title: Livestock ectoparasites: integrated management in a changing climate.
abstract: The prevalence of livestock ectoparasites is the result of a complex interaction of factors such as parasite and host abundance, host susceptibility, climate and, critically, farmer husbandry and intervention strategies, all of which change seasonally in space and time. Given the complexity of the interacting factors, the effects of any climate change on disease incidence are hard to predict, as accordingly are the optimal husbandry responses required to ameliorate any effects. Here cutaneous myiasis in sheep, by the blowfly Lucilia sericata in the United Kingdom, is used to highlight the impact of a range of such issues. Cutaneous myiasis would be expected to be highly sensitive to even small changes in climate and therefore provides a good model to illustrate the problems inherent in attempting to predict the effect of climate change on livestock disease incidence. Both simulation and spatial species distribution models, show that the range of elevated temperatures predicted by current climate change scenarios are likely to result in an elongated blowfly season with earlier spring emergence and a higher cumulative incidence of strike. Strike incidence would be expected to increase, particularly for ewes in early summer. However, under higher IPCC emissions senarios (+3 °C), parts of central and southern England may become too hot and dry for strike by L. sericata to persist in mid-summer. Under these conditions, it is possible that other, more pathogenic Mediterranean agents of myiasis, such as Wohlfahrtia magnifica could replace L. sericata. Nevertheless, the models suggest that simple changes in some husbandry practices, such as shearing or trap use, could have an important effect in reducing early season ewe strike incidences by L. sericata. The work reviewed here, suggests that climate warming is likely to increase the risk of fly strike incidence, with consequent animal welfare and economic problems. However, practical measures exist which, with modest changes in husbandry practices, should be able to manage expected increases in strike, under the range of climate changes currently predicted. The work demonstrates that attempts to predict the likely impact of climate change on disease incidence must take into account changes in farmer behaviour and animal management practices as well as parasite biology.
authors.affiliation: Veterinary Parasitology & Ecology Group, School of Biological Sciences, University of Bristol, Bristol BS8 1UG, United Kingdom. richard.wall@bristol.ac.uk
authors.forename: Richard
authors.initials: R
authors.lastname: Wall
authors.forename: Hannah
authors.initials: H
authors.lastname: Rose
authors.forename: Lauren
authors.initials: L
authors.lastname: Ellse
authors.forename: Eric
authors.initials: E
authors.lastname: Morgan
mesh_terms: D000822:Animal Husbandry / Q000379:methods; D000818:Animals; D057231:Climate Change; D004198:Disease Susceptibility; D005060:Europe / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D058751:Livestock / Q000469:parasitology*; D008954:Models, Biological; D009198:Myiasis / Q000453:epidemiology / Q000469:parasitology / Q000662:veterinary*; D010571:Pest Control / Q000379:methods; D012621:Seasons; D012756:Sheep; D012757:Sheep Diseases / Q000453:epidemiology / Q000469:parasitology*; D012876:Skin Diseases, Parasitic / Q000453:epidemiology / Q000469:parasitology / Q000662:veterinary*; D013696:Temperature