effect of exposure to fluoride, nitrogen compounds and so2 on the numbers of spruce shoot aphids on norway spruce seedlings.development of spruce shoot aphid (cinara pilicornis hartig) populations was monitored in natural and artificial infestations of norway spruce (picea abies karst.) seedlings, exposed to air pollutants in an experimental field. the pollutants, applied both singly and in mixtures, were gaseous sulphur dioxide, naf (30 mg l-1 f) and ca(no3)2 or (nh4)2so4 in aqueous solutions (200 mg l-1 n). aphid numbers on 10 seedlings in each treatment and two control plots were counted at 2-week intervals. at th ...199128313157
conifer aphids in an air-polluted environment. i. aphid density, growth and accumulation of sulphur and nitrogen by scots pine and norway spruce seedlings.the population dynamics of conifer aphids on pine and spruce seedlings growing in plastic pots were studied along a gradient from a pulp mill emitting mainly so(2). at five locations, two apterous females of the grey pine aphid (schizolachnus pineti l.) feeding on needles, and two apterous females of the spruce shoot aphid (cinara pilicornis hartig) feeding on the stem, were transferred to the leader shoot of 10 pine and spruce seedlings, respectively. the sulphur concentrations of the transplan ...199315091863
the response of spruce shoot aphid cinara pilicornis hartig to ambient and filtered air at two elevations and pollution climates.the effects of ambient air compared to filtered air on the reproduction of females and mean relative growth rate (mrgr) of nymphs of c. pilicornis on norway spruce was determined in open-top chambers at wengernalp in the swiss alps (1900 m a.s.l.) and at schönenbuch near the city of basle (400 m a.s.l.). the ambient concentration of o(3), the main pollutant at both sites, varied between 45 and 120 microg m(-3) (24-h mean) at both sites. a 5-8 day exposure of spruce saplings to ambient compared t ...199415091641
norway spruce and spruce shoot aphid as indicators of traffic pollution.two-year-old norway spruce (picea abies (l.) karst) seedlings were exposed to traffic emissions along roadsides with three different traffic densities and speed limits; highway, street and a quiet local road. the responses of the exposed seedlings as a host plant and those of spruce shoot aphid (cinara pilicornis hartig) were studied. the concentrations of soluble n and free amino acids, defence chemicals (total phenolics, monoterpenes) were analysed, and aphid growth and reproduction were studi ...200015092976
responses of spruce seedlings (picea abies) to exhaust gas under laboratory conditions--i. plant-insect interactions.the effects of motor vehicle exhaust gas on norway spruce seedlings (picea abies (l.) karst) and plant-insect interaction of spruce shoot aphid (cinara pilicornis hartig) was studied. the exhaust gas concentrations in the fumigation chambers were monitored and controlled by measuring the concentration of nitrogen oxides (no(x)) with a computer aided feedback system. the concentrations of major exhaust gas components (black carbon [bc], fine particles, vocs and carbonyl compounds) in the chamber ...200015093012
semiochemicals related to the aphid cinara pilicornis and its host, picea abies: a method to assign nepetalactone diastereomers.volatiles released by seedlings of norway spruce infested with the aphid cinara pilicornis were analyzed using spme-gc-ms. among the stress-induced compounds released by the host plant, citronellol, cis-trans-nepetalactone and cis-trans-nepetalactol was found. these compounds originated from the aphids and they were assumed to be pheromone components for this aphid species. to determine the relative stereochemistry of the nepetalactone, a diagnostic method was developed. the method was based on ...200818166192
the effects of phytophagous insects on water and soil nutrient concentrations and fluxes through forest stands of the level ii monitoring network in the uk.the effects of insect defoliators on throughfall and soil nutrient fluxes were studied in coniferous and deciduous stands at five uk intensive monitoring plots (1998 to 2008). links were found between the dissolved organic carbon (doc), nitrogen (n) and potassium (k) fluxes through the forest system to biological activity within the canopy. underlying soil type determined the leaching or accumulation of these elements. under oak, monitored at two sites, frass from caterpillars of tortrix viridan ...201020961599
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