Reduced-Risk Management of Rhagoletis cerasi Flies (Host Race Prunus) in Combination with a Preliminary Phenological Model

Seasonal flight activity of Rhagoletis cerasi (L.) (Diptera: Tephritidae) adults was monitored using yellow sticky traps at sweet cherry orchards under different management regimes in Bursa, northwestern Turkey, during 1997–1998. In the reduced-risk backyard orchards, soil ploughing in the fall or spring to destroy the pupae was combined with a single application of an insecticide, while conventionally managed orchards received six to seven insecticide applications for controlling adults. Traps in commercial orchards caught significantly fewer adults than those in reduced-risk backyard orchards. Levels of cherry fruit fly fruit damage were very low (0.1%) in commercial orchards, whereas infestation rates averaged 2.2% in reduced-risk orchards. A preliminary phenology model was developed for optimal timing of insecticide applications based on air temperature summations since 1 February. In the reduced-risk backyard orchards, the first flies were captured between 25 May and 2 June, corresponding to an average degree-day (DD) accumulation of 582.50 ± 10.50 DD at an altitude of 150 m. However, first adult emergence at 1170 m was recorded between 6 and 14 June, averaging 667.50 ± 14.50 DD. Adult emergence exhibited bimodal peaks in a single flight at low altitude but there was a single peak at high altitude sites. Total adult flight period averaged 459 ± 29.50 and 649 ± 25.50 DD at low and high altitude sites, respectively. Our prediction model suggests that the optimum spray-window for a single insecticide application occurs between 577.70 and 639.40 DD at 150 m and between 780.90 and 848.60 DD at 1170 m

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

<p>Abstract</p> <p>Background</p> <p>The deer ked (<it>Lipoptena cervi</it>), 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 (<it>Alces alces</it>) 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.</p> <p>Methods</p> <p>In 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.</p> <p>Results</p> <p>Deer 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 (<it>Pinus sylvestris</it>) 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.</p> <p>Conclusions</p> <p>Deer 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.</p