Research Project: Cattle Fever Tick Control and Eradication

Location: Livestock Arthropod Pests Research

2018 Annual Report

Objectives
Objective 1: Reduce the cost of pasture quarantine by developing new methods of treating cattle for cattle fever ticks. Subobjective 1A: Evaluate the efficacy of novel long-acting (LA) acaricides for CFT control. Subobjective 1B: Detect tick infestation by non-invasive procedures. Objective 2: Evaluate efficacy of novel technologies for control of cattle fever ticks and mitigation of acaricide resistance. Subobjective 2A: Evaluate natural products with acaricidal properties for tick control. Subobjective 2B: Evaluate natural products with repellent or attractant properties for tick control. Objective 3: Develop methods that decrease the impact of wildlife as reservoirs of cattle fever ticks. Subobjective 3A: Evaluate efficacy of anti-tick vaccine formulations for control of ticks on wildlife. Objective 4: Improve species distribution and ecological niche models of cattle fever tick species and specify changes likely to occur due to climate change. Subobjective 4A: Update and mine the historical CFT GIS database to produce maps and tools to support APHIS eradication efforts. Subobjective 4B: Assess effect of climate change predictions on recurring cycles of CFT outbreak activity. Objective 5: Develop biological control agents against the pathogenic landscape created by Arundo donax and measure impact on invasive ticks. Subobjective 5A. Investigate the biology and host range of the arundo leafminer under quarantine conditions as a candidate biological control agent for release in the CFT PQZ. Subobjective 5B. Determine if biological control agents mitigate negative impact of Arundo donax on operations by the Cattle Fever Tick Eradication Program by increasing visibility within the PQZ. Subobjective 5C. Investigate other benefits of biological control intervention, including decreased habitat suitable for CFT larvae, and use these measurements to predict effects of climate change. Objective 6: Innovate technologies to mitigate the negative impact of ecological interactions between invasive species. Subobjective 6A. Investigate role of ants and ground-dwelling predator beetles on the survival of CFT and biological control agents in the PQZ affected by A. donax. Objective 7: Develop biological control against livestock pests. Subobjective 7A. Conduct foreign exploration in the native ranges of CFT to search for tick-specific biological control agents. Objective 8: Assess the effects of global climate change on effectiveness of livestock pest control in south Texas and northern Mexico. Subobjective 8A. Investigate the potential for climate change to alter the viability of CFT larvae in the PQZ.

Approach
Utilize our unique laboratory resources and infrastructure to evaluate new formulations of compounds for long-acting efficacy against strains of cattle fever ticks that are susceptible or resistant to commercially available acaricidal products. This effort will help prioritize efforts with stakeholder groups to deliver products the Cattle Fever Tick Eradication Program can use in the Permanent Quarantine Zone. Assess utility of non-invasive procedures, like near-infrared spectroscopy of livestock fecal samples, to detect cattle fever tick infestations. Finding non-invasive alternatives to hands-on inspection (scratching) offer the potential to streamline operations and enhance detection of infestations by Cattle Fever Tick Eradication Program personnel. Screen plant-derived substances to identify novel compounds that are active against cattle fever ticks. Research on natural products will enable the discovery of molecules that could be optimized for acaricidal efficacy. Determine immunogenicity in white-tailed deer of novel Bm86-based vaccine developed to vaccinate cattle in the Permanent Quarantine Zone. Confirming that the novel Bm86-based vaccine developed for cattle can also elicit a specific immune response against cattle fever ticks in white-tailed deer will provide a tool that could be used to minimize the impact of wildlife as tick reservoirs. Refine methods applied to cattle fever tick outbreaks using remote sensing technologies and models predicting habitat suitability and species distribution. The improvement of those methods could be used to develop science-based predictive tools the Cattle Fever Tick Eradication Program could use to adapt future strategies. Overall, the approaches described above aim to deliver science-based tools that the Cattle Fever Tick Eradication Program can integrate to adapt operations, mitigate the impact of global change, and keep the U.S. free of cattle fever ticks in a sustainable manner. Develop biological control agents against giant reed including testing of the leaffeeding arundo leafminer, for release in the PQZ; determine if the leafminer, and two other agents which have already been released, can mitigate negative impact of giant reed on operations by the CFT Eradication Program by increasing visibility within the PQZ and investigate other benefits, including reduction of habitat suitable for cattle fever tick larvae; investigate the role of ants and ground-dwelling predator beetles on the survival of cattle fever tick in the PQZ in areas with and without giant reed; conduct foreign exploration in the native ranges of cattle fever tick to search for tick-specific parasitic insects and nematodes, and evaluate their potential as biological control agents to directly target cattle fever tick; assess the effects of global climate change on livestock pest control in south Texas by conducting field ecological studies in cattle fever tick infested pastures at the CFTRL; conduct field studies to investigate the effects of increased summer rainfall to determine its impact on exotic African range grasses and giant reed and their effect on cattle fever tick survival.

