Environmental risk factors for Ixodes ricinus ticks and their infestation on lambs in a changing ecosystem: Implications for tick control and the impact of woodland encroachment on tick-borne disease in livestock

Gilbert, L., Brunker, K. , Lande, U., Klingen, I. and Grøva, L. (2017) Environmental risk factors for Ixodes ricinus ticks and their infestation on lambs in a changing ecosystem: Implications for tick control and the impact of woodland encroachment on tick-borne disease in livestock. Agriculture, Ecosystems and Environment, 237, pp. 265-273. (doi: 10.1016/j.agee.2016.12.041)

Abstract

Despite global deforestation some regions, such as Europe, are currently experiencing rapid reforestation. Some of this is unintended woodland encroachment onto farmland as a result of reduced livestock pasture management. Our aim was to determine the likely impacts of this on exposure to ticks and tick-borne disease risk for sheep in Norway, a country experiencing ecosystem changes through rapid woodland encroachment as well as increases in abundance and distribution of Ixodes ricinus ticks and tick-borne disease incidence. We conducted surveys of I. ricinus ticks on ground vegetation using cloth lure transects and counts of ticks biting lambs on spring pastures, where lambs are exposed to infection with Anaplasma phagocytophilum, the causative agent of tick-borne fever in livestock. Pastures had higher densities of I. ricinus ticks on the ground vegetation and more ticks biting lambs if there was more tree cover in or adjacent to pastures. Importantly, there was a close correlation between questing tick density on pastures and counts of ticks biting lambs on the same pasture, indicating that cloth lure transects are a good proxy of risk to livestock of tick exposure and tick-borne disease. These findings can inform policy on environmental tick control measures such as habitat management, choice of livestock grazing area and off-host application of tick control agents.

• Item Type: Articles
• Additional Information: This study was funded by the Norwegian Foundation for Research Levy on Agricultural Products (FFL) and the Agricultural Agreement Research Funds (JA), the Møre og Romsdal Council and County Governor in Møre og Romsdal through the project TICKLESS (project number 207737). L. Gilbert received addition support from the Scottish Government's Rural and Environment Science and Analytical Services Division (RESAS) and K. Brunker had additional support from the Natural Environment Research Council (NERC) and the University of Aberdeen.
• Keywords: Anaplasma, bush encroachment, reforestation, sheep, tick-borne disease, woodland expansion.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Brunker, Dr Kirstyn and Gilbert, Dr Lucy
• Authors: Gilbert, L., Brunker, K., Lande, U., Klingen, I., and Grøva, L.
• Subjects: Q Science > QL Zoology
• College/School: College of Medical Veterinary and Life Sciences > School of Biodiversity, One Health & Veterinary Medicine
• Journal Name: Agriculture, Ecosystems and Environment
• Publisher: Elsevier
• ISSN: 0167-8809
• ISSN (Online): 1873-2305
• Published Online: 08 January 2017
• Copyright Holders: Copyright © 2017 Elsevier B.V.
• First Published: First published in Agriculture, Ecosystems and Environment 237: 265-273
• Publisher Policy: Reproduced in accordance with the publisher copyright policy