Controlling Ectoparasites on Welsh Organic Sheep Farms

1. Organophosphate (OP) based dips offer a broad spectrum control against all major ectoparasites in the UK. However, there is continuing controversy over the safety to dip operators and the environment. The use of OPs is prohibited by organic standards, primarily because of concerns about mammalian toxicity. 2. Organic farmers are permitted to use synthetic pyrethroids (SPs)(dip products and pour-on products) and/or macrocyclic lactones (injectable products) to treat/control ectoparasites providing a derogation has been obtained from the certifying body. 3. SPs have been shown to be considerably more toxic to aquatic organisms than OPs. The environmental impact of SPs is not limited to levels in dip but also to residues in sheep fleeces. SPs may be removed from the wool by climatic conditions and then deposited in the local environment. 4. The Environment Agency have indicated that the majority of sheep dip pollution incidents involve SP dips. Concerns have been raised that as organic farmers can only use SP based dips they may be contributing to the higher levels of SP based pollution incidents. 5. There is little information as to current practices amongst organic sheep farmers to control/treat ectoparasites or on how these farmers dispose of the spent dip. In order to address this lack of information a survey was carried out by ADAS Pwllpeiran to investigate current practices amongst sheep farmers in Wales. For comparison purposes both conventional and organic farmers were included in the survey. 6. In total, 134 questionnaires were completed with 96 completed by conventional sheep farmers and the remaining 38 being completed by either in-conversion organic farmers or fully registered organic farmers. 7. Results showed that 58% of organic farmers surveyed treated their flocks for ectoparasites compared to 67% of conventional farmers. 8. Of the organic farmers surveyed, 52.6% listed flystrike as a parasite for which they treated their flocks. This was comparable to conventional farmers where 58.3% listed flystrike. Only 21.1% of organic farmers surveyed listed scab compared to 61.5% of conventional farmers. Less than 10% of both conventional and organic farmers surveyed treated for other ectoparasites. Those who did listed lice and ticks as the main ectoparasites. 9. Despite a large percentage of conventional farmers listing scab as an ectoparasite to be treated, only 11.5% of those surveyed treated for ‘scab only’ compared to 51.0% who treated for scab in combination with other ectoparasite control. A similar pattern was seen amongst organic farmers surveyed, where only 2.6% treated for ‘scab only’ whereas 18.4% treated for scab in combination with other ectoparasite control. 10. Of the organic farmers surveyed, 36.8% treated for ‘flystrike only’ compared to 7.3% of conventional farmers. 11. Despite other ectoparasites such as lice and ticks being listed by both conventional and organic farmers neither of these two parasites were treated singly but were always treated in combination with other ectoparasites. 12. Of conventional farmers surveyed who treated for ectoparasite control, 76.1% listed plunge dipping as the preferred dipping method compared to only 22.7% of the organic farmers surveyed who treated for ectoparasites. 13. The use of pour-on products was higher amongst organic farmers with 54.5% using pour-ons as a treatment method compared to 16.5% of conventional farmers. 14. Less than 5% of the organic farmers who treated for ectoparasites used a combination of treatments compared to 19% of conventional farmers who treated for ectoparasites. 15. When asked how often they treated for ectoparasites, 54% of organic farmers treated once a year compared to 42% of conventional farmers. 27% of organic farmers treated twice a year whereas 52% of conventional farmers treated twice a year. 14% of organic farmers treated three or more times a year compared to 7% of conventional farmers. 16. All organic farmers who carried out plunge dipping operations used a SP based product however of the conventional farmers who carried out plunge dipping, 39% used an SP based product. Overall, 16% of organic farmers surveyed used an SP based dip product compared to 24% of conventional farmers surveyed. Of all conventional farmers surveyed 38% used an OP based dip product. 17. Where farmers carried out plunge dipping, 53% of conventional farmers diluted spent dip before spreading to land compared to 83% of organic farmers who carried out plunge dipping operations. Of all the farmers surveyed who carried out plunge dipping only 1 treated dip with slaked lime before spreading. 18. Of all organic farmers surveyed, 5% used a mobile dipping contractor compared to 23% of conventional farmers surveyed. 19. Where contractors were used on organic holdings they were also responsible for the disposal of spent dip. The contractor was responsible for the disposal of dip on 74% of conventional holdings using contractors for dipping. 20. On 42% of the holdings using contractors, the spent dip was removed from the farm whereas on 32% of holdings the spent dip was spread on the farm land. 26% of farmers using contractors in this survey did not know how the contractor disposed of spent dip. 21. The percentage of farmers treating their flocks for ectoparasite infestations is similar for organic (58%) and conventional (69%) sheep farmers however there is a marked difference in the species of ectoparasites treated. 22. Of the conventional farmers who treated their flocks for ectoparasites, 86% listed scab as a major parasite compared to only 36% of organic farmers who also treated their flocks for ectoparasites. 23. Overall, only 3% of the organic farmers surveyed treated their sheep specifically for scab, compared to 11% of conventional farmers surveyed. 24. Of organic farmers surveyed, 37% treated their flocks specifically for blowfly strike compared to only 7% of conventional farmers surveyed. 25. Of the conventional farmers surveyed, 51% treated their flocks for more than one ectoparasite infestations compared to 18% of organic farmers surveyed. 26. From the evidence of several of the completed survey forms some farmers appeared to be using incorrect treatment methods and some were using multiple treatment methods to treat ectoparasite infestations. The use of incorrect treatments or multiple treatments is largely a reflection of the plethora of products available and suggests a lack of understanding as to which products are appropriate and licensed for the treatment of specific ectoparasites. 27. The survey found that fewer organic sheep farmers use SP dips than conventional sheep farmers do. As there are fewer organic sheep farmers overall, there is little evidence that organic sheep farmers contribute disproportionately to the level of SP based pollution incidents. 28. Summary of Recommendations: A. A further in-depth survey would be valuable to elucidate the extent of the scab problem in the national organic flock. B. Both organic and conventional farmers have difficulty in selecting the best/ most appropriate treatment for their flocks. An educational campaign would help to remedy this problem. C. Annual training courses for certifying bodies and advisors to keep up to date with developments in research and products are recommended. D. Given the potential for SP dips to cause major environmental damage if disposed of incorrectly it is a mandatory requirement that organic farmers are licensed by EA to dispose of spent dip. Inspectors should ensure cross compliance where organic farmers are using dip. E. Certifying bodies need to consider all the available evidence as to what chemicals should be permitted to treat scab and other ectoparasites and where appropriate make alterations to the standards. F. Inspection of dips facilities and EA licence should be part of the annual inspection procedures. G. Certification bodies should collate information on dipping practices and dip disposal. H. Where a pollution incident occurs on an organic holding this should be reported to the relevant certifying body. I. Development and evaluation of IPM programmes should be assessed as a management tool to reduce use of chemical treatments whilst promoting good animal husbandry and management. IPM programmes should be incorporated with animal health plans

