Culicoides biting midges (Diptera: Ceratopogonidae) are biological vectors of economically important arboviruses of livestock. Two such arboviruses, bluetongue virus (BTV) and Schmallenberg virus (SBV) have recently emerged in northern Europe inflicting unprecedented outbreaks of disease in this region. The aim of the current investigation was to explore both host seeking behaviour and surveillance methods for livestock-associated Culicoides species in the UK. To achieve this aim, a series of field-based, manipulative experiments were conducted using three farm sites in southern England. These studies demonstrated that host preference had a significant impact upon several parameters important in determining arbovirus transmission. Culicoides were found to be differentially attracted to different breeds of sheep (p<0.05) and blood feeding efficiency was shown to be determined in part by whether the sheep had been sheared (p<0.05). In addition the presence of an alternative host (a cow and its calf) was demonstrated to lead to an increased Culicoides biting rate on sheep held in close proximity (p<0.05), increasing the risk of arbovirus transmission. Preliminary studies of volatile chemicals produced by hosts illustrated that while these attracted livestock-associated Culicoides at rates higher than those recorded in un-baited traps (p<0.05), collections only represented a small proportion of those collected on hosts themselves. These studies, however, provided a platform for future investigations of this area. Finally, the use of light-emitting diode (LED) baited suction traps was trialled as a means of improving detection sensitivity in surveillance of Culicoides populations. This study found that certain Culicoides species demonstrated increased sensitivity to specific wavelengths (p<0.05) and integration of these commercially available traps could improve our understanding of the abundance, geographic distribution and behaviour of these species.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:639433 |
| Date | January 2013 |
| Creators | Hope, Andrew |
| Publisher | University of Liverpool |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://livrepository.liverpool.ac.uk/16273/ |
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