摘要:

AbstractFive species of stored‐product insects, [Tribolium castaneum(Herbst),T. confusum(DuVal),Rhyzopertha dominica(F.),Sitophilus oryzae(L.) andS. granarius(L.)], exposed to phosphine in nitrogen and various oxygen‐deficient atmospheres, showed reduced susceptibility to three concentrations of phosphine (0.02, 0.04 and 0.2 mg litre−1). The last two species also showed reduced susceptibility to phosphine at 2.0 mg litre−1. Generally mortality increased progressively as the level of oxygen was raised. There was a close relationship between the ability of insects to withstand anoxia and survival from phosphine tr

ISSN:0031-613X    

DOI:10.1002/ps.2780120202

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractThe responses of five species of adult stored‐product insects [Tribolium castaneum(Herbst),T. confusum(DuVal),Rhyzopertha dominica(F.),Sitophilus oryzae(L.) andS. granarius(L.)] to various doses of phosphine in atmospheres of air or nitrogen were determined. A fewS. oryzaeandS. granariussurvived phosphine concentrations up to 80 mg litre−1for 24 h in normal (air) or nitrogen atmospheres. By contrast,T. castaneum, T. confusumandR. dominicacould not tolerate more than 0.2 mg phosphine litre−1in air for 12 h. However, they could tolerate up to 10 mg phosphine litre−1in nitrogen for that period. Increasing the phosphine concentration resulted in increased mortalities of the last three species. The possible mechanism underlying this response is discussed. The reproductive potential of insects surviving phosphine exposure in a nitrogen atmosphere was una

ISSN:0031-613X    

DOI:10.1002/ps.2780120203

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractEmpirical equations were used to calculate the moisture content of surface soil from measurements of rainfall and daily maximum and minimum air temperatures. Air temperatures were also used to calculate soil temperatures. There was good agreement between calculated and measured moisture contents and temperatures from Wellesbourne and from some sites in North America. The equations were incorporated into a simulation model for the prediction of herbicide persistence. Results from the model were essentially the same, whether calculated or measured soil moistures and temperatures were used in the calculations.

ISSN:0031-613X    

DOI:10.1002/ps.2780120204

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractDiflubenzuron was absorbed and metabolised relatively slowly by the two‐spotted spider miteTetrunychus urticaeKoch. Diflubenzuron metabolites, tentatively identified by coincident chromatography with reference standards, included 4‐ chlorophenylurea, 2, 6‐difluorobenzoic acid, 4‐chloroformanilide, 2, 6‐difluoro‐benzamide, and two compounds monohydroxylated in the chloroaniline moiety. There was little absorption of diflubenzuron when applied topically to leaves of bean plants. However, there was translocation of radioactive material when diflubenzuron was injected into the stern. In this case, the radioactivity, which was confined largely to vascular tissue, apparently moved acropetally but exhibited very little or no basipetal movement. Bean plants metabolised injected diflubenzuron, and certain of the metabolites were similar to those isolated

ISSN:0031-613X    

DOI:10.1002/ps.2780120205

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractAn automatic apparatus is described for the determination of the crystallisation temperature of liquid pesticide formulations. Its purpose was to reduce possible errors in such determinations. Depending on whether or not seed crystals were added, different crystallisation temperatures were obtained; an automatic pneumatic seeding device was therefore developed. The influence that the varying times of adding crystals had on the crystallisation temperature is illustrated by examples. Depending on the rate of temperature drop chosen, different crystallisation temperatures were obtained. The lowest rate of temperature drop came closest to the ‘true’ crystallisation temperature. A simple method is also described that allows the simultaneous determination of the crystallisation temperatures of a large number of samp

ISSN:0031-613X    

DOI:10.1002/ps.2780120206

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractThe effect of four herbicides (2, 4‐D, di‐allate, benzoylprop‐ethyl and glyphosate) and one insecticide (malathion) on 1, 3‐β‐glucanase and urease activities in soil was investigated in the laboratory. Concentrations equivalent to five times the recommended field application rates of the pesticides, applied as their formulations, had no effect on the activity of either enzyme, under a variety of incubation conditions, which included various moisture regimes and soil treatments. The soil enzyme systems could only be disrupted by unrealistically high dosage rates of the active ingredients (0.1–1.0 g kg−1of soil), Thus 1, 3‐β‐glucanase activity was enhanced by 2, 4‐D, inhibited by di‐allate, benzoylprop‐ethyl and malathion, but unaffected by glyphosate; whereas urease activity was inhibited by 2, 4‐D, but unaffected by di‐allate, ben

ISSN:0031-613X    

DOI:10.1002/ps.2780120207

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractA technique using gas‐liquid chromatography combined with chemical‐ionisation mass spectrometry is described for the simultaneous quantitative measurement of bioresmethrin and piperonyl butoxide. It is sensitive to 0.2 ng bioresmethrin and 2 ng piperonyl butoxide. The amounts of these compounds, in extracts of 50‐g samples of laboratory‐fortified wheat, were det

ISSN:0031-613X    

DOI:10.1002/ps.2780120208

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractThe metabolism and conjugation of 3‐phenoxybenzyl alcohol, a plant metabolite of permethrin and cypermethrin, have been examined in abscised cotton leaves. Mature cotton leaves were treated by petiole uptake of an aqueous solution of [α‐14C]‐3‐phenoxybenzyl alcohol. Initially there was rapid formation of a compound identified as the glucosyl 3‐phenoxybenzyl ether. Subsequently more polar compounds were formed and these were shown to be disaccharide conjugates of the alcohol with glucose and pentose sugars. The alcohol and its mono‐ and disaccharide conjugates were shown to undergo interconversion in cotton leaves, and evidence was obtained from experiments with [14C]glucose for the ready exchange of the glucose units on the conjugates with free glucose in the leaves. No larger carbohydrate conjugates of 3‐phenoxybenzyl alcohol were detected under the c

ISSN:0031-613X    

DOI:10.1002/ps.2780120209

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractThe toxicity of two fumigants to microsclerotia (MS) ofVerticillium dahliaein air and in soil was determined in sealed containers. 1, 2‐Dibromoethane (DBE, ethylene dibromide) at 470 μ ml−1of air, or at 12.5 μ g−1of soil, killed 97% of the MS, both after incubation for 16 days. 1, 3‐Dichloropropene (1, 3‐D) at 20 μ ml−1of air, however, killed 100% of the MS after incubation for 30 h, and at 100 μ g−1of soil after incubation for 3 days. Higher temperatures increased the toxicity of both DBE and 1, 3‐D to the MS. The toxicity of DBE increased with increase in soil moisture between 0–80% of field capacity while the toxicity of 1, 3‐D increased between 0–20% of field capacity and was constant between

ISSN:0031-613X    

DOI:10.1002/ps.2780120210

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractA simple two‐compartment model, introducing a parameter (λ) to represent the relative thermodynamic capacities of the compartments, is described for the movement of insecticide from the insect surface (compartment 1) to the region within the insect (compartment 2); loss from compartment 2 is considered. First‐order rate constants are assumed for penetration (kp) and elimination (ke). The differential equations describing the rates of change of insecticide in each compartment after application of insecticide are solved analytically, and terms describing (a) the integrals of mass of compound in each compartment with time after application, (b) time to a maximum level of insecticide in compartment 2, and (c) distribution and loss of compound from the system with time, are derived. Methods for estimating the three parameters of the model (kp,keand λ) are presented. Further properties of the model with possible toxicological significance have been identified; in particular, the total integral for material in compartment 2 depends only on the elimination rate constant and the applied

ISSN:0031-613X    

DOI:10.1002/ps.2780120211

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY