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United States Department of Agriculture

Agricultural Research Service

Research Project: TECHNOLOGY TO CONTROL TICKS AFFECTING LIVESTOCK AND HUMANS

Location: Tick and Biting Fly Research

2006 Annual Report


1.What major problem or issue is being resolved and how are you resolving it (summarize project aims and objectives)? How serious is the problem? Why does it matter?
Ticks are efficient vectors of numerous disease agents to livestock, humans, and other vertebrate animals. Cattle fever ticks, Boophilus microplus and B. annulatus, are vectors of Babesia bovis and B. bigemina, the causative agents of cattle fever that crippled the cattle industry in the southern U.S. until they were eradicated in 1943. These ticks are still prevalent in Mexico adjacent to the Texas border and, thus far, the Cattle Fever Tick Eradication Program (CFTEP) has prevented re-infestations into the U.S., except within and near the cattle fever tick quarantine zone (buffer zone) that extends along the Rio Grande from Del Rio to Brownsville, TX. For many years, the reoccurring infestations have been eradicated by dipping cattle in coumaphos or by vacating cattle from infested and exposed premises. However, ticks resistant to all major groups of acaricides have been discovered in Mexico, and populations of white-tailed deer and exotic ungulate species that are secondary hosts for the ticks are increasing and compromising the option of pasture vacation. Therefore, the Animal Plant Health Inspection Service, Veterinary Services (APHIS, VS) is in need of alternative acaricides and treatment strategies that can be implemented on cattle in the likely event that acaricide-resistant ticks are introduced into the U.S. Perhaps of equal importance is the need to have alternative acaricides, specialized treatment methods, and strategies available for eradication of infestations of resistant cattle fever ticks feeding on white-tailed deer and exotic ungulate species. In addition, there is a human health need to control ticks feeding on white-tailed deer because they are keystone hosts for both the blacklegged tick, Ixodes scapularis, and, the lone star tick, Amblyomma americanum, that transmit disease agents causing Lyme disease, southern tick-associated rash illness (STARI), human ehrlichioses, human babesiosis, and other diseases of humans throughout much of the U.S. New and improved technologies developed to eradicate cattle fever ticks on deer can also be evaluated for potential in controlling these medically important ticks. Besides the need for practical and efficacious tick control technology, APHIS, VS needs a better understanding of major risk factors that lead to the re-introduction of ticks gained through predictive and diagnostic epidemiological risk assessment models of the reoccurring Boophilus infestations within and near the tick quarantine zone to expedite discovery and eradication of new infestations.

The overall objective of this research is to support the needs of APHIS, VS and citizens of the U.S. by developing practical and efficacious technologies, strategies, and epidemiological tools to control ticks of medical and veterinary importance feeding on cattle, white-tailed deer, and other important hosts in efforts both to maintain eradication of cattle fever ticks from the U.S. and to reduce risk of human infection with tick-borne disease agents. Specific objectives are:

1. Evaluate procedures employed by the CFTEP for eradicating cattle fever ticks, evaluate new acaricides with unique chemistries, and develop treatment strategies for their use to control outbreaks of both susceptible and acaricide resistant Boophilus ticks.

2. Develop and evaluate technology to control ticks of medical and veterinary importance by treating white-tailed deer and exotic ungulate species.

3. Develop geographical information system (GIS) databases and create diagnostic and predictive epidemiological models from records of historical Boophilus tick infestations in South Texas for use by VS to determine factors useful in identification of areas at high risk of re-infestation.

The research to be undertaken falls under NP 104 - Veterinary, Medical and Urban Entomology and addresses goal 4.1 Chemical Pesticides and Repellents. The specific goals are: (1) 4.1.1 Develop the capacity to test existing compounds against Diptera and ticks that transmit disease, and (2) 4.1.2 Develop and test novel means of applying pesticides and repellents that are more efficient, inexpensive and selective, including the development of toxic baits, methods to bond agents to material, and area repellents.

Cattle producers, medical and veterinary disease regulatory agencies, citizens subject to tick-borne diseases or pestilence from ticks, and other scientists will benefit from the research. Livestock producers, especially those in the southeastern quadrant of the U.S., will continue to operate in an environment that is free of cattle fever ticks and bovine babesioses. Regulatory agencies will have improved, safe, efficient, and efficacious methods with which to sustain efforts to eradicate Boophilus ticks. The public will benefit from reduced risk of tick bite and tick-borne diseases, including Lyme disease, STARI, human ehrlichioses, human babesiosis, and others serious pathogens.


2.List by year the currently approved milestones (indicators of research progress)
Year 1 (FY 2005)

Determine the efficacy of amitraz against strains of amitraz-resistant ticks from Mexico.

Evaluate the effectiveness of permethrin treatments delivered against the lone star tick to white-tailed deer via the '4-poster' and provide the EPA the data.

Determine if GIS analysis of historical data on cattle fever tick outbreaks predicts re-infestation risk in Zapata, Co., Texas.

Year 2 (FY 2006)

Determine the efficacy of coumaphos treatments of tick-infested cattle against strains of Boophilus microplus from Mexico with various patterns of resistance and cross-resistance to organophosphate acaricides.

Assess the effect of the population density of the host on the suitability of the white-tailed deer as a host of B. microplus and B. annulatus.

Determine consumption rates and the relative palatability to white-tailed deer of both untreated corn and corn treated with several macrocyclic lactone acaricides potentially effective for the control of Boophilus ticks infesting deer.

Complete the first phase of multi-year experiments to evaluate the effectiveness of the non-target animal excluder for the '4-poster'.

Determine if analyses of historical GIS data on cattle fever tick outbreaks predict re-infestation risk to cattle herds in the cattle fever tick quarantine zone in South Texas. Year 3 (FY 2007)

Complete experiments to determine the effect of rainfall on the efficacy of coumaphos treatments for the control of Boophilus ticks on cattle.

Complete trials to obtain estimates of the efficacy of new acaricides and strategies for their use to control Boophilus ticks on cattle.

Characterize the suitability of nilgai, a widespread exotic antelope species that occurs in South Texas and northern Mexico, as a host for Boophilus ticks.

Complete the second phase of multi-year experiments to evaluate the effectiveness of the non-target animal excluder for the '4-poster'.

Use GIS analysis, historical data, and current aerial photographs to estimate effects of changes in landscape use/ecology on the potential habitats of B. microplus and B. annulatus within the cattle fever tick quarantine zone in South Texas, and in adjacent areas south of the Rio Grande in northern Mexico.

Year 4 (FY 2008)

Determine the efficacy of the '4-poster' treatment device for the control of Boophilus ticks on white-tailed deer under South Texas field conditions.

Characterize the suitability of the axis deer as a host for Boophilus ticks.

Complete the final phase of multi-year experiments to evaluate the effectiveness of the non-target animal excluder for the '4-poster'.

Use GIS databases to investigate, elucidate, and quantify practical aspects and factors involved in the epidemiology of Boophilus spp. infestations.

Year 5 (FY 2009)

Determine whether in the absence of cattle, the feeding of systemically active macrocyclic lactone-medicated whole kernel corn to deer at a prescribed rate will result in efficacy sufficient to eradicate Boophilus ticks from experimental pastures in South Texas.

Characterize the suitability of the fallow deer as a host for Boophilus ticks.

Complete trials to obtain estimates of the efficacy of new acaricides and strategies for their use to control Boophilus ticks on cattle.


