bluuebunny/crossref_metadata_2025 huggingface dataset:
New chlorinated juvenile hormone analogues and their biological activity
Authors: Piccardi Paolo , Massardo Pietro , Bettarini Franco , Longoni Angelo
Published: November 2006

In the search for new juvenile hormone analogues (JHAs), a general approach was chosen based on the substitution of the isoprene unit, that carries the epoxy function in the natural hormone JHIII, by 3,3,3‐trichloropropyl, 2,2‐dichlorocyclopropyl‐ methyl, 3,3‐dichloroallyl, or 3‐chloroprop‐2‐ynyl groups. Accordingly, several terpenoid aromatic JHAs were prepared with, or without, oxygen atoms in the aliphatic chain. Structure‐biological activity relationships of the most active compounds toward the yellow mealworm (Tenebrio molitor) and the large cabbage white butterfly (Pieris brassicae) are given. With a view to preparing synthetically accessible analogues, some alkyl phenyl ethers were also made, which were not branched in the aliphatic chain and were related terminally to the most active compounds. They were only moderately active against insects when tested for morphogenetic activity, but exhibited a good field persistence. The occurrence of a moderate acaricidal activity among these analogues prompted the examination of several 1,4‐disubstituted‐phenyl derivatives. The ovicidal effectiveness of these products against a susceptible strain of the two‐spotted spider mite, Tetranychus urticae, was ten or 100 times higher than that of the well known and highly potent JHAs.
Effects of certain herbicides on the oxidative decarboxylation of tryptophan by peroxidase
Authors: Scarponi Luciano , Tafuri Francesco , Perucci Piero
Published: November 2006

Non‐enzymic and peroxidase‐catalysed oxidative decarboxylations of tryptophan (TPP) were studied. The in‐vitro rate of enzymic reaction was affected by various herbicides at low concentrations (10−5−10−4M): dinoseb, 2,4‐D, dichlobenil and benazolin acted as inhibitors; on the other hand, chlorpropham, bromacil, diphenamid and 4‐ethylamino‐6‐isopropylamino‐1,3,5‐triazin‐2‐ol (hydroxyatrazine) were stimulatory. The results of in‐vivo experiments showed that chlorpropham and 2,4‐D changed the activity of peroxidase from Brassica germinated seeds in vivo, as they do in vttro. Determinations of consumed TPP were carried out either by spectro‐photometry or by chromatography.
The photolysis of quinomethionate in benzene solution
Authors: Clark Terence , Thomas Loeffler R. S.
Published: November 2006

The photolysis of quinomethionate in benzene solution was found to result in complete cleavage of the dithiole ring with loss of both sulphur atoms. Products isolated and identified were those arising from the reaction of intermediate radicals with oxygen and with the solvent. They were identified, by gas chromatography‐mass spectrometry and by comparison with authentic samples synthesised by known methods, as 6‐methyl‐1,2,3,4‐tetrahydroquinoxaline‐2,3‐dione and 6‐ and 7‐methyl‐3‐phenyl‐1,2‐ dihydroquinoxalin‐2‐one. A mechanism that accounts for the formation of these products is presented.
Hydrolysis of cyanazine and related diaminochloro‐1,3,5‐ triazines. Part II: hydrolysis in sulphuric acid solutions
Authors: Terence Grayson B.
Published: November 2006

Hydrolysis of cyanazine in sulphuric acid solutions involves primary attack at the nitrile group to give first the corresponding amide and then the carboxylic acid followed subsequently by displacement of the chlorine atom. Comparison of the respective reaction rates showed that, in sulphuric acid solutions (at concentrations around 0.5M) at 25°C, the rate of this attack at the nitrile group is approximately ten times faster than at the chlorine atom. The kinetic data indicate that in these moderately acid solutions the mechanism of cyanazine hydrolysis corresponds to an A‐2 reaction involving prior protonation of the nitrile group followed by rate determining nucleophilic attack by water. However, at higher acidities, the rates decelerate which leads both to diversion from the Zucker‐Hammett postulate for simple A‐2 reactions and to undue curvature in the Bunnett or Bunnett‐Olsen linear free‐energy plots, so that with the present data such a conclusion cannot be extended to the reaction in solutions of acidity higher than 0.5M. Removal of the chlorine atom attached to the 1,3,5‐triazine ring in atrazine was also found to be an A‐2 reaction in moderately acid solutions, but at higher acidities ([H+]>2M), there is an acceleration in the rate. It is suggested that this is a consequence of diprotonation of the diamino‐1,3,5‐triazine molecule.
Pesticide breakdown by soil enzymes
Authors: Burns Richard G. , Edwards Jennifer A.
Published: November 2006

A proportion of natural substrate decay in soil is effected by extracellular enzymes tenaciously associated with the humic colloids. This indigenous catalytic component (‘accumulated’ enzyme) may also be involved in pesticide breakdown, particularly the organophosphorus compounds and the acylanilides, and this possibility is considered here. Additionally, guide‐lines for detecting and then confirming the presence of accumulated pesticide‐degrading enzymes are suggested.
The pyrethrins and related compounds; Part XXIV: synthesis, 13C‐nuclear magnetic resonance spectra and insecticidal activity of cycloalkyl analogues of fenvalerate
Authors: Elliott Michael , Farnham Andrew W. , Janes Norman F. , Johnson Diana M. , Pulman David A.
Published: November 2006

Close isosteres of fenvalerate [(RS)‐α‐cyano‐3‐phenoxybenzyl (RS)‐2‐(4‐chlorophenyl)‐3‐methylbutyrate], in which cyclopropyl groups replace isopropyl have insecticidal activity close to or greater than the parent compounds, and diminished intravenous toxicity to rats. A direct toxicological relationship of these compounds to fenvalerate itself and to chrysanthemate esters is indicated by the consistently greater activity of esters from one of an enantiomeric pair of acids. Other esters with larger alkyl or cycloalkyl groups, or spiropentane analogues of chrysanthemates are less active insecticides. 13C‐Nuclear magnetic resonance spectra suggest that in the α‐cyanobenzyl esters there is an intramolecular through‐space interaction in solution. The relationships between the chemical structures of the compounds synthesised and their relative activities to different insect species and toxicity to rats are discussed.
The metabolism of the herbicide flamprop‐methyl in rats and some comparative data for dogs, mice and rabbits
Authors: Crayford John V. , Hutson David H.
Published: November 2006

[14C]Flamprop‐methyl administered orally to rats (3‐4 mg kg−1 body weight) was excreted mostly via the faeces (78.7 and 61.6% in males and females, respectively). Elimination was rapid and 90% of the dose of 14C was excreted in faeces and urine 0‐48 h after dosing. The distribution of 14C between faeces and urine was different in males and females. No expired [14C]carbon dioxide was detected and less than 2% of the dose remained in the animals 4 days after dosing. The predominant metabolic pathway was hydrolysis of the ester bond to afford the carboxylic acid which was excreted unchanged and as its glucuronide conjugate. Aromatic hydroxylation occurred at the para‐ and meta‐positions of the N‐benzoyl ring. N‐(3)‐Chloro‐ 4‐fluorophenyl‐N‐(3,4‐dihydroxybenzoyl)‐DL‐alaninate was also formed. This hydroxylated form of flamprop‐methyl was partially O‐methylated at the 3‐hydroxy group. Flamprop‐methyl was also metabolised and eliminated rapidly by dogs, mice and rabbits. The last of these three species afforded very little aromatic hydroxylation and also differed from the others in that the metabolites were eliminated mostly in the urine. Aromatic hydroxylation lay in the order: male rat = female rat > dog= mouse>rabbit (female).
The toxicity of mixtures of a pyrethroid with organophosphorus insecticides to Tetranychus urticae Koch
Authors: Bruce Chapman R. , Penman David R.
Published: November 2006

Laboratory studies of the cotoxicity of a pyrethroid insecticide, fenvalerate, and several organophosphorus insecticides against the two‐spotted spider mite, Tetranychus urticae Koch, showed that a useful degree of potientation of toxicity occurred. The most effective combination of fenvalerate and azinphos‐methyl was found to be a 1:1 ratio. Phosphates and phosphorodithioates in combination with fenvalerate were more toxic than phosphoromonothioates. The results suggest a practical method of improving the acaricidal activity of pyrethroid insecticides.
Foliar pesticide residues in relation to worker re‐entry
Authors: McEwen Freeman L. , Ritcey Gwen , Braun Heinz , Frank Richard , Ripley Brian D.
Published: November 2006

