Landscape Planning & Tick Management

A Residential Perspective

Kirby C. Stafford III, Ph.D.

Vice Director, State Entomologist

The Connecticut Agricultural Experiment Station

New Haven, CT

Promoting Community IPM for Preventing Tick-Borne Diseases

EPA Conference

29-30 March 2011, Arlington, VA
• Personal Protection Measures

• Habitat or landscape modifications 

• Biological & natural control

• Area-wide chemical control

• Host reduction or exclusion

• Host-targeted acaricides

• Host-targeted vaccines

Tick Management

www.ct.gov/caes
• Emergence of Lyme disease has been linked to reforestation 

and suburbanization that expose humans to habitat and hosts 

that favor Ixodes scapularis.

• Many studies have linked forest edge (reviewed Killilea et al. 

2008) and lower host diversity (LoGiudice et al. 2003, etc.) 

(favoring deer and white-footed mice) with the risk of Lyme 

disease.

• Authors examined LD incidence and land-cover metrics for 

12 counties in Maryland.
• LD incidence rate most explained by edge-contrast index, a 

measure of forest-herbaceous edge plus larger percent forest 

cover.

• Two landscapes with 50% forest cover, but different forest & 

edge interspersion (below). Figure on right with high forest & 

edge interspersion offers more shelter-foraging opportunities 

deer and mice and access suburban and rural residents –

features that would increase peridomestic exposure.

50% forest (dark shading)
• 67.3% woods, 21.6% ecotone, 2% on the lawn

• 82% nymphs are within 3-m of the lawn edge with woods, 

stone walls, ecotone, etc.

ALDF

Distribution Ixodes scapularis home environment:

Lyme disease risk is linked to

peridomestic exposure

• Estimated 75% ticks are picked up 

outdoors at home

• Indicated activity: Play 47%; Yard 

work 18%; Gardening 12%; 

Elsewhere neighborhood 4%

Maupin et al. 1991; Stafford & Magnarelli 1993; Carroll et al. 1992

Risk linked to peridomestic activity:

Data: Stamford Health Department
Hartford Courant June 20, 1998
K. Stafford

Residential Landscape Management

Mowing, pruning

Clearing brush

Restrict groundcover

Leaf litter removal

Landscape barriers

Deer fencing

Deer resistant plantings
Med. Vet. Entomol. 1995. 9:293-299

J. Vector Ecol. 2006. 31:412-417

• Insecticidal soap and silical gel with pyrethrin & PBO 

provided 78-100% control nymphal ticks pachysandra, 

sod, stones or woodchips.

• Alaska yellow cedar sawdust or woodchips and cellulose 

acted as barriers to nymphal tick movement, but only the 

sawdust impeded crossing up to 1 month.
Leaf Litter Removal Landscape Barriers

Yard Edge 49-70% reduction Yard Edge 35-77% reduction

Clean-up Stone Walls Reduce Groundcover

The Hour (Norwalk), Friday, June 23, 2000 The Westport News, Friday, March 23, 2001

From 1999-2002, three CT health districts initiated intensive 

community-based intervention programs to increase 

awareness of Lyme disease and encourage use of prevention 

measures

Landscape Brochure

Vector-borne & Zoonotic Dis. 2008. 8:769-776

• KAB survey 1999, 2002, 2004 in three CT health districts

• In WWHD, use all environmental measures increased 

from 1999 to 2002 and were sustained as of 2004.

• Most respondents willing remove brush or leaf litter 

(91%) or place wood chip or gravel barriers (82%).

• Fewer willing to use deer fences (52%) or spray pesticide 

(47%).

• 44% willing to spend up to $100, 37% spend more than 

$100. 
Am. J. Prev. Med. 2009. 37:201-206

• Examined personal protection, landscape modification, 

and chemical control in a prospective case-control study in 

CT.

• Checking for ticks within 36 hours of time in the yard was 

protective against LD.

• Bathing within 2 hours of time in the yard was protective.

• Fencing of any type was protective, but mechanism 

unclear.

• No other landscape modifications (mowing, leaf litter 

clearing, presence of playscapes, mulch or gravel barrier) 

were protective.

• Having stone wall, birdfeeders, vegetable garden, woods 

adjacent to property made no difference between cases and 

control (sample size also small in some cases).
NOFA Standards for 

Organic Land Care

• This is the heart of the 

Organic Land Care Program

• Provides a definition of 

“organic” in land care

• This definition is used for 

educational purposes (course, 

public outreach)

• Also specifies materials and 

practices that professionals 

pledge to use in providing 

organic land care to their 

clients
Tick (Pest) Management

NOFA Standards Organic Land Care

• Preferred

Tick bite prevention (avoid tick areas, pants in socks, repellents?) 

Tick checks to detect and remove before pathogen transmission

Environmental modifications (landscape practices)

Host management (deer fencing & herbal, soap, human hair as repellents)

• Allowed

Biological agents (parasites & pathogens)

Diatomaceous earth & insecticidal soaps

Botanical insecticides, including plant extracts, such as pyrethrum and 

minimum-risk or 25b insecticides (Section 25b FIFRA), which are 

exempt Federal registration and do not have to demonstrate efficacy

• Prohibited

All synthetic insecticides and piperonyl butoxide as an insecticide 

synergist

Any pesticide formulated with any inert ingredient not allowed by the 

National Organic Program.
Ticks and Invasive Plants

Light blue – states and provinces with barberry (http://plants.usda.gov)

Red – state where barberry reported invasive (http://www.nps.gov)

Blue dots – reported cases of Lyme disease in 2006 (http://www.cdc.gov)

Lyme disease incidence is high in many states where 

Japanese barberry, Berberis thunbergii, is reported invasive.
Odds ratio & 95% CI associating I. scapularis with 

habitat (A) and specific plant species (B)

0.0

1.0

2.0

3.0

4.0

5.0

6.0

Ferns Deciduous

Litter

Composition

Shrub Layer Canopy

Closure

Grasses OR's

A

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

Barberry Holly Hemlock

Saplings

Honeysuckle OR'

s

B

Environ. Entomol. 2004. 33:900-906
Higher tick counts associated with exotic invasive forest 

understory than native forest understory or open understory 

forests.

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

Exotics Moist ferns Native shrubs Grasses No veg. Saplings Herbs

Flagged Adults

Flagged Nymphs Mean # questing ticks/grid station (n=441 stations)

J. Med. Entomol. 2006. 43: 1142-1152
Barberry Control and Ticks

• Barberry infested 40-70% sites and was 

reduced from 62% of cover to 3% cover 

by mechanical cutting and burning with 

propane in controlled areas in 3 sites in 

CT

• Questing adult blacklegged tick 

abundance greatest in areas Japanese 

barberry

• Greater abundance larval ticks on mice 

in barberry

• Larval ticks sig. fewer in 2008 in 

controlled areas

Environ. Entomol. 2009. 38:977-984
Barberry Control and Ticks # B. burgdorferi infected ticks/ha

Mean # of larval ticks/captured mouse

A

A

B

B

B

B

A

AB

B

A

AB

B
280

121

30

0

50

100

150

200

250

300

350

Full barberry Controlled 

barberry

No barberry

Density (ticks/ha) of Borrelia burgdorferiinfected adult blacklegged ticks

Barberry Management. Questing adult blacklegged tick abundance was 

greatest in areas with Japanese barberry. This invasive plant provides 

suitable habitat for the tick and rodent hosts. Managing Japanese barberry 

significantly reduced the density of spirochete infected ticks to nearly 60% 

of that of unmanaged infestations.

Environ. Entomol. 2010. 39:1911-1921
25

• Personal prevention measures and tick checks.

• Landscape management practices.

• Deer fencing, resistant plantings, and accepted repellents.

• Pyrethrin insecticides (limited effectiveness w/o PBO) with 

desiccants and insecticidal soap

• Biological (Metarhizium should be an option by 2012).

• Botanical compounds, plant essential oils.

• Host-targeted insecticides much better environmentally, but 

chemicals used are not organic (permethrin, fipronil). 

Limited use to date.

What fits within an organic or least-toxic 

tick management framework?
Where do we go from here?

Panel Discussion

• How can we engage the landscape design 

professions in the prevention of tick-borne 

diseases?

• What is the best way to provide information on 

tick-borne disease prevention to professional 

planners and landscape architects?

• How can landscape design foster both conservation 

and prevention of tick-borne disease?

Entomopathogenic Fungi

http://www.entsoc.org/Pubs/Periodicals/JME/index.htm

Applications of Beauveria bassiana provided 38-75% 

control of the blacklegged tick, while Metarhizium 

anisopliae F52 (Tick-Ex) provided 53-74% control at 

the lower rate evaluated.

J. Med. Entomol. 2010. 47: 862-867

J. Med. Entomol. 2010. 47: 1107-1115
Natural Compounds for Tick Control

Nootkatone (Alaska yellow cedar, grapefruit)

CT studies 2008-2010, 100% control was observed for up to 

4 wks post application 1st year, 80% in 2nd year with ligninencapsulated nootkatone. Due to volatility, < 2-4% 

nootkatone remained by1 week posttreatment.

J. Econ. Entomol. 209. 102: 2316-2324

NJ studies 2006 & 2008, 100% control was observed for 1-

2 days, 82-88% after 7-10 days postapplication. A high 

pressure spray resulted in 98-100% control at 42 d postapplication.
Minimum Risk Pesticides

• Minimum-risk pesticides exempt by EPA under 

Section 25b FIFRA

1. Mosquito Barrier (99.3% Garlic Juice)

2. EcoEXEMPT IC2 (10% rosemary oil)

• Garlic in our 2009 and 2010 trials appeared to 

suppress or control tick activity for 2-3 weeks. No 

nymphs and few adult ticks were recovered 1-2 weeks 

post-application with EcoEXEMPT in Maine studies 

in 2008.

J. Med. Entomol. 2010. 47: 695-698