New Records for Ectoparasites of Michigan Bats

During 1978, 1979, and 1981 ectoparasites of bats were collected in 16 counties of the Upper and Lower peninsulas in connection with an extensive study of Michigan bat populations (Kurta 1980, 1982). The two insect and five acarine species recovered include four new records for Michigan and two new host records for the United States. All are listed with comments on past records of Michigan bat ectoparasites

Ectoparasites and Other Arthropod Associates of the Hairy-tailed Mole, \u3ci\u3eParascalops Breweri\u3c/i\u3e

A total of 33 taxa of ectoparasites and other associates was taken on seven individuals of the Hairy-tailed Mole, Parascalops breweri, from New York and New England. The most abundant form was the glycyphagid mite, Labidophorus nearcticus

Ectoparasites and Other Arthropod Associates of Some Voles and Shrews From the Catskill Mountains of New York

Reported here from the Catskill Mountains of New York are 30 ectoparasites and other associates from 39 smoky shrews, Sorex fumeus, 17 from 11 masked shrews, Sorex cinereus, 11 from eight long-tailed shrews, Sorex dispar, and 31 from 44 rock voles, Microtus chrotorrhinus

Additional Records of Michigan Bat Ectoparasites

New Michigan county records for Ischnopsyllidae, Cimicidae, Spinturnicidae, Macro- nyssidae, and Trombiculidae from bats are given along with two new bat/parasite records for the United States

Ectoparasitic Arthropods Collected From Some Northern Ohio Mammals

Ectoparasitic arthropods were collected from some fur-bearing mammals in northern Ohio. Specimens representing seven mammalian species were examined and found to collectively harbor acarines, fleas, and biting lice. Species determinations were made and new host and state records noted