Progress Report
Objective 2. Completed and published study on the effects of p-anisaldehyde, an organic compound and constituent of synthetic and natural fragrances, on Amblyomma americanum, which is commonly known as the lone star tick. p-Anisaldehyde was found to have moderately toxic effects on the lone star tick. Completed and published study on effects of p-anisaldehyde on lone star larvae, which deterred their movement. Completed and submitted manuscript on Surround® (kaolin) and CimeXa™ (silica aerogel) effects on the lone star tick in lab assays, and on A. maculatum, commonly known as the gulf coast tick, in field tests. CimeXa™, in particular, had strong lethal effects against tick larvae and to a somewhat lesser extent, nymphs. Objective 4. Conducted study, and manuscript is being written on interactions between ecological factors and hard ticks in the south Texas coastal plains. Soil conditions were shown to have an effect on hard tick distribution such that there are large areas of the south Texas coastal plains with very few ticks due to complex interactions based on soil salinity. Those areas are easily identifiable by the dominant plant that grows there, which will assist with streamlining tick surveillance. Ecological interactions that integrate wild host activity, soil salinity, predator activity, and vegetational communities with tick populations were characterized. Objective 5. Studies on Arundo donax, commonly known as carrizo cane, along the Rio Grande showed long-term increases in within-stand visibility since biological control agents were released in 2009. Within-stand visibility has increased from an average of 9 feet in 2009 to more than 30 feet in 2018. This change in plant density and above ground biomass resulted in shifts in the plant community with significant regrowth of desirable native riparian species. Additionally, field studies along the Rio Grande in Eagle Pass, Texas documented significant water use conservation following release of the carrizo cane biological control agents. Analysis of climate data from sites along the Rio Grande in the Cattle Fever Tick Permanent Quarantine Zone (PQZ) showed the temperatures in south Texas increase the level of damage caused by biological control agents as compared to climates in the native range in Mediterranean Europe. The effect is augmented further when biocontrol agent releases, whether inundative or inoculative, occur. This indicates that the increased level of damage in the PQZ by the biological control agents to invasive carrizo cane reduce the favorability of the environment for survival of cattle fever ticks. However, in other areas of Texas with different climate where carrizo cane is not as invasive as in south Texas, parasitoids like the carrizo cane wasp that are not used as biological control agents in those areas do not hinder carrizo cane propagation. The carrizo cane leafminer, Lasioptera donacis, was released on the Rio Grande near Brownsville, TX. In collaboration with the USDA-ARS European Biological Control Laboratory in Thessaloniki, Greece, the collection, rearing, and shipping of leafminers for release in Texas continues. Field studies in Mediterranean Europe found that the site conditions and climate along the Rio Grande in Texas are suitable for establishment of the carrizo cane leafminer. Field sites on the Rio Grande are being monitored weekly to document establishment of this important biological control agent. Objective 6. Field studies along the Rio Grande documented that landscapes invaded by the carrizo cane have significant lower populations of beneficial tick feeding ants and beetles as compared to stands of desirable native vegetation. The interaction of exotics weeds facilitating the invasion and survival of cattle fever ticks is an example of an ecological concept termed the ‘pathogenic landscape.’ It is hypothesized that the transition of the riparian plant community from carrizo cane to native vegetation associated with the release of the biological control agents will create a biological barrier to cattle fever tick invasion in the transboundary region between Texas and Mexico along the Rio Grande. However, these effects may depend on the tick species and ecosystem under consideration. A study investigated the role of ants as predators of the lone star tick. At locations in south, west, and central Texas, predatory ant species – including the red imported fire ant – did not attack lone star tick eggs, larvae, nymphs, and unfed and replete adults. ARS scientist at Kerrville, Texas determined that the mud flat fiddler crab, Uca rapax, is an extremely effective predator on ixodid tick eggs in areas where the crab exists. According to estimates using Geographic Information System (GIS) technology, these areas encompass about 25% of the South Texas coastal plains, which includes a wildlife corridor.

