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1.
Stephen D. Reay Joanne M. Thwaites Roberta L. Farrell Patrick J. Walsh 《Integrated Pest Management Reviews》2001,6(3-4):283-291
The role of the bark beetle Hylastes ater in the re-establishment of Pinus radiata forest in New Zealand is discussed. H. ater was found to be a dominant factor in seedlings mortality in the first year following planting. However, seedling mortality is usually relatively low. In contrast, it was found the large numbers of seedlings were sub-lethally damaged by H. ater feeding attempts, particularly in high risk sites. High risk sites were identified as sites that were harvested during March and April (autumn) when the peak flight activity of H. ater occurred, and subsequently planted with P. radiata seedlings the following winter. H. ater was found to vector sapstain fungi to seedlings during feeding attempts, and a strong relationship between the severity of damage and presence of sapstain fungi was identified. The role of H. ater as a vector of these fungi and the potential implications to the New Zealand forest industry are discussed. 相似文献
2.
A bioassay method has been developed for the screening of pyrethroids for contact toxicity against Limnoria species which should prove suitable for insecticides with low water-solubility. Less than 1% of a topically applied dose of cypermethrin (4.8 ng per isopod) was lost to the sea-water from the body surface; the pharmacokinetics of cypermethrin in the isopod accounted for the fate of the remainder. LD50 parameter estimates obtained by this method represent measurements of absolute toxicity; NRDC 161b proved the most effective of three pyrethroids tested. 相似文献
3.
German AJ Cannon MJ Dye C Booth MJ Pearson GR Reay CA Gruffydd-Jones TJ 《Journal of Feline Medicine and Surgery》2005,7(1):33-41
Four cases of oesophageal stricture subsequent to doxycycline administration are reported. All cases were young to middle age (median age 3 years; range 1-7 years), and either domestic shorthair or domestic longhair breed. In all cases the predominant clinical sign was regurgitation, which developed at variable times after doxycycline administration. In all cases the reason for doxycycline use was treatment or prophylaxis of suspected infections (Mycoplasma haemofelis, Chlamydophila felis or Bordetella bronchiseptica), and the duration of therapy was variable. In one case the stricture was definitively diagnosed at post mortem examination, in the three other cases, definitive diagnosis was by endoscopy. Balloon dilation was successful in the three cases that were treated. This is the largest case series, to date, of oesophageal disease in cats associated with doxycycline administration. Caution should be exercised when administering oral medication to cats, especially doxycycline, and should be accompanied either by a water or food swallow. 相似文献
4.
The toxicity of a number of topically applied pyrethroids has been tested against adult male desert locusts, Schistocerca gregaria: the most potent proved to be 5-benzyl-3-furylmethyl (+)-trans-chrysanthemate (bioresmethrin) with a weighted mean LD50 of 4.0 μg/g. The remaining compounds may be ranked in order of toxicity as follows: 5-benzyl-3-furylmethyl (±)-cis-trans-chrysanthemate (resmethrin) > 4-allyl-2,6-dimethyl-benzyl(+)-trans-chrysanthemate > 4-allylbenzyl (+)-trans-chrysanthemate > 2,4,6-trimethylbenzyl (+)-cis-trans-chrysanthemate > 2,3,4-trimethylbenzyl (+)-cis-trans-chrysanthemate > 2,4-dimethylbenzyl (±)-cis-trans-chrysanthemate; 2-methylbenzyl (±)-cis-trans-chrysanthemate. A small factor of synergism (4.2) was obtained with bioresmethrin following pre-treatment with sesamex, but with resmethrin the synergistic ratio (1.6) was of little practical significance. 相似文献
5.
Martyn G. Ford Richard C. Reay David Pert Peggy E. Ellis Lawrence J. McVeigh 《Pest management science》1977,8(3):203-210
The contact toxicity of ten pyrethroids to larvae of Spodoptera littoralis (Boisd.) was investigated by topical application, and symptoms observed for different combinations of dose and time. Several compounds were sufficiently active to suggest that they may prove useful for the control of populations in the field. Structure and activity are discussed with particular reference to time-dose-response relationships: speed of action is related to both chemical structure and applied dose. 相似文献
6.
Abstract The toxicity of a number of topically applied pyrethroids has been tested in the laboratory against three species of locusts and parathion-resistant and susceptible strains of the Egyptian cotton leafworm. Bioresmethrin, resmethrin and 5-benzyl-3-furylmethyl (+)-cis-chrysanthemate (NRDC 119) proved to be extremely active against one or more of these pests and there were small but noteworthy improvements with the synergists sesamex and TBTP. The field potential of the pyrethroids is discussed against the background of environmental problems associated with some of the insecticides in current use. 相似文献
7.
