# Quantitative models of Rhipicephalus (Boophilus) ticks: historical review and synthesis

Hsiao-Hsuan Wang, Michael S. Corson, William E. Grant, Pete D. Teel

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Hsiao-Hsuan Wang, Michael S. Corson, William E. Grant, Pete D. Teel. Quantitative models of Rhipicephalus (Boophilus) ticks: historical review and synthesis. Ecosphere, 2017, 8 (9), pp.1-27. 10.1002/ecs2.1942. hal-02628456

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# Quantitative models of *Rhipicephalus* (*Boophilus*) ticks: historical review and synthesis

HSIAO-HSUAN WANG,<fnref n="1" />,† MICHAEL S. CORSON,<fnref n="2" /> WILLIAM E. GRANT,<fnref n="1" /> AND PETE D. TEEL<fnref n="3" />

**Citation:** Wang, H.-H., M. S. Corson, W. E. Grant, and P. D. Teel. 2017. Quantitative models of *Rhipicephalus* (*Boophilus*) ticks: historical review and synthesis. Ecosphere 8(9):e01942. 10.1002/ecs2.1942

**Abstract.** Several tick species, in what is now known as the subgenus *Boophilus* in the genus *Rhipicephalus*, are economically important ectoparasites of livestock and other ungulates; as vectors of pathogens that kill cattle, they remain among the most studied ticks in the world. Researchers have developed quantitative computer models of *Rhipicephalus* ticks since the early 1970s to study complex biological and ecological relationships that influence management or eradication of ticks and tick-borne diseases. We review the 45-yr history of *Rhipicephalus* (*Boophilus*) models, which were developed and applied first in Australia, 10 yr later in North and South America, then soon after in Africa. Models progressed from analytical models of a portion of tick life cycles, to simulation models of complete life cycles or ecoclimatic indices, to the current emphasis on GIS-based bioclimatic envelope models estimated from remotely sensed data and tick presence records. Earlier models were used primarily to predict effects of management techniques, such as use of sterile hybrid ticks, pasture rotation, acaricides, vaccines, and resistant cattle, while more recent models have been used to predict the potential for range expansion, especially due to global climate change and wildlife hosts, as well as in the face of competition with other tick species. We summarize characteristics of these models and compare those of population dynamics and bioclimatic envelope models. We discuss the past and present utility of these models and provide a perspective on future *Rhipicephalus* (*Boophilus*) modeling efforts.

**Key words:** analytical model; cattle tick; *Rhipicephalus* (*Boophilus*) annulatus; *Rhipicephalus* (*Boophilus*) australis; *Rhipicephalus* (*Boophilus*) decoloratus; *Rhipicephalus* (*Boophilus*) microplus; simulation model.

**Received** 1 March 2017; revised 19 May 2017; accepted 21 June 2017. Corresponding Editor: Andrew W. Park.

**Copyright:** © 2017 Wang et al. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. Hsiao-Hsuan Wang and Michael S. Corson contributed equally to this work.

† E-mail: hsuan006@tamu.edu

## INTRODUCTION

The subgenus *Boophilus*, genus *Rhipicephalus* (Acari: Ixodidae), contains six currently recognized species of ticks that primarily parasitize ungulates (Guglielmone et al. 2014): *Rhipicephalus annulatus*, *R. australis*, *R. decoloratus*, *R. geigyi*, *R. kohlsi*, and *R. microplus*. All six species are multivoltine (more than one generation per year) and exhibit a

one-host life history (larvae, nymphs, and adults feed and develop on a single host) that is followed by oviposition, incubation, and larval life in off-host habitats (Murrell and Barker 2003, Nicholson et al. 2009). *Rhipicephalus decoloratus* (Koch) is distributed in sub-Saharan Africa (Estrada-Peña et al. 2006a), while *R. geigyi* (Aeschlimann and Morel) has a narrow but wide east-west sub-Saharan distribution from Senegal to Uganda, and *R. kohlsi*

<footnote n="1">¹Department of Wildlife and Fisheries Sciences, Texas A&M University, College Station, Texas 77843 USA</footnote>

<footnote n="2">²SAS, INRA, Agrocampus Ouest, 35000 Rennes, France</footnote>

<footnote n="3">³Department of Entomology, Texas A&M AgriLife Research, College Station, Texas 77843 USA</footnote>
(Hoogstraal and Kaiser) has a north-south distribution from Syria to Yemen (Kolonin 2009). *Rhipicephalus decoloratus* and *R. geigyi* tend to infest cattle, while *R. kohlsi* tends to infest sheep and goats. These three tick species have not appreciably expanded beyond their original distributions. In contrast, *R. annulatus* (Say) inhabits arid and temperate climates of the Mediterranean region to southern Russia, central Africa, parts of the Middle East, India, and Mexico (Estrada-Peña et al. 2006a, Kolonin 2009), and prior to 1943, it inhabited most of the southern United States (USA; Graham and Hourrigan 1977). *Rhipicephalus microplus* (Canestrini) originated in tropical climates of the Indian subcontinent and is now considered pan-tropical (George 1990, Estrada-Peña et al. 2006a). *Rhipicephalus australis* (Fuller), formerly considered a subspecies of *R. microplus* (Roberts 1970) but recently reinstated as a sibling species (Estrada-Peña et al. 2012), has Australasian, Southeast Asian, and Pacific Island distribution (Guglielmone et al. 2014). Mitochondrial genome sequences support the elevation of *R. australis* to species (McCooke et al. 2015) and indicate that *Rhipicephalus* (*Boophilus*) populations from southern China and northern India likely represent a cryptic species (Burger et al. 2014). Explorers, settlers, and soldiers of the 16th-20th centuries expanded the distributions of *R. microplus*, *R. australis*, and *R. annulatus* by moving infested cattle (Estrada-Peña and Salman 2013). It is estimated that 80% of the world's cattle population is exposed to parasitism by *R. microplus* or *R. australis* (de Castro et al. 1997).

Blood loss and irritation due to tick feeding cause direct losses of livestock reproduction, growth, and production of meat, milk, and draft services (Graf et al. 2004, de la Fuente et al. 2007). Additional indirect losses are caused by tick-transmitted pathogens, resulting in substantial morbidity and mortality (Graf et al. 2004, de la Fuente et al. 2007). For cattle within the range of *R. annulatus*, *R. microplus*, or *R. australis* populations, the main tick-borne pathogens are *Babesia bigemina* (Smith and Kilborne) and *Babesia bovis* (Babes), causal agents of bovine babesiosis, and *Anaplasma marginale* (Theiler), causal agent of anaplasmosis, each with significant economic impacts on cattle production (Estrada-Peña et al. 2006a). Consequently, these species have received much research attention in regions where they

coincide with high cattle production, primarily Australia and the Americas.

The discovery that *R. annulatus* was responsible for transmitting *B. bigemina* from infected to noninfected cattle (Smith and Kilborne 1893) was followed by research and development of methods to control babesiosis by suppressing or eliminating tick populations (Graham and Hourrigan 1977). Control methods initially focused on farming/ranching practices of the period, but the discovery of acaricides and the plunge dip vat permitted large numbers of animals to be effectively treated if properly regulated (Graham and Hourrigan 1977). In the United States, systematic dipping of cattle in acaricides was found to effectively eradicate both *R. annulatus* and *R. microplus* from large regions. A national eradication program began in 1907 officially removed them from the United States by 1943, but emerging vulnerabilities along the U.S.-Mexico border in Texas have increased reintroductions of ticks and continuously threaten the southern United States (Racelis et al. 2012). Changes in land use, intergenerational land fractionation, a diversity of native and exotic hosts, changes in vegetation, and transboundary economic, social, and political issues risk compromising this hard-won biosecurity in the United States (Pérez de León et al. 2012). A similar zone exists in New South Wales, Australia (officially *R. australis*-free since 2004), along the fenced and monitored border it shares with the part of Queensland inhabited by *R. australis* (West 2005). Tick eradication programs in Australia became more difficult as *R. australis* acquired resistance to successive acaricide compounds from the 1930s (Angus 1996). Likewise, acaricide resistance contributed to the inability to eradicate *R. microplus* and *R. annulatus* from all parts of Mexico and *R. microplus* from Argentina (George et al. 2004). *Rhipicephalus australis* and *R. microplus* are recognized as two of the most pesticide-resistant arthropods in the world (Whalon et al. 2008).

Researchers took advantage of increasing computer power and availability in the 1970s to develop the first computer models of *Rhipicephalus* (*Boophilus*) life history and ecology. As research interests of laboratories in multiple countries shifted among tick life history, ecology, control, management, and eradication, models integrated field and laboratory data, predicted
consequences of management strategies, and generated new hypotheses to be tested in future experiments or predicted in future models. In the current global context, modeling can be used to study interactions between behavior of cattle and deer (or other wildlife species) in tick-infested landscapes, identify dynamic relationships between host diversity and tick dispersal and maintenance, and improve tactics to suppress or eliminate ticks; these aspects have been identified as gaps in the ability to develop effective strategies to control ticks affecting livestock and wildlife (Morgan et al. 2004). Moreover, predicting future impacts of climate oscillations and perturbations by modeling normal and extreme conditions would better inform regulatory officials and policy makers about operational needs and regulatory changes, as suggested for other disease systems influenced by global change (Anyamba et al. 2012).

Herein, we first provide a chronology of quantitative models developed to simulate either population dynamics or the “bioclimatic envelope” (Araújo and Peterson 2012) of *Rhipicephalus (Boophilus)* ticks; it demonstrates how models (1) evolved over time to address new research topics and (2) propagated throughout the global research community. We then categorize the models by mathematical structure and output; compare and contrast their structures, data, and dynamics; and suggest how and what kinds of models can complement future research and applications to decrease negative effects of tick parasitism; increase food security; and promote agricultural, environmental, and social stability and sustainability. We limited the review to references in the scientific literature that describe new model structure, evaluation, or predictions in some detail, which resulted in 101 references describing 113 model instances (Tables 1–4, Figs. 1, 2; Appendix S1: Fig. S1). This review is similar to one performed on the modeling of tick-borne pathogens carried mainly by *Ixodes ricinus* (L.) ticks (Norman et al. 2016).

## CHRONOLOGY OF *RHIPICEPHALUS* (*BOOPHILUS*) MODELS

### Australian initiation (1973–1989)

In 1973, researchers from Australia's Commonwealth Scientific and Industrial Research

Organization (CSIRO) developed the first model explicitly representing *Rhipicephalus* ticks (Sutherst et al. 1973), an analytical model predicting on-host mortality of *Rhipicephalus australis*. The following year, they introduced the TICK1 simulation model, with a weekly time step (Sutherst and Dallwitz 1979). By 1980, they had produced an analytical model (PICKUP) that predicted larval host finding (Sutherst et al. 1978), added additional driving variables to their model of on-host mortality (Sutherst et al. 1979b), and began to develop TICK2, a more detailed simulation model with a daily time step (Maywald et al. 1980).

In the late 1970s, they also produced a Leslie matrix model of *R. australis* population dynamics (MATIX) to simulate integrated tick-management strategies (Sutherst et al. 1979a), including those for crossbred cattle (Sutherst et al. 1980a, b). They also combined MATIX with models of population genetics to evaluate development of acaricide resistance (Sutherst and Comins 1979) and with decision-analysis models (Elder et al. 1983, Norton et al. 1983, 1984, Elder and Morris 1986) to predict effects of management strategies. They developed a model to predict off-host larval mortality (LARVS; Utech et al. 1983) and then combined it with their model of on-host mortality (Bourne et al. 1988). They also developed a model of interspecific competition (STERHB) between *Rhipicephalus microplus* and *Rhipicephalus decoloratus*, the first *Rhipicephalus* model applied to Africa (Sutherst 1987a). By 1987, their TICK2 model, the first simulation model of ticks to have a daily time step, was operational; it also represented each cow individually (Dallwitz 1987a, b, c).

