Parasitism of the deer ked,Lipoptena cervi, on the moose,Alces alces, in eastern Finland

Abstract

The deer ked, Lipoptena cervi L. (Diptera: Hippoboscidae), is an ectoparasitic fly that spread to Finland in the early 1960s from the southeast across the Soviet border. It is currently a common parasite of the moose, Alces alces (Artiodactyla: Cervidae), in the southern part of the country and its area of distribution is gradually spreading to Finnish Lapland, where it will come into contact with another potential cervid host, the semi-domesticated reindeer, Rangifer tarandus tarandus. The aim of this study was to determine the intensity of deer ked parasitism on the moose in eastern Finland. Whole skins of 23 moose were examined for the presence of deer keds, which were extracted and their total numbers estimated. The intensity of deer ked parasitism was correlated to the age, sex, skin area and anatomical region of the host. Bulls had the highest total number of keds (10616 ± 1375) and the highest deer ked density (35.7 ± 4.4 keds/dm(2) of skin). Cows had a higher total number of keds than calves (3549 ± 587 vs. 1730 ± 191), but ked densities on cows and calves were roughly equal (11.8 ± 1.7 vs. 9.4 ± 1.1 keds/dm(2) of skin). The density of keds was highest on the anterior back, followed by the posterior back, front limbs, abdomen, head and hind limbs. The sex ratio of deer keds was close to equal (male : female, 1.0 : 1.1). After they had consumed blood, male keds were heavier than females. As the total numbers and densities of deer keds were higher than reported previously on moose or for any other louse fly species, the effects of parasitism on the health of the host species should be determined.

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

“…Our results revealed a deer ked infestation prevalence of 100%, similar to that Paakkonen et al . [28] report from Finnish moose. Despite different histories of colonization [6] and a higher density of definitive hosts in Norway compared to Finland [8], the deer ked is apparently an ectoparasite well-adapted to Fennoscandian moose and seems able to exploit the entire moose population within its distribution range.…”

“…Kortet [31] argues that movement is the main cue in ked host selection and therefore calves might be less exposed to winged keds sitting in the vegetation, waiting to flying onto any moving object passing by. In a closely related study in Finland, Paakkonen et al [28] stated that bulls had about three times the intensity of keds compared to cows. Our model also predicted significantly higher ked intensity in bulls compared to cows, but the sex difference was less pronounced (Figure 2).…”

Survey of selected tick-borne diseases in dogs in Finland

“…At this point it remains to be determined if the deer ked can successfully transmit Bartonella to moose or other mammals. The deer ked has drawn strong public attention in the last years in Finland, as this parasite has been rapidly spreading northward from the Southeast and dispersing into new areas [19]. The incidental infestation of deer keds to humans is well known in Finland, which is a nuisance for people who participate in outdoor activities, such as hunters, berry pickers, as well as other people who spend time in forested areas during late summer and early autumn.…”

Hair-Loss Epizootic in Moose (Alces Alces) Associated With Massive Deer Ked (Lipoptena Cervi) Infestation

“…In Finland, average numbers of keds in normally coated cows and calves were 3,549 and 1,730, respectively (Paakkonen et al, 2010). We found 16,496, 11,014, and 5,938 keds in the coats of three cows with severe hair loss and 10,687 in the coat of a calf with a normal coat (Table 1).…”