摘要:

AbstractA new class of compounds derived from hydroquinone ethers showed high and predominantly ovicidal activity against the two‐spotted spider mite,Tetranychus urticaeKoch. The sequence of compounds synthesised and the factors which appeared to have contributed most to the discovery of these promising acaricides are presente

ISSN:0031-613X    

DOI:10.1002/ps.2780170502

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractThe vapour pressures of the separate isomers of permethrin have been determined over a range of temperatures by two laboratories using different versions of the gas saturation method. A statistical analysis of the sets of data from the two laboratories shows no significant differences for thecisisomers but a small difference in the 20°C extrapolated values for thetransisomer exists. However, this difference is discounted as arising from experimental error and the mean values of the estimated vapour pressures at 20°C are given as 2.5 μPa (cis) and 1.5 μPa (tra

ISSN:0031-613X    

DOI:10.1002/ps.2780170503

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractThe addition of 20% molasses to water did not reduce the rate of evaporation of water from spray droplets. The 20% molasses droplets evaporated at the same rate as water droplets untilca20% of their volume was left. When sprayed under field conditions at 30% relative humdity (r.h.) the volume median diameter (v.m.d.) of the 20% molasses spray (132 μm) was larger than the v.m.d. of the water spray (116 μm) and more droplets smaller than 19 μm were captured on magnesium oxide slides than with the water spray. The addition of molasses improved the impaction efficiency of droplets by increasing their density, and increased the minimum size to which a given droplet could evapora

ISSN:0031-613X    

DOI:10.1002/ps.2780170504

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractAn intensifier (factor 161) identified on the second autosome in a pyrethroid‐resistant strain of houseflies (Musca domesticaL.) was isolated and introduced into a strain withsuper‐kdr. Unlike E0.39, which on its own also confers very weak (20 μg fly−1) but produced much less intensification of resistance to WL 48281, the (1R)cis (αS) isomer of cypermethrin, which differs from deltamethrin only in having chlorine instead of bromine substituents in the acid side‐chain. Intensification was strongly decreased by piperonyl butoxide and propyl prop‐2‐ynylphenylphosphonate (NIA) but was unaffected byS,S,S‐tributyl phosphorotrithioate (DEF). This synergism suggests involvement of oxidative rather than esteratic metabolism in the intensification ofsu

ISSN:0031-613X    

DOI:10.1002/ps.2780170505

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractThe photochemical degradation of the herbicide isoproturon in aqueous and non‐aqueous solutions and in soils has been investigated. Four new photometabolites were formed in non‐aqueous solution and three in soil. These were characterised by spectroscopic methods and identified by comparison with authentic synthetic samples such as 3‐(4‐isopropylphenyl)‐1‐methylurea; 3‐(4‐isopropylphenyl)urea; 4,4′‐diisopropylazobenzene and 4,4′‐diisopropylazoxybenzene. The pathway of formation of these pho

ISSN:0031-613X    

DOI:10.1002/ps.2780170506

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractThe variation in tolerance to diflubenzuron [1‐(4‐chlorophenyl)‐3‐(2,6‐difluorobenzoyl)urea] was examined in fourth instar larvae of seven strains ofAedes aegypti, some of which were resistant to DDT and permethrin. The difference between the least and the most tolerant to diflubenzuron was approximately two‐fold. There was no correlation with resistance to the other insecticides. A DDT‐resistant strain (T8) was selected 10 times (during 12 generations) with diflubenzuron. The LC50to diflubenzuron had increased 3.3 times by the S8generation but there was no further increase in later generations despite further selection. Associated with this increase, a marked decrease in resistance to DDT was observed but no change in permethrin tolerance. A genetically enriched strain (Hotchpotch) was synthesised from 35 strains of different geographic origin and crossed to the selected T8 strain before subsequent generations were selected five times with diflubenzuron. This procedure resulted in an 8 to 12‐fold increase in the LC50value over that for unselected T8, accompanied by a decrease in the slope of the log dose against probit

ISSN:0031-613X    

DOI:10.1002/ps.2780170507

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractThe uptake, accumulation, metabolism and excretion of gamma‐HCH (the gamma isomer of 1,2,3,4,5,6‐hexachlorocyclohexane) by a highly gamma‐HCH‐resistant strain ofSitophilus granariuswas studied. It was found that the resistant strain was able to excrete a large proportion of a topically‐applied dose of gamma‐HCH in its frass pellets; under comparable conditions a susceptible strain accumulated a high body load of gamma‐HCH. Neither strain metabolised gamma‐HCH to any significant extent over a 48‐h pe

ISSN:0031-613X    

DOI:10.1002/ps.2780170508

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractA series of 2‐(1‐alkenyl)‐3‐hydroxy‐1,4‐naphthoquinones has been prepared and their toxicities assessed againstMusca domestica. By comparison with analogous compounds having saturated 2‐alkyl substituents, or unsaturated substituents with an unconjugated double bond (e.g. lapachol), it was demonstrated that the α‐unsaturation of the substituent is responsible for a significant increase in the toxicity. The effect of the compounds against several other insect species andTetranychus urticaefollows completely di

ISSN:0031-613X    

DOI:10.1002/ps.2780170509

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractThe effects of IBP (S‐benzylO,O‐diisopropyl phosphorothioate) on tips of single hyphae ofPyricularia oryzaewere investigated by interference contrast microscopy. Labelling hyphae with calcofluor white followed by IBP treatment revealed that elongation of apices of almost all hyphae at the colony margin was inhibited after treatment for 4 h. Successive observations on single hyphae of an IBP‐sensitive isolate indicated that apical cells stopped elongating approximately 10 min after the onset of treatment with 2 μg IBP ml−l. Small vacuoles appeared after 50 min; later they increased in number and size, and coalesced, finally producing a chain‐like arrangement of vacuoles in the cytoplasm. When hyphae were treated with 10 μg IBP ml−1, cessation of elongation and vacuolation occurred earlier than when treated with 2 μg ml−1. Apical cells of hyphae of an IBP‐tolerant isolate appeared unaltered even when treated with 10 μg ml−1. These results indicate that a major effect of IBP is to inhibit specifically the growth of apical cells of the

ISSN:0031-613X    

DOI:10.1002/ps.2780170510

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractThe effects of molasses on some of the physicochemical properties and on the sprayability of a carbaryl wettable powder (w.p.) and triazophos emulsifiable concentrate (e.c.) were studied in the laboratory and the field. When sprayed in the laboratory on bean leaves, the deposit obtained from either formulation decreased as the percentage of molasses was increased. In an aerial application field trial on cotton, 10% molasses gave a smaller deposit of active ingredient than obtained in the absence of additive, while 20% molasses gave a greater deposit, with either formulation. Molasses had an adverse effect on some properties of the spray mixtures, which resulted in lower deposits when spraying was done at high humidity in the laboratory. This effect was offset when spraying was done at lower humidity in the field, because molasses improved the impaction of droplets by increasing their density and by preventing the complete evaporation of small droplets.

ISSN:0031-613X    

DOI:10.1002/ps.2780170511

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY