We conducted a scoping review of the literature following the Arksey and O’Malley methodological framework, which includes 5 stages: (i) identifying a research question, (ii) identifying relevant studies, (iii) performing study selection, (iv) charting and collating, and (v) summarizing and reporting results (Arksey and O’Malley 2005). Our protocol was drafted using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Protocols for Scoping Reviews and is detailed within this manuscript (Tricco et al. 2018). The PRISMA-ScR checklist associated with this review is available in Supplementary File 3.

A comprehensive search of the electronic databases PubMed and Web of Science was conducted for research pertaining to applied tick control. Searches were conducted using terms to identify studies on tick control in the environment, control of ticks on animals, evaluation of both field and laboratory acaricide efficacy, evaluation of acaricide resistance, and evaluation of ITM. The complete search terms and PubMed search strategy are outlined in Supplementary File 1-T1. Reference lists of articles identified through the database searches were reviewed for additional relevant publications. Review articles were not included in the scoping review, but relevant primary sources identified from review articles were included. Articles were not limited by date of publication.

Searches of the databases were conducted on 4 March 2022 and 25 August 2023.

Research articles were included if they met the following criteria: (i) conducted in North America, including Mexico, United States, and Canada; (ii) empirical study; and (iii) explicitly included an assessment of any, or a combination of, the following: control of ticks in the environment, control of ticks on animals (livestock, domestic, wildlife), acaricide efficacy trials, ITM, acaricide resistance assays that report mortality metrics, repellency assays that report mortality metrics, or community-based assessments that directly address willingness to pay for tick control, acceptability of tick control interventions, and/or implementation of tick control services. Studies that did not meet any one of the above criteria were excluded from the scoping review.

The review process was conducted using Covidence systematic review software (Covidence, Veritas Health Information, Melbourne, Australia). After removing duplicates, each article was screened for inclusion by title and abstract by a single reviewing author (JG, EM, KM, or JP). The remaining articles underwent a full-text review and were screened by 2 reviewers independently (EM, JP, AL, or CW). Conflicts regarding article inclusion or exclusion were resolved and finalized by the reviewers.

Authors EM and JP developed a project-specific data extraction template within Covidence (see Supplementary File 2). Characteristics of the included literature were documented within this template (authors EM, JP, AL) and exported as a database. Descriptive statistics of the exported literature characteristics were analyzed using Microsoft Excel and IBM SPSS Statistics (Version 28.0.0.0).

Articles included in this review were summarized based on several categorizations (Table 1). First, we divided articles by those focused on ticks of public health importance, which were defined as medically important tick species associated with the transmission of pathogens affecting human health within the genera Amblyomma, Dermacentor, Ixodes, and Rhipicephalus. The remainder of articles were classified as agricultural/wildlife, which was defined as articles that focused on evaluating tick control in the context of livestock or wildlife health. Second, we summarized the control interventions evaluated within the included articles by the following focus areas: environmental control using acaricides, habitat modification, host-targeted intervention, acaricide susceptibility trial, and community-based assessments. Definitions of these focus areas are further delineated in Table 1. Lastly, articles were grouped into climate regions according to the National Oceanic and Atmospheric Administration (NOAA) regional climate classification system. This system divides states in the contiguous United States into 9 climatically consistent regions based on current and historical conditions; these regions roughly align with the distributions of medically important tick species (Karl and Koss 1984, Eisen et al. 2017).

The earliest applied tick control study with a public health focus identified in this scoping review was published in 1944 and funded by the United States Department of Agriculture (USDA) (Smith and Gouck 1944) (Fig. 2A). Few applied tick control studies (n = 11) were published between 1940 and 1979. These studies focused largely on control of Amblyomma (n = 7, 64%), followed by Dermacentor (n = 2, 18%), and Rhipicephalus (n = 1, 9%); one study focused on Amblyomma, Dermacentor, and Ixodes concurrently (Smith and Gouck 1944). The 3 studies published prior to 1959 were supported exclusively through US federal funding (Smith and Gouck 1944, Smith et al. 1946, McDuffie et al. 1950) (Fig. 2B). Additional funding sources began to appear in published articles in the 1960s and 1970s and included nonprofit organizations (Nelson 1969) and state sources (Hoch et al. 1971). Thirty-six percent (n = 4) of the studies published between 1940 and 1979 did not report a funding source (Mount et al. 1968, 1976, Clymer et al. 1970, Wilkinson 1977).

Applied tick control research began to increase in the 1980s, with 172 articles published between January 1980 and August 2023. This period saw an increasing shift in focus to control of Ixodes ticks (n = 128, 60%) as compared to other tick species (see Fig. 2A). Additionally, funding from US Department of Health and Human Services (DHHS) agencies became more common beginning in the 1980s (Fig. 2C). However, it was not until the 1990s that a large increase in applied tick control research occurred due to increased funding from the US Centers for Disease Control and Prevention (CDC) (Fig. 2C). The increase in applied tick control was driven by a focus on Ixodes ticks, which remained the primary focus of applied tick control research until the late 2000s.

Overall, the majority of the applied tick control research conducted in North America received funding from US federal agencies (n = 110, 60%). US federal funding was provided by 16 different agencies, with the largest proportion of publications supported by the CDC (n = 56), USDA (n = 24), and the US Department of Defense (DOD; n = 11) (Table 4). Figure 2A–C provides a summary of applied tick control publications across time by (a) tick genera, (b) primary funding organizations, and (c) different US federal funding organizations. Figure 2A–C reports the number of publications assessing control of each listed tick genus and receiving funding from each listed entity. Some publications reported on more than one tick genus concurrently or received funding from more than one entity, which is not reflected in this figure.

Most articles included in this review were authored by researchers affiliated with only a public agency (n = 72, 39.3%) or affiliated only with an academic institution (n = 51, 27.9%). Of the articles conducted by researchers affiliated with only a public agency, the most common affiliations for studies focused on Ixodes ticks were the Connecticut Agricultural Experiment Station (n = 18), USDA (n = 15), Freehold Area Health Department (New Jersey, n = 11), CDC (n = 8), Monmouth County Mosquito Control Commission (New Jersey, n = 8), and the New Jersey Department of Health (n = 7); the most common affiliations for studies focused on metastriate ticks were the USDA (n = 15) and CDC (n = 6) (studies listed in Table 5). Public-only research affiliates received funding from the CDC, USDA, or did not report their funding source (Supplementary File 1-T3).

Academically affiliated researchers were associated with one of 24 separate academic institutions. Articles conducted by researchers affiliated with only an academic institution were most commonly located in New York State (n = 13), Rhode Island (n = 5), and Massachusetts (n = 5) for studies focused on Ixodes ticks and were most commonly located in Florida (n = 5) and Oklahoma (n = 4) for studies focused on metastriate ticks (Table 5). Academic-only research affiliates had the most diversity in funding sources, source but predominantly received funding from the CDC, academic institutions, nonprofit associations, or did not report their funding (Supplementary File 1-T3).

Twenty-eight studies (15.3%) were authored by a partnership of authors affiliated with public agencies and academic institutions. The most commonly observed partnerships included those between (i) universities and federal agencies (n = 14), and (ii) universities and state agencies (n = 5). Funding for these academic-public partnership studies most commonly came through federal agencies (excluding CDC or USDA), from the CDC, from academic institutions, or were not reported. Only 10 studies (5.5%) were authored by researchers affiliated solely with private institutions, which included veterinary health and pharmaceutical companies (n = 6), independent contract research firms (n = 6), and agronomic service corporations (n = 3). The remaining 22 (12.0%) studies included a mixture of public agency, private agency, and academic author affiliations.

