Managing Japanese Barberry (Ranunculales: Berberidaceae) Infestations Reduces Blacklegged Tick (Acari: Ixodidae) Abundance and Infection Prevalence WithBorrelia burgdorferi(Spirochaetales: Spirochaetaceae)

Abstract

In many Connecticut forests with an overabundance of white-tailed deer (Odocoileus virginianus Zimmermann), Japanese barberry (Berberis thunbergii DC) has become the dominant understory shrub, which may provide a habitat favorable to blacklegged tick (Ixodes scapularis Say) and white-footed mouse (Peromyscus leucopus Rafinesque) survival. To determine mouse and larval tick abundances at three replicate sites over 2 yr, mice were trapped in unmanipulated dense barberry infestations, areas where barberry was controlled, and areas where barberry was absent. The number of feeding larval ticks/mouse was recorded. Adult and nymphal ticks were sampled along 200-m draglines in each treatment, retained, and were tested for Borrelia burgdorferi (Johnson, Schmid, Hyde, Steigerwalt, and Brenner) presence. Total first-captured mouse counts did not differ between treatments. Mean number of feeding larval ticks per mouse was highest on mice captured in dense barberry. Adult tick densities in dense barberry were higher than in both controlled barberry and no barberry areas. Ticks sampled from full barberry infestations and controlled barberry areas had similar infection prevalence with B. burgdorferi the first year. In areas where barberry was controlled, infection prevalence was reduced to equal that of no barberry areas the second year of the study. Results indicate that managing Japanese barberry will have a positive effect on public health by reducing the number of B. burgdorferi-infected blacklegged ticks that can develop into motile life stages that commonly feed on humans.

Prevalence and Genetic Characterization of Powassan Virus Strains Infecting Ixodes scapularis in Connecticut

“…16 Adult ticks were collected in October through December of 2008, 2010, and 2011, and during April and May in 2011, and March and April in 2012. Host-seeking nymphs were collected by the same procedure described for adult ticks during May and June 2008 from two locations in Fairfield, two locations in Middlesex, and three locations in New London Counties, Connecticut.…”

Analysis and Prediction of Land Use Changes Related to Invasive Species and Major Driving Forces in the State of Connecticut

“…One especially problematic invasive plant in Connecticut is Berberis thunbergii (Japanese barberry). This perennial woody shrub provides excellent habitats for Lyme-disease carrying ticks thereby increasing the risk of infection in humans [12,13] in addition to altering ecosystem functions, such as nitrogen cycling, in invaded areas [14]. Japanese barberry was the second most frequently observed invasive plant at rare species sites in New England, and invasive plant presence was correlated with decreases in rare species population size [7].…”

Invasive honeysuckle eradication reduces tick-borne disease risk by altering host dynamics

“…However, although there is phenomenological support for potential biotic effects of plant invasions on tick-borne disease risk mediated via tick hosts, mechanistic understanding has remained elusive. Studies conducted in the northeastern United States (31,32) have demonstrated that human risk of exposure to Lyme disease, which is caused by the bacterium Borrelia burgdorferi and transmitted by the black-legged tick (Ixodes scapularis), is increased by several exotic shrubs, including honeysuckle and Japanese barberry (Berberis thunbergii). The ecological mechanisms through which these plant invasions influence Lyme disease risk remain unknown, however, and an enhanced understanding of the mechanisms that drive disease risk is critical to mitigation and control strategies.…”