In 1985, they introduced CLIMEX, a bioclimatic envelope model that predicted an “ecoclimatic index” for a species’ population at a given geographic point as a function of indices of potential growth and stress (Sutherst and Maywald 1985). CLIMEX was used to predict distributions of *R. australis* in southern Australia and *R. microplus* in southern Africa (Sutherst 1987b); to analyze climate-change effects on tick distribution (Maywald and Sutherst 1989); and, when integrated into an expert system, to help agricultural advisors recommend tick-management strategies (Sutherst and Bottomley 1989).
<table><caption>Table 1. Chronological list of 76 references that include 79 population dynamics models of *Rhipicephalus* (Boophilus) ticks, indicating key reference and model characteristics.</caption><thead><tr><th rowspan="2">References</th><th rowspan="2">Location of system modeled†</th><th rowspan="2">Sp.‡</th><th rowspan="2">Type§</th><th colspan="5">Reference char.¶</th><th colspan="4">Model characteristics#</th></tr><tr><th>D</th><th>SA</th><th>P</th><th>E</th><th>S</th><th>A</th><th>Name</th><th>Lang.</th><th>Time step||</th><th>Max. time span||</th><th>Overall spatial scale</th></tr></thead><tbody><tr><td>Sutherst et al. (1973)</td><td>AU</td><td>au</td><td>P</td><td>●</td><td>-</td><td>●</td><td>●</td><td>-</td><td>●</td><td>-</td><td>-</td><td>-</td><td>Cow</td></tr><tr><td>Sutherst and Dallwitz (1979)</td><td>Qld., AU</td><td>au</td><td>C</td><td>●</td><td>●</td><td>●</td><td>●</td><td>-</td><td>-</td><td>-</td><td>Fortran</td><td>1 w</td><td>35 mo</td><td>Ranch</td></tr><tr><td>Sutherst et al. (1978)</td><td>AU</td><td>au</td><td>P</td><td>●</td><td>●</td><td>●</td><td>-</td><td>-</td><td>●</td><td>PICKUP</td><td>-</td><td>1 d</td><td>50 d</td><td>Pasture</td></tr><tr><td>Sutherst et al. (1979a)</td><td>Qld., AU</td><td>au</td><td>C</td><td>●</td><td>●</td><td>●</td><td>●</td><td>-</td><td>-</td><td>MATIX</td><td>Fortran</td><td>1 w</td><td>1 y</td><td>Ranch</td></tr><tr><td>Sutherst et al. (1979b)</td><td>AU</td><td>au</td><td>P</td><td>-</td><td>-</td><td>●</td><td>-</td><td>-</td><td>●</td><td>-</td><td>-</td><td>1 gn</td><td>-</td><td>Cow</td></tr><tr><td>Sutherst and Comins (1979)</td><td>AU</td><td>au</td><td>P</td><td>●</td><td>●</td><td>●</td><td>-</td><td>-</td><td>●</td><td>-</td><td>-</td><td>1 gn</td><td>4 gn</td><td>Pasture</td></tr><tr><td>Sutherst et al. (1980b) (79)</td><td>Qld., AU</td><td>au</td><td>C</td><td>-</td><td>-</td><td>●</td><td>-</td><td>-</td><td>-</td><td>MATIX</td><td>Fortran</td><td>1 w</td><td>1 y</td><td>Ranch</td></tr><tr><td>Sutherst et al. (1980a) (79)</td><td>Qld., AU</td><td>au</td><td>C</td><td>-</td><td>-</td><td>●</td><td>-</td><td>-</td><td>-</td><td>MATIX</td><td>Fortran</td><td>1 w</td><td>1 y</td><td>Ranch</td></tr><tr><td>Maywald et al. (1980)††</td><td>Qld. and NSW, AU</td><td>au</td><td>C</td><td>●</td><td>-</td><td>●</td><td>●</td><td>-</td><td>-</td><td>TICK1</td><td>Fortran</td><td>1 w</td><td>30 mo</td><td>Pasture</td></tr><tr><td>Maywald et al. (1980)††</td><td>Qld., AU</td><td>au</td><td>C</td><td>●</td><td>●</td><td>●</td><td>-</td><td>-</td><td>-</td><td>MATIX</td><td>Fortran</td><td>1 w</td><td>4 y</td><td>Pasture</td></tr><tr><td>Maywald et al. (1980)††</td><td>AU</td><td>au</td><td>C</td><td>●</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>TICK2</td><td>Fortran</td><td>1 d</td><td>1 y</td><td>Ranch</td></tr><tr><td>Osburn and Knipling (1982)</td><td>US</td><td>m, an</td><td>P</td><td>-</td><td>-</td><td>●</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>3 mo</td><td>21 mo</td><td>4000 ha</td></tr><tr><td>Elder et al. (1983)</td><td>Qld., AU</td><td>au</td><td>C</td><td>-</td><td>-</td><td>●</td><td>-</td><td>-</td><td>-</td><td>MATIX</td><td>-</td><td>-</td><td>-</td><td>Ranch</td></tr><tr><td>Norton et al. (1983)</td><td>AU</td><td>au</td><td>C</td><td>●</td><td>●</td><td>●</td><td>-</td><td>-</td><td>-</td><td>MATIX</td><td>-</td><td>1 w</td><td>eq.</td><td>Ranch</td></tr><tr><td>Smith (1983)</td><td>-</td><td>m</td><td>P</td><td>●</td><td>-</td><td>●</td><td>-</td><td>-</td><td>-</td><td>-</td><td>Basic</td><td>3 mo</td><td>eq.</td><td>Pasture</td></tr><tr><td>Utech et al. (1983)</td><td>Qld., AU</td><td>au</td><td>P</td><td>-</td><td>-</td><td>●</td><td>●</td><td>-</td><td>-</td><td>LARVS</td><td>-</td><td>1 d</td><td>3 mo</td><td>Pasture</td></tr><tr><td>Weidhaas et al. (1983)</td><td>US</td><td>b</td><td>C</td><td>●</td><td>-</td><td>●</td><td>-</td><td>-</td><td>-</td><td>-</td><td>Fortran</td><td>1 w</td><td>21 mo</td><td>Pasture</td></tr><tr><td>Smith (1984)</td><td>-</td><td>m</td><td>-</td><td>-</td><td>●</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td></tr><tr><td>Smith et al. (1984)</td><td>BR/UY</td><td>m</td><td>P</td><td>-</td><td>-</td><td>●</td><td>●</td><td>-</td><td>-</td><td>-</td><td>Basic</td><td>3 mo</td><td>eq.</td><td>Pasture</td></tr><tr><td>Norton et al. (1984)</td><td>Qld., AU</td><td>au</td><td>C</td><td>●</td><td>●</td><td>●</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>1 w</td><td>4 y</td><td>1-2 pastures</td></tr><tr><td>de la Vega and Díaz (1985a, b, c)</td><td>Cuba</td><td>m</td><td>P</td><td>-</td><td>-</td><td>●</td><td>-</td><td>-</td><td>●</td><td>-</td><td>-</td><td>1 d</td><td>d → fh</td><td>♀ & eggs</td></tr><tr><td>de la Vega and Díaz (1986)</td><td>Cuba</td><td>m</td><td>P</td><td>-</td><td>-</td><td>●</td><td>●</td><td>-</td><td>-</td><td>-</td><td>-</td><td>1 d</td><td>d → fh</td><td>♀ & eggs</td></tr><tr><td>Elder and Morris (1986)</td><td>Qld., AU</td><td>au</td><td>C</td><td>-</td><td>●</td><td>●</td><td>-</td><td>●</td><td>-</td><td>-</td><td>-</td><td>-</td><td>10 y</td><td>Ranch</td></tr><tr><td>Dallwitz (1987a, b, c)</td><td>AU</td><td>au</td><td>C</td><td>●</td><td>-</td><td>-</td><td>-</td><td>●</td><td>-</td><td>TICK2</td><td>Fortran</td><td>1 d</td><td>-</td><td>Ranch</td></tr><tr><td>de la Vega and Díaz (1987)</td><td>Cuba</td><td>m</td><td>P</td><td>-</td><td>-</td><td>●</td><td>-</td><td>-</td><td>●</td><td>-</td><td>-</td><td>1 d</td><td>3 mo</td><td>Larval cohort</td></tr><tr><td>Sutherst (1987a)</td><td>Africa</td><td>m, d</td><td>P</td><td>●</td><td>-</td><td>●</td><td>-</td><td>-</td><td>-</td><td>STERHB</td><td>-</td><td>1 gn</td><td>10 gn</td><td>Range overlap</td></tr><tr><td>Bourne et al. (1988)</td><td>AU</td><td>au</td><td>P</td><td>●</td><td>-</td><td>●</td><td>-</td><td>-</td><td>●</td><td>-</td><td>-</td><td>1 w</td><td>4.5 y</td><td>Ranch</td></tr></tbody></table>
<table><caption>(Table 1. Continued)</caption><thead><tr><th rowspan="2">References</th><th rowspan="2">Location of system modeled†</th><th rowspan="2">Sp.‡</th><th rowspan="2">Type§</th><th colspan="5">Reference char.¶</th><th colspan="3">Model characteristics#</th><th rowspan="2">Overall spatial scale</th></tr><tr><th>D</th><th>SA</th><th>P</th><th>E</th><th>S</th><th>A</th><th>Name</th><th>Lang.</th><th>Time step||</th><th>Max. time span||</th></tr></thead><tbody><tr><td>de la Vega et al. (1988)</td><td>Cuba</td><td>m</td><td>P</td><td>●</td><td>–</td><td>●</td><td>–</td><td>●</td><td>–</td><td>–</td><td>1 d</td><td>43 d</td><td>2 pastures</td></tr><tr><td>Smith (1989, 1991)</td><td>BR/PY</td><td>m</td><td>P</td><td>●</td><td>–</td><td>●</td><td>–</td><td>–</td><td>–</td><td>MS Works</td><td>1 w</td><td>eq.</td><td>Pasture</td></tr><tr><td>Popham and Garris (1991, 1989)</td><td>Puerto Rico, US</td><td>m</td><td>C</td><td>●</td><td>–</td><td>●</td><td>–</td><td>●</td><td>–</td><td>–</td><td>1 d</td><td>1000 d</td><td>33 ha</td></tr><tr><td>Höner and Gomes (1990)</td><td>BR</td><td>m</td><td>–</td><td>–</td><td>–</td><td>–</td><td>–</td><td>–</td><td>degree-day</td><td>–</td><td>1 d</td><td>–</td><td>Country</td></tr><tr><td>Mount et al. (1991)</td><td>Americas/ AU</td><td>m, an</td><td>C</td><td>●</td><td>–</td><td>●</td><td>●</td><td>–</td><td>BCTSIM</td><td>Basic</td><td>1 w</td><td>3 y</td><td>World</td></tr><tr><td>Strey et al. (1991)</td><td>Texas, US/MX</td><td>an</td><td>P</td><td>●</td><td>–</td><td>●</td><td>●</td><td>–</td><td>●</td><td>SAS</td><td>1 d</td><td>141 d</td><td>Egg mass</td></tr><tr><td>de la Vega and Díaz (1992)</td><td>Cuba</td><td>m</td><td>P</td><td>–</td><td>–</td><td>●</td><td>–</td><td>●</td><td>–</td><td>–</td><td>1 d</td><td>68 d</td><td>2 pastures</td></tr><tr><td>Haile et al. (1992)</td><td>Americas/ AU/Africa</td><td>m, an</td><td>C</td><td>●</td><td>–</td><td>●</td><td>●</td><td>–</td><td>BCTSIM</td><td>Basic</td><td>1 w</td><td>>5 y</td><td>World</td></tr><tr><td>de la Vega et al. (1993)</td><td>Cuba</td><td>m</td><td>P</td><td>●</td><td>–</td><td>●</td><td>–</td><td>–</td><td>DESPOBLE</td><td>–</td><td>1 d</td><td>140 d</td><td>Egg mass</td></tr><tr><td>Höner et al. (1993)††</td><td>SC, BR</td><td>m</td><td>C</td><td>–</td><td>–</td><td>●</td><td>–</td><td>–</td><td>BCTSIM</td><td>Basic</td><td>1 w</td><td>–</td><td>Pasture</td></tr><tr><td>Höner et al. "(1993)††</td><td>SC, BR</td><td>m</td><td>–</td><td>–</td><td>–</td><td>●</td><td>–</td><td>–</td><td>Agro_ degree_day</td><td>–</td><td>1 d</td><td>1 y</td><td>Pasture</td></tr><tr><td>Arantes et al. (1995)</td><td>MG, BR</td><td>m</td><td>–</td><td>–</td><td>–</td><td>●</td><td>–</td><td>–</td><td>BRAMATIX</td><td>–</td><td>1 d</td><td>1 y</td><td>Ranch</td></tr><tr><td>Saueressig and Höner (1995)</td><td>Federal District, BR</td><td>m</td><td>–</td><td>–</td><td>–</td><td>●</td><td>–</td><td>–</td><td>Agro_ degree_day</td><td>–</td><td>1 d</td><td>–</td><td>Pasture</td></tr><tr><td>Floyd et al. (1995)</td><td>Qld., AU</td><td>au</td><td>C</td><td>–</td><td>●</td><td>●</td><td>●</td><td>–</td><td>TICK2</td><td>Fortran</td><td>1 d</td><td>5 y</td><td>Ranch</td></tr><tr><td>Lodos et al. (1995)</td><td>Cuba/ BR</td><td>m</td><td>C</td><td>●</td><td>–</td><td>●</td><td>●</td><td>–</td><td>TICKSIM</td><td>C++</td><td>1 w</td><td>1 y</td><td>Pasture</td></tr><tr><td>Rodríguez (1995)</td><td>Cuba</td><td>m</td><td>C</td><td>●</td><td>–</td><td>–</td><td>–</td><td>●</td><td>–</td><td>–</td><td>1 w</td><td>33 w</td><td>Cow</td></tr><tr><td>Labarta et al. (1996)</td><td>Cuba</td><td>m</td><td>C</td><td>–</td><td>–</td><td>●</td><td>●</td><td>–</td><td>–</td><td>Pascal</td><td>1 w</td><td>1 y</td><td>Cow</td></tr><tr><td>Teel et al. (1996)</td><td>Texas, US/MX</td><td>b</td><td>C</td><td>●</td><td>●</td><td>●</td><td>–</td><td>–</td><td>–</td><td>STELLA</td><td>1 d</td><td>720 d</td><td>1000 ha</td></tr><tr><td>Hall et al. (1996)</td><td>AU</td><td>au</td><td>C</td><td>●</td><td>–</td><td>●</td><td>●</td><td>–</td><td>TICK1</td><td>Fortran</td><td>1 d</td><td>1 y</td><td>Continent</td></tr><tr><td>Sutherst et al. (1996)</td><td>AU</td><td>au</td><td>C</td><td>–</td><td>–</td><td>●</td><td>–</td><td>–</td><td>TICK1</td><td>–</td><td>–</td><td>–</td><td>Continent</td></tr><tr><td>Dixon et al. (1997)</td><td>Qld., AU</td><td>au</td><td>C</td><td>●</td><td>●</td><td>●</td><td>–</td><td>–</td><td>●</td><td>Matlab</td><td>1 w</td><td>1 y</td><td>Pasture</td></tr><tr><td>Abramson et al. (1997)</td><td>AU</td><td>au</td><td>C</td><td>●</td><td>–</td><td>●</td><td>–</td><td>–</td><td>TICK1</td><td>Fortran</td><td>1 w</td><td>10 y</td><td>Continent</td></tr><tr><td>Teel et al. (1997)</td><td>Texas, US/MX</td><td>b</td><td>C</td><td>–</td><td>–</td><td>●</td><td>–</td><td>–</td><td>–</td><td>STELLA</td><td>1 d</td><td>5 y</td><td>800 ha</td></tr><tr><td>Beugnet et al. (1998)</td><td>NC</td><td>au</td><td>C</td><td>●</td><td>●</td><td>●</td><td>–</td><td>–</td><td>–</td><td>–</td><td>3 w</td><td>3 y</td><td>150 ha</td></tr><tr><td>Teel et al. (1998)</td><td>Texas, US/MX</td><td>b</td><td>C</td><td>–</td><td>–</td><td>●</td><td>–</td><td>–</td><td>–</td><td>STELLA</td><td>1 d</td><td>2 y</td><td>800 ha</td></tr><tr><td>Basher (1998)</td><td>AU</td><td>au</td><td>C</td><td>–</td><td>–</td><td>●</td><td>–</td><td>–</td><td>TICK1</td><td>–</td><td>–</td><td>1 y</td><td>Continent</td></tr><tr><td>Lodos et al. (1999)</td><td>Cuba/BR/MX</td><td>b</td><td>C</td><td>●</td><td>●</td><td>●</td><td>●</td><td>–</td><td>TICKSIM</td><td>C++</td><td>1 w</td><td>3 y</td><td>Pasture</td></tr><tr><td>Sutherst et al. (1999)</td><td>Qld., AU</td><td>au</td><td>C</td><td>●</td><td>–</td><td>●</td><td>●</td><td>–</td><td>●</td><td>–</td><td>1 d</td><td>d → fh</td><td>Egg mass</td></tr></tbody></table>
<table><caption>(Table 1. Continued)</caption><thead><tr><th rowspan="2">References</th><th rowspan="2">Location of system modeled†</th><th rowspan="2">Sp.‡</th><th rowspan="2">Type§</th><th colspan="5">Reference char.¶</th><th colspan="4">Model characteristics#</th></tr><tr><th>D</th><th>SA</th><th>P</th><th>E</th><th>S</th><th>A</th><th>Name</th><th>Lang.</th><th>Time step||</th><th>Max. time span||</th><th>Overall spatial scale</th></tr></thead><tbody><tr><td>Smith et al. (1999, 2000)</td><td>BR/UY</td><td>m</td><td>—</td><td>●</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>MS Works</td><td>1 w</td><td>2 y</td><td>Herd</td></tr><tr><td>Hernández-Arrieta et al. (2000)</td><td>VZ</td><td>m</td><td>C</td><td>●</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>STELLA</td><td>1 d</td><td>3 y</td><td>Ranch</td></tr><tr><td>Lodos et al. (2000)</td><td>Cuba/BR</td><td>m</td><td>C</td><td>●</td><td>●</td><td>●</td><td>●</td><td>—</td><td>TICKSIM</td><td>C++</td><td>1 w</td><td>8 mo</td><td>Pasture</td></tr><tr><td>Fonseca et al. (2000)</td><td>MG, BR</td><td>m</td><td>C</td><td>—</td><td>—</td><td>●</td><td>●</td><td>—</td><td>BCTSIM</td><td>Basic</td><td>1 w</td><td>1 y</td><td>Pasture</td></tr><tr><td>Sutherst (2000)</td><td>Qld., AU</td><td>au</td><td>C</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>TICK2</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Sutherst et al. (2000)</td><td>Qld., AU</td><td>au</td><td>C</td><td>—</td><td>●</td><td>●</td><td>—</td><td>—</td><td>TICK2</td><td>—</td><td>—</td><td>eq.</td><td>Pasture</td></tr><tr><td>Corson et al. (2001)</td><td>Texas, US/MX</td><td>b</td><td>C</td><td>●</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>STELLA</td><td>1 d</td><td>1190 d</td><td>800 ha</td></tr><tr><td>Sutherst (2001)</td><td>Qld., AU</td><td>au</td><td>C</td><td>—</td><td>—</td><td>●</td><td>●</td><td>—</td><td>TICK1/2</td><td>—</td><td>—</td><td>2 y</td><td>Herd</td></tr><tr><td>Estrada-Peña (2002)</td><td>sub-Saharan Africa</td><td>d</td><td>C</td><td>●</td><td>●</td><td>●</td><td>●</td><td>—</td><td>BDM</td><td>ERDAS Imagine</td><td>10 d</td><td>16 y</td><td>64 km²</td></tr><tr><td>Delgado (2002)</td><td>MG, BR</td><td>m</td><td>C</td><td>—</td><td>—</td><td>●</td><td>●</td><td>—</td><td>BCTSIM</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Corson et al. (2003)</td><td>Texas, US</td><td>b</td><td>C</td><td>—</td><td>—</td><td>●</td><td>—</td><td>●</td><td>—</td><td>STELLA</td><td>1 d</td><td>2 y</td><td>800 ha</td></tr><tr><td>Teel et al. (2003)</td><td>Texas, US</td><td>b</td><td>C</td><td>●</td><td>●</td><td>●</td><td>—</td><td>●</td><td>—</td><td>STELLA</td><td>1 d</td><td>2 y</td><td>100 ha</td></tr><tr><td>White et al. (2003)</td><td>AU</td><td>au</td><td>C</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>TICK1</td><td>—</td><td>1 w</td><td>1 y</td><td>Continent</td></tr><tr><td>Corson et al. (2004)</td><td>Texas, US</td><td>b</td><td>C</td><td>●</td><td>●</td><td>●</td><td>●</td><td>●</td><td>BoopMod</td><td>STELLA</td><td>1 h</td><td>2 y</td><td>Pasture</td></tr><tr><td>Estrada-Peña et al. (2006b)</td><td>NE AR</td><td>m</td><td>C</td><td>—</td><td>—</td><td>●</td><td>—</td><td>●</td><td>BoopMod</td><td>Fortran</td><td>1 h</td><td>10 y</td><td>Region</td></tr><tr><td>Zeman and Lynen (2010)</td><td>TZ</td><td>m, d</td><td>C</td><td>●</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>unitless</td><td>eq.</td><td>2500 deme cells</td></tr><tr><td>Merino et al. (2011)</td><td>Tmp., MX</td><td>m</td><td>C</td><td>—</td><td>—</td><td>●</td><td>●</td><td>●</td><td>—</td><td>Simgua</td><td>1 d</td><td>1000 gn</td><td>Cattle</td></tr><tr><td>Miller et al. (2012)</td><td>Texas, US</td><td>an</td><td>C</td><td>—</td><td>—</td><td>●</td><td>—</td><td>●</td><td>—</td><td>—</td><td>1 d</td><td>10 y</td><td>Region</td></tr><tr><td>Estrada-Peña et al. (2014)</td><td>NE MX</td><td>b</td><td>C</td><td>●</td><td>—</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>10 d</td><td>5 y</td><td>Region</td></tr><tr><td>Wang et al. (2016)</td><td>Texas, US</td><td>m</td><td>C</td><td>●</td><td>●</td><td>●</td><td>●</td><td>●</td><td>—</td><td>NetLogo</td><td>1 w</td><td>7 y</td><td>900 ha</td></tr></tbody></table>

Note: The symbol “●” signifies “yes/present,” while “—” signifies “no/absent.”