The majority of articles included in this review conducted research at sites within the United States (n = 174, 95.1%), followed by sites in Canada (n = 5, 2.7%) and Mexico (n = 1, 0.55%); 3 (1.6%) studies were conducted in both the United States and another country (Table 4).

Of the studies conducted in the United States, the majority (n = 98, 53.6%) were conducted within NOAA Region I (Northeast). The states with the highest volume of studies conducted within them include New Jersey (n = 29), Connecticut (n = 28), and New York (n = 25), followed distantly by Texas (n = 10) and Oklahoma (n = 9). Tick control evaluations targeting Ixodes ticks predominated in NOAA Region I (Northeast), while Regions II (Southeast), IV (Ohio Valley), and V (South) had a higher proportion of studies targeting Amblyomma ticks. No applied tick control studies were identified with study sites located in NOAA Regions VI (Northern Rockies & Plains) or VIII (Northwest). Figure 3 portrays the distribution of applied tick control studies evaluating ticks of public health importance across the contiguous U.S. by NOAA region.

The length of time these studies were conducted was largely 1 year or less (n = 52, 28.4%), followed by 2 years (n = 30, 16.4%), 3 years (n = 26, 14.2%), and 4 years (n = 16, 8.7%) (Table 4). Twenty-six (14.2%) studies were conducted over 5 years or more. Thirty-three (18.0%) articles did not report the length of study. After the 1990s, when funding for tick control work increased, length of study did not increase.

A total of 131 studies included in this review evaluated applied tick control interventions for Ixodes ticks. The most common vector targeted in the studies we identified was I. scapularis, which was assessed in 68.5% (n = 126) of the public health studies identified in this review; studies reporting control results for I. dammini were grouped with I. scapularis (Sanders 1998). Five studies focused on the western blacklegged tick, Ixodes pacificus Cooley & Kohls (Table 4).

Tick control interventions for Ixodes ticks predominantly focused on host-targeted approaches (n = 56, 42.7%) and environmental acaricide control approaches (n = 37, 28.2%), followed by acaricide susceptibility assessments (n = 23, 17.6%), habitat modification (n = 20, 15.3%), and community-based assessments (n = 7, 5.3%) (Table 4). Twelve studies (9.3%) incorporated multiple interventions, though only 5 of these were designed as ITM interventions (Stafford et al. 2003, Schulze et al. 2007, Williams et al. 2018, Mandli et al. 2021, Keesing et al. 2022). The most common length over which Ixodes-focused studies collected data was 1 year (n = 36, 27.5%), followed by 2 years (n = 22, 16.8%) and 3 years (n = 18, 13.7%); a large proportion of these studies (n = 26, 19.8%) did not report the period of data collection (Table 4).

Of the 57 studies evaluating host-targeted control interventions, the majority focused on white-tailed deer (n = 25, 43.9%) and/or rodents (n = 24, 42.1%); 7 (12.3%) studies focused on domestic pets, 2 (3.5%) on humans, and 1 (1.8%) on livestock. Deer-targeted interventions predominantly evaluated the 4-poster system (n = 15), while others evaluated deer exclusion (n = 3), deer removal (n = 6), and systemic treatments (n = 1). Rodent-targeted interventions predominantly evaluated acaricides delivered topically via nesting material (n = 12) and/or bait boxes (n = 12) and rodent removal (n = 1), while one study evaluated systemic treatments. Interventions targeting domestic pets exclusively evaluated tick control products delivered systemically or with spot treatments. Human-focused studies evaluated the impact of permethrin-treated clothing used during walking surveys (Table 5).

