摘要:

AbstractA series of electric‐field measurements taken in the vicinity of spinning disc atomisers maintained at a high potential is described. Information on the space charge density, droplet mobility and droplet trajectories is deduced from a theory which is developed in the paper. Direct evidence of improved performance in strong winds compared with uncharged sprays was obtaine

ISSN:0031-613X    

DOI:10.1002/ps.2780100202

出版商:John Wiley&Sons, Ltd    

年代:1979

数据来源: WILEY

摘要:

AbstractThe earthworm,Eisenia foetida, eliminated parathion and carbofuran at first order rates when continually rinsed in water after treatment with the pesticides. This experiment was also carried out onLumbricus rubellusfor comparison. Carbofuran which is more soluble in water, was eliminated quicker than parathion. The later rate of elimination was very similar for the two species, but immediately after injection the rate was much higher inE. foetida. The metabolism of 1‐ethyl14C labelled parathion and paraoxon (diethyl 4‐nitrophenyl phosphate) was studied inE. foetida. The worm was able to convert parathion to paraoxon by a rather slow process although this metabolite could not be detected in the worms due to its rapid transformation to diethyl hydrogen phosphate. Indirectly, paraoxon can be postulated as a parathion metabolite because of a progressive depression of cholinesterase level observed after treatment with parathion. Small amounts of diethyl hydrogen phosphate were detected as a metabolite of parathion; this is also an indication of paraoxon formation. During the 30 h following injection of parathion, only 4.4% of the applied dose was recovered as water‐soluble metabolites (2.8% in the worms and 1.6% in the sand surrounding them), while 52% was recovered as unmetabolised parathion. Because of inefficient injection, only 70‐59% of the dose thought to be injected was recovered. Therefore the part of the actual applied dose that remained unmetabolised was probably even greater (88%). Five days after injection of parathion, 15 and 9.3 % of the recovered radioactivity in the surrounding sand and in the worm extracts, respectively, was identified asO,O‐diethylO‐hydrogen phosphorothioate, 3.7 and 7.0% as diethyl hydrogen phosphate, 8.8 and 3.3% asO‐ethylO‐4‐nitrophenylO‐hydrogen phosphorothioate (desethylparathion) and/orO‐4‐aminophenylO,O‐diethyl phosphorothioate, while 70.3 and 80.4% was unmetabolised parathion. Paraoxon was very quickly hydrolysed to diethyl hydrogen phosphatein vivoandin vitro. The in‐vitro hydrolysis was associated with a microsomal fraction and was not inhibited by ethylenediaminetetra‐acetic acid or 4‐(chloromercuri)benzoic acid, and incompletely by aldicarb. Cholinesterase and arylesterase were therefore excluded as enzym

ISSN:0031-613X    

DOI:10.1002/ps.2780100203

出版商:John Wiley&Sons, Ltd    

年代:1979

数据来源: WILEY

摘要:

AbstractThe degree of inhibition and the rate of recovery of total cholinesterase level were investigated after in‐vivo treatment of the earthwormEisenia foetida(Savigny) with aldicarb, carbaryl, carbofuran, oxamyl, and theO‐analogues of bromophos (bromo‐phosoxon), parathion (paraoxon), parathion‐methyl (paraoxon‐methyl), and trichloronate (trichloronatoxon). The results can be explained by the presence of two cholinesterases (E1 and E2), which were demonstrated by in‐vitro inhibition studies. E1 was the most sensitive to all the inhibitors tested. The in‐vivo reactivation rate after inhibition with paraoxon was very high for E1 and very low for E2. Therefore, pretreatment with paraoxon probably increased the toxicity of carbaryl. It was concluded that the toxicity towardsE. foetidacan be explained in terms of cholinesterase inhibition, provided that the action on the two cholinesterases and the worms' tolerance for a transient but almost total cholinesterase depression are taken into account. Data are given showing that two other species of earthworms also contain different types of cholinesterases with respect to reactions wi

ISSN:0031-613X    

DOI:10.1002/ps.2780100204

出版商:John Wiley&Sons, Ltd    

年代:1979

数据来源: WILEY

摘要:

AbstractGlasshouse screening of ten pesticides and the effect of water damping showed that all of the pesticides, with the possible exceptions of quinomethionate and heptenophos, were suitable for use in integrated control programmes involvingEncarsia formosa. About 50 pesticides were screened in the laboratory for residual effects on adultE. formosa. They were grouped according to whether their effects were harmful, moderate or negligible. Acaricides, except quinomethionate, had negligible effects; fungicides generally had negligible effects though a few had moderate effects. Insecticides were equally divided between those which were harmful or moderate in effect. Individual examples are discussed more fully in relation to previous work and their commercial use in integrated control programmes. The two screening methods produced similar results though the laboratory method had the advantage of being much more rapid. Attention is drawn to the need for a simple test to identify pesticides having sublethal effects on natural enemies and for the standardisation of test methods.

