摘要:

AbstractPhotodecomposition of the organophosphorus insecticide iodofenphos (O‐2,5‐dichloro‐4‐iodophenylO,O‐dimethyl phosphorothioate) has been studied in solution and on glass, soil and leaf surfaces. Iodofenphos underwent dehalogenation, oxidation and clearage of the P‐O‐aryl linkage on irradiation in hexane and methanol and produced a mamber of photo‐products which were characterised by1H‐NMR and mass spectroscopy. It has been observed that, as compared to dark conditions, the degradation of iodofenphos on soil, glass and leaf surface was accelerated under illum

ISSN:0031-613X    

DOI:10.1002/ps.2780260102

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractLarvae of the Large White butterfly, Pieris brassicae L.,are important pests of cruciferous crops. Third and fifth instars were treated topically with sublethal doses of the formamidine pesticide chlordimeform, which induced a number of excitatory actions at doses as low as 0·2 μg g−1. Normal feeding was inhibited. Also, a locomotor‐stimulant action was observed but higher doses interfered with this action by disrupting proleg coordination. Older larvae were less susceptible to these effects. Within 5 h, excitation was substantially reduced in all larvae. The results are discussed in terms of possible sublethal contributions to crop prote

ISSN:0031-613X    

DOI:10.1002/ps.2780260103

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractA simple small‐scale method for the determination of fenvalerate residues on cattle hair by gas–liquid chromatography with electron capture detection was developed and applied to the determination of fenvalerate residues from BovaidRear tags. Recoveries were found to be 96–104% at 10–100 μg g−1levels of fenvalerate. The minimum detection limit of this method was 1 pg g−1. With one ear tag, fenvalerate was adequately distributed over the entire body and persisted for at least 80 days on the ha

ISSN:0031-613X    

DOI:10.1002/ps.2780260104

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractSeveral observations suggested that enhanced mixed function oxidase (MFO)activity was one of several factors contributing to permethrin and dichlorvos resistance in the mushroom pest, Lycoriella mali (Fitch) (Diptera: Sciaridae).This was investigated using the mixed function oxidase inhibitor, piperonyl butoxide(PBO),in topical application bioassays with reference and field‐selected resistant strains. At the LD50,strains of resistant colonies(AV1, AV2, TK1)used in this study were 41‐(AV1),34‐(AV2),and 62‐fold(TK1) resistant to permethrin, relative to the reference strain (ONT9).Permethrin in the reference strain was only synergized 2‐(ONT9)and 4‐ (ONT13) at the LD50.Synergist ratios for resistant strains were 12(AV1),34(AV2)and 94(TK1)at the LD50.Moderate dichlorvos resistance was twice documented in the AV strain. Resistance ratios of 37(AV4)and 52(AV9)were observed at the LD50,relative to the reference strain(ONT10).Dichlorvos was synergized only 2‐fold at the LD50in the reference strain(ONT10).However, PBO abolished dichlorvos resistance in the AV9 strain. The effectiveness of PBO in these studies indicated that enhanced MFO activity was present in resistantL. malifrom southeastern Pennsylvania. Resistance to DDT(54‐fold at the LD50)was also documented. Other factors, such as an altered target site(kdr), may also have contributed to control failures

ISSN:0031-613X    

DOI:10.1002/ps.2780260105

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractA number of quinazolin‐4(3H)‐one carbothioamides, pyrazoles, pyrazolones and tetrazole derivatives have been synthesised by the reaction of 2‐hydrazino‐3‐(4‐substituted phenyl)‐quinazolin‐4(3H)‐ones with the appropriate aryl isothiocyanate, acetyl acetone, ethylacetoacetate and nitrous acid. All the compounds were tested invitro for antibacterial, insecticidal and antifungal activity and found to h

ISSN:0031-613X    

DOI:10.1002/ps.2780260106

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractIn this overview, the colloidal aspects of pesticidal and pharmaceutical formulations of the dispersion type are described. The nature and magnitude of the interaction forces between particles or droplets in a dispersion are briefly described. These include double‐layer, steric and van der Waals' interactions. Combinations of these interaction energies govern the stability/instability of dispersions. The various states of suspensions and emulsions can be described in terms of energy‐distance curves. Particular attention is given to the various break‐down processes, such as flocculation, coalescence, Ostwald ripening and phase inversion. Some guidelines for the stabilisation of suspensions and emulsions are given. The following practical aspects of dispersion and emulsion formulation are discussed: (a) creaming, sedimentation and their prevention; (b) the assessment of the state and long term physical stability of suspensions, including particle and droplet size analysis and rheology. In the latter case, both steady‐state shear stress–shear rate and low deformation (oscillatory, constant stress and shear wave propagation) are very useful in the control and assessment of the long term physical stability; (c) mixed suspensions and emulsions i.e. suspoemulsions. The possible interactions between suspension particles and emulsion droplets are briefly described; (d) multiple emulsions that can be applied for sustained release; (e) microemulsions, their formation and characterisation illustrating the potential application of these systems in formulations: (f) microencapsulation, describing the most common procedures for preparation of such systems. These include interfacial polymerisation and condensation and coacervation t

ISSN:0031-613X    

DOI:10.1002/ps.2780260107

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractThe deployment of entomopathogenic fungi for the control of insect pests offers an environmentally‐acceptable strategy. Major obstacles to their application include variability in effectiveness due to uncontrolled environmental parameters (temperature, humidity)and development of suitable formulation techniques. Strains differ considerably in genetic ability to cause mortality and to spread within populations. Pathogenicity is the result of the interaction of numerous individual traits determining germination and penetration, followed by successful growth within the target host, which is a prerequisite for induction of mortality. No effective singlegene determined toxin has been reported for entomopathogenic fungi, but the application of gene cloning techniques for specific proteases is a likely future development. Genetic manipulation techniques, designed to recombine complex traits associated with pathogenicity via the parasexual cycle, are described here in relation to successful steps achieved in strain improvement programmes which involve:(a) Verticillium lecanii (Zimm.)Viegas against the glasshouse whitefly:Trialeurodes vaporariorumand the aphidMacrosiphoniella sanborni; (b) Metarhizium anisopliae (Metsch.)Sorokin against the rice brown planthopperNilaparvata lugen

ISSN:0031-613X    

DOI:10.1002/ps.2780260108

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractPossibilities of using genetic manipulation to improve the effectiveness of mycoherbicides are discussed. Particular emphasis is given to fungal genes involved in the production of specialised structures essential for colonisation and reproduction in pathogenesis and in regulating pathogen specificity. Example are given of relevant genetic transformations in fungi which have already been achieved. In the short term, manipulation of genes encoding for specific enzymes or toxins is considered to be the most promising approach for improving mycoherbicide performance.

ISSN:0031-613X    

DOI:10.1002/ps.2780260109

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

ISSN:0031-613X    

DOI:10.1002/ps.2780260110

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

ISSN:0031-613X    

DOI:10.1002/ps.2780260111

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY