ovale in the region, including at the probable site infection for a human spotted fever case. This tick is a known vector of Rickettsia parkeri Atlantic rainforest strain in Brazil. These results reinforce the need for further studies of ticks and tick-borne agents in order to improve our knowledge of tick-borne diseases in the Amazon at large.

Multiscale analysis of climate, habitat, and host relationships to predict blacklegged tick presence and abundance in Ohio, USA

ContextIxodes scapularis (the blacklegged tick) is a prominent disease vector that has rapidly expanded across eastern North America in recent decades due to land use and climate change. Predictive modeling is popular for ecological inference and disease management, but few models have considered the multiscale tick and host relationships that drive blacklegged tick expansion.ObjectivesPredict the probability of occurrence and relative abundance of the blacklegged tick in Ohio, USA at an informative resolution for disease surveillance (800-m2) following CDC guidelines. Determine drivers of tick expansion at the tick and host level through a multiscale analysis of climate, habitat, and host density variables.MethodsWe modeled blacklegged tick occurrence and abundance using Integrated Nested Laplace Approximation to analyze the relationships of climate, habitat, and host density with field-collected data from 161 sites. We analyzed habitat variables at several spatial scales (800–5000-m2) expecting they would be most influential at scales relevant to white-tailed deer home range size.ResultsOccurrence and abundance decreased in drier, hotter areas with higher precipitation variability, and increased in heavily forested areas at the spatial scale relevant to deer home range size (1500-m2). Only the abundance model included host density variables, indicating that host densities influence abundance but not occurrence.ConclusionsOur spatial projections show a high probability of occurrence and relative abundance throughout Ohio. Multiscale frameworks are vital for understanding the continuously changing distributions and abundances of arthropod disease vectors that rely on hosts for range expansion.

Ecological overview of hard ticks (Ixodida: Ixodidae) in Nagasaki prefecture of western Japan during winter 2021–2022

In Japan, Japanese spotted fever, Lyme disease and severe fever with thrombocytopenia syndrome caused by Ixodidae species are endemic. To prevent and control the diseases, fundamental understandings in tick ecology are crucial. Hence, this study aimed to analyse tick species richness and abundance across Nagasaki prefecture including its remote islands from a wide range of environments. A total of 74 sampling points screening during winter 2021–2022, using dragging method resulted in 14,883 tick samples (279 adults, 7148 nymphs and 7456 larvae) in 11 species belonging to four genera. Haemaphysalis flava dominated adult populations, while H. formosensis was predominant among nymphs. Both species are possible vectors of Japanese spotted fever and severe fever with thrombocytopenia syndrome. The ecological analysis revealed more complex species distribution in the remote islands compering to the main island in both adults and nymphs. In addition, the ground temperature was a significant regulatory factor for both adults and nymphs. The research provides valuable insights on tick distributions, ecological groupings and environmental preferences in Nagasaki. These findings contribute to the fundamental understanding of tick ecology and could contribute to design strategies for tick population control and tick-borne disease prevention in Nagasaki or possibility to nearby areas.