Accomplishments
1. Understanding how nilgai may spread cattle fever ticks through the landscape in south Texas. Nilgai movement across the Gulf Coast in south Texas complicates efforts to keep the U.S. cattle fever tick-free. Around the world, exotic and invasive wildlife species that are hosts for ticks impede efforts to protect local livestock from ticks and tick-borne diseases. The presence of nilgai, a wildlife host for cattle fever ticks originally from the Indian subcontinent and classified in the same family as cattle, presents such a case. It complicates efforts to keep the U.S. bovine herd free of cattle fever ticks, which transmit the microbes causing bovine babesiosis, a deadly disease of cattle. This was documented through collaborative efforts by ARS scientists in Kerrville, Texas by updating our Geographic Information System (GIS) database to include historical tick infestation data, host source data, and geographical data related to the increasing populations of nilgai in south Texas. Studies to enhance our understanding of how nilgai may spread cattle fever ticks through the landscape in south Texas revealed that: 1) they are unlikely to cross 1.25 m high cattle fences located parallel to paved highways; and, 2) females are more likely to disperse the ticks than males. This information was integrated into the database to compare activity patterns between nilgai and white-tailed deer, which is a native wildlife species and cattle fever tick host that also compromises the cattle fever tick-free status of the U.S. The science-based knowledge generated through this research can be used to enhance integrated strategies for the management of cattle fever ticks infesting nilgai and white-tailed deer.

2. Seed southern cattle fever tick survival in the environment. The southern cattle fever tick (SCFT) is an economically destructive disease vector because it transmits the microbes causing bovine babesiosis, which kills cattle. SCFT can spend 80–90% of their life cycle as a seed tick after emerging from eggs laid by the mother in the environment where they wait to latch on cattle, or another host to complete the parasitic phase of their life cycle. An environmental study conducted in a south Texas pasture by ARS scientists in Edinburg, Texas over a two-year period where seed SCFT were surveyed showed that survival rates varied among seasons with the overall highest populations recorded in the spring and the lowest in the fall. Larger numbers were collected from exposed habitats in the winter whereas canopied habitats in the summer had 10-fold larger seed SCFT numbers. In the spring, exposed and canopied habitats showed no difference in tick larval survival rates. The interaction between season and habitat strongly influence the survival of seed SCFT waiting to latch on a host with relative humidity being a key weather variable. This information can be used to develop effective interventions that target seed SCFT when they are off the host trying to survive in the environment.

3. Developing methods to treat cattle fever tick infestations in nilgai. Nilgai antelope, native to India and established in the rangelands of south Texas and northeast Mexico, are highly mobile hosts of cattle fever ticks and implicated in the widespread movement of this serious livestock pest that is also a vector of the microbes causing bovine babesiosis, and anaplasmosis. There are no methods to kill cattle fever ticks infesting nilgai. Ideally, the methods should be generally recognized as safe. A remotely activated sprayer developed through collaborative efforts by ARS scientists in Edinburg and Kerrville, Texas to treat cattle fever tick infestations in nilgai is activated when nilgai cross under established fence crossings or visit common latrines. Additional research showing that a roundworm able to cause death to insects and available commercially available was able to affect cattle fever ticks allowed the testing of the nematode in the sprayer. This nematode, which because of its activity against cattle fever ticks can be described as acaropathogenic, is native to South Texas and non-toxic to mammals and other vertebrates. Large-scale, i.e. ~40,000 acres, deployment and testing of the nilgai sprayer on ranchland in Willacy Co. is underway in cooperation with Texas A&M Kingsville, Caesar Kleberg Wildlife Research Institute.

4. Multidimensional impact of integrated carrizo cane management in the Eastern sector of the U.S.-Mexico transboundary region. Carrizo cane, an invasive weed, creates an environment conducive for cattle fever ticks and impairs U.S. Border Patrol operations in some sectors of the Rio Grande that also form part of the Permanent Quarantine Zone (PQZ) managed by the Cattle Fever Tick Eradication Program (CFTEP). Methods for integration of mechanical topping technology with biological control agents were transferred by ARS scientists in Edinburg, Texas to the US Border Patrol, USDA-APHIS-Veterinary Services, and Kunafin Insectary for management of carrizo cane along 350 river miles in the CFTEP PQZ along the Rio Grande. Topping of cane at 3 feet with specialized tractors causes growth of cane side shoots, which are readily attacked by the carrizo cane wasp and scale biocontrol agents. This method provided immediate visibility of the international border for law enforcement agencies and causes carrizo cane long-term suppression, which leads to re-emergence of desirable native vegetation. Establishment of native vegetation along the Rio Grande increases population levels of native cattle fever tick predator ants and beetles. This integrated solution meets the needs of Federal agencies tasked with managing this invasive weed along the international border.

5. Evaluation of natural products that can be used for tick control. Cattle fever ticks, and other hard ticks, can become resistant to synthetic acaricides. Natural products were tested by ARS scientists in Kerrville and Edinburg, Texas to determine if they can be used to kill ticks, especially those that are resistant to commercially available synthetic acaricides. A commercial concentrate containing essential oils, and its active components, killed acaricide resistant and susceptible cattle fever ticks in laboratory experiments. p-Anisaldehyde, a botanically-based compound produced by fennel, cranberries, vanilla, and other plants showed killing activity and reproductive effects against the lone star tick in bioassays. The dust products Surround®, containing kaolin, and CimeXa™, containing silica, affecting pests through desiccation were bioassayed for activity against the lone star tick. CimeXa™ was relatively more effective than Surround® against the lone star tick in laboratory tests. When tested in the field, CimeXa™ attained >95% control within 24 hr against natural populations of the immature stages of the Gulf Coast tick when applied to cordgrass during relatively high wind conditions, which indicates that this inert and organic product with potentially long-residual activity has properties that distinguish it from other pesticidal products used for hard tick control.

6. Evaluation of natural products for repellent or attractant properties against ticks. Alternatives to the common use of, or technologies that can be used together with synthetic chemicals to kill ticks are needed to advance integrated approaches for tick control. The use of repellents and deterrents could be a useful tactic to prevent tick bites and mitigate the risk of tick-borne disease transmission. Laboratory tests by ARS scientists in Kerrville, Texas showed that p-anisaldehyde deterred the movement of the immature stage of the lone star tick. An implication of these research findings is that p-anisaldehyde might be developed to deter tick movement up grass stems thereby interfering with their ability to find a host, or if applied to animals deter the ticks from biting and blood feeding.

7. Unraveling the ecology of hard ticks in the south Texas Coastal Plains. The ecology of the recent incursion of the southern cattle fever tick into parts of the south Texas coastal plains, which include a wildlife corridor (WC), remains to be fully understood. Field studies by ARS scientists in Kerrville, Texas revealed interactions between soil conditions involving salinity and moisture that strongly affect hard tick populations in the WC caused by saline tidal and storm surge action, humidity, and the predominance of the mud flat fiddler crab (MFFC). MFFC are efficient tick egg predators and saline water destroys tick eggs such that hard tick populations on highly saline soils are negligible whereas greater tick populations were observed in areas with low-salinity soil. Ticks were scarce in areas where the sea ox eye plant typically grows in dense near-monocultures on highly saline soil that are identifiable by the plant’s distinctive color, which enabled the production of a Geographic Information System (GIS) map to show the distribution of those areas relative to the WC. Examination of mammalian tracks and dung in the WC helped determine wild host animal activity and revealed that some animals disperse ticks in high salinity and low salinity areas where tick survival apparently depends on saline water and MFFC predation levels on tick eggs. Most ant species appeared unable to detect lone star tick eggs, which could explain why tick populations in the presence of ants, including the red imported fire ant, can be high relative to saline soil areas subject to tides, storm surges, and MFFC predation. Identifying areas where hard ticks, particularly one-host ticks such as cattle fever ticks, are sparse can help streamline surveillance activities conducted by the Cattle Fever Tick Eradication Program and other stakeholders pursuing tick control in the south Texas coastal plains.

8. Enhanced understanding of where, when, and how parasitoids can be used to control carrizo cane. Carrizo cane is an exotic plant that is problematic because of its effect on water flow of rivers, streams, and canals displacing indigenous riparian plant communities, which makes it extremely difficult to control even with herbicides, fire, and mowing due to its tendency to grow back quickly after treatment. The carrrizo cane wasp, Tetramesa romana, was introduced from the Mediterranean region and is used in south Texas for integrated carrizo cane biocontrol. Studies in the Texas Hill Country by ARS scientists in Kerrville, Texas, where different ecological conditions exist as compared to south Texas, showed that the wasp does not attack carrizo cane stalks, even when young, and while lateral shoots growing from the cane nodes are used for oviposition, the larvae developing within do not necessarily kill the shoots. Under these conditions, shoots might grow longer when infested and proliferate, and wasps did not reduce stalk density and growth infesting the carrizo cane for only a short time during the lifetime of the plant. This study highlighted the need for research to understand how different ecosystems can influence the performance of a parasitoid on its plant host for biocontrol purposes, and that integrated biocontrol strategies are a more effective approach to manage exotic invasive weeds like carrizo cane.

9. Ants as predators of the lone star tick in Texas. Ants have been reported as being effective predators of hard ticks. Field experiments conducted by ARS scientists in Kerrville, Texas in west, central, and south Texas, including the south Texas coastal plains, used lone star tick eggs, larvae, nymphs, unfed adults, and replete adults to determine whether or not ants under natural conditions fed on them. While other baits such as small pieces of meat and dead house flies attracted foraging ants, none of the species of predatory ants encountered were attracted to any lone star tick life stage. In some instances, harvester ants pulled replete adult ticks away from their colonies and carried tick eggs away to dispose of them beyond the circular colony clearing. The likely reason for the lack of predation against lone star ticks was determined to be chemically-based. This research shows that more field studies are required to ascertain the role of ants as predators across tick species in Texas.