Of the 38 studies evaluating environmental acaricide control approaches, the majority focused on chemical acaricides (n = 24, 63.2%), followed by entomopathogenic fungi (n = 10, 25.6%) and naturally derived acaricides (n = 9, 23.7%); 2 (5.3%) studies evaluated control with parasitoids and 1 (2.6%) evaluated control with desiccant and insecticidal soap. The most commonly evaluated chemical acaricide classes were pyrethroids (n = 13) and carbamates (n = 9). The naturally derived acaricides consisted of botanically derived products (n = 7), nootkatone (n = 6), and 25(b) minimum risk products (n = 5). The US Environmental Protection Agency defines 25(b) minimum risk pesticides products as those containing active ingredients that are exempt from the Federal Insecticide, Fungicide, and Rodenticide Act; the 25(b) products evaluated in these studies included active ingredients such as rosemary oil, peppermint oil, and geraniol (U.S. Environmental Protection Agency 2024).

Most of the 20 studies evaluating habitat modifications focused on landscape management approaches (n = 10, 50.0%), while others evaluated controlled burns (n = 6, 30.0%) and invasive plant removal (n = 4, 20.0%). The focus of the 23 acaricide susceptibility studies was evenly distributed across chemical and naturally derived acaricides and entomopathogenic fungi. Of the 7 studies that included a community-based assessment component, 4 included assessments of acceptability regarding tick control interventions, 3 measured implementation of tick control through Knowledge, Attitudes, and Practices (KAP) surveys, and 1 measured use of private pest control services, prioritization of public tick control interventions, and willingness to pay for tick control, respectively (Table 5).

The majority of Ixodes research occurred in New Jersey (n = 27, 20.6%), Connecticut (n = 26, 19.9%), and New York (n = 22, 16.8%) (Table 4; Fig. 3). The counties in these states with the most Ixodes research included Monmouth County, NJ (n = 23), Westchester County, NY (n = 11), and Fairfield County, CT (n = 10). Most Ixodes-focused control interventions were conducted in residential settings (n = 73, 55.7%); of these, 63% (n = 46) were conducted in suburban settings, 35.6% (n = 26) in rural settings, and 1.4% (n = 1) in urban settings. Of the studies conducted in residential settings, most focused on host-targeted (n = 45) and environmental acaricide control (n = 24) interventions. Host-targeted interventions in rural residential areas focused almost exclusively on deer, while host-targeted interventions conducted in suburban residential areas were more equally dedicated to deer and rodent-targeted interventions.

Other common study settings included parks (n = 19, 14.5%), wilderness areas (n = 19, 14.5%), and military bases (n = 14, 10.7%). Studies conducted in parks focused mostly on host-targeted interventions, and studies conducted in military bases focused mostly on environmental acaricide control interventions. Studies conducted in wilderness areas had an even distribution of environmental acaricide, host-targeted, and habitat modification interventions. The 23 studies evaluating acaricide susceptibility were conducted in laboratory settings (Table 4).

Funding for Ixodes-focused control studies was predominantly provided through CDC (n = 51, 38.9%), followed by non-profit funders (n = 23, 17.6%); 20.6% of Ixodes-focused control studies (n = 27) did not report a funding source. Most studies were supported exclusively by one funding source (n = 69, 52.7%), the majority of which were funded by a US federal agency (n = 49, 72.1%). Of these studies, exclusively CDC-supported work (n = 35) most often focused on environmental acaricide control (n = 14, 40.0%) followed by host-targeted interventions (n = 8, 22.9%), while most exclusively USDA-supported work (n = 7) focused on host-targeted interventions (n = 5, 71.4%) (Table 4).

Articles on control of Ixodes ticks were most frequently authored by researchers only affiliated with public agencies (n = 50, 38.2%), followed by authors only affiliated with academic institutions (n = 34, 26.0%), and partner authorships between public and academic institutions (n = 20, 15.3%). Authors affiliated with only public agencies most often researched environmental acaricide control approaches (n = 14, 28.0%) and host-targeted approaches (n = 14, 28.0%). Authors affiliated with only academic institutions largely researched host-targeted tick control interventions (n = 14, 41.2%), followed by environmental acaricide control (n = 6, 17.6%) and acaricide susceptibility assessments (n = 6, 17.6%). Research conducted in partnership with authors from public agencies and academic institutions most often researched host-targeted control (n = 6, 30.0%) and acaricide susceptibility assessments (n = 5, 25.0%) (Table 4).

Fifty-nine studies investigated tick control interventions for Amblyomma ticks; 53 (89.8%) of these studies investigated control of Amblyomma americanum (Linnaeus); 6 (10.2%) studies included both A. americanum and A. maculatum Koch; and one study (1.7%) included A. americanum, A. maculatum, and A. cajennense (Fabricius) (Table 4).

The majority of Amblyomma-focused control studies evaluated environmental acaricide interventions (n = 24, 40.7%), followed by host-targeted interventions (n = 21, 35.6%), habitat modifications (n = 16, 27.1%), acaricide susceptibility assessments (n = 8, 13.6%), with one community-based assessment (1.7%). The most common length over which Amblyomma-focused studies collected data was 1 year (n = 14, 23.7%), followed by 3 years (n = 10, 16.9%) and 2 years (n = 9, 15.3%); 18.6% of these studies (n = 11) did not report the period of data collection (Table 4).

Of the 24 studies focused on environmental acaricide interventions, most applied chemical acaricides to reduce tick populations in the environment (n = 21, 87.5%), followed by 4 (16.7%) studies evaluating naturally derived acaricides and 2 (8.3%) studies evaluating entomopathogenic fungi; 2 studies evaluated more than one acaricide type. The most commonly evaluated chemical acaricide classes were organophosphates (n = 12), followed by pyrethroids (n = 6) and carbamates (n = 4), while the most commonly evaluated natural acaricides were 25(b) minimum risk and other botanically derived products (Table 5).

Of the 21 studies focused on host-targeted evaluations, the majority (n = 16, 76.2%) focused on deer, followed by 4 (19.0%) studies that evaluated flea and tick control products for domestic pets delivered systemically or with spot treatments. The deer-targeted studies evaluated 4-poster systems (n = 9), with others focused on deer exclusion (n = 4) and topical and systemic acaricide treatment (n = 3, respectively). Of the 16 studies on habitat modifications, most conducted controlled burns (n = 7), followed by vegetation removal or thinning (n = 5). Two studies focused on the removal of invasive plant species, and 2 studies conducted landscape management to reduce tick populations. The community-based assessment measured willingness to pay for tick control services (Table 5).

Amblyomma-focused studies largely occurred in New Jersey (n = 10, 16.9%), Oklahoma (n = 9, 15.3%), and Texas (n = 9, 15.3%). The largest proportion of Amblyomma-focused studies was conducted in the wilderness setting (n = 17, 28.8%), followed by military bases (n = 14, 23.7%), and residential settings (n = 13, 22.0%). The wilderness-based studies were largely habitat modification trials, while studies conducted on military bases were mostly environmental acaricide interventions. Studies conducted in residential settings were predominantly focused on host-targeted interventions (Table 4).

Most research on the control of Amblyomma ticks was published from 1980–present (n = 51, 86.4%), with only 8 studies published prior to 1980. Funding for Amblyomma-focused control studies was provided by the USDA (n = 15, 25.4%), followed by the CDC (n = 10, 16.9%), and academic institutions (n = 9, 15.3%); 28.8% (n = 17) of Amblyomma-focused control studies did not report a funding source (Table 4).

Articles on control of Amblyomma ticks were most frequently authored by researchers only affiliated with public agencies (n = 30, 50.8%), followed by only academic institutions (n = 15, 25.4%), and public and academic partnerships (n = 5, 8.5%). Authors affiliated with only public agencies most often researched environmental acaricide control approaches (n = 12, 40.0%) and host-targeted approaches (n = 8, 26.7%). Authors affiliated with only academic institutions largely researched habitat interventions (n = 6, 40.0%), followed by acaricide susceptibility assessments (n = 3, 20.0%). Research conducted in partnership with authors from public agencies and academic institutions most often researched host-targeted control (n = 2, 40.0%) (Table 5).

