Modelling the distribution of Culicoides bluetongue vectors in north wales : [Abstract 101]

Bluetongue (BT) serotype-8 emerged in northern Europe in 2006 and the UK initiated a vaccination campaign in 2007. With Wales accounting for 15% of ail sheep within the EU community, incursions of BT could cause devastating production losses. To provide insight into the distribution and density of BT vectors in Wales, satellite-derived climate environmental and soil variables were analysed within a GIS. Surveillance of #Culicoides biting# midges (CBMs) was carried out on 25 farms in Baia, north Wales, over 12 nights in July 2008. Environmental variables were assessed using a farm questionnaire soil data was obtained from the National Soil Resources 'Institute. MOD imagery from the NASA Terra satellite, including day/night-time land surface temperature, middle infrared reflectance, NDVI and EVI, was also obtained. High "1km) spatial regression models were built to investigate explanatory parameters for the CBM variation between farms. Models were produced for each midge trapped, as well as a model for ail species combined. The #C.obsoletus# group, present on farms, represented 62% of individuals trapped. The between-farm variation in was up to 200%. Models produced explain up to 88% of catch variation (species dependent). Only one model explained less than 500/0 of the variation (#C. festivipennis#; 23.28%). The #C. obsoletus# species (main BT vector in UK) model accounts for 85.5% of the variation. It includes the number of sheep on a farm and use of insecticides, alongside climatic variables. Freely accessible climate and environmental data has proved beneficial in modelling CBM distribution. Quickbird satellite imagery and ordinance survey data are being assessed in terms of producing similar models for Bala and will be compared to the current models. Trapping at multiple sites per farm is being undertaken to produce higher resolution models of CBM density in relation to on-farm environmental variables. (Texte intégral)

Bibliographic Details

Main Authors:	Kluiters, Georgette, Guis, Hélène, Labuschagne, Karien, Baylis, Matthew
Format:	conference_item biblioteca
Language:	eng
Published:	s.n.
Subjects:	L73 - Maladies des animaux, L72 - Organismes nuisibles des animaux, U10 - Informatique, mathématiques et statistiques, Culicoides, virus bluetongue, fièvre catarrhale ovine, mouton, http://aims.fao.org/aos/agrovoc/c_10196, http://aims.fao.org/aos/agrovoc/c_9342, http://aims.fao.org/aos/agrovoc/c_976, http://aims.fao.org/aos/agrovoc/c_8369, http://aims.fao.org/aos/agrovoc/c_8294,
Online Access:	http://agritrop.cirad.fr/559472/ http://agritrop.cirad.fr/559472/1/document_559472.pdf
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