Review Publications
Klafke, G.M., Miller, R., Tidwell, J.P., Barreto, R., Guerrero, F., Kaufman, P., Perez De Leon, A.A. 2017. Mutation in the sodium channel gene corresponds with phenotypic resistance of Rhipicephalus sanguineus sensu lato (Acari: Ixodidae) to pyrethroids. Journal of Medical Entomology. 54(6):1639-1642.
Romero-Salas, D., Cruz-Romero, A., Aguilar-Dominguez, M., Ibarra-Priego, N., Barradas-Pina, F.T., Nogueira-Domingues, L., Castro-Arellano, I., Lohmeyer, K.H., Perez De Leon, A.A. 2018. Seroepidemiology of bovine herpes virus-1 infection in water buffaloes from Mexico. Tropical Biomedicine. 35(2):541-552.
Lohmeyer, K.H., May, M.A., Thomas, D.B., Perez De Leon, A.A. 2018. Implication of nilgai antelope (Artiodactyla: Bovidae) in reinfestations of Rhipicephalus (Boophilus) microplus (Acari: Ixodidae) in South Texas: A review and update. Journal of Medical Entomology. 55(3):515-522. https://doi.org/10.1093/jme/tjy004.
Manter, D.K., Delgado, J.A., Blackburn, H.D., Harmel, R.D., Perez De Leon, A.A., Honeycutt, C.W. 2017. A new concept: national living soil repository. Proceedings of the National Academy of Sciences. 114:13587–13590. https://doi.org/10.1073/pnas.1720262115.
Vial, L., Ducheyne, E., Filatov, S., McVey, D.S., Sindryakova, I., Morgunov, S., Perez de Leon, A.A., Kolbasov, D., De Clercq, E. 2017. Spatial multi-criteria decision analysis for modelling suitable habitats of Ornithodoros soft ticks in the Western Palearctic region. Veterinary Parasitology. 249:2-16. https://doi.org/10.1016/j.vetpar.2017.10.022.
Goolsby, J., Singh, N., Ortega-S, A., Hewitt, D.G., Campbell, T., Wester, D., Perez De Leon, A.A. 2017. Comparison of natural and artificial odor lures for nilgai (Boselaphus tragocamelus) and white-tailed deer (Odocoileus virginianus) in South Texas: developing treatment for cattle fever tick eradication. International Journal for Parasitology: Parasites and Wildlife. 6:100-107.
Singh, N., Goolsby, J., Shapiro Ilan, D.I., Setamou, M., Perez De Leon, A.A. 2018. Effect of immersion time on efficacy of entomopathogenic nematodes against engorged females of Cattle Fever Tick, Rhipicephalus (Boophilus) microplus. Experimental and Applied Acarology. 43(1):19-28. https://doi.org/10.3958/059.043.0120.
Singh, N., Goolsby, J., Shapiro Ilan, D.I., Miller, R., Thomas, D.B., Klafke, G., Tidwell, J.P., Racelis, A., Grewal, P., Perez De Leon, A.A. 2018. Efficacy of entomopathogenic nematodes (Rhabditida: Heterorhabditidae and Steinernematidae) against engorged females of the cattle fever tick Rhipicephalus (Boophilus) microplus (Acari: Ixodidae). Southwestern Entomologist. 43(1):1-17. https://doi.org/10.3958/059.043.0119.
Singh, N.K., Miller, R., Klafke, G., Goolsby, J., Thomas, D.B., Perez De Leon, A.A. 2018. In-vitro efficacy of a botanical acaricide and its active ingredients against larvae of susceptible and acaricide-resistant strains of Rhipicephalus (Boophilus) microplus Canestrini (Acari: Ixodidae). Ticks and Tick Borne Diseases. 9(2):201-206.
Barradas Piña, F., Da Silva Rodrigues, V., De Oliveria Souza Hi, L., Valério Garcia, M., Cavalcante Barros, J., Perez De Leon, A.A., Andreotti, R. 2017. Life cycle of Amblyomma mixtum (Acari: Ixodidae) parasitizing different hosts under laboratory conditions. Experimental and Applied Acarology. https://doi.org/10.1007/s10493-017-0178-y.
Goolsby, J., Singh, N., Thomas, D.B., Ortega, A., Hewitt, D., Campbell, T., Perez De Leon, A.A. 2017. Comparison of chemical attractants against dung beetles and application for rangeland and animal health. Southwestern Entomologist. 42(2):339-346.
Singh, N., Goolsby, J., Ortega, A., Hewitt, D., Campbell, T., Perez De Leon, A.A. 2017. Comparative daily activity patterns of Nilgai, Boselaphus tragocamelus and white-tailed deer, Odocoileus virginianus in South Texas. Subtropical Agriculture and Environments. 68:7-12.
Martinez Jimenez, M., Goolsby, J., Racelis, A., Perez De Leon, A.A., Negrete Arroyos, D. 2017. Introduction, establishment and dispersal in Mexico of the wasp Tetramesa romana, biological control agent of the giant reed. Southwestern Entomologist. 42(2):427-434.