4a.List the single most significant research accomplishment during FY 2006.
Alternative acaricides reduce organophosphate resistance in fever ticks: Acaricide resistance in cattle fever ticks is a serious threat to the Eradication Program and considerable effort is being made to minimize its development. ARS scientists at the Cattle Fever Tick Research Laboratory, Moore Field, TX, demonstrated that the acquisition of organophosphate (OP) resistance in Boophilus microplus ticks caused a 34% reduction in fecundity and fertility of eggs as compared to a susceptible strain of ticks. These results suggest that in the absence of selection pressure with OP acaricides the frequency of OP-resistant individuals in the population would decline through time to the point where, at some point, the use of OP acaricides would result in virtual elimination of the ticks. Based on these results, when OP-resistant ticks are detected in a tick population the use of alternative non-OP acaricides should be considered to reduce the selection pressure against OP chemicals, so that subsequently a return to the use of OP acaricides would be possible. This research is authorized under National Program 104 - Veterinary, Medical and Urban Entomology and addresses goal 4.1 Chemical Pesticides and Repellents and specific goals 4.1.1 - Develop the capacity to test existing compounds against Diptera and ticks that transmit disease and 4.1.2 - Develop and test novel means of applying pesticides and repellents that are more efficient, inexpensive and selective, including the development of toxic baits, methods to bond agents to material, and area repellents.


4b.List other significant research accomplishment(s), if any.
Doramectin injection may not kill late stage ticks: In efforts to identify additional acaricides of potential use in the Fever Tick Eradication Program, scientists at the ARS Cattle Fever Tick Research Laboratory, Moore Field, TX, evaluated efficacy of the macrocyclic lactone endectocide, doramectin, against Boophilus microplus ticks in the late stages of parasitic development. Results showed that if a single doramectin injection at 200µg/kg of body weight was administered to infested cattle at 18 days after tick infestation, the level of control was 99.9%. However, if treatment was administered at 19 days after ticks were infested on the cattle the level of control was 96.1% and if administered at 20 days the level of control was only 88.6%. These results show that ticks undergoing rapid engorgement at the time treatment is applied fail to imbibe enough acaricide laced blood to kill them. This demonstrates that the use of injectable macrocyclic lactones at port facilities should be carefully considered, because if the infested cattle are not held for at least 4 days after treatment there is a definite risk of dispersing viable fully engorged female ticks to areas outside of the quarantine zone. This research is authorized under National Program 104 - Veterinary, Medical and Urban Entomology and addresses goal 4.1 Chemical Pesticides and Repellents and specific goals 4.1.1 - Develop the capacity to test existing compounds against Diptera and ticks that transmit disease and 4.1.2 - Develop and test novel means of applying pesticides and repellents that are more efficient, inexpensive and selective, including the development of toxic baits, methods to bond agents to material, and area repellents.

Deer can sustain fever ticks beyond quarantine period: As marginal but viable hosts, white-tailed deer and other wild ungulates have long been suspected of compromising efforts to maintain eradication of cattle fever ticks from the U.S. Field studies conducted by scientists at the ARS Cattle Fever Tick Research Laboratory, Moore Field, TX, to evaluate the ability of white-tailed deer to sustain a natural tick population in the absence of cattle showed that the deer were able to sustain the tick population for at least 9 months, which is longer than the specified regulatory quarantine period. However, results indicated the tick population was not sustained for 18 months. These results provide the Eradication Program personnel with a basis for considering a change in duration of the quarantine period whenever deer are present and involved in an outbreak on premises within the quarantine zone. This research is authorized under National Program 104 - Veterinary, Medical and Urban Entomology and addresses goal 4.1 Chemical Pesticides and Repellents and specific goals 4.1.1 - Develop the capacity to test existing compounds against Diptera and ticks that transmit disease and 4.1.2 - Develop and test novel means of applying pesticides and repellents that are more efficient, inexpensive and selective, including the development of toxic baits, methods to bond agents to material, and area repellents.

No acaricide resistant fever ticks discovered in outbreaks this year: Scientists at the ARS Cattle Fever Tick Research Laboratory, Moore Field, TX, are always on the lookout for acaricide resistant in outbreak strains of ticks submitted by APHIS Fever Tick Eradication Program personnel. Discriminating dose bioassays were used to evaluate the acaricide susceptibility of all 12 different outbreak strains of Boophilus ticks that were submitted, and all strains were determined to be susceptible to all major classes of acaricides. These results are used by Eradication Program personnel to prescribe specific regulatory procedures and requirements for infested and adjacent premises and are essential in determining acaricides used for intervention. This research is authorized under National Program 104 - Veterinary, Medical and Urban Entomology and addresses goal 4.1 Chemical Pesticides and Repellents and specific goals 4.1.1 - Develop the capacity to test existing compounds against Diptera and ticks that transmit disease and 4.1.2 - Develop and test novel means of applying pesticides and repellents that are more efficient, inexpensive and selective, including the development of toxic baits, methods to bond agents to material, and area repellents.