† Location: AU, Australia; BR, Brazil; MG, Minas Gerais; MX, Mexico; NC, New Caledonia; NSW, New South Wales; Paraguay, PY; Qld., Queensland; SC, Santa Catarina; Tmp., Tamaulipas; TZ, Tanzania; UY, Uruguay; US, United States; VZ, Venezuela.

‡ Species represented: au, *R. australis*; m, *R. microplus*; an, *R. annulatus*; d, *R. decoloratus*; b, merged *R. microplus/annulatus*.

§ Type of model: P, portion of life cycle; C, complete life cycle.

¶ Reference characteristics: D, describe model details (equations); SA, perform sensitivity analysis; P, make predictions; E, evaluate model accuracy.

# Model characteristics: S, stochastic; A, analytical; Lang., language or software.

|| Time step and time span: m, minute; d, day; w, week; mo, month; gn, generation; y, yr; d→fh, drop to first hatch; d→ll, drop to last larva; eq., equilibrium.

†† Multiple models described in one reference.
<table><caption>Table 2. Chronological list of 76 references that include 79 population dynamics models of *Rhipicephalus* (*Boophilus*) ticks, indicating key model content.</caption><thead><tr><th rowspan="2">References</th><th colspan="5">Stages†</th><th colspan="5">Drivers‡</th><th colspan="5">Management§</th><th colspan="5">Factors¶</th><th colspan="2">Other#</th></tr><tr><th>PO</th><th>O</th><th>E</th><th>FL</th><th>OL</th><th>T</th><th>H</th><th>P</th><th>Ev</th><th>SM</th><th>PS</th><th>RG</th><th>AT</th><th>C</th><th>V</th><th>EA</th><th>HR</th><th>AR</th><th>HF</th><th>CC</th><th>TD</th><th>B</th><th>S</th></tr></thead><tbody><tr><td>Sutherst et al. (1973)</td><td>—</td><td>—</td><td>—</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Sutherst and Dallwitz (1979)</td><td>—</td><td>●</td><td>●</td><td>●</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>●</td><td>●</td><td>—</td><td>●</td><td>—</td><td>—</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Sutherst et al. (1978)</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Sutherst et al. (1979a)</td><td>—</td><td>●</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Sutherst et al. (1979b)</td><td>—</td><td>—</td><td>—</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Sutherst and Comins (1979)</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Sutherst et al. (1980b)</td><td>—</td><td>●</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Sutherst et al. (1980a)</td><td>—</td><td>●</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Maywald et al. (1980)‖</td><td>—</td><td>●</td><td>●</td><td>●</td><td>●</td><td>●</td><td>—</td><td>●</td><td>●</td><td>—</td><td>●</td><td>—</td><td>●</td><td>—</td><td>—</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Maywald et al. (1980)‖</td><td>—</td><td>●</td><td>●</td><td>●</td><td>●</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Maywald et al. (1980)‖</td><td>●</td><td>●</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Osburn and Knipling (1982)</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td></tr><tr><td>Elder et al. (1983)</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Norton et al. (1983)</td><td>—</td><td>●</td><td>●</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>●</td><td>—</td><td>—</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Smith (1983)</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Utech et al. (1983)</td><td>—</td><td>—</td><td>—</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Weidhaas et al. (1983)</td><td>—</td><td>●</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td></tr><tr><td>Smith (1984)</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Smith et al. (1984)</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Norton et al. (1984)</td><td>—</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>de la Vega and Díaz (1985a, b, c)</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>de la Vega and Díaz (1986)</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Elder and Morris (1986)</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Dallwitz (1987a, b, c)</td><td>—</td><td>—</td><td>●</td><td>●</td><td>●</td><td>—</td><td>●</td><td>●</td><td>—</td><td>—</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>de la Vega and Díaz (1987)</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Sutherst (1987a)</td><td>—</td><td>—</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td></tr><tr><td>Bourne et al. (1988)</td><td>—</td><td>—</td><td>—</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>de la Vega et al. (1988)</td><td>—</td><td>—</td><td>—</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Smith (1991)</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Popham and Garris (1991)</td><td>—</td><td>●</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Höner and Gomes (1990)</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Mount et al. (1991)</td><td>●</td><td>●</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Strey et al. (1991)</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>de la Vega and Díaz (1992)</td><td>—</td><td>—</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Haile et al. (1992)</td><td>●</td><td>●</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>de la Vega et al. (1993)</td><td>—</td><td>—</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Höner et al. (1993)‖</td><td>●</td><td>●</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Höner et al. (1993)‖</td><td>●</td><td>●</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Arantes et al. (1995)</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Saueressig and Höner (1995)</td><td>●</td><td>●</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Floyd et al. (1995)</td><td>—</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Lodos et al. (1995)</td><td>●</td><td>●</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Rodríguez (1995)</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Labarta et al. (1996)</td><td>—</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Teel et al. (1996)</td><td>●</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Hall et al. (1996)</td><td>●</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>●</td><td>—</td><td>—</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Sutherst et al. (1996)</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Dixon et al. (1997)</td><td>●</td><td>●</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Abramson et al. (1997)</td><td>—</td><td>—</td><td>—</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Teel et al. (1997)</td><td>●</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Beugnet et al. (1998)</td><td>—</td><td>—</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr></tbody></table>
<table><caption>(Table 2. Continued)</caption><thead><tr><th rowspan="2">References</th><th colspan="5">Stages†</th><th colspan="3">Drivers‡</th><th colspan="4">Management§</th><th colspan="4">Factors¶</th><th colspan="2">Other#</th></tr><tr><th>PO</th><th>O</th><th>E</th><th>FL</th><th>OL</th><th>T</th><th>H</th><th>P</th><th>Ev</th><th>SM</th><th>PS</th><th>RG</th><th>AT</th><th>C</th><th>V</th><th>EA</th><th>HR</th><th>AR</th><th>HF</th><th>CC</th><th>TD</th><th>B</th><th>S</th></tr></thead><tbody><tr><td>Teel et al. (1998)</td><td>●</td><td>●</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Basher (1998)</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Lodos et al. (1999)</td><td>●</td><td>●</td><td>●</td><td>●</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>●</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td></tr><tr><td>Sutherst et al. (1999)</td><td>—</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Smith et al. (1999, 2000)</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td></tr><tr><td>Hernández-Arrieta et al. (2000)</td><td>●</td><td>●</td><td>●</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Lodos et al. (2000)</td><td>●</td><td>●</td><td>●</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>●</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Fonseca et al. (2000)</td><td>●</td><td>●</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Sutherst (2000)</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Sutherst et al. (2000)</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Corson et al. (2001)</td><td>●</td><td>●</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Sutherst (2001)</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Estrada-Peña (2002)</td><td>●</td><td>●</td><td>●</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Delgado (2002)</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td></tr><tr><td>Corson et al. (2003)</td><td>●</td><td>●</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td></tr><tr><td>Teel et al. (2003)</td><td>●</td><td>●</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td></tr><tr><td>White et al. (2003)</td><td>—</td><td>—</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Corson et al. (2004)</td><td>●</td><td>●</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Estrada-Peña et al. (2006b)</td><td>●</td><td>●</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Zeman and Lynen (2010)</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td></tr><tr><td>Merino et al. (2011)</td><td>●</td><td>●</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Miller et al. (2012)</td><td>●</td><td>●</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Estrada-Peña et al. (2014)</td><td>●</td><td>●</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Wang et al. (2016)</td><td>●</td><td>●</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr></tbody></table>

Note: The symbol “●” signifies “yes/present,” while “—” signifies “no/absent.”

† Stages: PO, female preoviposition; O, female oviposition; E, eggs; FL, free larvae; OL, on-host larvae.

‡ Drivers: T, air temperature; H, air humidity; P, precipitation; Ev, evaporation; SM, soil moisture.

§ Management: PS, pasture spelling; RG, rotational grazing; AT, acaricide treatment; C, culling; V, vaccination vs. ticks; EA, economic analysis.

¶ Factors: HR, host resistance; AR, acaricide resistance; HF, host finding; CC, climate change; TD, tick detection.

# Other: *Babesia* spp.; S, sterile hybrid ticks.

|| Multiple models described in one reference.

## The Americas emerge (1982–1995)

Nearly 10 yr after *Rhipicephalus* models emerged in Australia, they began to appear in the Americas. Researchers from the U.S. Department of Agriculture, Agricultural Research Service (USDA-ARS), predicted effects of releasing sterile male hybrid (*Rhipicephalus annulatus* × *R. microplus*) larvae as an eradication strategy (Osburn and Knipling 1982). They later integrated much of this model into a more complex model that represented each life cycle stage explicitly (Weidhaas et al. 1983). Beginning at the same time, the original CSIRO model of on-host mortality was incorporated into the first simulation model of *Babesia bovis* to represent the vector population (Smith 1983, 1984); it was applied to sites in Brazil and Uruguay (Smith et al. 1984) and later transformed into a spreadsheet version (Smith 1991).

From 1985 to 1993, researchers from Cuba's National Center for Animal and Plant Health (CENSA) and the University of Havana (UH) published articles about modeling *R. microplus* in Cuba. They first built analytical degree-day models of preoviposition and incubation (de la Vega and Díaz 1985a, b, c, 1986), using them to predict effects of quarantine paddocks (de la Vega et al. 1988, de la Vega and Díaz 1992). They next built a degree-day model of larval longevity (de la Vega and Díaz 1987) and combined it with their previous model to predict the duration of the entire off-host phase (de la Vega et al. 1993). During the same period, researchers from the Brazilian Agricultural Research Corporation (EMBRAPA) predicted distribution of *R. microplus* at multiple sites in Brazil using CLIMEX alone (Saueressig and Honer 1993) or in combination with a degree-day
<table><caption>Table 3. Chronological list of 33 references that include 34 bioclimatic envelope models of *Rhipicephalus* (Boophi- *lus*) ticks, indicating key reference and model characteristics.</caption><thead><tr><th rowspan="2">References</th><th rowspan="2">Location of system modeled†</th><th rowspan="2">Species‡</th><th colspan="4">Reference characteristics§</th><th colspan="3">Model characteristics¶</th></tr><tr><th>Desc.</th><th>SA</th><th>Pred.</th><th>Eval.</th><th>Analy.</th><th>Type</th><th>Calc.#</th><th>Spatial res.</th><th>Spatial extent</th></tr></thead><tbody><tr><td>Sutherst and Maywald (1985)</td><td>world</td><td>au</td><td>●</td><td>–</td><td>●</td><td>–</td><td>–</td><td>CLIMEX</td><td>EI</td><td>Point</td><td>World</td></tr><tr><td>Sutherst (1987b)</td><td>SE AU/ZA</td><td>au/m||</td><td>●</td><td>–</td><td>●</td><td>–</td><td>–</td><td>CLIMEX</td><td>EI</td><td>Point</td><td>Region</td></tr><tr><td>Sutherst and Maywald (1987)</td><td>Africa</td><td>m||</td><td>–</td><td>–</td><td>●</td><td>–</td><td>–</td><td>CLIMEX</td><td>EI</td><td>Point</td><td>Continent</td></tr><tr><td>Sutherst and Bottomley (1989)</td><td>world</td><td>au/m</td><td>●</td><td>–</td><td>–</td><td>–</td><td>–</td><td>CLIMEX</td><td>EI</td><td>Point</td><td>World</td></tr><tr><td>Maywald and Sutherst (1989)</td><td>AU/ZA</td><td>au/m</td><td>●</td><td>–</td><td>–</td><td>–</td><td>–</td><td>CLIMEX</td><td>EI</td><td>Point</td><td>Continent</td></tr><tr><td>Höner and Gomes (1990)</td><td>BR</td><td>m</td><td>–</td><td>–</td><td>●</td><td>–</td><td>–</td><td>CLIMEX</td><td>EI</td><td>Point</td><td>Country</td></tr><tr><td>Höner et al. (1993)</td><td>S BR</td><td>m</td><td>–</td><td>–</td><td>●</td><td>–</td><td>–</td><td>CLIMEX</td><td>EI</td><td>Point</td><td>Region</td></tr><tr><td>Saueressig and Höner (1993)</td><td>S BR</td><td>m</td><td>–</td><td>–</td><td>–</td><td>–</td><td>–</td><td>CLIMEX</td><td>EI</td><td>Point</td><td>Region</td></tr><tr><td>Arantes et al. (1995)</td><td>Minas Gerais, BR</td><td>m</td><td>–</td><td>–</td><td>●</td><td>–</td><td>–</td><td>CLIMEX</td><td>EI</td><td>Point</td><td>Region</td></tr><tr><td>Saueressig and Höner (1995)</td><td>Federal District, BR</td><td>m</td><td>–</td><td>–</td><td>●</td><td>–</td><td>–</td><td>CLIMEX</td><td>EI</td><td>Point</td><td>Pasture</td></tr><tr><td>Sutherst et al. (1996)</td><td>AU</td><td>au||</td><td>●</td><td>–</td><td>●</td><td>–</td><td>–</td><td>CLIMEX</td><td>EI</td><td>Point</td><td>Continent</td></tr><tr><td>Estrada-Peña (1999)</td><td>South America</td><td>m</td><td>●</td><td>–</td><td>●</td><td>●</td><td>●</td><td>GIS</td><td>cokriging</td><td>8 km</td><td>17.8 × 10<sup>6</sup> km<sup>2</sup></td></tr><tr><td>Cumming (2000)</td><td>Africa</td><td>m, an, d, g||</td><td>●</td><td>–</td><td>●</td><td>–</td><td>●</td><td>GIS</td><td>GLM</td><td>¼°</td><td>Continent</td></tr><tr><td>Sutherst (2001)</td><td>eastern AU</td><td>au</td><td>–</td><td>–</td><td>●</td><td>–</td><td>–</td><td>CLIMEX</td><td>EI</td><td>Point</td><td>Region</td></tr><tr><td>Estrada-Peña (2001)</td><td>Central America</td><td>m</td><td>●</td><td>–</td><td>●</td><td>–</td><td>●</td><td>GIS</td><td>cokriging</td><td>–</td><td>Region</td></tr><tr><td>Cumming (2002)</td><td>Africa</td><td>m, an, d, g||</td><td>●</td><td>–</td><td>–</td><td>–</td><td>●</td><td>GIS</td><td>GLM</td><td>¼°</td><td>Continent</td></tr><tr><td>Jubb and Campbell (2002)</td><td>Victoria, AU</td><td>au</td><td>–</td><td>–</td><td>●</td><td>–</td><td>–</td><td>CLIMEX</td><td>EI</td><td>Point</td><td>Local pastures</td></tr><tr><td>Estrada-Peña (2002)</td><td>sub-Saharan Africa</td><td>d</td><td>●</td><td>–</td><td>●</td><td>–</td><td>–</td><td>GIS</td><td>GLM</td><td>64 km<sup>2</sup></td><td>Region</td></tr><tr><td>Guglielmone et al. (2003)</td><td>NE AR</td><td>m</td><td>●</td><td>–</td><td>●</td><td>–</td><td>●</td><td>GIS</td><td>cokriging</td><td>8 km</td><td>13,039 km<sup>2</sup></td></tr><tr><td>Estrada-Peña (2003)</td><td>Africa</td><td>d||</td><td>●</td><td>●</td><td>●</td><td>–</td><td>●</td><td>GIS</td><td>Gower</td><td>–</td><td>Continent</td></tr><tr><td>Fonseca et al. (2005)</td><td>RJ, BR</td><td>m</td><td>●</td><td>–</td><td>●</td><td>–</td><td>●</td><td>GIS</td><td>–</td><td>25 m</td><td>ca. 250 km<sup>2</sup></td></tr><tr><td>Estrada-Peña et al. (2005)</td><td>Americas</td><td>m</td><td>●</td><td>●</td><td>●</td><td>–</td><td>●</td><td>GIS</td><td>Gower</td><td>°</td><td>Continent</td></tr><tr><td>Estrada-Peña et al. (2006c)</td><td>MX</td><td>m</td><td>●</td><td>–</td><td>●</td><td>–</td><td>●</td><td>GIS</td><td>Gower, ANOVA</td><td>8 or 100 km<sup>2</sup></td><td>Country</td></tr><tr><td>Estrada-Peña and Venzel (2006)</td><td>Texas, US/NE MX</td><td>m, an</td><td>●</td><td>●</td><td>●</td><td>●</td><td>●</td><td>GIS</td><td>climate</td><td>1.1 or 4 km<sup>2</sup></td><td>Region</td></tr><tr><td>Estrada-Peña et al. (2006b)</td><td>NE AR</td><td>m</td><td>●</td><td>●</td><td>●</td><td>–</td><td>●</td><td>GIS</td><td>Gower, ANOVA</td><td>6.25 km<sup>2</sup></td><td>Region</td></tr><tr><td>Rabiee et al. (2006)</td><td>NSW, AU</td><td>au</td><td>●</td><td>–</td><td>●</td><td>–</td><td>–</td><td>CLIMEX</td><td>EI</td><td>Point</td><td>Region</td></tr></tbody></table>
<table><caption>(Table 3. Continued)</caption><thead><tr><th rowspan="2">References</th><th rowspan="2">Location of system modeled†</th><th rowspan="2">Species‡</th><th colspan="3">Reference characteristics§</th><th colspan="4">Model characteristics¶</th></tr><tr><th>Desc.</th><th>SA</th><th>Pred.</th><th>Eval.</th><th>Analy.</th><th>Type</th><th>Calc.#</th><th>Spatial res.</th><th>Spatial extent</th></tr></thead><tbody><tr><td>Cumming and van Vuuren (2006)</td><td>world</td><td>m, an, d, g||</td><td>●</td><td>–</td><td>●</td><td>–</td><td>●</td><td>GIS</td><td>GLM</td><td>317 km²</td><td>World</td></tr><tr><td>Estrada-Peña and Venzal (2007)</td><td>Med.</td><td>an||</td><td>●</td><td>–</td><td>●</td><td>–</td><td>●</td><td>GIS</td><td>ENFA</td><td>6.25 km²</td><td>Region</td></tr><tr><td>Lynen et al. (2008)</td><td>Tanzania</td><td>m, d</td><td>●</td><td>–</td><td>●</td><td>–</td><td>●</td><td>GIS</td><td>ENFA</td><td>–</td><td>Country</td></tr><tr><td>Sutherst and Bourne (2009)††</td><td>Africa</td><td>m</td><td>–</td><td>–</td><td>●</td><td>–</td><td>–</td><td>CLIMEX</td><td>EI</td><td>Point</td><td>Subcontinent</td></tr><tr><td>Sutherst and Bourne (2009)††</td><td>Africa</td><td>m</td><td>●</td><td>–</td><td>–</td><td>–</td><td>●</td><td>GIS</td><td>GLM</td><td>Point</td><td>Subcontinent</td></tr><tr><td>De Clercq et al. (2013)</td><td>West Africa</td><td>m</td><td>●</td><td>–</td><td>●</td><td>●</td><td>–</td><td>Maxent</td><td>–</td><td>1 km²</td><td>Region</td></tr><tr><td>Giles et al. (2014)</td><td>southern US</td><td>m, an</td><td>●</td><td>–</td><td>●</td><td>●</td><td>–</td><td>GARP, Maxent</td><td>–</td><td>1 km²</td><td>Region</td></tr><tr><td>Phillips et al. (2014)</td><td>southern Texas, US</td><td>m</td><td>●</td><td>–</td><td>●</td><td>●</td><td>●</td><td>GIS</td><td>GLM</td><td>900 m²</td><td>265 km²</td></tr></tbody></table>

