Factors affecting deer ked (Lipoptena cervi) prevalence and infestation intensity in moose (Alces alces) in Norway

Abstract

BackgroundThe deer ked (Lipoptena cervi), a hematophagous ectoparasite of Cervids, is currently spreading in Scandinavia. In Norway, keds are now invading the south-eastern part of the country and the abundant and widely distributed moose (Alces alces) is the definitive host. However, key factors for ked abundance are poorly elucidated. The objectives of our study were to (i) determine deer ked infestation prevalence and intensity on moose and (ii) evaluate if habitat characteristics and moose population density are determinants of deer ked abundance on moose.MethodsIn order to identify key factors for deer ked abundance, a total of 350 skin samples from the neck of hunted moose were examined and deer keds counted. Infestation intensity was analyzed in relation to moose age and sex, moose population density and landscape characteristics surrounding the killing site.ResultsDeer ked infestation prevalence was 100%, but infestation intensity varied from 0.001 to 1.405 keds/cm2. Ked intensity was highest in male yearlings (~1.5 years) and positively associated with longitude and Scots pine (Pinus sylvestris) dominated habitat and negatively associated with bogs and latitude. Moose population density during autumn showed a tendency to be positively associated, while altitude tended to be negatively associated with ked intensity.ConclusionsDeer keds exploit the whole moose population within our study area, but are most prevalent in areas dominated by Scots pine. This is probably a reflection of Scots pine being the preferred winter browse for moose in areas with highest moose densities in winter. Ked intensity decreases towards the northwest and partly with increasing altitude, probably explained by the direction of dispersal and reduced temperature, respectively. Abundant deer ked harm humans and domestic animals. Moose management authorities should therefore be aware of the close relationship between moose, deer ked and habitat, using the knowledge as a management tool for locally regulating the ked burden.

Comparative morphology of the deer ked Lipoptena fortisetosa first recorded from Italy

“…However, L. cervi prefers yearlings to adults because the latter are less active and movement has been shown to be one of the most relevant factors in host selection in this species. In fact, the parasite rests in vegetation and waits for a host to pass by and hence is more likely to encounter a host that moves more (Madslien et al ., ).…”

Phenology of deer ked (Lipoptena cervi) host-seeking flight activity and its relationship with prevailing autumn weather

“…The deer ked Lipoptena cervi (Diptera: Hippoboscidae) is a blood sucking ectoparasite of cervids that has become very common in large areas of Norway, Sweden and Finland in recent years [ 1 , 2 ]. Deer ked infestation intensity can be high on cervids, especially on moose, the main host in Fennoscandia [ 3 – 5 ]. Modeling suggest that moose density is an important factor for invasion rate [ 6 ].…”

Vertical transmission of Bartonella schoenbuchensis in Lipoptena cervi

“…Lipoptena cervi (deer ked) is an obligate hematophagous ectoparasite of cervids and domesticated animals [ 1 , 2 ], which occasionally bites humans [ 3 ]. This species has a Palearctic distribution and belongs to a highly specialized family of flies (Diptera: Brachycera), called louse flies (Hippoboscidae) [ 4 , 5 ].…”

“…This third instar larva is deposited on the cervid fur as a white prepupa, which immediately starts to pupate. The fully developed and darkened pupa drops to the ground and remains there until August-September, after which a new generation of winged adult keds can emerge [ 2 , 15 ].…”