Twenty-nine studies evaluated applied tick control interventions for Dermacentor ticks. Of these, 79.3% (n = 23) assessed Dermacentor variabilis (Say). Five studies included D. occidentalis Marx, and one study included D. andersoni Stiles (Table 4).

Most tick control interventions for Dermacentor ticks assessed host-targeted (n = 15, 51.7%) and habitat modification (n = 9, 31.0%) approaches, followed by acaricide susceptibility assessments (n = 6, 20.7%) and environmental acaricide control (n = 5, 17.2%); no studies for this genus incorporated community-based assessments (Table 5). Four studies (13.8%) incorporated multiple interventions, though only 2 of these were designed as ITM interventions (Bloemer et al. 1986, Zimmerman et al. 1988). The most common length over which Dermacentor-focused studies collected data was 1 year (n = 7, 25.0%), followed by 2 years (n = 4, 14.3%); 32.1% of these studies (n = 9) did not report the period of data collection (Table 4).

Of the 15 studies evaluating host-targeted control interventions, 40.0% (n = 6) evaluated tick control products for domestic pets delivered systemically or with spot treatments. Other host-targeted studies focused on deer (n = 5, 33.3%) or rodents (n = 4, 26.7%), with one (6.7%) study assessing permethrin-treated clothing used during walking surveys. Deer-focused studies evaluated 4-poster systems (n = 3) or deer exclusion (n = 2); the deer 4-poster studies were primarily designed as interventions for populations of A. americanum and/or I. scapularis, with Dermacentor ticks evaluated as a secondary target. Rodent-focused studies evaluated the use of acaricides delivered via nesting (n = 2), bait boxes (n = 1), bait cubes (n = 1), or rodent removal (n = 1) (Table 5).

Of the 9 studies evaluating habitat modification interventions, half (n = 5, 55.6%) evaluated the impact of controlled burns or natural fires. Other habitat modification interventions included landscape management approaches (n = 2, 22.2%), invasive plant removal (n = 1, 11.1%), and vegetation thinning/removal (n = 1, 11.1%). The 6 acaricide susceptibility trials evaluated active ingredients of pyrethroids, nootkatone, botanically derived pesticides, entomopathogenic fungi, and DEET. The 5 studies evaluating environmental acaricide control approaches evaluated active ingredients of organophosphates, pyrethrin, herbicides, and a variety of insecticides no longer available for use (Table 5).

Most research on the control of Dermacentor ticks was published from 1980 to present (n = 26, 89.7%), with only 3 studies published prior to 1980. Funding for Dermacentor-focused control studies was provided through CDC (n = 6, 20.7%), followed by academic institutions (n = 5, 17.2%), USDA (n = 4, 13.8%), private industry funders (n = 4, 13.8%), and other U.S. federal agencies (n = 2, 6.9%); 31.0% (n = 9) of Dermacentor-focused control studies did not report a funding source. CDC-funded studies focused primarily on habitat modification approaches (n = 4, 66.7%). USDA-supported work focused on environmental acaricide control approaches (n = 2 50.0%), habitat modification (n = 3, 75.0%), and host-targeted approaches (n = 2, 50.0%). The majority of studies funded through private industry investigated host-targeted control methods for domestic pets (n = 3, 75.0%).

Articles on control of Dermacentor ticks were most frequently authored by researchers affiliated with only academic institutions (n = 9, 31.0%) and only public agencies (n = 9, 31.0%). Most authors at public agencies were affiliated with federal programs including USDA (n = 4) and CDC (n = 2). Authors affiliated with only academic institutions studied habitat interventions, host-targeted control, and acaricide susceptibility assessments (n = 3, 33.3%, respectively). Authors affiliated with only public agencies studied environmental acaricide control approaches, host-targeted control, and use of multiple control approaches (n = 2, 22.2%, respectively). Research conducted in partnership with authors from public agencies and academic institutions (n = 4) focused on host-targeted control (n = 2), environmental acaricide control (n = 1), and habitat management (n = 1) (Table 5).