Note: The symbol “●” signifies “yes/present,” while “–” signifies “no/absent.”

† Location: AR, Argentina; AU, Australia; BR, Brazil; Med., Mediterranean; MX, Mexico; NSW, New South Wales; RJ, Rio de Janeiro State; US, United States; ZA, South Africa.

‡ Species represented: au, *R. australis*; m, *R. microplus*; an, *R. annulatus*; d, *R. decoloratus*; g, *R. geigyi*.

§ Reference characteristics: Desc., describe model details (equations); SA, perform sensitivity analysis; Pred., make predictions; Eval., evaluate model accuracy.

¶ Model characteristics: Analy., analytical; Calc., calculation method; spatial res., spatial resolution.

# Calculation method: EI, ecoclimatic index; GLM, generalized linear model; Gower, Gower similarity; ANOVA, analysis of variance; ENFA, ecological niche factor analysis.

|| Includes non-*Rhipicephalus (Boophilus)* tick species.

†† Multiple models described in one reference.

model (Honer and Gomes 1990, Saueressig and Honer 1995) or population dynamics model (Höner et al. 1993, Arantes et al. 1995).

In the United States, Popham and Garris (1991) developed a stochastic stage-structured transition matrix model of *R. microplus* to evaluate eradication strategies in Puerto Rico, while Strey et al. (1991) developed an analytical model of incubation of *R. annulatus* eggs. USDA-ARS researchers developed BCTSIM, which simulated the entire life cycle of *R. microplus* or *R. annulatus* (Mount et al. 1991) and later modified it to represent transmission of *Babesia* spp. by either tick species (Haile et al. 1992).

### Australasia returns (1995–2006)

Several years of hiatus in tick model publishing in Australasia ended with the modification of TICK2 to represent vaccination against *R. australis* (Floyd et al. 1995). Later, Dixon et al. (1997) transformed BCTSIM into a stage-based transition matrix model to evaluate it with elasticity analysis, while Beugnet et al. (1998) created a

matrix-based model to simulate control strategies for *R. australis* in New Caledonia.

TICK1 was revived to predict the influence of climate change on *R. australis* distribution in Australia and the latter's influence on beef cattle liveweight (Hall et al. 1996, Sutherst et al. 1996) and economic cost to the country's beef industry (Abramson et al. 1997, Basher 1998, White et al. 2003). Sutherst et al. (1996) also used CLIMEX to predict future ecoclimatic suitability for *R. australis* in Australia due to climate change. Commonwealth Scientific and Industrial Research Organization researchers later developed analytical models of egg production and hatching for inclusion in TICK1 (Sutherst et al. 1999), used TICK2 to simulate tick predation (Sutherst et al. 2000), and compared TICK2 predictions to observed tick counts on cattle (Sutherst 2000). They also used CLIMEX and TICK2 to predict distribution of *R. australis* and its on-host dynamics, respectively, in eastern Australia (Sutherst 2001). Jubb and Campbell (2002) used CLIMEX to predict *R. australis* habitat suitability
<table><caption>Table 4. Chronological list of 33 references that include 34 bioclimatic envelope models of *Rhipicephalus* (*Boophi-lus*) ticks, indicating key model content.</caption><thead><tr><th rowspan="2">References</th><th colspan="8">Drivers†</th><th colspan="5">Management‡</th><th colspan="2">Factors§</th><th colspan="2">Other¶</th></tr><tr><th>TP</th><th>TA</th><th>T</th><th>H</th><th>R</th><th>NDVI¶</th><th>El</th><th>DL</th><th>LU</th><th>CD</th><th>PS</th><th>RG</th><th>AT</th><th>EA</th><th>HR</th><th>AR</th><th>CC</th><th>B</th></tr></thead><tbody><tr><td>Sutherst and Maywald (1985)</td><td>●</td><td>—</td><td>●</td><td>—</td><td>●</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Sutherst (1985, 1987b)</td><td>●</td><td>—</td><td>●</td><td>—</td><td>●</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Sutherst and Maywald (1987)</td><td>●</td><td>—</td><td>●</td><td>—</td><td>●</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Sutherst and Bottomley (1989)</td><td>●</td><td>●</td><td>●</td><td>—</td><td>●</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>●</td><td>—</td><td>●</td></tr><tr><td>Maywald and Sutherst (1989)</td><td>●</td><td>—</td><td>●</td><td>—</td><td>●</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td></tr><tr><td>Höner and Gomes (1990)</td><td>●</td><td>—</td><td>●</td><td>—</td><td>●</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>●</td><td>●</td><td>—</td></tr><tr><td>Höner et al. (1993)</td><td>●</td><td>—</td><td>●</td><td>—</td><td>●</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Saueressig and Höner (1993)</td><td>●</td><td>—</td><td>●</td><td>—</td><td>●</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Arantes et al. (1995)</td><td>●</td><td>—</td><td>●</td><td>—</td><td>●</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Saueressig and Höner (1995)</td><td>●</td><td>—</td><td>●</td><td>—</td><td>●</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Sutherst et al. (1996)</td><td>●</td><td>—</td><td>●</td><td>—</td><td>●</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td></tr><tr><td>Estrada-Peña (1999)</td><td>●</td><td>●</td><td>●</td><td>—</td><td>●</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Cumming (2000)</td><td>●</td><td>—</td><td>●</td><td>—</td><td>●</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Sutherst (2001)</td><td>●</td><td>—</td><td>●</td><td>—</td><td>●</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Estrada-Peña (2001)</td><td>●</td><td>—</td><td>●</td><td>—</td><td>●</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td></tr><tr><td>Cumming (2002)</td><td>●</td><td>—</td><td>●</td><td>—</td><td>●</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Jubb and Campbell (2002)</td><td>●</td><td>—</td><td>●</td><td>—</td><td>●</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Estrada-Peña (2002)</td><td>●</td><td>●</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>●</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Guglielmone et al. (2003)</td><td>●</td><td>—</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>●</td><td>●</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Estrada-Peña (2003)</td><td>●</td><td>—</td><td>●</td><td>—</td><td>●</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td></tr><tr><td>Fonseca et al. (2005)</td><td>●</td><td>—</td><td>●</td><td>—</td><td>●</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td></tr><tr><td>Estrada-Peña et al. (2005)</td><td>●</td><td>—</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Estrada-Peña et al. (2006c)</td><td>●</td><td>●</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Estrada-Peña and Venzal (2006)</td><td>●</td><td>—</td><td>●</td><td>—</td><td>●</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Estrada-Peña et al. (2006b)</td><td>●</td><td>—</td><td>●</td><td>—</td><td>●</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>●</td><td>—</td><td>—</td></tr><tr><td>Rabiee et al. (2006)</td><td>●</td><td>—</td><td>●</td><td>—</td><td>●</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><td>Cumming and van Vuuren (2006)</td><td>●</td><td>—</td><td>●</td><td>—</td><td>●</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td></tr><tr><td>Estrada-Peña and Venzal (2007)</td><td>●</td><td>—</td><td>●</td><td>—</td><td>●</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td></tr><tr><td>Lynen et al. (2008)</td><td>●</td><td>●</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td></tr><tr><td>Sutherst and Bourne (2009)#</td><td>●</td><td>—</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td></tr><tr><td>Sutherst and Bourne (2009)#</td><td>●</td><td>—</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td></tr><tr><td>De Clercq et al. (2013)</td><td>●</td><td>●</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td></tr><tr><td>Giles et al. (2014)</td><td>●</td><td>●</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td></tr><tr><td>Phillips et al. (2014)</td><td>●</td><td>●</td><td>●</td><td>●</td><td>●</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td><td>●</td><td>—</td><td>—</td></tr></tbody></table>

Note: The symbol “●” signifies “yes/present,” while “—” signifies “no/absent.”

† Drivers: TP, tick presence; TA, tick absence; T, air temperature; H, air humidity; NDVI, Normalized Difference Vegetation Index; El, elevation; DL, daylength.

‡ Management: LU, land use; CD, cattle density; PS, pasture spelling; RG, rotational grazing; AT, acaricide treatment; EA, economic analysis.

§ Factors: HR, host resistance; AR, acaricide resistance.

¶ Other: CC, climate change; B, *Babesia* spp.

# Multiple models described in one reference.

in Victoria, while Rabiee et al. (2006) spatially interpolated CLIMEX point predictions to predict risk of *R. australis* infestation in New South Wales.

## Renewed efforts in the Americas (1995–2004)

During the same period, researchers from Cuba’s Centro de Ingeniería Genética y Biotecnología (CIGB) used the model of Weidhaas

et al. (1983) to predict effects of vaccination (with and without acaricide applications) on *R. microplus* populations in Cuba (Rodríguez 1995, Labarta et al. 1996). They then switched their base model to BCTSIM and adapted it to create a new model (TICKSIM) by modifying its vaccine submodel (Lodos et al. 1995, 2000) and adding a sterile-hybrid-release submodel (Lodos et al. 1999). Later, BCTSIM was recalibrated by
<figure><img src="image_2.png" /><figcaption>Fig. 1. *Rhipicephalus (Boophilus)*-model reference chronology and interconnections from 1973 to 1995, categorized by geographic region of application. Colors on arrows on the right edge identify connections to references in Fig. 2. Box shape represents species included (more than one possible): isosceles trapezoid, *R. australis*; rectangle, *R. microplus*; oval, *R. annulatus*; parallelogram, *R. decoloratus*; hexagon, three previous + *R. geigyi*; bullet, merged *R. microplus/annulatus*. Box outline represents type of model: dashed, analytical; solid, simulation. Thickness of outline represents how much life cycle simulated: thin, partial; thick, complete. Box shade represents model type: white, population dynamics; gray, bioclimatic envelope. Arrows represent borrowing: solid, equations or data; dashed, concepts. Tables 1–4 provide details about the models in these references.</figcaption></figure>
<figure><img src="image_3.png" /><figcaption>Fig. 2. *Rhipicephalus (Boophilus)-model* reference chronology and interconnections from 1995 to 2016, categorized by geographic region of application. Colors on arrows on the left edge identify connections to references in Fig. 1. Box shape represents species included (more than one possible): isosceles trapezoid, *R. australis*; rectangle, *R. microplus*; oval, *R. annulatus*; parallelogram, *R. decoloratus*; hexagon, three previous + *R. geigyi*; bullet, merged *R. microplus/annulatus*. Box outline represents type of model: dashed, analytical; solid, simulation. Thickness of outline represents how much life cycle simulated: thin, partial; thick, complete. Box shade represents model type: white, population dynamics; gray, bioclimatic envelope. Arrows represent borrowing: solid, equations or data; dashed, concepts. Tables 1–4 provide details about the models in these references.</figcaption></figure>
Brazilian researchers to simulate *R. microplus* in Minas Gerais (Fonseca et al. 2000, Delgado 2002). Smith et al. (2000) used their spreadsheet model to analyze effects of tick-control strategies on enzootic stability of babesiosis in Brazil and Paraguay.

