Does covering of farm-associated Culicoides larval habitat reduce adult populations in the United Kingdom?
Culicoides biting midges (Diptera: Ceratopogonidae) are the biological vectors of a range of internationally important arboviruses of livestock, including bluetongue virus (BTV) and the recently emerging Schmallenberg virus (SBV). Culicoides species in the subgenus Avaritia (in the UK: Culicoides obsoletus Meigen, Culicoides scoticus Downes & Kettle, Culicoides dewulfi Goetghebuer and Culicoides chiopterus Meigen) have been implicated in BTV transmission in northern Europe and to a varying degree utilise cattle dung as a larval development substrate. The collection of cattle dung into heaps on farms provides a localised source of Culicoides emergence in close proximity to livestock. This study assesses the impact of covering dung heaps prior to the onset of adult Culicoides activity with the aim of reducing recruitment to the local adult populations at four livestock farms in England. Light suction trap catches of adult Culicoides from these farms were compared with those from four untreated control farms from a wide geographic range across the UK. It was demonstrated that implementing control of emergence from dung heaps did not have a significant impact upon the local adult subgenus Avaritia abundance at the treated farm holdings and that the onset of Culicoides activity was similarly unaffected. Use of this method in isolation is unlikely to have an effect in reducing the risk of BTV and SBV transmission. The implications of these results for control of farm-associated Culicoides in Europe are discussed.
Vector-borne Viral Diseases Programme, The Pirbright Institute, Ash Road, Pirbright, Surrey GU24 0NF, UK; Spatial Ecology and Epidemiology Research Group, Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK. Electronic address: lara.harrup@pirbright.ac.uk.
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LE
Harrup
Vector-borne Viral Diseases Programme, The Pirbright Institute, Ash Road, Pirbright, Surrey GU24 0NF, UK.
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S
Gubbins
Vector-borne Viral Diseases Programme, The Pirbright Institute, Ash Road, Pirbright, Surrey GU24 0NF, UK.
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J
Barber
Vector-borne Viral Diseases Programme, The Pirbright Institute, Ash Road, Pirbright, Surrey GU24 0NF, UK.
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E
Denison
Vector-borne Viral Diseases Programme, The Pirbright Institute, Ash Road, Pirbright, Surrey GU24 0NF, UK.
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PS
Mellor
NERC Centre for Ecology and Hydrology, Bush Estate, Penicuik, Edinburgh EH26 0QB, UK.
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BV
Purse
Vector-borne Viral Diseases Programme, The Pirbright Institute, Ash Road, Pirbright, Surrey GU24 0NF, UK.
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Carpenter
D000383:Agriculture / Q000379:methods*; D000818:Animals; D002519:Ceratopogonidae / Q000502:physiology*; D007303:Insect Vectors / Q000502:physiology*; D007814:Larva; D008018:Life Cycle Stages / Q000502:physiology; D010571:Pest Control / Q000379:methods*; D011156:Population Density; D006113:United Kingdom
Arbovirus; Bluetongue virus; Culicoides; Diptera; Schmallenberg virus