Most Dermacentor-focused studies were conducted in the United States (n = 27, 93.1%) followed by Canada (n = 2, 6.9%). The largest proportion of Dermacentor-focused studies were conducted in laboratory settings (n = 11, 37.9%). These lab-based studies were evenly distributed across host-targeted evaluations and acaricide susceptibility trials. Field-based studies were mostly conducted in wilderness settings (n = 5, 17.2%), parks (n = 5, 17.2%), residential areas (n = 4, 13.8%), or university experiment stations (n = 5, 17.2%). Studies conducted in wilderness settings were focused primarily on habitat modification, while studies conducted in other areas incorporated environmental acaricide and host-targeted control interventions. The states where Dermacentor was most frequently studied included California (n = 6, 20.7%), Texas (n = 4, 14.3%), and Virginia (n = 4, 14.3%).

Twelve studies evaluated applied tick control interventions for Rhipicephalus ticks, exclusively evaluating control of Rhipicephalus sanguineus (Latreille). Tick control interventions for R. sanguineus were mostly focused on host-targeted approaches (n = 7, 58.3%) and acaricide susceptibility trials (n = 5, 41.7%); no studies for this genus focused on habitat modification. Most Rhipicephalus-focused studies (n = 8, 66.7%) did not report the period of data collection (Table 4).

The largest proportion of R. sanguineus studies was conducted in laboratory settings (n = 9, 75.0%). These lab-based studies were evenly distributed across host-targeted evaluations and acaricide susceptibility trials (Table 4). Five susceptibility trials evaluated chemical acaricides (pyrethroids, organophosphates, and carbamates), naturally derived acaricides (nootkatone, pyrethrin), and entomopathogenic fungi. Four lab-based host-targeted studies evaluated tick control products for domestic pets delivered systemically or with spot treatments (Table 5).

Three studies incorporated multiple interventions and were designed as ITM studies to address RMSF outbreaks along the US-Mexico border (Drexler et al. 2014, Straily et al. 2016, Alvarez-Hernandez et al. 2020). These studies evaluated environmental acaricide control using pyrethroids, host-targeted treatment (domestic and free-roaming dogs) using Seresto collars (active ingredients include imidacloprid and flumethrin), and community education and outreach on bite prevention and control approaches for R. sanguineus. These studies were conducted in residential settings, including rural, urban, and suburban areas in Sonora, Mexico, and indigenous nation territory in the United States, and gathered data across the entire calendar year.

Funding for Rhipicephalus-focused control studies was provided through private industry (n = 4, 33.3%), CDC (n = 2, 16.7%), USDA (n = 1, 8.3%), and nonprofit funders (n = 1, 8.3%), or was not reported (n = 5, 41.7%). Of the studies supported by industry, most (n = 3, 75.0%) focused on host-targeted approaches. CDC supported 2 studies, one of which focused on acaricide susceptibility and the other investigated multiple control methods for RMSF. USDA funded one study that investigated acaricide susceptibility (Table 4).

Most of the authors researching control of Rhipicephalus ticks were affiliated with academic institutions (n = 4, 33.3%) or private agencies (n = 4, 33.3%). Authors affiliated with only academic institutions exclusively studied acaricide susceptibility, while authors affiliated with only private organizations exclusively studied host-targeted approaches (n = 4, 100.0%, respectively). Research conducted in partnership with authors from public agencies and academic institutions (n = 2) focused on evaluating approaches that included multiple control methods (n = 2, 100.0%) (Table 5). The majority of Rhipicephalus-targeted studies occurred in the United States in Texas, Arizona, and Florida (n = 8, 66.7%). The remaining studies were conducted in both the United States and Mexico (n = 3, 25.0%) and Mexico only (n = 1, 8.3%).