During this period, researchers from Texas A&M University (TAMU) developed a new model focusing specifically on daily habitat influences on *R. microplus* and *R. annulatus* populations in south Texas (Teel et al. 1996). They later adapted it to simulate rotational grazing strategies (Teel et al. 1997, 1998), acaricide treatments (Corson et al. 2001), and inspection of cattle for ticks under continuous (Teel et al. 2003) and rotational (Corson et al. 2003) grazing. Hernández-Arrieta et al. (2000) adapted the original TAMU model to simulate *R. microplus* in rotational grazing systems in Venezuela. Later, Corson et al. (2004) built a new simulation model (BoopMod) to predict influences of hourly microclimate, habitat heterogeneity, and within-pasture cattle movement. By this time, Sutherst (1998) had voiced concern: "The present situation, with parasitologists each doing their own thing in terms of developing and using software tools, is like the tower of Babel." It was a call for development of more generic approaches using common scientific terms and computer languages to facilitate communication and collaboration in the research and management of vector-borne diseases.

### *Rise of bioclimatic envelope models (1999–present)*

Increasing availability of remote-sensing data throughout the 1990s helped shift *Rhipicephalus* research toward GIS-based bioclimatic envelope models (Araújo and Peterson 2012), which differed from mechanistic, physiologically based approaches such as CLIMEX. Initial studies focused on South America, predicting habitat suitability for *R. microplus* in South America (Estrada-Peña 1999), Central America (Estrada-Peña 2001), northeastern Argentina (Guglielmone et al. 2003), and Rio de Janeiro State, Brazil (Diersmann et al. 2002, Fonseca et al. 2005). Later studies predicted habitat suitability for *R. microplus* in the Americas from 1950 to 1999 (Estrada-Peña et al. 2005) and for *R. annulatus* and *R. microplus* along the Texas–Mexico border (Estrada-Peña and Venzal 2006), identified climate factors determining the latter's

habitat suitability in Mexico (Estrada-Peña et al. 2006c), and predicted effects of climate change on habitat suitability for the latter in central Argentina, in combination with BoopMod to predict the probability of permanent populations (Estrada-Peña et al. 2006b).

During the same period, tick distributions were predicted for four *Rhipicephalus* (*Boophilus*) species (among many others) in Africa (Cumming 2000, 2002) and, in response to climate change, in the world (Cumming and van Vuuren 2006). Estrada-Peña (2002) predicted habitat suitability for *R. decoloratus* in sub-Saharan Africa but also built a population dynamics model of it driven by remotely sensed temperature and vegetation data. Estrada-Peña (2003) used remote-sensing data to predict habitat suitability for *R. decoloratus* (and three other species) in South Africa. Estrada-Peña and Venzal (2007) analyzed how climate influenced habitat suitability and ecological niche of *R. annulatus* (and five other species) in the Mediterranean region. Similarly, Lynen et al. (2008) predicted distribution ranges of *R. microplus* and *R. decoloratus* in Tanzania. Sutherst and Bourne (2009) repeated Cumming's 2002 study using only climate data and compared its predictions of range extensions of *R. microplus* in Africa due to climate change to those of CLIMEX. De Clercq et al. (2013) predicted climate suitability and distribution range of *R. microplus* in southern West Africa. Most recently, Giles et al. (2014) correlated *R. annulatus* and *R. microplus* presence and climate data in the southern United States, while Phillips et al. (2014) predicted south Texas habitats favorable to white-tailed deer (*Odocoileus virginianus* (Zimmerman)), a recognized host of *R. microplus* and *R. annulatus*, and habitats favorable to *R. microplus* larvae.

### *Return of population dynamics models (2010–present)*

In a return to population dynamics models, Zeman and Lynen (2010) built Lotka–Volterra models of *R. decoloratus* and *R. microplus* competition in Tanzania, while Merino et al. (2011) used *R. microplus* data and BoopMod to predict effects of subolesin vaccination and RNAi on tick populations in Mexico. The following year, Miller et al. (2012) also used BoopMod to predict effects of vaccination on *R. annulatus* outbreaks
in the Permanent Quarantine Zone of the U.S. Cattle Fever Tick Eradication Program. Estrada-Peña et al. (2014) predicted effects of white-tailed deer vaccination on *R. annulatus* and *R. microplus* in northeastern Mexico, while Wang et al. (2016) developed a spatially explicit, individual-based, stochastic *R. microplus* model for south Texas rangelands.

## COMPARISON OF REFERENCES AND MODELS

We summarize this large number of models by categorizing them by (1) “family” (if present), (2) tick species, and (3) mathematical structure and output. “Family” figuratively groups a given model and those adapted from it, often developed by the same or some of the same researchers. “Mathematical structure” distinguishes analytical models (i.e., temporal dimension ignored or implicit) from simulation models, whose explicit representation of the temporal dimension can capture additional interactions between variable environmental conditions and the phenology of tick life stages. “Output” distinguishes population dynamics models from bioclimatic envelope models. The choice and order of other distinguishing characteristics are arbitrary, but are based on over three decades of conversations between an acarologist and an ecological systems modeler. They range from generic (e.g., temporal and spatial scales, stochasticity) to increasingly tick-centric (e.g., representation of development, mortality, and fecundity) characteristics.

### Model family

Due to the continual adaptation and application of pre-existing models, the 101 references necessarily described development and/or use of a smaller number of model families. Model families used most often include CLIMEX (15 refs), the family from TAMU (11 refs), MATIX (nine refs), TICK2 (eight refs), the family from CENSA/UH (eight refs), TICK1 (seven refs), Smith's *Babe-sia* model (five refs), and BCTSIM (five refs).

### Rhipicephalus (Boophilus) species included

Of the 113 model instances, 70 (62%) represented *Rhipicephalus microplus* (41% exclusively so), probably due to its wider distribution than other *Rhipicephalus* (Boophilus) ticks, followed by

40 (35%) representing *Rhipicephalus australis* (33% exclusively so). Twenty-one model instances (19%) represented *Rhipicephalus annulatus* (only 3% exclusively so), nine (7%) represented *Rhipi-cephalus decoloratus* (only 3% exclusively so), and three (3%) represented *Rhipicephalus geigyi*. We found no models of *Rhipicephalus kohlsi*. Models of Weidhaas et al. (1983) and those from TAMU com-bined data for *R. microplus* (including *R. australis* at the time) and *R. annulatus* to create general *R. microplus/annulatus* models (bullet-shaped boxes; Figs. 1, 2).

### Model mathematical structure and output

Most model instances were simulation models (69% of all instances) focused on population dynamics (56% of all instances). Before 1999, all analytical models focused only on population dynamics, while those published since 1999 focused more on the bioclimatic envelope. In the following paragraphs, we describe and compare in more detail models of the bioclimatic envelope (34 instances) versus those of population dynam-ics (79 instances).

*Characteristics of bioclimatic envelope models.*—Of the instances of bioclimatic envelope models, 44% used CLIMEX, 47% used analytical correla-tive species distribution models, and 6% used machine-learning models (Maxent). CLIMEX, which has been used for the longest time (since 1985), can represent habitat suitability for any poikilothermic species (Sutherst et al. 2007). Nietschke et al. (2007) contrasted CLIMEX to its successor DYMEX, which has a phenology com-ponent. CLIMEX appears to predict general pop-ulation trends fairly well, but may be challenged by non-climate influences, such as biotic interac-tions, evolutionary change, and dispersal ability, as may all bioclimatic envelope models (Sinclair et al. 2010). Analytical and machine-learning models, which have become dominant (58% of all model instances since 2005), correlate tick presence/absence and presence only, respectively, with local climate characteristics, using a variety of approaches (e.g., logistic regression, multiple regression). In these models, factors such as Nor-malized Difference Vegetation Indices can serve as an approximation of local temperature and humidity. Olwoch et al. (2007) discussed positive and negative aspects of bioclimatic envelope models for *Rhipicephalus* ticks.
*Characteristics of population dynamics models.*—
1. *Temporal and spatial scales.*—Temporal and spa-
tial scales of a model should be long enough and
large enough, respectively, to encompass the
main questions the model was developed to
address, while the time step and spatial resolu-
tion should be short enough and small enough,
respectively, not to overlook important func-
tional and structural differences in the system
modeled. When noted, most instances of popula-
tion dynamics models followed a daily (35%) or
weekly (32%) time step, although some had time
steps as short as 1 h (Corson et al. 2004) or as
long as one tick generation (~3–4 months;
Sutherst et al. 1979a, Sutherst 1987b). Although
TICK2 (Dallwitz 1987a) interpolated hourly tem-
peratures from daily temperature data to drive
development rates, BoopMod (Corson et al.
2004) was the first to simulate all processes at an
hourly time step. Half of the instances of popula-
tion dynamics models simulated periods ≤2 yr
(51%), though continuous time spans ranged
from 43 days (Sutherst et al. 1978, de la Vega
et al. 1988) to 1000 generations (Merino et al.
2011). Spatial scales of these models also varied
greatly. Most encompassed a ranch or single- or
multi-pasture area (57%), but spatial scale ranged
from a single egg mass (de la Vega et al. 1993) to
multiple locations in the world (Haile et al.
1992). To represent infestations at large scales, 12
instances of population dynamics models were
applied to multiple point locations to predict
potential geographic distribution of ticks.

2. *Stochasticity*.—Stochasticity should be included in models when it is important to represent explicitly inherent variability in the system being modeled and/or uncertainty associated with estimates of model parameters. On the other hand, stochasticity makes the models more difficult to analyze and broadens the uncertainty in their predictions. Hence, only 15% of the pop- ulation dynamics models contained stochastic variables, representing factors such as *Babesia* transmission (Dallwitz 1987b), cattle price and season severity (Elder and Morris 1986), number of standard ticks on cows (Corson et al. 2003, Teel et al. 2003), and habitat preferences (Corson et al. 2004). Sutherst (1983) recommended “stochastic elements to provide probabilities of persistence as well as estimates of population size.” The model of Popham and Garris (1991)

included more stochastic variables than any
other model, with probability density functions
for development and mortality rates and nor-
mally distributed sex ratios and host resistance
levels.

3. *Model structure.*—Only 20% of the popula-
tion dynamics models had an analytical struc-
ture. Some authors integrated these analytic
models into existing simulation models (Utech
et al. 1983, Sutherst et al. 1999), while others
created simulation models to perform analytical
calculations (e.g., sum degree-days; de la Vega
et al. 1993). Dixon et al.'s (1997) analytical trans-
formation and elasticity analysis of BCTSIM
(Mount et al. 1991) suggested that decreasing
fecundity would increase effectiveness of control
methods, something that no other model appar-
ently had identified to that point.

4. *Weather*.—More than half of the population
dynamics models (56%) represented temperature
explicitly to drive processes within them. Some
models included factors affecting egg develop-
ment besides temperature, such as the develop-
ment models of de la Vega and Díaz (1985a) and
Strey et al. (1991). Most models used temperature
to calculate development rates, though some
models used temperature to calculate mortality
rates (Utech et al. 1983, de la Vega and Díaz 1987)
or host-finding rates (Mount et al. 1991, Haile
et al. 1992, Hernández-Arrieta et al. 2000). Only
41% of the population dynamics models, repre-
senting mostly the model families of TAMU,
TICK1, TICK2, and TICKSIM, explicitly included
a measure of ambient moisture, usually as a stress
factor influencing off-host mortality (Utech et al.
1983, Dallwitz 1987a). Factors used to represent
ambient moisture in models included precipita-
tion/evaporation (Sutherst and Dallwitz 1979,
Sutherst and Maywald 1985, Dallwitz 1987a,
Mount et al. 1991, Lodos et al. 1999), ambient rel-
ative humidity (Popham and Garris 1991), and
saturation deficit (Utech et al. 1983, Mount et al.
1991, Haile et al. 1992, Lodos et al. 1999, Corson
et al. 2004). All models that represented ambient
moisture explicitly did the same for temperature.
Finally, some population dynamics models were
driven by GIS-based climate or vegetation data
(Estrada-Peña 2002, Miller et al. 2012, Estrada-
Peña et al. 2014, Wang et al. 2016).

All simulation models using ambient moisture
explicitly, and most using temperature explicitly,
ran with historical weather data. Ideally, models should use microclimate data to reflect the temperature and relative humidity ticks experience; among simulation models, only BoopMod (Corson et al. 2004) appears to have done so. Because use of meso- or macroclimate data may bias predictions of off-host development and mortality, researchers have tried to adjust these data for different habitat types to correct for possible biases (Mount et al. 1991, Haile et al. 1992).

The time step over which models aggregated weather data also influenced their results. As time step increases, weather fluctuations that may influence development and/or mortality rates become lost in a mean value. Sometimes, weather data existed at a temporal scale larger than the model's time step. For example, though running on a daily time step, some models (Popham and Garris 1991, Hernández-Arrieta et al. 2000) used monthly weather data without attempting to estimate daily fluctuations. In contrast, BCTSIM (Mount et al. 1991) estimated weekly weather from monthly weather, while TICK2 (Dallwitz 1987a) interpolated daily maximum and minimum temperatures to estimate hourly temperature.

5. *Development rates*.—Population dynamics models using temperature to drive development rates usually represented development as degree-days above a minimum developmental threshold (Sutherst and Dallwitz 1979, de la Vega and Díaz 1985a, Dallwitz 1987a, Mount et al. 1991, Strey et al. 1991). Others predicted development rates from field data (Sutherst et al. 1979b, Popham and Garris 1991), or as development periods that were fixed by season (Teel et al. 1996, Hernández-Arrieta et al. 2000) or independent of season (Weidhaas et al. 1983). In contrast, Popham and Garris (1991) used fixed probability density functions to simulate development from one stage to the next.

6. *Mortality rates*.—Population dynamics models represented mortality rates in similar fashions. All those that represented ambient moisture explicitly used it to influence mortality rates. BoopMod (Corson et al. 2004) estimated larval mortality rates as the sum of daily saturation deficit over a threshold. Sutherst and Dallwitz (1979) developed a unique method, using precipitation and evaporation to calculate a Soil Dryness Index that influenced egg mortality.

Their model also included the influence of cold stress on egg mortality. Some models, however, used temperature alone to predict mortality rates (e.g., for larvae, de la Vega and Díaz 1987).

Some simulation models used both temperature and ambient moisture to influence mortality. BCTSIM (Mount et al. 1991) set off-host mortality rates for optimal conditions and modified them with indices of temperature, saturation deficit, and precipitation. In the probability density functions of Popham and Garris (1991), all off-host stages died at temperatures above 30°C or relative humidities below 30%, thresholds much lower than those used in any other model.

As with development rates, the remaining models fixed mortality rates by stage or season. Weidhaas et al. (1983) fixed weekly mortality rates regardless of season, while Osburn and Knipling (1982) did the same for larval mortality. Sutherst et al. (1979b), however, varied egg and larval mortality rates by season. Unlike all other models, TICK2 captured the greater sensitivity of young eggs to desiccation by decreasing a stress multiplier as eggs age (Maywald 1987). Estimated mortality rates influence the duration of life stages, including the one most important to managers: larval longevity. de la Vega and Díaz 1987 estimated last larval death from a cohort at 703 degree-days. Utech et al. (1983) calculated accumulated stress on questing larvae as a function of daily maximum temperature, though saturation deficit at 15:00 worked just as well. Their attempts to improve predictions of larval longevity by including soil moisture, minimum temperature, or precipitation were unsuccessful. On-host mortality rates in some models remained fixed during a simulation (Weidhaas et al. 1983, Teel et al. 1996), while others depended on cattle type and on-host tick density (Sutherst et al. 1973, Mount et al. 1991). Sutherst et al. (1979a) included the latter two variables and added a third, season.

7. *Fecundity*.—Population dynamics models had the same variety when simulating fecundity. Egg production remained constant for some (e.g., 3000/female; Weidhaas et al. 1983), but varied by season for others (e.g., 200–2000/female; Sutherst et al. 1979b). Popham and Garris (1991) varied egg mass size with values obtained from a normal distribution. Others represented egg production as a function of temperature (Sutherst
and Dallwitz 1979) or of mean temperature during oviposition and cattle type (Mount et al. 1991). Most models representing eggs assumed a 1:1 female-to-male sex ratio for them, but a few (Mount et al. 1991, Hernández-Arrieta et al. 2000, Corson et al. 2004) used the more precise value of 1.36:1 (Davey and Cooksey 1988) once it became available.