ISSN:0031-613X    

DOI:10.1002/ps.2780100205

出版商:John Wiley&Sons, Ltd    

年代:1979

数据来源: WILEY

摘要:

AbstractA procedure which enables the identification of the hydrolysis products of a number of phosphoric and phosphorothioic esters was developed. This procedure, which includes thin‐layer chromatography (t.l.c.), gas chromatography and u.v. spectroscopy, has been used to demonstrate that surface hydrolysis on kaolinite is a general property of bioactive phosphoric and phosphorothioic esters. The path of hydrolysis was shown to be the breakage of the PO A or PSA bond, where A is the electron attracting moiety of the organic mol

ISSN:0031-613X    

DOI:10.1002/ps.2780100206

出版商:John Wiley&Sons, Ltd    

年代:1979

数据来源: WILEY

摘要:

AbstractThe insecticidal and acaricidal action, anti‐cholinesterase activity and toxicity to rats of a new experimental pesticide,O‐ethylO‐isopropylO‐(5‐methoxy‐1‐methyl‐6‐oxo‐1H‐pyridazin‐4‐yl) phosphorothioate (I), and those of some by‐products found in the technical material, are described. High insecticidal and acaricidal effectiveness ofIwas found in laboratory and field trials. The activity as a soil insecticide in field trials was equal to, or greater than, that of othe

ISSN:0031-613X    

DOI:10.1002/ps.2780100207

出版商:John Wiley&Sons, Ltd    

年代:1979

数据来源: WILEY

摘要:

AbstractFeeding the last instar larvae ofNephantis serinopa, the coconut black‐headed caterpillar, on coconut leaves that had been dipped in diflubenzuron suspensions (0.2‐4.0 g litre−1) and dried, inhibited the moulting process and caused morphogenetic deformities of their pupae. The inhibition of moulting ranged from 27.5 to 75% The maximum effect was produced by suspensions of 4.0 g litre−1when only 5% of the larvae survived to become adults against 97.5% of untreated

ISSN:0031-613X    

DOI:10.1002/ps.2780100208

出版商:John Wiley&Sons, Ltd    

年代:1979

数据来源: WILEY

摘要:

AbstractThe persistence of the herbicide 2,4,5‐T was studied at different controlled temperatures and moisture levels in Regina heavy clay. Degradation approximated to first‐order kinetics and the half‐life varied from about 4 days at 35°C and 34% soil moisture to about 60 days at 10°C and 20% soil moisture. The laboratory data were used in conjunction with the appropriate measurements of surface soil temperature and moisture content in the field to simulate the degradation pattern for the herbicide in five separate micro‐plot experiments. Satisfactory agreement with the observed patterns of loss was obtained in two of the experiments but in the other three, the model over‐estimated rates of loss. It is suggested that the reason for this was the difficulty of obtaining a correct measure of soil moisture content to use in the simulat

ISSN:0031-613X    

DOI:10.1002/ps.2780100209

出版商:John Wiley&Sons, Ltd    

年代:1979

数据来源: WILEY

摘要:

AbstractThe factors affecting photochemical production of radicals, the reaction of these radicals with oxygen, the factors affecting the formation of singlet oxygen and superoxide anions and the reactivity of these species are discussed. The effect of the medium upon the course of photo‐oxidation reactions and methods for investigating the mechanisms of these reactions are summarise

ISSN:0031-613X    

DOI:10.1002/ps.2780100210

出版商:John Wiley&Sons, Ltd    

年代:1979

数据来源: WILEY

ISSN:0031-613X    

DOI:10.1002/ps.2780100211

出版商:John Wiley&Sons, Ltd    

年代:1979

数据来源: WILEY