N. J. Cowan D. Famulari P. E. Levy M. Anderson M. J. Bell R. M. Rees D. S. Reay U. M. Skiba 《European Journal of Soil Science》2014,65(5):643-652
A dynamic chamber method was developed to measure fluxes of N2O from soils with greater accuracy than previously possible, through the use of a quantum cascade laser (QCL). The dynamic method was compared with the conventional static chamber method, where samples are analysed subsequently on a gas chromatograph. Results suggest that the dynamic method is capable of measuring soil N2O fluxes with an uncertainty of typically less than 1–2 µg N2O‐N m?2 hour?1 (0.24–0.48 g N2O‐N ha?1 day?1), much less than the conventional static chamber method, because of the greater precision and temporal resolution of the QCL. The continuous record of N2O and CO2 concentration at 1 Hz during chamber closure provides an insight into the effects that enclosure time and the use of different regression methods may introduce when employed with static chamber systems similar in design. Results suggest that long enclosure times can contribute significantly to uncertainty in chamber flux measurements. Non‐linear models are less influenced by effects of long enclosure time, but even these do not always adequately describe the observed concentrations when enclosure time exceeds 10 minutes, especially with large fluxes. 相似文献
8.
Ecological studies in New Zealand require consideration of the impact of exotic (introduced) organisms from disparate environments. A survey of Ophiostoma species isolated and identified from Pinus radiata stumps, the bark beetle Hylastes ater collected from these stumps and from P. radiata seedlings following sublethal damage by H. ater, was undertaken in 10 reforestation sites in New Zealand. Nine Ophiostoma species were isolated and identified in this survey. Ophiostoma galeiformis and Ophiostoma huntii were isolated most frequently from all the substrates sampled. Ophiostoma floccosum, Ophiostoma setosum, Leptographium procerum and Leptographium truncatum were also isolated from stumps, damaged seedlings and beetles. Ophiostoma quercus was only isolated from stumps and beetles and Ophiostoma ips only from beetles. A strong relationship between the severity of H. ater feeding damage, and the presence and number of species of Ophiostoma was found. Eight Ophiostoma species were transmitted by H. ater to P. radiata seedlings in laboratory transmission experiments. From the results of this field survey and the laboratory experiments we confirm that H. ater is a vector of Ophiostoma species to P. radiata seedlings in New Zealand. 相似文献
9.
N. P. McNamara H. I. J. Black T. G. Piearce D. S. Reay & P. Ineson 《Soil Use and Management》2008,24(1):1-7
There is growing evidence that land use is an important factor in influencing soil methane (CH4) fluxes, and afforestation is viewed as a potential tool for mitigating CH4 releases from soils. However, the influence of different tree species on soil CH4 fluxes is not well understood. We measured soil CH4 fluxes under four tree species and grassland on similar soils at the Gisburn Experimental Forest (NW England) at 2 weekly intervals over 12 months using a static chamber technique. The treatments were Norway spruce (Picea abies), Scots pine (Pinus sylvestris), oak (Quercus petraea), alder (Alnus glutinosa) and grassland. Positive soil CH4 fluxes were observed from grassland plots (average 4.6 kg/ha/year) and negative fluxes from all four tree species (average of all tree species ?0.5 kg/ha/year). There were, however, no statistically significant differences between individual treatments. Soil water table depth and moisture content had the greatest influence on soil CH4 fluxes. It is possible that the afforestation of shallow organic and/or poorly drained soils such as these may have a relatively low capacity for mitigating CH4 fluxes. Although methanotrophic bacteria may exist (i.e. there is the potential for oxidation), they may not be able to dominate due to their requirements for specific environmental conditions. 相似文献
10.
Methane oxidation in temperate soils: effects of inorganic N 总被引：1，自引：0，他引：1
Additions of inorganic nitrogen (N) to an oak soil with significant potential for methane (CH4) oxidation resulted in differential reduction in CH4 oxidation capacity depending on N species added. Nitrate, rather than nitrite or ammonium, proved to be the strongest inhibitor of CH4 oxidation in oak soil. Both high (CH4 at 10 μl l−1) and low (CH4 at 5 ml l−1) affinity CH4 oxidation in oak soil was completely inhibited at a nitrate concentration similar to that present in an alder soil from the same experimental site. The alder soil showed no capacity for low affinity CH4 oxidation. A ‘low nitrate’ forest soil (oak) showed high affinity, low capacity CH4 oxidation upto around 1 ml l−1 CH4, above which both high and low affinity CH4 oxidation became apparent following a lag phase, indicating either an induced high affinity uptake mechanism or the existence of distinct low affinity and high affinity methanotroph populations. High affinity CH4 oxidation became saturated at CH4 concentrations >500 μl l−1, while low affinity CH4 oxidation became saturated at ∼30 ml l−1 CH4. In a ‘high nitrate’ forest soil (alder), CH4 oxidation appeared to be due to high affinity CH4 oxidation only and became undetectable at CH4 concentrations >5 ml l−1. 相似文献