Ectoparasites of Isle Royale, Michigan

Isle Royale National Park is a rocky archipelago of approximately 200 islands and islets in northwestern Lake Superior. Politically it belongs to the State of Michigan situated 50 miles to the southeast. The main island lies parallel to the Canadian shore, which is from 12 to 15 miles to the northwest. It is 45 miles long, and 9 miles wide at its broadest point. A review of the climatological, vegetational, and geological features of the island is given by Mech (1966). Most of the material included in this paper was collected incidently by Johnson during a three-year study (1966-68) of the food habits of the red fox (Vulpes vulpes (Linnaeus)), and population dynamics of three of its principal prey species--the snowshoe rabbit (Lepus americanus), red squirrel (Tamiasciurus hudsonicus), and deer mouse (Peromyscus maniculatus) (see Johnson, 1969). The remaining material (196061) was collected by L. D. Mech during his studies of gray wolf (Canis lupus Linnaeus)-moose (Alces alces) relationships (see Mech, 1966)

When is a parasite not a parasite? Effects of larval tick burdens on white-footed mouse survival

Many animal species can carry considerable burdens of ectoparasites: parasites living on the outside of a host's body. Ectoparasite infestation can decrease host survival, but the magnitude and even direction of survival effects can vary depending on the type of ectoparasite and the nature and duration of the association. When ectoparasites also serve as vectors of pathogens, the effects of ectoparasite infestation on host survival have the potential to alter disease dynamics by regulating host populations and stabilizing transmission. We quantified the impact of larval Ixodes scapularis tick burdens on both within-season and overwinter survival of white-footed mice (Peromyscus leucopus) using a hierarchical Bayesian capture-mark-recapture model. I. scapularis and P. leucopus are, respectively, vectors and competent reservoirs for the causative agents of Lyme disease, anaplasmosis, and babesiosis. Using a data set of 5587 individual mouse capture histories over sixteen years, we found little evidence for any effect of tick burdens on either within-season or overwinter mouse survival probabilities. In male mice, tick burdens were positively correlated with within-season survival probabilities. Mean maximum tick burdens were also positively correlated with population rates of change during the concurrent breeding season. The apparent indifference of mice to high tick burdens may contribute to their effectiveness as reservoir hosts for several human zoonotic pathogens.Fil: Hersh, Michelle H.. Cary Institute of Ecosystem Studies; Estados Unidos. Bard College. Program in Biology; Estados Unidos. Sarah Lawrence College; Estados UnidosFil: LaDeau, Shannon L.. Cary Institute of Ecosystem Studies; Estados UnidosFil: Previtali, Maria Andrea. Universidad Nacional del Litoral. Facultad de Humanidades y Ciencias. Departamento de Ciencias Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: Ostfeld, Richard S.. Cary Institute of Ecosystem Studies; Estados Unido

Using host species traits to understand the consequences of resource provisioning for host–parasite interactions

1.Supplemental food provided to wildlife by human activities can be more abundant and predictable than natural resources, and subsequent changes to wildlife ecology can have profound impacts on host–parasite interactions. Identifying traits of species associated with increases or decreases in infection outcomes with resource provisioning could improve assessments of wildlife most prone to disease risks in changing environments. 2.We conducted a phylogenetic meta-analysis of 342 host–parasite interactions across 56 wildlife species and three broad taxonomic groups of parasites to identify host-level traits that influence whether provisioning is associated with increases or decreases in infection. 3.We predicted that dietary generalists that capitalize on novel food would show greater infection in provisioned habitats owing to population growth and food-borne exposure to contaminants and parasite infectious stages. Similarly, species with fast life histories could experience stronger demographic and immunological benefits from provisioning that affect parasite transmission. We also predicted that wide-ranging and migratory behaviors could increase infection risks with provisioning if concentrated and non-seasonal foods promote dense aggregations that increase exposure to parasites. 4.We found that provisioning increased infection with bacteria, viruses, fungi, and protozoa (i.e., microparasites) most for wide-ranging, dietary generalist host species. Effect sizes for ectoparasites were also highest for host species with large home ranges but were instead lowest for dietary generalists. In contrast, the type of provisioning was a stronger correlate of infection outcomes for helminths than host species traits. 5.Our analysis highlights host traits related to movement and feeding behavior as important determinants of whether species experience greater infection with supplemental feeding. These results could help prioritize monitoring wildlife with particular trait profiles in anthropogenic habitats to reduce infectious disease risks in provisioned populations