Agricultural

Research

Service

Research Strategies to Control Ticks 

on White-tailed Deer

Host-targeted Control of Field Populations of Blacklegged 

and Lone Star Ticks to Reduce the Risk of Tick-borne 

Disease Transmission 

J. Mathews Pound, PhD

Research Entomologist

USDA Agricultural Research Service

Knipling-Bushland U.S. Livestock Insects Research Laboratory

Kerrville, Texas

Promoting Community IPM for Preventing Tick-Borne Diseases

March 31, 2011

Arlington, VA
Agricultural

Research

Service

Importance of White-tailed Deer in 

the Life Cycle of Blacklegged Ticks

Promoting Community IPM for Preventing Tick-Borne Diseases

March 31, 2011

Arlington, VA
Agricultural

Research

Service

Host-Targeted Control of Ticks on Deer

• Objective: Primarily to prevent the successful feeding 

of adult ticks on white-tailed deer to effectively remove 

them as a source of blood and interrupt the tick life 

cycle. In addition, control of larval and nymphal ticks 

increases overall efficacy. 

Promoting Community IPM for Preventing Tick-Borne Diseases

March 31, 2011

Arlington, VA
Agricultural

Research

Service

Methods of Preventing Ticks from 

Feeding on Deer 

• Depopulation or density reduction of deer herds

– Capture (trap or anesthetize) and transport - Expensive, difficult to 

find acceptable relocation site

– Dispatch and donate - Less expensive, objections from the public

– Immuno-contraception – GonaConTM - Expensive, labor intensive, 

and very slow efficacy, long term effects on densities not known

• Anti-tick vaccines for deer – several labs involved

– None presently available

• Delivery by injection or ingestion

– Lessons from anti-tick vaccines for cattle fever ticks

• Only injectable formulations are available thus far – as labor intensive as immunocontraception of deer

• Efficacy in cattle of 30 to 85% control – not known for deer

• Frequent (6 month) re-inoculations required

Promoting Community IPM for Preventing Tick-Borne Diseases

March 31, 2011

Arlington, VA
Agricultural

Research

Service

Methods of Preventing Ticks from 

Feeding on Deer 

• Potential chemical tick control agents

– Systemically active acaricides – Macrocyclic lactones (ivermectin, 

doramectin, moxidectin, etc.)

• Topical application – Pour-on formulations (Little residual activity)

• Injectable application – Injectable formulations (Labor intensive)

• Oral application – Medicated baits such as whole kernel corn (Selective feeding 

required)

– Topically active acaricides

• Pyrethroids - Permethrin, cypermethrin, cyhalothrin, etc. (Long residual activity)

• Formamidines – Amitraz (Highly efficacious against ticks, long residual activity)

• Macrocyclic lactones – Ivermectin, etc. (Little residual activity as topical)

• Organophosphates – Coumaphos, etc. (Limited use - being taken off the market)

• Phenylpyrazoles – Fipronil, etc. (Highly efficacious, not for use on food animals)

• Neonicotinoids – Imidacloprid (Efficacious against fleas, does not kill ticks)

• And perhaps others

Promoting Community IPM for Preventing Tick-Borne Diseases

March 31, 2011

Arlington, VA
Agricultural

Research

Service

Boophilus spp. Tick Infestations

1906

Beginning of National Campaign

1943

National Eradication Campaign 

Complete

Promoting Community IPM for Preventing Tick-Borne Diseases

March 31, 2011

Arlington, VA
Agricultural

Research

Service

Acaricide Delivery Technologies 

Developed for White-tailed Deer

• Delivery of systemically active acaricides

– Medicated bait

• Ivermectin-medicated whole kernel corn

• Delivery of topically active acaricides

– „4-Poster‟ Deer Treatment Bait Stations

• Applying Y-Tex ‘4-Poster’ Tickicide (10% oily formulation of permethrin)

– „2-Poster‟ Deer Treatment Feeder Adapters

• Also applying Tickicide 

– Automatically attached acaricidal deer collars (neckbands)

• Applying long-lasting slow-release collars impregnated with 9% amitraz

Promoting Community IPM for Preventing Tick-Borne Diseases

March 31, 2011

Arlington, VA
Agricultural

Research

Service

Whole Kernel Corn as a Bait and Dosing 

Medium for White-tailed Deer

• When in the presence of abundant natural forage, white-tailed 

deer will consume only ca. 1 to 1.5% of body weight per day in 

whole kernel corn, i.e. a 100 pound deer will consume only ca. 1 

to 1.5 pounds of corn daily.

• Unlike cracked corn or pelleted feeds very clean whole kernels 

are resistant to uptake of moisture and thus do not mold as 

rapidly in an outdoor environment.

• Whole kernels have minimal surface area as compared with 

cracked corn or pelleted feeds which makes them easier to coat 

with liquid formulations.