8. *Host encounter rate*.—Most population dynamics models used a constant host-larvae encounter rate (Sutherst and Dallwitz 1979, Sutherst et al. 1979a, Weidhaas et al. 1983, Teel et al. 1996) or varied the rate by season (Sutherst et al. 1979b). Popham and Garris (1991) again used a probability density function to represent larval encounter. Others, however, explicitly included the influence of other factors. For example, Mount et al. (1991) varied encounter rate as a function of host density, ambient temperature, and larval density, which provided negative feedback on encounter rate. The complex encounter-rate model of Sutherst et al. (1978), PICKUP, required estimates of host density, larval density, mean cow speed, and width of area swept per cow to predict the encounter rate. TICK2 appeared to use the same method (M. J. Dallwitz, *personal communication*). Most models defined encounter rate with a single variable that represented both spatial encounter of the grazing host with larvae and the number or proportion of larvae picked up. In contrast, models from TAMU represented encounter rate and pickup rate separately.

## GEOGRAPHIC SUMMARY

Models in Australia tended to focus first on farm-level management techniques such as pasture "spelling" (i.e., excluding grazing to increase ground cover and forage quality) and acaricide use, and then on climate-driven bioclimatic envelope models (i.e., CLIMEX). Models in South America first focused on duration of the off-host phase and then bioclimatic envelope models and effectiveness of anti-tick vaccines. Those in North America first focused on release of sterile hybrid males, then complex cattle-tick-landscape models focusing on eradication, then a combination of GIS-based bioclimatic envelope models and cattle-tick-landscape models focusing on control and/or management. Models infrequently adopted equations or data from previous models from another

continent, or even laboratory, due in part to the timing and objectives of each region's research programs. Notably, to our knowledge, CLIMEX has not been applied to North America alone (nor adopted by North American researchers), and non-CLIMEX bioclimatic envelope models have not been applied to Australia. Somewhat surprising is the absence of any specifically Asian model, despite the presence of *Rhipicephalus australis* throughout Southeast Asia (Guglielmone et al. 2014).

Significantly, most models of Australian *Rhipicephalus* connect to one another due to their common source: the CSIRO. Its 15-yr ascendancy (1973–1989) produced four primary *Rhipicephalus* models (i.e., TICK1, MATIX, TICK2, CLIMEX) and four secondary models (i.e., Sutherst et al. 1973, PICKUP, LARVS, STERHB). The few other researchers around the world who constructed *Rhipicephalus* models during this period had different goals (Smith 1983, Weidhaas et al. 1983) or models too simple to incorporate into the Australians' existing models (Osburn and Knipling 1982, de la Vega and Díaz 1985a). Consequently, although Australian modeling studies acknowledged the existence of other *Rhipicephalus* models, they had no need to borrow from them.

Models in South America show a similar pattern, with most produced by five groups: Smith et al., CENSA/UH, EMBRAPA, CIGB, and Estrada-Peña et al. Unlike models in Australia and North America, South American models borrowed model concepts and structure more frequently, sometimes beginning with a pre-existing model and reparameterizing it for South American conditions (Lodos et al. 1995, Saueresig and Honer 1995, Hernández-Arrieta et al. 2000). Most models in North America came from three groups: USDA-ARS, TAMU, and Estrada-Peña et al. This smaller number of sources hides a relatively large diversity in focus and structure of North American models.

As pioneers of a *Rhipicephalus* (*Boophilus*) modeling program (Sutherst 1993), CSIRO researchers appear to have had the right approach: First build simple models to explore different aspects of a problem, use them to generate testable hypotheses and identify needed data, and finally test the hypotheses or obtain new data with field or laboratory experiments. In some cases, they used field and laboratory results to improve
previous models or to construct new ones, some
of which they later integrated into pre-existing
models. As Sutherst et al. (1979a) emphasized,
“...the greatest value of this modelling approach
lies in its ability to identify the key ecological and
managerial questions that lead to improved pest
control and to focus research and extension effort
towards this end.” Indeed, some tick data identi-
fied as lacking during development of BoopMod
(Corson et al. 2004) were later provided by an
Australian laboratory experiment (Sutherst and
Bourne 2006).

Researchers in both Australia and South America had the ability to conduct experiments with live *Rhipicephalus* (*Boophilus*); in contrast, eradication of *Rhipicephalus microplus* and *Rhipicephalus annulatus* in the United States meant that few researchers in that country could do so (Popham and Garris 1991, Strey et al. 1991). The USDA-ARS Cattle Fever Tick Research Laboratory has generated much laboratory data about *Rhipicephalus* (*Boophilus*), but it has performed outdoor studies only in stalls or biosecure pastures. Consequently, most North American models based themselves on an amalgam of U.S. laboratory or Mexican and Australian field and laboratory data. Except for rough field observations before and during the U.S. eradication program, no field data exist to evaluate models of *Rhipicephalus* (*Boophilus*) populations in the United States. As a result, TAMU researchers evaluated their models with sensitivity analyses and comparisons with Australian field studies, which did not provide direct comparison with the scenarios simulated.

The reinstatement of *R. australis* as a sibling
species of *R. microplus* (Estrada-Peña et al. 2012,
Guglielmone et al. 2014) has spurred new eco-
logical studies of *R. microplus* in South America
(Canevari et al. 2016). It may also spur reconsider-
ation of past model predictions and revision of
existing models, especially those that used data
from one species to represent the other species,
or those developed by merging data from both
species together. Although basic model structure
is unlikely to change, models may require
recalibration to represent the species or even
local "variety" of *Rhipicephalus* (*Boophilus*) more
accurately, depending on the modeler's question.

Ultimate use of these models has also varied.
More than others, the Australians applied their

models to cattle production systems in the field.
Elder et al. (1983) were able to predict quantita-
tively effects of changing breed type in Queens-
land. In particular, the decision-analysis model of
Elder and Morris (1986) appeared robust and
detailed enough to support their management
suggestions. Even a regional tick ecology pro-
gram in Africa was based on predictions of Aus-
tralian tick models (Sutherst 1987b). Other
models helped determine appropriate pasture
spelling and rotation periods and could be
applied to other tick species. TICK1 was used to
create the T3HOST model, and TICK2 also simu-
lated two- and three-host ticks (Sutherst 1985).
Models have been useful for walking the man-
agement tightrope between enzootic stability and
instability/outbreaks of bovine babesiosis (e.g.,
Smith et al. 2000). South American researchers
also used their models in a similar way, with de
la Vega and Díaz (1987) using them to identify
future research and Lodos et al. (2000) beginning
to apply them to vaccine-related management
decisions. Most models in North America, how-
ever, have remained untested theoretical con-
structs, serving mainly to identify the most
important factors to vary in the next model, but
some may be directly applicable in planning
strategies to maintain eradication in the United
States in the face of global change, including
climate change (Pérez de León et al. 2012), which
is predicted to expand habitat suitable for *Rhipi-
cephalus* ticks to the north (Giles et al. 2014).

As Walker (2011) noted, complex mechanistic
models may be too complex for management
purposes. Models with fewer parameters to
calibrate may be just as effective at predicting
appropriate timing of management (Dye 1992).
Sutherst (1987b) stated that models “offer an
escape” from the “waste of resources” caused by
isolated field research of the same parasite spe-
cies in similar climates. Sutherst and Bottomley
(1989) stressed the importance of using expert
systems to disseminate the knowledge of the
world’s few tick experts and to compensate for a
decreasing number of field experiments.

Thus, differing characteristics of *Rhipicephalus*
populations within regions, and each region's
organized reaction to them, have led to differ-
ences in ranking of important factors among
models. For example, host resistance was impor-
tant in Australian and South American models,
in part because eradication was rarely an option. Conversely, larval longevity was important in North American models because it influences the success of pasture quarantines. Models also reflected changing research priorities over time. Acaricide resistance, which appeared in Australian models almost from the beginning, interested few North American researchers until R. microplus began to display acaricide resistance in Mexico. This alignment of research priorities may promote greater collaboration between Australian and North American Rhipicephalus (Boophilus) modelers in the future, despite the separation of R. microplus and R. australis.

LESSONS FROM THE PAST AND PERSPECTIVES FOR THE FUTURE

Perhaps the most important lesson emerging from 45 yr of Rhipicephalus (Boophilus) modeling on several continents is that a diverse suite of modeling approaches is necessary, given the wide range of scales (i.e., genetic to global) of Rhipicephalus biological, ecological, and management issues. Some models need less detail and accuracy in biological submodels because of their large spatial and temporal scales (e.g., global) or uncertainties in other submodels (e.g., encounter rate, human factors). Even when focused at different scales, however, models with similar purposes have converged over time to include most of the same important factors. More recent models of Rhipicephalus population dynamics, for example, include explicit representation of temperature and ambient moisture, both drivers of development and mortality rates. Similarly, bioclimatic envelope models calculate indices of temperature and ambient moisture, either directly, from weather data (Sutherst and Maywald 1985), or indirectly, from remotely sensed vegetation or geographic data (e.g., Giles et al. 2014).

Although from a theoretical point of view it seems trivial to conclude that model structure and level of detail depend on model purpose, in practice this lesson seems hard to apply or learn. Models do not arise by logical inference from data about the real system, and reasons for choosing one model structure over another are not found in the data themselves, but rather in ideas about how a model will help connect the data to other knowledge (Lander 2010). To

decide how useful this connection is, that is, to evaluate the usefulness of a model, we must clearly identify (1) the purpose of the model, (2) the criteria the model must meet to be declared useful, and (3) the intended context for the model. Arguably, Rykiel's (1996) observation that the last two items are seldom specified for ecological models remains valid. Model context, often overlooked, embodies all model assumptions, especially those that are unstated and relegated to the system environment of the model. Dixon et al. (1997) argued that increasing the number of parameters in a model may increase its realism, but may reduce its interpretability.

Two of the most pressing reasons for developing a new generation of Rhipicephalus (Boophilus) models are to assess effects of global change (Pérez de León et al. 2012) on (1) tick eradication/management programs and (2) emergence/reemergence/expansion of tick-borne diseases. The scope of global change includes interactions among environmental, climate, social, political, and technological changes at multiple temporal and spatial scales. Global change influences ecological processes, which influence tick biology and ecology and consequently the epidemiology of pathogens transmitted by ticks (Reisen 2010, Tabachnick 2010).

Questions arise about which criteria to use to assess how well Rhipicephalus (Boophilus) models serve the purposes described above. We suggest that models must be able to generate appropriate spatial–temporal dynamics of both ticks and pathogens in response to changes in climatic conditions, landscape structure, and host–community composition. Current climate-driven GIS-based bioclimatic envelope models estimate potential changes in habitat suitability resulting from changes in climatic conditions and patterns of land use (e.g., see review by Walker 2011), and current mechanistic population dynamics models predict probability of tick persistence under given environmental conditions (e.g., Miller et al. 2012). Direct comparison of predictions of bioclimatic envelope models with those of mechanistic population dynamics models (e.g., Höner et al. 1993; Estrada-Peña et al. 2006b, 2014) appears useful.

It is now widely recognized that native wildlife serves as important reservoirs and dispersal agents of Rhipicephalus (Boophilus) ticks (Cançado
et al. 2009, De Meeûs et al. 2010, Pérez de León et al. 2012). Indeed, *Rhipicephalus australis* in New Caledonia has adapted to parasitize Rusa deer (*Cervus timorensis russa* (de Blainville); Barré et al. 2011). In response, wildlife hosts are now explicitly represented in *Rhipicephalus* (*Boophilus*) models (e.g., Zeman and Lynen 2010, Estrada-Peña et al. 2014, Phillips et al. 2014, Wang et al. 2016).

Models of other tick species have been used to explore (1) the efficacy of novel approaches to tick control such as targeting acaricides at specific types of hosts (Wang et al. 2012), (2) effects of seasonal fluctuations in host densities and abundances of tick life stages on dynamics of vector-borne pathogens (Wang et al. 2015), and (3) effects of changes in host diversity and community composition on disease risk (LoGiudice et al. 2003). Development of analogous models for *Rhipicephalus* (*Boophilus*) would provide the ability to hypothesize specific cause–effect relationships, test their ability to generate the patterns of tick abundance and pathogen prevalence observed in the field, and simulate how these patterns might be changed by specific interventions in time and space, and in the tick life cycle.

## ACKNOWLEDGMENTS

This research was supported in part by Texas A&M AgriLife Research Project TEX08911. The open access publishing fees for this article were covered in part by the Texas A&M University Open Access to Knowledge Fund (OAKFund), supported by the University Libraries and the Office of the Vice President for Research.

## LITERATURE CITED

* Abramson, D., I. Foster, J. Giddy, A. Lewis, R. Sosic, R. W. Sutherst and N. White 1997. The Nimrod computational workbench: a case study in desktop metacomputing. In 20th Australasian Computer Science Conference. Macquarie University, Sydney, New South Wales, Australia.

* Angus, B. M. 1996. The history of the cattle tick *Boophilus microplus* in Australia and achievements in its control. International Journal for Parasitology 26:1341–1355.

* Anyamba, A., K. J. Linthicum, J. L. Small, K. M. Collins, C. J. Tucker, E. W. Pak, S. C. Britch, J. R. Eastman, J. E. Pinzon, and K. L. Russell. 2012. Climate teleconnections and recent patterns of human and

animal disease outbreaks. PLoS Neglected Tropical Diseases 6:e1465.

* Arantes, G. J., A. O. Marques, and M. R. Honer. 1995. O carrapato do bovino, *Boophilus microplus*, no município de Uberlândia, MG: análise da sua resistência contra carrapaticidas comerciais. Revista Brasileira de Parasitologia Veterinária 4:89–93.

* Araújo, M. B., and A. T. Peterson. 2012. Uses and misuses of bioclimatic envelope modeling. Ecology 93:1527–1539.

* Barré, N., J. Happold, J.-M. Delathière, D. Desoutter, M. Salery, A. de Vos, C. Marchal, R. Perrot, M. Grailles, and A. Mortelecque. 2011. A campaign to eradicate bovine babesiosis from New Caledonia. Ticks and Tick-borne Diseases 2:55–61.

* Basher, R. E., et al. 1998. Australasia. Pages 105–148 in R. T. Watson, M. C. Zinyowera, R. H. Moss, and D. J. Dokken, editors. The regional impacts of climate change: an assessment of vulnerability. Cambridge University Press, New York, New York, USA.

* Beugnet, F., K. Chalvet-Monfray, and P. Sabatier. 1998. Use of a mathematical model to study the control measures of the cattle tick *Boophilus microplus* population in New Caledonia. Veterinary Parasitology 77:277–288.

* Bourne, A. S., R. W. Sutherst, I. D. Sutherland, G. F. Maywald, and D. A. Stegeman. 1988. Ecology of the cattle tick (*Boophilus microplus*) in subtropical Australia. III. Modelling populations on different breeds of cattle. Australian Journal of Agricultural Research 39:309–318.

* Burger, T. D., R. Shao, and S. C. Barker. 2014. Phylogenetic analysis of mitochondrial genome sequences indicates that the cattle tick, *Rhipicephalus (Boophilus) microplus*, contains a cryptic species. Molecular Phylogenetics and Evolution 76:241–253.

* Cançado, P. H. D., C. A. Zucco, E. M. Piranda, J. L. H. Faccini, and G. M. Mourão. 2009. *Rhipicephalus (Boophilus) microplus* (Acari: Ixodidae) as a parasite of pampas deer (*Ozoctoceros bezoarticus*) and cattle in Brazil's Central Pantanal. Revista Brasileira de Parasitologia Veterinária 18:42–46.

* Canevari, J., A. Mangold, A. Guglielmone, and S. Nava. 2016. Population dynamics of the cattle tick *Rhipicephalus (Boophilus) microplus* in a subtropical subhumid region of Argentina for use in the design of control strategies. Medical and Veterinary Entomology 31:6–14.

* Corson, M. S., P. D. Teel, and W. E. Grant. 2001. Influence of acaricide resistance on cattle-fever tick (*Boophilus spp.*) infestations in semi-arid thornshrublands: a simulation approach. Experimental and Applied Acarology 25:171–184.

* Corson, M. S., P. D. Teel, and W. E. Grant. 2003. Simulating detection of cattle-fever tick (*Boophilus spp.*)
infestations in rotational grazing systems. Ecological Modelling 167:277-286.

Corson, M. S., P. D. Teel, and W. E. Grant. 2004. Microclimate influence in a physiological model of cattle-fever tick (*Boophilus spp.*) population dynamics. Ecological Modelling 180:487-514.

Cumming, G. S. 2000. Using habitat models to map diversity: pan-African species richness of ticks (Acari: Ixodida). Journal of Biogeography 27:425-440.