Fifteen studies (8.2%) conducted ITM evaluations (Table 4). Only 2 ITM studies evaluated more than one tick species concurrently (Bloemer et al. 1986, Zimmerman et al. 1988). These 2 studies evaluated D. variabilis and A. americanum using a combination of environmental acaricide control and deer-targeted interventions. One of these studies was funded by the USDA, and the other did not report a funding source. The remainder of the ITM studies evaluated Amblyomma ticks (n = 5), Ixodes ticks (n = 5), and Rhipicephalus ticks (n = 3). Amblyomma-focused ITM studies evaluated a combination of environmental acaricide control and habitat modification interventions, with 2 studies also including host-targeted approaches. These studies were funded by the USDA, Department of Commerce, state funders, or otherwise not reported. Ixodes-focused ITM studies evaluated a combination of environmental acaricide control and host-targeted interventions (n = 4) and habitat modification and host-targeted interventions (n = 1); the host-targeted interventions targeted deer and/or rodent hosts. These studies were funded by the CDC, USDA, academic institutions, nonprofit and private donors, and state funders. The 3 Rhipicephalus-targeted ITM studies addressed RMSF outbreaks along the US-Mexico border using environmental acaricide, host-targeted, and community-based assessments and were CDC-funded.

Thirty-nine (21.3%) studies evaluated control for more than one tick species concurrently (Table 4). Of these, 22 assessed 2-tick species, 60% of which paired Ixodes and Amblyomma ticks (n = 14), followed by Amblyomma-Dermacentor (n = 4) and Ixodes-Dermacentor (n = 2). Most of the 2-tick studies evaluated environmental acaricide control and host-targeted control interventions (n = 9, respectively), followed by habitat modification (n = 5). Eight of these 9 host-targeted interventions focused on deer. Six studies evaluated 3-tick species concurrently, 5 of which evaluated Ixodes, Amblyomma, and Dermacentor ticks; the remainder evaluated a mixture of Dermacentor, Ixodes, and Rhipicephalus ticks. Most of these 3-tick studies evaluated host-targeted interventions and acaracide susceptibility (n = 3, respectively); host-targeted interventions included deer, rodent, and human hosts. Seven (18.0%) studies evaluated 4 tick species concurrently, and 4 studies (10.3%) evaluated 5 tick species concurrently. These studies were dominated by host-targeted and acaricide susceptibility assessments; host-targeted assessments were predominantly focused on flea and tick treatment for domestic pets. Multi-tick studies were predominantly CDC-funded (n = 14, 35.9%), followed by funder not reported (n = 9, 23.1%) and USDA-funded (n = 5, 12.8%).

There are limitations to this scoping review. First, while we did exclude duplicate articles in the review process, we did not track whether multiple articles reported segmented results from the same individual research study. Given this limitation, we may have included multiple publications reporting results from one research study. This effect was not accounted for in the summary statistics, and thus, our results reflect the number of publications on applied tick control research rather than the discrete number of studies conducted. Second, while we did include a small number of articles that incorporated community-based assessments (i.e., KAP surveys), tick bite prevention surveys and community assessments did not generally fall within the primary focus of this review, and we expect that relevant articles were not captured in our search strategy. Thus, the results reported are not a comprehensive reflection of the broad KAP literature related to TBD knowledge or use of tick bite prevention and control strategies by the public. Third, assessment of the rigor of study design and relevance of measured outcomes to public and veterinary health were beyond the scope of this review. As such, we did not review the outcomes measured in tick control studies—such as density of infected ticks or human-tick encounters—nor the effect of tick control interventions on these outcomes. Additionally, we categorized each article’s primary focus area as either public health or agriculture/wildlife; however, TBDs present a One Health issue. While a small number of studies fell within the One Health Framework, it was not a study characteristic targeted in our data extraction process. Lastly, while we made every effort to identify relevant applied tick control studies meeting our inclusion criteria, we may have overlooked relevant research that is not incorporated into the summary provided here.