• Corn is only ca. 7 to 9% protein so it does not increase population 

densities in deer that require a minimum of 10 to 13% dietary 

protein. 

Promoting Community IPM for Preventing Tick-Borne Diseases

March 31, 2011

Arlington, VA
Agricultural

Research

Service

Systemic Acaricide Technology:

Ivermectin-medicated Whole Kernel Corn 

• Ivomec Pour-on mixed with recleaned whole kernel corn at 2ml per 

pound of corn

• Re-bagged and fed to deer at ca. 1 

pound medicated corn per cwt deer 

per day (ca. 1% body wt per deer per 

day)

• Should result in ca. 30 ppb 

ivermectin in blood serum

• 8 to10 ppb in serum controls 100% 

of ticks feeding on deer

Promoting Community IPM for Preventing Tick-Borne Diseases

March 31, 2011

Arlington, VA
Agricultural

Research

Service

Medicated-Bait Field Trials

• Kerr Wildlife Management Area, Hunt, TX

– After 3 seasons of treatment achieved 92, 93, and 100% control of 

free-living adult, nymphal, and larval lone star ticks.

• Fairfield Glade, TN

– White-tailed deer within a large housing development were fed 

ivermectin-medicated corn, and residents were so pleased with 

reduced tick densities that they elected to fund continued treatment 

of deer after research terminated.

• Apache Ranch, Webb County, TX

– In 1992, an elk herd was selectively fed ivermectin-medicated corn on this 6,500 acre 

ranch, and a cattle fever tick infestation was successfully eradicated for the first time 

since 1956.

• Catarina Ranch, Webb County, TX

– Beginning in 1996, white-tailed deer on 22,000 acres of the 40,000 acre ranch were 

treated with over 22 tons of ivermectin-medicated corn, and in 1997 a cattle fever tick 

infestation lasting over 90 years was eradicated for the first time ever on record. 

Promoting Community IPM for Preventing Tick-Borne Diseases

March 31, 2011

Arlington, VA
Agricultural

Research

Service

Topical Control of Ticks

(10% Permethrin) 

„4-Poster‟ Deer Treatment Bait Stations

Promoting Community IPM for Preventing Tick-Borne Diseases

March 31, 2011

Arlington, VA
Agricultural

Research

Service

Impact of the „4-Poster‟ for Control of 

Ticks on White-tailed Deer at the Kerr 

Wildlife Management Area

• Left – A white-tailed deer from the 96-acre Control Pasture 

showing a normal lone star tick infestation

• Right – A white-tailed deer from the 96-acre Treatment 

Pasture showing the efficacy of oily 2% amitraz passively 

applied using a single ‘4-Poster’ Deer Treatment Bait Station

Promoting Community IPM for Preventing Tick-Borne Diseases

March 31, 2011

Arlington, VA
Agricultural

Research

Service

„4-Poster‟ Deer Treatment Bait Station 

Trials

• Kerr Wildlife Management Area, Hunt, TX

– After 3 seasons of treatment achieved 94, 92, and 88% control of 

free-living adult, nymphal, and larval lone star ticks using an oily 2% 

formulation of amitraz.

• USDA Northeast Area-wide Tick Control Project – MD, NJ, NY, CT, 

and RI

– After 5 years of treatment achieved 60 to 82% control (meta-analysis 

of 71% for the entire project) of blacklegged ticks using an oily 2% 

formulation of amitraz.

• Goddard Space Flight Center, Greenbelt, MD

– After 3 years of treatment, achieved 98% control of free-living 

nymphal blacklegged ticks. As a result of this high degree of 

efficacy, Goddard Space Flight Center elected to expand the 

treatment area and continue treatments.

Promoting Community IPM for Preventing Tick-Borne Diseases

March 31, 2011

Arlington, VA
Agricultural

Research

Service

Cylindrical Feed Chute Deer Feeder 

with ARS „2-Poster‟ Treatment Adapter

Promoting Community IPM for Preventing Tick-Borne Diseases

March 31, 2011

Arlington, VA
Agricultural

Research

Service

The „2-Poster‟ Deer Treatment Feeder Adapter

For use on new or existing feed 

chute type deer feeders

Promoting Community IPM for Preventing Tick-Borne Diseases

March 31, 2011

Arlington, VA
Agricultural

Research

Service

Amitraz Collars Applied to White-tailed Deer 

Effective in Reducing Free-living Populations 

of Lone Star Ticks

Promoting Community IPM for Preventing Tick-Borne Diseases

March 31, 2011

Arlington, VA
Agricultural

Research

Service

Functions of the Automatic Deer 

Collaring Device

• At initial entry of deer into feed area of collaring device

– Senses and individually identifies previously collared deer vs. those without 

collars by reading RFID tags on collars

– Senses the presence of un-collared “deer-shaped” animals

– Senses body position and automatically applies collars to properly positioned deer

– Automatically sizes collars to individual deer during application

– Automatically reloads the next collar from magazine onto collaring arms

– Records video and still photos of each deer to correlate with RFID tag on attached 

collar and later identify sex and approximate age of deer.

– Automatically records weight and height at withers of deer being collared

• At subsequent visit of previously collared deer

– Programmable to automatically inject specific deer

– Programmable to automatically detach collars from specific deer

Promoting Community IPM for Preventing Tick-Borne Diseases

March 31, 2011

Arlington, VA
Agricultural

Research

Service

The 5th Generation Robotics, Electronics, and 

Computer Enabled Automatic Collaring 

Device for White-tailed Deer

Promoting Community IPM for Preventing Tick-Borne Diseases

March 31, 2011

Arlington, VA
Agricultural

Research

Service

Efficacy of Host-Targeted Technologies to Reduce 

Free-living Populations of Lone Star Ticks

-10

0

10

20

30

40

50

60

70

80

90

100

Before Year 1 Year 2 Year 3

Ivermectin

'4-poster'

Collars

Promoting Community IPM for Preventing Tick-Borne Diseases

March 31, 2011

Arlington, VA
Agricultural

Research

Service

Interference from Non-Target Animals

• The most important non-target animals that interfere 

with deer treatments are raccoons, feral hogs, bear, 

and squirrels

– As hosts for immature ticks, raccoons that are treated topically while 

accessing ‘4-Posters’ have a positive effect on reducing tick 

densities. Other non-target animals have negative effects on 

efficiency and success of the ‘4-Poster’ and other treatment 

technologies

Promoting Community IPM for Preventing Tick-Borne Diseases

March 31, 2011

Arlington, VA
Agricultural

Research

Service

Promoting Community IPM for Preventing Tick-Borne Diseases

March 31, 2011

Arlington, VA
Agricultural

Research

Service

Promoting Community IPM for Preventing Tick-Borne Diseases

March 31, 2011

Arlington, VA
Agricultural

Research

Service

Hogzilla...

Promoting Community IPM for Preventing Tick-Borne Diseases

March 31, 2011

Arlington, VA
Agricultural

Research

Service

A Solid Steel “Bear-Proof” 4-Poster

Promoting Community IPM for Preventing Tick-Borne Diseases

March 31, 2011

Arlington, VA
Agricultural

Research

Service

Bear-Proof ? The first night...

Promoting Community IPM for Preventing Tick-Borne Diseases

March 31, 2011

Arlington, VA
Agricultural

Research

Service

Non-target Animal Excluder Fence

• Low (24 inch) 30-foot diameter circular utility panel 

and garden hose topped fence with 3 electric fence 

wires and supported by short T-posts 

– Excludes feral hogs and almost all raccoons

– Permits access by fawns, yearlings, and adult deer

– More expensive than non-electrified fence

– Easy to step over to service feeders

Promoting Community IPM for Preventing Tick-Borne Diseases

March 31, 2011

Arlington, VA
Agricultural

Research

Service

Hog and Raccoon Excluder Fence

Promoting Community IPM for Preventing Tick-Borne Diseases

March 31, 2011

Arlington, VA
Agricultural

Research

Service

Promoting Community IPM for Preventing Tick-Borne Diseases

March 31, 2011

Arlington, VA
Agricultural

Research

Service

Fence charger lasts 4 to 6 months on 

4 D-cells

Promoting Community IPM for Preventing Tick-Borne Diseases

March 31, 2011

Arlington, VA
Agricultural

Research

Service

Promoting Community IPM for Preventing Tick-Borne Diseases

March 31, 2011

Arlington, VA
Agricultural

Research

Service

Relative Toxicity – LD50 to Rats

(LD50=Dose that is lethal to 50% of the rats. Larger 

values are less toxic)

• Permethrin (10%) = >5050 mg/kg oral

• Roundup (herbicide) =>5000 mg/kg oral

• Picaridin (insect repellent) = 4743 mg/kg oral

• Sodium bicarbinate (baking soda) = 4220 mg/kg oral

• Sodium chloride (table salt) = 3000 mg/kg oral

• Deet (28%) (insect repellent) = 2000 mg/kg oral

• Ultra Downy (fabric softener) = 2000 mg/kg oral

• Imidacloprid (10%) (insecticide) = 1943 mg/kg oral

• Amitraz (100%) (insecticide) = 800 mg/kg oral

• Fipronil (1%) (insecticide)= 750 mg/kg oral

• Tylenol (pain reliever) = 714 mg/kg oral

• Ibuprofen (pain reliever)= 636 mg/kg oral

• Aspirin (pain reliever)= 200 mg/kg oral

• Ivermectin (endecticide) = 50 mg/kg oral

• Note: Permethrin fed to rats at150 mg/kg/day for 6 

months = No observable effect