Martinez Evora, P., Sanches, G.S., Guerrero, F., Perez De Leon, A.A., Bechara, G.H. 2017. Immunogenic potential of Rhipicephalus (Boophilus) microplus aquaporin 1 against Rhipicephalus sanguineus in domestic dogs. Revista Brasileira de Parasitologia Veterinaria. 26(1):60-66.
Gross, A.D., Temeyer, K.B., Day, T.A., Perez De Leon, A.A., Kimber, M.J., Coats, J.R. 2017. Interaction of plant essential oil terpenoids with the southern cattle tick tyramine receptor: A potential biopesticide target. Chemico Biological Interactions. 263:1-6.
Marshall, M., Goolsby, J., Vacek, A.T., Mastoras, A., Kashefi, J., Chaskopoulou, A., Smith, L., Badillo, I., Reilly, F.J., Perez De Leon, A.A., Racelis, A. 2018. Biotic and abiotic factors influencing infestation levels of the arundo leafminer, Lasioptera donacis, in its native range in Mediterranean Europe. Subtropical Agriculture and Environments. 69:8-18.
Costa-Junior, L.M., Miller, R., Alves, P.B., Blank, A.F., Li, A.Y., Perez De Leon, A.A. 2016. Acaricidal efficacies of Lippia gracilis essential oil and its phytochemicals against organophosphate-resistant and susceptible strains of Rhipicephalus (Boophilus) microplus. Veterinary Parasitology. 228:60-64.
Goolsby, J., Jung, J.A., Landivar, J., McCutcheon, W., Lacewell, R., Duhaime, R., Puhger, R., Baca, D., Hasel, H., Varner, K., Miller, B., Schwartz, A., Perez De Leon, A.A. 2016. Evaluation of unmanned aerial vehicles (UAVs) for detection of cattle in the Cattle Fever Tick Permanent Quarantine Zone. Subtropical Agriculture and Environments. 67:24-27.
Almazán, A., Aguilar Tipacamu, G., Rodríguez, S., Mosqueda, J., Perez De Leon, A.A. 2018. Immunological control of ticks and tick-borne diseases that impact cattle health and production. Frontiers in Bioscience. 23:1535-1551.
Kim, H., Filatov, S., Lopez, J., Perez De Leon, A.A., Teel, P. 2018. Blood feeding of Ornithodoros turicata larvae using an artificial membrane system. Medical and Veterinary Entomology. 31(s):230-233.
Wilder, H.K., Krishnavajhala, A., Boyle, W.K., Damania, A., Thornton, J.A., Perez De Leon, A.A., Teel, P.D., Lopez, J.E. 2017. Imaging of Borrelia turicatae producing the green fluorescent protein reveals persistent colonization of the Ornithodoros turicata midgut and salivary glands from nymphal acquisition through transmission. Applied and Environmental Microbiology. 83(5):2503-2516.
Foley, A.M., Goolsby, J., Ortega Jr, A., Ortega Sr, A., Perez De Leon, A.A., Hewitt, D.G., Campbell, T., Singh, N.K. 2017. Movement patterns of Nilgai antelope (Boselaphus tragocamelus) in South Texas: implications for cattle fever tick management. Journal of Wildlife Management. 146:166-172.
Swale, D., Li, Z., Guerrero, F., Perez De Leon, A.A., Foil, L. 2017. Role of inward rectifier potassium channels in salivary gland function and sugar feeding of the fruit fly, Drosophila melanogaster. Pesticide Biochemistry and Physiology. 141:41-49.
Barrero, R., Guerrero, F., Black, M., McCooke, J., Schilkey, F., Perez De Leon, A.A., Miller, R., Bruns, S., Dobry, J., Mikhaylenko, G., Stormo, K., Bell, C., Tao, Q., Bogden, R., Moolhuijzen, P., Hunter, A., Bellgard, M. 2017. Gene-enriched draft genome of the cattle tick Rhipicephalus microplus: Assembly by the hybrid Pacific Biosciences/Illumina approach enabled analysis of the highly repetitive genome. International Journal for Parasitology. 47(9):569-583.
Konganti, K., Guerrero, F., Schilkey, F., Ngam, P., Jacobi, J., Umale, P., Perez De Leon, A.A., Threadgill, D. 2018. A whole genome assembly of the horn fly, Haematobia irritans, and prediction of genes with roles in metabolism and sex determination. G3, Genes/Genomes/Genetics. 8:1675-1686.
Perez De Leon, A.A., Mahan, S., Messenger, M., Ellis, D., Varner, K., Schwartz, A., Baca, D., Andreotti, R., Rodriguez Valle, M., Rosario Cruz, R., Dominguez Garcia, D., Comas Pagan, M., Oliver Canabal, C., Urdaz, J., Collazo Mattei, F., Soltero, F., Guerrero, F., Miller, R. 2018. Public-private partnership experience enabling translational research for anti-tick vaccine used in integrated Rhipicephalus (Boophilus) microplus and R. annulatus tick eradication in the United States of America. Book Chapter. 5:275-298.