4c.List significant activities that support special target populations.
None.


5.Describe the major accomplishments to date and their predicted or actual impact.
People at risk to parasitism by the lone star tick and infection with disease agents it transmits will benefit from the availability of an effective, safe, and environmentally friendly new pesticide product formulated specifically for use with the '4-Poster' Deer Treatment Bait Station. Experimental results demonstrated efficacy for the control of lone star ticks on white-tailed deer of passive treatments with 4-Poster Tickicide (10% permethrin) administered when deer were feeding on bait dispensed by the commercially available '4-Poster' Deer Treatment Bait Station. The efficacy data from the experiment were submitted to the EPA and were the basis for a determination that conditional approval of the pesticide could be amended to include use of the product to control lone star ticks on white-tailed deer. 4-Poster Tickicide and the '4-Poster' Deer Treatment Bait Station are sold together for the control of the black-legged and lone star ticks on white-tailed deer and are approved for use in 47 of the 48 contiguous states in the United States. This accomplishment addresses Project Plan milestone "Evaluate the effectiveness of permethrin treatments delivered against the lone star tick to white-tailed deer via the '4-Poster' and provide the EPA the data;" component 4, goals 4.1.1 and 4.1.2 of the NP 104 action Plan; and performance measure 3.2.1 in the ARS Strategic Plan.


6.What science and/or technologies have been transferred and to whom? When is the science and/or technology likely to become available to the end-user (industry, farmer, other scientists)? What are the constraints, if known, to the adoption and durability of the technology products?
None.


7.List your most important publications in the popular press and presentations to organizations and articles written about your work. (NOTE: List your peer reviewed publications below).
Davey, R.B., Miller, A.J., George, J.E., Klavons, J.A. 2006. Efficacy of a single injection of doramectin against adult female Boophilus microplus (Acari: Ixodidae) ticks in the late stages of parasitic development. 50th Annual Meeting of the Livestock Insect Workers' Conference, June 25-28, 2006, Amarillo, TX.

George, J.E. 2005. Responses to questions regarding the Cattle Fever Tick Eradication Program directed to the Agricultural Research Service. South Texas Agriculture Conference, August 2, 2005, Zapata, TX. Kammlah, D.M. 2005. Development of GIS mapping technologies for use in epidemiological investigations of Boophilus infestations. South Texas Agriculture Conference, August 2, 2005, Zapata, TX.

Kammlah, D.M. 2005. Update on the GIS databases for the Cattle Fever Tick Eradication Program by area. APHIS-VS Fever Tick Eradication Program Preliminary Review, November 29, 2005, Laredo, TX.

Kammlah, D.M., Pound, J.M., George, J.E., Duhaime, R.A., Bowers, E.J. 2006. Development of Geographic Information Systems (GIS) technologies for use in epidemiological investigations of Boophilus spp. tick infestations. 50th Annual Meeting of the Livestock Insect Workers' Conference, June 25-28, 2006, Amarillo, TX.

Miller, J.A., Pound, J.M. 2005. Technologies for the control of ticks on white-tailed deer and other wild ungulates. APHIS-VS Fever Tick Eradication Program Preliminary Review, November 29, 2005, Laredo, TX.

Miller, J.A., Pound, J.M., Lohmeyer, K.H., Klavons, J.A. 2006. A sustained release gel formulation containing doramectin for control of lone star ticks and horn flies on cattle. 50th Annual Meeting of the Livestock Insect Workers' Conference, June 25-28, 2006, Amarillo, TX.

Miller, J.A., Pound, J.M., Lohmeyer, K.H., Klavons, J.A., George, J.E. 2006. Liquid molasses for delivery of avermectins. 50th Annual Meeting of the Livestock Insect Workers' Conference, June 25-28, 2006, Amarillo, TX.