Cumming, G. S. 2002. Comparing climate and vegetation as limiting factors for species ranges of African ticks. Ecology 83:255-268.

Cumming, G. S., and D. P. van Vuuren. 2006. Will climate change affect ectoparasite species ranges? Global Ecology and Biogeography 15:486-497.

Dallwitz, M. J. 1987a. Ecological models. 3. TICK2—a general program for modelling ticks and tick-borne diseases. Pages 77–78 in *Ticks and tick-borne diseases*. ACIAR, Canberra, Australian Capital Territory, Australia.

Dallwitz, M. J. 1987b. Modelling tick-borne diseases in TICK2. Pages 88–89 in *Ticks and tick-borne diseases*. ACIAR, Canberra, Australian Capital Territory, Australia.

Dallwitz, M. J. 1987c. Modelling tick management. 4. TICK2. Pages 145 in *Ticks and tick-borne diseases*. ACIAR, Canberra, Australian Capital Territory, Australia.

Davey, R. B., and L. M. Cooksey. 1988. Sex ratios of *Boophilus* ticks (Acari: Ixodidae) reaching adulthood on cattle. Journal of Medical Entomology 25:82-84.

de Castro, J. J., A. D. James, B. Minjauw, G. U. Di Giulio, A. Permin, R. G. Pegram, G. B. Chizyuka, and P. Sinyangwe. 1997. Long-term studies on the economic impact of ticks on Sanga cattle in Zambia. Experimental & Applied Acarology 21:3-19.

De Clercq, E. M., A. Estrada-Peña, S. Adehan, M. Madder, and S. O. Vanwambeke. 2013. An update on distribution models for *Rhipicephalus microplus* in West Africa. Geospatial Health 8:301-308.

de la Fuente, J., C. Almazán, M. Canales, J. M. Perez de la Lastra, K. M. Kocan, and P. Willadsen. 2007. A ten-year review of commercial vaccine performance for control of tick infestations on cattle. Animal Health Research Reviews 8:23-28.

de la Vega, R., and G. Díaz. 1985a. Aplicacion de las constantes termicas en el control de la garrapata del ganado vacuno (*Boophilus microplus*). I. Cálculo de las constantes térmicas. Revista de Salud Animal 7:141-148.

de la Vega, R., and G. Díaz. 1985b. Aplicacion de las constantes termicas en el control de la garrapata del ganado vacuno (*Boophilus microplus*). II. Estimación del inicio de la eclosión en condiciones

naturales simuladas. Revista de Salud Animal 7:307-316.

de la Vega, R., and G. Díaz. 1985c. Aplicacion de las constantes termicas en el control de la garrapata del ganado vacuno (*Boophilus microplus*). III. Simplificaciones del método de estimación de los períodos de la fase no parasitaria. Revista de Salud Animal 7:441-446.

de la Vega, R., and G. Díaz. 1986. Aplicacion de las constantes termicas en el control de la garrapata del ganado vacuno (*Boophilus microplus*). IV. Pronóstico del inicio de la eclosión en condiciones de intemperie. Revista de Salud Animal 8:337-345.

de la Vega, R., and G. Díaz. 1987. Aplicación de las constantes térmicas en el control de la garrapata del ganado vacuno (*Boophilus microplus*). V. Supervivencia larvaria en el laboratorio. Revista de Salud Animal 9:259-265.

de la Vega, R., and G. Díaz. 1992. Aplicacion de las constantes termicas en el control de la garrapata del ganado vacuno (*Boophilus microplus*). VIII. Validación del programa de cuarentena. Revista de Salud Animal 14:133-136.

de la Vega, R., F. Farradá, and G. Díaz. 1988. Aplicación de las constantes térmicas en el control de la garrapata del ganado vacuno (*Boophilus microplus*). VI. Cuarentena. Revista de Salud Animal 10:71-75.

de la Vega, R., F. Farradá, and G. Díaz. 1993. Aplicacion de las constantes termicas en el control de la garrapata del ganado vacuno (*Boophilus microplus*). VII. Despoblamiento. Revista de Salud Animal 15:163-171.

De Meeús, T., B. B. Koffi, N. Barré, M. de Giné-Wichatitsky, and C. Chevillon. 2010. Swift symmetric adaptation of a species of cattle tick to a new deer host in New Caledonia. Infection, Genetics and Evolution 10:976-983.

Delgado, F. E. F. 2002. Aviliação do controle estratégio do *Boophilus microplus* (Canestrini, 1887), pelo programa BABSIM, em propriedades dos Campos das Vertentes e Sul Minas. Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.

Diersmann, E. M., A. H. Fonseca, and M. J. Pereira. 2002. Análise espacial e temporal do *Boophilus microplus* (Canestrini, 1887) (Acari: Ixodidae) através de um SGI. Congresso Brasileiro de Parasitologia Veterinária, Sao Paulo, Sao Paulo, Brazil.

Dixon, P., N. Friday, P. Ang, S. Heppell, and M. Kshatriya. 1997. Sensitivity analysis of structured-population models for management and conservation. Pages 471–513 in S. Tuljapurkar and H. Caswell, editors. Structured-population models in marine, terrestrial, and freshwater systems. Chapman & Hall, New York, New York, USA.
Dye, C. 1992. The analysis of parasite transmission by bloodsucking insects. Annual Review of Entomology 37:1–19.

Elder, J. K., S. G. Knott, and J. F. Kearnan. 1983. A coordinated approach to control of the cattle tick (*Boophilus microplus*) in south east Queensland, Australia. Pages 392–399 in *Third International Symposium on Veterinary Epidemiology and Economics. Veterinary Medicine Publishing Company, Arlington, Virginia, USA*.

Elder, J. K., and R. S. Morris. 1986. The use of decision analysis to compare cattle tick control strategies under conditions of risk. Preventive Veterinary Medicine 3:523–535.

Estrada-Peña, A. 1999. Geostatistics and remote sensing using NOAA-AVHRR satellite imagery as predictive tools in tick distribution and habitat suitability estimations for *Boophilus microplus* (Acari: Ixodidae) in South America. Veterinary Parasitology 81:73–82.

Estrada-Peña, A. 2001. Climate warming and changes in habitat suitability for *Boophilus microplus* (Acari: Ixodidae) in Central America. Journal of Parasitology 87:978–987.

Estrada-Peña, A. 2002. A simulation model for environmental population densities, survival rates and prevalence of *Boophilus decoloratus* (Acari: Ixodidae) using remotely sensed environmental information. Veterinary Parasitology 104:51–78.

Estrada-Peña, A. 2003. Climate change decreases habitat suitability for some tick species (Acari: Ixodidae) in South Africa. Onderstepoort Journal of Veterinary Research 70:79–93.

Estrada-Peña, A., A. Bouattour, J. Camicas, A. A. Guglielmone, I. Horak, F. Jongejan, A. Latif, R. Pegram, and A. Walker. 2006a. The known distribution and ecological preferences of the tick subgenus *Boophilus* (Acari: Ixodidae) in Africa and Latin America. Experimental and Applied Acarology 38:219–235.

Estrada-Peña, A., M. S. Corson, J. M. Venzal, A. J. Mangold, and A. A. Guglielmone. 2006b. Changes in climate and habitat suitability for the cattle tick *Boophilus microplus* in its southern Neotropical distribution range. Journal of Vector Ecology 31: 158–167.

Estrada-Peña, A., Z. García, and H. F. Sánchez. 2006c. The distribution and ecological preferences of *Boophilus microplus* (Acari: Ixodidae) in Mexico. Experimental and Applied Acarology 38:307–316.

Estrada-Peña, A., D. Carreón, C. Almazán, and J. de la Fuente. 2014. Modeling the impact of climate and landscape on the efficacy of white tailed deer vaccination for cattle tick control in northeastern Mexico. PLoS ONE 9:e102905.

Estrada-Peña, A., and M. Salman. 2013. Current limitations in the control and spread of ticks that affect livestock: a review. Agriculture 3:221.

Estrada-Peña, A., C. Sanchez Acedo, J. Quílez, and E. Del Cacho. 2005. A retrospective study of climatic suitability for the tick *Rhipicephalus (Boophilus) microplus* in the Americas. Global Ecol- ogy and Biogeography 14:565–573.

Estrada-Peña, A., and J. M. Venzal. 2006. High-resolution predictive mapping for *Boophilus annulatus* and *B. microplus* (Acari: Ixodidae) in Mexico and Southern Texas. Veterinary Parasitology 142:350–358.

Estrada-Peña, A., and J. M. Venzal. 2007. Climate niches of tick species in the Mediterranean region: modeling of occurrence data, distributional constraints, and impact of climate change. Journal of Medical Entomology 44:1130–1138.

Estrada-Peña, A., J. M. Venzal, S. Nava, A. J. Mangold, A. A. Guglielmone, M. B. Labruna, and J. de la Fuente. 2012. Reinstatement of *Rhipicephalus (Boophilus) australis* Fuller, the Australian Cattle Tick (Acari: Ixodidae) with redescription of the adult and larval stages. Journal of Medical Entomology 49:794–802.

Floyd, R. B., R. W. Sutherst, and J. Hungerford. 1995. Modelling the field efficacy of a genetically engineered vaccine against the cattle tick, *Boophilus microplus*. International Journal for Parasitology 25:285–291.

Fonseca, A. H., M. J. S. Pereira, M. H. B. Góes, and J. X. Silva. 2005. Distribuição espaço-temporal de *Boophilus microplus* (Acari: Ixodidae) analisada por geoprocessamento no município de Seropédica, Estado do Rio de Janeiro, Brasil. Revista Brasileira de Parasitologia Veterinária 14:167–172.

Fonseca, A. H., M. J. S. Pereira, and R. C. Leite. 2000. Desempenho do programa BABSIM no estudo epidemiológico de *Boophilus microplus* (Canestrini, 1889) (Acari: Ixodidae). Arquivo Brasileiro de Medicina Veterinaria e Zootecnia 52:342–349.

George, J. E. 1990. Wildlife as a constraint to the eradication of *Boophilus* spp. (Acari: Ixodidae). Journal of Agricultural Entomology 7:119–125.

George, J. E., J. M. Pound, and R. B. Davey. 2004. Chemical control of ticks on cattle and the resistance of these parasites to acaricides. Parasitology 129:S353–S366.

Giles, J. R., A. T. Peterson, J. D. Busch, P. U. Olafson, G. A. Scoles, R. B. Davey, J. M. Pound, D. M. Kammlah, K. H. Lohmeyer, and D. M. Wagner. 2014. Invasive potential of cattle fever ticks in the southern United States. Parasites & Vectors 7:189.

Graf, J.-F., R. Gogolewski, N. Leach-Bing, G. A. Sabatinini, M. B. Molento, E. L. Bordin, and G. J. Arantes.
2004. Tick control: an industry point of view. *Parasitology* 129:S427-S442.

Graham, O. H., and J. L. Hourrigan. 1977. Eradication programs for the arthropod parasites of livestock. *Journal of Medical Entomology* 13:629-658.

Guglielmone, A. A., R. Giorgi, A. Sodiro, R. Gay, A. Canal, A. J. Mangold, and A. Estrada-Peña. 2003. Aptitud ecológica de los departamentos Castellanos y Las Colonias, Santa Fe, para sustentar hipotéticas poblaciones de la garrapata común del vacuno, *Boophilus microplus* (Acari: Ixodidae). *Revista de Investigaciones Agropecuarias* 32:75-92.

Guglielmone, A. A., R. G. Robbins, D. A. Apanaskevich, T. N. Petney, A. Estrada-Peña, and I. G. Horak. 2014. The genus *Rhipicephalus*. Pages 527-603 in *The hard ticks of the world*. Springer, Dordrecht, The Netherlands.

Haile, D. G., G. A. Mount, and L. M. Cooksey. 1992. Computer simulation of *Babesia bovis* (Babes) and *B. bigemina* (Smith & Kilborne) transmission by *Boophilus* cattle ticks (Acari:Ixodidae). *Journal of Medical Entomology* 29:246-258.

Hall, N., P. Whish-Wilson, and N. White. 1996. An approach to costing the impact of global warming, on the suitability of different parts of Australia, for cattle tick. *In* 40th Annual Conference of the Australian Agricultural and Resource Economics Society, Melbourne, Australia.

Hernández-Arrieta, F. J., P. D. Teel, M. S. Corson, and W. E. Grant. 2000. Simulation of rotational grazing to evaluate integrated pest management strategies for *Boophilus microplus* (Acari: Ixodidae) in Venezuela. *Veterinary Parasitology* 92:139-149.

Honer, M. R., and A. Gomes. 1990. O manejo integrado de moscas-dos-chifres, berne e carrapato em gado de corte. Page 60 Circulara Tecnica.

Höner, M. R., C. G. Paloschi, A. P. de Souza, C. I. Ramos and A. A. H. Beck. 1993. Epidemiologia e controle do carrapato de bovinos *Boophilus microplus* no Estado de Santa Catarina. Empresa Pesquisa Agropecuaria e Difusão de Tecnologia de Santa Catarina S.A. (EPAGRI), Florianópolis, Santa Catarina, Brazil

Jubb, T. F., and N. J. Campbell. 2002. Cattle tick (*Boophilus microplus*) in Victoria on horses from Queensland. Australian Veterinary Journal 80:92-93.

Kolonin, G. V. 2009. Fauna of Ixodid ticks of the world (Acari: Ixodidae). http://www.kolonin.org/1.html

Labarta, V., M. Rodríguez, M. L. Penichet, R. Lleonart, L. Lorenzo-Luaces, and J. de la Fuente. 1996. Simulation of control strategies for the cattle tick *Boophilus microplus* employing vaccination with a recombinant Bm86 antigen preparation. Veterinary Parasitology 63:131-160.

Lander, A. D. 2010. The edges of understanding. BMC Biology 8:40.

Lodos, J., O. Boué, and J. de la Fuente. 2000. A model to simulate the effect of vaccination against *Boophilus* ticks on cattle. *Veterinary Parasitology* 87:315-326.

Lodos, J., M. E. Ochagavia, M. Rodriguez, and J. de la Fuente. 1999. A simulation study of the effects of acaricides and vaccination on *Boophilus* cattle-tick populations. *Preventive Veterinary Medicine* 38:47-63.

Lodos, J., M. E. Ochagavia, M. Rodríguez, and J. de la Fuente. 1995. Computer simulation of *Boophilus microplus* cattle tick population dynamics employing acaricides and vaccination control methods. Pages 131-145 in *Recombinant vaccines for the control of the cattle tick*. Elfos Scientiae, Havana, Cuba.

LoGiudice, K., R. S. Ostfeld, K. A. Schmidt, and F. Keesing. 2003. The ecology of infectious disease: effects of host diversity and community composition on Lyme disease risk. *Proceedings of the National Academy of Sciences* 100:567-571.

Lynen, G., P. Zeman, C. Bakuname, G. Di Giulio, P. Mtui, P. Sanka, and F. Jongejan. 2008. Shifts in the distributional ranges of *Boophilus* ticks in Tanzania: evidence that a parapatric boundary between *Boophilus microplus* and *B. decoloratus* follows climate gradients. *Experimental and Applied Acarology* 44:147-164.

Maywald, G. F. 1987. Modelling tick populations. 2. Developmental phase. Pages 39-43 in *Ticks and tick-borne diseases. Proceedings of an International Workshop*. Australian Center for International Agricultural Research, Nyanga, Zimbabwe.

Maywald, G. F., M. J. Dallwitz, and R. W. Sutherst. 1980. A systems approach to cattle tick control. Pages 132-139 in *Fourth Biennial Conference of the Simulation Society of America*. University of Queensland, Brisbane, Queensland, Australia.

Maywald, G. F., and R. W. Sutherst. 1989. CLIMEX: recent developments in a computer program for comparing climates in ecology. Pages 134-140 in *Proceedings of the Simulation Society of Australia/IMACS Eighth Biennial Conference, September 25-27*. Central Printery Australian National University, Canberra, Australia.

McCooke, J. K., F. D. Guerrero, R. A. Barrero, M. Black, A. Hunter, C. Bell, F. Schilkey, R. J. Miller, and M. I. Bellgard. 2015. The mitochondrial genome of a Texas outbreak strain of the cattle tick, *Rhipicephalus (Boophilus) microplus*, derived from whole genome sequencing Pacific Biosciences and Illumina reads. *Gene* 571:135-141.

