## 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 DepartmentHartford Courant June 20, 1998K. Stafford 

## Residential Landscape Management Mowing, pruning 

### Clearing brush Restrict groundcover Leaf litter removal Landscape barriers Deer fencing Deer resistant plantingsMed. 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 GroundcoverThe 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 BrochureVector- 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) A B Environ. Entomol . 2004. 33:900 - 906Higher tick counts associated with exotic invasive forest understory than native forest understory or open understory forests. 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 B280
121 30 0 50 100 150 200 250 300 350

Full barberry Controlled barberry No barberry Density (ticks/ha) of Borrelia burgdorferi infected 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 - 192125 • 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 1 st year, 80% in 2 nd year with lignin encapsulated 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