Treatment of White-Tailed Deer with an Acaricide for the Control of Ixodes scapu

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Topical Treatment of White-Tailed Deer with an Acaricide for

the Control of Ixodes scapularis (Acari: Ixodidae) in a Connecticut Lyme

Borreliosis Hyperendemic Community

 

http://www.liebertonline.com/doi/abs/10.1089/vbz.2008.0161

 

Vector-Borne and Zoonotic Diseases

 

Topical Treatment of White-Tailed Deer with an Acaricide for the Control of

Ixodes scapularis (Acari: Ixodidae) in a Connecticut Lyme Borreliosis

Hyperendemic Community

 

 

Kirby C. Stafford, Anthony J. Denicola, J. Mathews Pound, J. Allen Miller,

John E. George.

Vector-Borne and Zoonotic Diseases.

August 2009, 9(4): 371-379. doi:10.1089/vbz.2008.0161.

Published in Volume: 9 Issue 4: August 3, 2009

 

Abstract

 

The 4-Poster device for the topical treatment of white-tailed deer,

Odocoileus virginianus (Zimmermann), against ticks using the acaricide

amitraz, was evaluated in a Lyme borreliosis endemic community in

Connecticut. As part of a 5-year project from 1997 to 2002, 21-24 of the

4-Posters were distributed at residential sites in Old Lyme, CT, in a core

treatment area of ?5.2km2 in fall 1997. The 4-Posters were active October

to

mid-December and March into May, corresponding to the peak periods of

activity for adult Ixodes scapularis in this particular area.

Corn consumption ranged from 361 to 4789kg/month for October and November

and 696-3130kg/month during April. Usage of 4-Posters by deer generally was

high (>90%), except during acorn masts in fall 1998 and 2001. Amitraz was

applied by rollers at the estimated rate of 1.3g active ingredient/ha/year.

The abundance of host-seeking I. scapularis nymphs declined significantly

(p<0.001) in the core treatment area, as compared to a control community in

Old Saybrook, CT, through 2004, over the project period from 1998 to 2003,

from 9.3/100m2 to 0.97/100m2, rising to 1.90/100m2 in 2004. From 1999

through 2003, there were 46.1%, 49.6%, 63.4%, 64.6%, and 70.2% reductions,

respectively, in the nymphal tick population in comparison with the

untreated community and initial tick abundance in 1998. Control of I.

scapularis adults declined to only 19.1% in 2004; 2 years after the

treatment of deer was discontinued.

Differences in nymphal tick abundance between the control and core

treatment

area were significant in 1999 (p=0.042) and highly significant in 2001

(p<0.001) and 2002 (p=0.002). The passive topical application to deer of

the

acaricide amitraz resulted in a significant decrease in the population of

free-living I. scapularis nymphs in the treated core in Connecticut.