Miller, R.J. 2005. Detecting and eradicating acaricide resistant ticks. South Texas Agriculture Conference, August 2, 2005, Zapata, TX.

Pound, J.M., Miller, J.A., George, J.E., Kammlah, D.M. 2005. Are white-tailed deer and other wild ungulates compromising the APHIS-VS Cattle Fever Tick Eradication Program? South Texas Agriculture Conference, August 2, 2005, Zapata, TX.

Pound, J.M., Miller, J.A., George, J.E. 2005. White-tailed deer and other wild ungulates – Their influence on the operational success of the Fever Tick Eradication Program. U.S. Animal Health Association – Parasitic Diseases Committee, November 9, 2005, Hershey, PA.

Pound, J.M., Miller, J.A., George, J.E., Kammlah, D.M. 2005. White-tailed deer and other wild ungulates – Their influence on the operational success of the Fever Tick Eradication Program. APHIS-VS Fever Tick Eradication Program Preliminary Review, November 29, 2005, Laredo, TX.

Pound, J.M., Miller, J.A., George, J.E., Kammlah, D.M. 2005. White-tailed deer and other wild ungulates – Their influence on the operational success of the Fever Tick Eradication Program. APHIS-VS Fever Tick Eradication Program Symposium on Effects of Wildlife on the Eradication Program, December 16, 2005 Austin, TX.

Pound, J.M., Miller, J.A., Lohmeyer, K.H., Kammlah, D.M., Klavons, J.A., George, J.E. 2006. Deployed Warfighters Protection Program – Activities at the Knipling-Bushland U.S. Livestock Insects Research Laboratory, Kerrville, TX. Second Annual Review of the ARS-DWFP Research Program, March 2, 2006, College Station, TX.

Pound, J.M., Miller, J.A. 2006. White-tailed deer and other wild ungulates – Their influence on the operational success of the Fever Tick Eradication Program and Procedures for proper deployment of the ARS-patented '4-Poster' deer treatment bait station. APHIS Fever Tick Eradication Program Annual Tick Inspector Training, May 1-4, 2006, Laredo, TX.

Pound, J.M., Miller, J.A. 2006. The Impact of '4-Poster' deer-targeted tick control technology on hunters and hunting. Shelter Island Hunter's Forum, May 6, 2006, Shelter Island, NY.

Pound, J.M., Miller, J.A. 2006. The '4-Poster' deer treatment bait station for community-based program to control tick-borne diseases in humans. Shelter Island Tick Forum, May 7, 2006, Shelter Island, NY.

Pound, J.M., Miller, J.A., George, J.E., Fish, D., Carroll, J.F., Schulze, T.L., Daniels, T.J., Falco, R.C., Stafford, K.C. III, Mather, T.N. 2006. The USDA Northeast Area-wide Tick Control Project – Summary and conclusions. 50th Annual Meeting of the Livestock Insect Workers' Conference, June 25-28, 2006, Amarillo, TX.

Flores, A. 2006. The continuing fight against cattle ticks. Agricultural Research, June 2006. p. 8-9.


Review Publications
Davey, R.B., Miller, J.A., George, J.E., Snyder, D.E. 2005. Effect of repeated spinosad treatments on cattle against Boophilus annulatus under south Texas field conditions. Southwestern Entomologist. 30(4):245-255.

Davey, R.B., George, J.E., Miller, R.J. 2006. Comparison of the reporductive biology between acaricide-resistant and acaricide-susceptible Rhipicephalus (Booplilus) microplus (Acari: Ixodidae). Veterinary Parasitology. 139:211-220.

George, J.E. 2005. Milestones from three decades of research by the Agricultural Research Service on the eradication of Boophilus ticks. In: Proceedings of 30th Anos al Servicio de la Granderia Nacional, 1975-2005, June 8-9, 2005, Jiutepec, Morelos, Mexico. 2005 CDROM.

Last Modified: 4/20/2014
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