Merino, O., C. Almazán, M. Canales, M. Villar, J. A. Moreno-Cid, A. Estrada-Peña, K. M. Kocan, and J. de la Fuente. 2011. Control of *Rhipicephalus (Boophilus) microplus* infestations by the combination of subolesin vaccination and tick autocidal control after subolesin gene knockdown in ticks fed on cattle. *Vaccine* 29:2248-2254.
Miller, R., A. Estrada-Peña, C. Almazán, A. Allen, L. Jory, K. Yeater, M. Messenger, D. Ellis, and A. A. Perez de León. 2012. Exploring the use of an anti-tick vaccine as a tool for the integrated eradication of the cattle fever tick, *Rhipicephalus (Boophilus) annulatus*. Vaccine 30:5682–5687.

Morgan, E. R., E. Milner-Gulland, P. R. Torgerson, and G. F. Medley. 2004. Ruminating on complexity: macroparasites of wildlife and livestock. Trends in Ecology & Evolution 19:181–188.

Mount, G. A., D. G. Haile, R. B. Davey, and L. M. Cooksey. 1991. Computer simulation of *Boophilus* cattle tick (Acari: Ixodidae) population dynamics. Journal of Medical Entomology 28:223–240.

Murrell, A., and S. C. Barker. 2003. Synonymy of *Boophilus* Curtice, 1891 with *Rhipicephalus* Koch, 1844 (Acari: Ixodidae). Systematic Parasitology 56:169–172.

Nicholson, W. L., D. E. Sonenshine, R. E. Lane, and G. Uilenberg. 2009. Ticks (Ixodida). Pages 483–532 in G. R. Mullin and L. Durden, editors. Medical and veterinary entomology. Elsevier, Amsterdam, The Netherlands.

Nietschke, B. S., R. D. Magarey, D. M. Borchert, D. D. Calvin, and E. Jones. 2007. A developmental database to support insect phenology models. Crop Protection 26:1444–1448.

Norman, R., A. Worton, and L. Gilbert. 2016. Past and future perspectives on mathematical models of tick-borne pathogens. Parasitology 143:850–859.

Norton, G. A., R. W. Sutherst, and G. F. Maywald. 1983. A framework for integrating control methods against the cattle tick, *Boophilus microplus* in Australia. Journal of Applied Ecology 20:489–505.

Norton, G. A., R. W. Sutherst, and G. F. Maywald. 1984. Implementation models: the case of the Australian cattle tick. Pages 381–394 in G. R. Conway, editor. Pest and pathogen control: strategic, tactical, and policy models. Wiley, Chichester, UK.

Olwoch, J. M., A. S. Van Jaarsveld, C. H. Scholtz, and I. G. Horak. 2007. Climate change and the genus *Rhipicephalus* (Acari: Ixodidae) in Africa. Onderstepoort Journal of Veterinary Research 74:45–72.

Osburn, R. L., and E. F. Knipling. 1982. The potential use of sterile hybrid *Boophilus* ticks (Acari: Ixodidae) as a supplemental eradication technique. Journal of Medical Entomology 19:637–644.

Pérez de León, A., P. D. Teel, A. N. Auclair, M. T. Messenger, F. D. Guerrero, G. Schuster, and R. J. Miller. 2012. Integrated strategy for sustainable cattle fever tick eradication in USA is required to mitigate the impact of global change. Frontiers in Physiology 3:1–17.

Phillips, P. L., J. B. Welch, and M. Kramer. 2014. Development of a spatially targeted field sampling technique for the southern cattle tick, *Rhipicephalus microplus*, by mapping whitetailed deer, *Odocoileus virginianus*, habitat in South Texas. Journal of Insect Science 14:88.

Popham, T. W., and G. I. Garris. 1991. Considerations when modeling alternative eradication strategies for *Boophilus microplus* (Canestrini) (Acari: Ixodidae) in Puerto Rico. Journal of Agricultural Entomology 8:271–289.

Rabiee, A., M. Playford, M. Stevenson, and I. J. Lean. 2006. Risk assessment on cattle ticks and tick fever. March 2006. Bovine Research Australasia, Camden, New South Wales, Australia.

Racelis, A. E., R. B. Davey, J. A. Goolsby, A. P. de León, K. Varner, and R. Duhaime. 2012. Facilitative ecological interactions between invasive species: *Arundo donax* stands as favorable habitat for cattle ticks (Acari: Ixodidae) along the US-Mexico border. Journal of Medical Entomology 49:410–417.

Reisen, W. K. 2010. Landscape epidemiology of vector-borne diseases. Annual Review of Entomology 55:461–483.

Roberts, F. H. S. 1970. Australian ticks. Commonwealth Scientific and Industrial Research Organisation, Yeerongpilly, Queensland, Australia.

Rodríguez, M., et al. 1995. Control of *Boophilus microplus* populations in grazing cattle vaccinated with a recombinant Bm86 antigen preparation. Veterinary Parasitology 57:339–349.

Rykiel, E. J. 1996. Testing ecological models: the meaning of validation. Ecological Modelling 90:229–244.

Saueressig, T. M., and M. R. Honer. 1993. Dinâmica populacional do carrapato *Boophilus microplus* nos cãerados do Distrito Federal, análises e simulações. Seminário Brasileiro de Parasitologia Veterinária 8:A3.

Saueressig, T. M., and M. R. Honer. 1995. Adjustment of simulations of cattle tick (*Boophilus microplus*) populations and field observations in the Planalto region of Brasília (DF). Revista Brasileira de Parasitologia Veterinária 4:9–13.

Sinclair, S. J., M. D. White, and G. R. Newell. 2010. How useful are species distribution models for managing biodiversity under future climates? Ecology and Society 15:8.

Smith, R. D. 1983. *Babesia bovis*: computer simulation of the relationship between the tick vector, parasite, and bovine host. Experimental Parasitology 56:27–40.

Smith, R. D. 1984. Epidemiology of babesiosis. Pages 207–232 in M. Ristic, P. Ambroise-Thomas, and J. P. Kreier, editors. Malaria and babesiosis: research findings and control measures. Martinus Nijhoff Publishers, Dordrecht, The Netherlands.

Smith, R. D. 1991. Computer simulation of bovine babesiosis using a spreadsheet age-class model with weekly updates. Journal of Agricultural Entomology 8:297–308.
Smith, R. D., D. E. Evans, J. R. Martins, V. H. Ceresér, B. L. Corréa, C. Petraccia, H. Cardozo, M. A. Solari, and A. Nari. 2000. Babesiosis (*Babesia bovis*) stability in unstable environments. Annals of the New York Academy of Sciences 916:510–520.

Smith, T., and F. L. Kilborne. 1893. Investigation into the nature, causation, and prevention of southern cattle fever. USDA, Bureau of Animal Industry, Washington, D.C., USA.

Smith, R. D., C. R. Madruga, R. H. Kessler, M. A. M. Schenk, H. Cardozo, M. A. Solari, and A. Nari. 1984. Pages 341–345 *in* Field validation of a computer simulation model of bovine babesiosis. Mississippi State University, Starkville, Massachusetts, USA.

Strey, O. F., P. D. Teel, D. R. Ring, and M. T. Longnecker. 1991. Modeling embryo development and emergence of *Boophilus annulatus* (Acari: Ixodidae). Journal of Medical Entomology 28:165–173.

Sutherst, R. W. 1983. Variation in the numbers of the cattle tick, *Boophilus microplus* (Canestrini), in a moist habitat made marginal by low temperatures. Journal of the Australian Entomological Society 22:1–5.

Sutherst, R. W. 1985. The role of models in tick control. Australian Veterinary Journal 62:32–37.

Sutherst, R. W. 1987a. The dynamics of hybrid zones between tick (Acari) species. International Journal for Parasitology 17:921–926.

Sutherst, R. W. 1987b. The role of models in tick control. Pages 32–37 *in* International Conference on Veterinary Preventive Medicine and Animal Production. Australian Veterinary Journal, Victoria, Australia.

Sutherst, R. W. 1993. Development and use of models of the life cycle and control of cattle tick. Agricultural Systems and Information Technology Newsletter 5:19–20.

Sutherst, R. W. 1998. Implications of global change and climate variability for vector-borne diseases: generic approaches to impact assessments. International Journal for Parasitology 28:935–945.

Sutherst, R. W. 2000. Climate variability, seasonal forecasting and invertebrate pests—the need for a synoptic view. Pages 381–397 *in* G. L. Hammer, N. Nicholls, and C. Mitchell, editors. Applications of seasonal climate forecasting in agricultural and natural ecosystems: the Australian experience. Kluwer Academic, Dordrecht, The Netherlands.

Sutherst, R. W. 2001. The vulnerability of animal and human health to parasites under global change. International Journal for Parasitology 31:933–948.

Sutherst, R. W., and W. Bottomley. 1989. ExperTik: experiences in the evaluation of expert systems for pest management. Pages 117–122 *in* Proceedings Simulation Society of Australia/IMACS Eighth Biennial Conference. September 25–27, 1989.

Central Printery Australian National University, Canberra, Australia.

Sutherst, R. W., and A. S. Bourne. 2006. The effect of desiccation and low temperature on the viability of eggs and emerging larvae of the tick, *Rhipicephalus (Boophilus) microplus* (Canestrini) (Ixodidae). International Journal for Parasitology 36:193–200.

Sutherst, R. W., and A. S. Bourne. 2009. Modelling non-equilibrium distributions of invasive species: a tale of two modelling paradigms. Biological Invasions 11:1231–1237.

Sutherst, R. W., A. S. Bourne, and I. D. Sutherland. 1999. Production and survival of eggs of the cattle tick *Boophilus microplus* (Acarina: Ixodidae) in the wet and dry tropics of north Queensland. Australian Journal of Entomology 38:340–347.

Sutherst, R. W., and H. N. Comins. 1979. The management of acaricide resistance in the cattle tick, *Boophilus microplus* (Canestrini) (Acari: Ixodidae), in Australia. Bulletin of Entomological Research 69:519–537.

Sutherst, R. W., and M. J. Dallwitz. 1979. Progress in the development of a population model for the cattle tick *Boophilus microplus*. Pages 557–563 *in* 4th International Congress of Acarology. Akadémiai Kiadó, Saalfelden, Austria.

Sutherst, R. W., and G. F. Maywald. 1985. A computerised system for matching climates in ecology. Agriculture, Ecosystems and Environment 13:281–299.

Sutherst, R. W., G. F. Maywald, and D. J. Kriticos. 2007. CLIMEX. Version 3: user's guide. Hearne Scientific Software, Melbourne, Victoria, Australia.

Sutherst, R. W., G. F. Maywald, and I. D. Sutherland. 1980a. The value of host resistance against cattle tick (*Boophilus microplus*) in Australia. Pages 408–415 *in* Proceedings of the Second International Symposium on Veterinary Epidemiology and Economics. Australian Government Publishing Service, Canberra, Australian Capital Territory, Australia.

Sutherst, R. W., G. F. Maywald, and I. D. Sutherland. 1980b. Analysis of control strategies for cattle tick on Zebu × British cattle. Pages 46–51 *in* 56th Annual Conference of the Australian Veterinary Association. Australian Veterinary Association, Sydney, New South Wales, Australia.

Sutherst, R. W., G. A. Norton, N. D. Barlow, G. R. Conway, M. Birley, and H. N. Comins. 1979a. An analysis of management strategies for cattle tick (*Boophilus microplus*) control in Australia. Journal of Applied Ecology 16:359–382.

Sutherst, R. W., K. B. W. Utech, M. J. Dallwitz, and J. D. Kerr. 1973. Intra-specific competition of *Boophilus microplus* (Canestrini) on cattle. Journal of Applied Ecology 10:855–862.
Sutherst, R. W., K. B. W. Utech, J. D. Kerr, and R. H. Wharton. 1979b. Density dependent mortality of the tick, *Boophilus microplus*, on cattle—further observations. Journal of Applied Ecology 16:397–403.

Sutherst, R. W., B. M. Wagland, and J. A. Roberts. 1978. The effect of density on the survival of *Boophilus microplus* on previously unexposed cattle. International Journal for Parasitology 8:321–324.

Sutherst, R. W., L. J. Wilson, and I. M. Cook. 2000. Predation of the cattle tick, *Boophilus microplus* (Canestrini) (Acarina: Ixodidae), in three Australian pastures. Australian Journal of Entomology 37:70–77.

Sutherst, R. W., T. Yonow, S. Chakraborty, C. O'Donnell, and N. White. 1996. A generic approach to defining impacts of climate change on pests, weeds and diseases in Australasia. Pages 281–307 in W. J. Bouma, G. I. Pearman, and M. R. Manning, editors. Greenhouse: Coping with climate change. CSIRO Publishing, Collingwood, Victoria, Australia.

Tabachnick, W. J. 2010. Challenges in predicting climate and environmental effects on vector-borne disease episystems in a changing world. Journal of Experimental Biology 213:946–954.

Teel, P. D., M. S. Corson, W. E. Grant, and M. T. Longnecker. 2003. Simulating biophysical and human factors that affect detection probability of cattle-fever ticks (*Boophilus* spp.) in semi-arid thornshrublands of South Texas. Ecological Modeling 170:29–43.

Teel, P. D., W. E. Grant, S. L. Marín, and J. W. Stuth. 1998. Simulated cattle fever tick infestations in rotational grazing systems. Journal of Range Management 51:501–508.

Teel, P. D., S. L. Marín, and W. E. Grant. 1996. Simulation of host-parasite-landscape interactions: influence of season and habitat on cattle fever tick (*Boophilus* sp.) population dynamics. Ecological Modelling 84:19–30.

Teel, P. D., S. Marin, W. E. Grant, and J. W. Stuth. 1997. Simulation of host-parasite-landscape interactions: influence of season and habitat on cattle fever tick (*Boophilus* sp.) population dynamics in rotational grazing systems. Ecological Modelling 97:87–97.

Utech, K. B. W., R. W. Sutherst, M. J. Dallwitz, R. H. Wharton, G. F. Maywald, and I. D. Sutherland.

1983. A model of the survival of larvae of the cattle tick, *Boophilus microplus*, on pasture. Crop and Pasture Science 34:63–72.

Walker, A. R. 2011. Eradication and control of livestock ticks: biological, economic and social perspectives. Parasitology 138:945–959.

Wang, H.-H., W. E. Grant, and P. D. Teel. 2012. Simulation of climate-host-parasite-landscape interactions: a spatially explicit model for ticks (Acari: Ixodidae). Ecological Modelling 243:42–62.

Wang, H.-H., W. E. Grant, P. D. Teel, and S. A. Hamer. 2015. Simulation of climate-tick-host-landscape interactions: effects of shifts in the seasonality of host population fluctuations on tick densities. Journal of Vector Ecology 40:247–255.

Wang, H.-H., P. D. Teel, W. E. Grant, G. Schuster, and A. A. Pérez de León. 2016. Simulated interactions of white-tailed deer (*Odocoileus virginianus*), climate variation and habitat heterogeneity on southern cattle tick (*Rhipicephalus (Boophilus) microplus*) eradication methods in south Texas, USA. Ecological Modelling 342:82–96.

Weidhaas, D. E., D. G. Haile, J. E. George, R. L. Osburn, and R. O. Drummond. 1983. A basic model for use in computer simulations of Boophilus tick biology and control. USDA Agricultural Research Service, Gainesville, Florida, USA.

West, G. 2005. Tick fever inquiry. New South Wales Department of Primary Industries, Orange, New South Wales, Australia.

Whalon, M. E., D. Mota-Sanchez, and R. M. Hollingworth. 2008. Analysis of global pesticide resistance in arthropods. Pages 5–31 in M. E. Whalon, D. Mota-Sanchez, and R. M. Hollingworth, editors. Global pesticide resistance in arthropods. CAB International, Wallingford, UK.

White, N., R. W. Sutherst, N. Hall, and P. Whish-Wilson. 2003. The vulnerability of the Australian beef industry to impacts of the cattle tick (*Boophilus microplus*) under climate change. Climatic Change 61:157–190.

Zeman, P., and G. Lynen. 2010. Conditions for stable parapatric coexistence between *Boophilus decoloratus* and *B. microplus* ticks: a simulation study using the competitive Lotka-Volterra model. Experimental and Applied Acarology 52:409–426.

## SUPPORTING INFORMATION

Additional Supporting Information may be found online at: http://onlinelibrary.wiley.com/doi/10.1002/ecs2.1942/full