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

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/dm² 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/dm² 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.     

Salt licks do not increase local densities of the deer ked,Lipoptena cervi,an abundant ectoparasite of cervids

The deer ked, Lipoptena cervi (Diptera: Hippoboscidae), is a common ectoparasite of the moose, Alces alces (Artiodactyla: Cervidae). Salt licks are widely used to manipulate moose movements to prevent damage to saplings and traffic accidents. They may cause moose to gather in small areas, which could create aggregates of deer ked pupae as the parasite is a short‐distance flyer and its dispersion depends on its hosts. We investigated whether the population density of flying deer keds could be influenced by manipulating salt licks and how environmental variables affect parasite density. Densities were estimated in 40 experimental sites with four treatments (no salt licks, introduced salt licks, removed salt licks, permanent salt licks) in September during 2007–2010. Forest edges, mixed forests on mineral soil and coniferous forests on peat soil were the habitats with high numbers of parasites. The manipulation of salt licks seemed to be ineffective in reducing the density of deer keds as the only factor to show statistical significance with parasite numbers in the mixed‐model analysis was year of determination. Annual deer ked densities correlated with the abundance of moose in the region. Moreover, high spring and summer temperatures seemed to increase the numbers of flying imagos.     

Responses of Leaf Processes in a Sensitive Birch (Betula pendulaRoth) Clone to Ozone Combined with Drought

Saplings of an ozone sensitive clone of birch (Betula pendulaRoth,KL-5-M) were well-watered or exposed to mild drought-stresscombined with ambient or elevated (1.5xthe ambient) ozone for11 weeks in open-field conditions in central Finland. Stomatalresponse, visible injury, chlorophyll and nutrient content,and changes in cellular anatomy and plant growth were studied.Drought stress alone, in ambient ozone, reduced stomatal densityand stomatal conductance. Drought stress and ozone effects wereadditive, reducing total leaf number, foliage area and starchformation in mesophyll cells. Drought stress and ozone effectswere additive, increasing the N concentration in the leaves,the thickness of the upper epidermal cell wall, the number ofpectinaceous projections of mesophyll cell walls, and the vacuolartannin-like depositions and phenolic droplets, regarded as signsof activated stress defence mechanisms. The increase in specificfoliage mass, cytoplasmic lipids (younger leaves), and a condensedappearance of the upper epidermal mucilaginous layer were causedby both drought and ozone, but were not additive. The resultsshow that combined drought stress contributed to birch responsesto 1.5xcurrent ambient ozone concentrations, corresponding tocritical-level ozone exposure. The only beneficial effect ofdrought stress was the slight reduction of visible leaf symptomsinduced by ozone in autumnal leaves.Copyright 1998 Annals ofBotany Company Birch,Betula pendula, sensitive clone, ozone, drought, microscopy.