Residues were determined at 8‐h intervals during the 48 h after application of endosulfan, leptophos, methamidophos, methomyl and mevinphos to head lettuce; of endosulfan, methamidophos and methomyl to cauliflower; and of parathion to onions and carrots. Residues of phosalone and parathion were measured on apple leaves 0, 1, 2, 4, 8 and 16 days after application. In addition, the portion of the residue on apple leaves that could be dislodged was measured, as well as the residues on gloves used to handle the apple foliage. There were large differences in the rates of disappearance of the insecticides, differences that must be known in determining safe re‐entry periods for workers.
The activity of amitraz against infestations of Rhipicephalus appendiculatus
Authors: Barry Haigh A. J. , Gichang Moses M.
Published: November 2006

Tick‐infested adult cattle were hand sprayed with solutions containing 178 or 250 mg amitraz litre−1, prepared from a miscible oil concentrate formulation. Both concentrations achieved clearance of infestation within 7 h of spraying. All stages of tick, collected from both sprayings, subsequently died with the exception of two engorged nymphs, which moulted successfully, and six half‐fully engorged females, which all laid small batches of eggs. The eggs from the ticks treated at the higher rate failed to hatch. Expulsion of adult Rhipicephalus appendiculatus, applied daily to a single bovine which had been sprayed once at the higher rate, ceased on the 11th day after spraying. All ticks expelled from the animal died within 24 h. First feeding on the animal was visible on day‐13 and fully engorged females were first observed 18 days after spraying.
Fungicidal activity and chemical constitution. Part XXI: The activity of substituted 1, 4‐naphthoquinones and quinoline‐5, 8‐diones against apple powdery mildew
Authors: James Carolyn S. , Loeffler R. S. Thomas , Woodcock David
Published: November 2006

Several series of alkyl‐substituted amino‐, bromo‐, chloro‐, fluoro‐ and hydroxy‐1, 4‐naphthoquinones, as well as some 6‐alkylaminoquinoline‐5, 8‐diones and 7‐alkyl‐6‐hydroxyquinoline‐5, 8‐diones were prepared and tested as protectant fungicides against apple powdery mildew (caused by Podosphaera leucotricha). While most of the compounds did not reduce infection when applied at 10−3M, several 3‐alkyl‐2‐bromo‐and 3‐alkyl‐2‐chloro‐1, naphthoquinones were found to have ED50 values below 50 × 10−5M.
Rate of volatilisation of pesticides from soil surfaces; comparison of calculated results with those determined in a laboratory model system
Authors: Burkhard Niklaus , Guth Johann A.
Published: November 2006

A laboratory model system for the determination of the volatility of non‐ionic pesticides from soil surfaces is presented. The pesticides examined were the insecticides methidathion, diazinon, and isazophos, the herbicide metolachlor, and the fungicide metalaxyl. The rates of volatilisation of these compounds from soil increased with increasing pesticide concentration, temperature and air flow rate and with decreasing soil organic matter content. The volatilities of the same pesticides were also calculated by using their vapour pressure, water solubility and soil adsorption data. The excellent correlation between calculated and experimental results showed that information on the volatility of a chemical can be obtained simply by calculation. Such calculations allow the classification of each pesticide according to its volatility, and therefore represent a useful alternative for volatility studies in laboratory model systems.
Identification and determination of mecarbam and its major degradation products in water and crops
Authors: Lynch Vincent P. , Hudson Harry R. , Pianka Max
Published: November 2006

Methods have been developed for the analysis by gas‐liquid chromatography and thin‐layer chromatography of mecarbam and a number of its degradation products which result from oxidation and/or partial hydrolysis. In acid solution, mecarbam was found to be relatively stable but it decomposed more readily under alkaline conditions to give O, O‐diethylhydrogen phosphorodithioate by fission of thesulphur‐carbon bond. At pH 9.2, the half‐life at room temperature was about 44 h. For residue analysis, a clean‐up procedure with Florisil was found to be preferable to one which employed alumina, as the latter caused cleavage of the ethoxycarbonyl group under certain conditions. Field trials with olives, oranges and pears showed that the parent pesticide, mecarbam, was the only significant detectable residue at any stage from treatment to harvesting, and that it tended to concentrate in the oil‐containing portion of the crop. Low levels of O, O‐diethyl S‐methylcarbamoylmethyl phosphorodithioate were also detected in residues from lucerne and from bean plants, and it was shown that this samemetabolite could be formed photolytically on filter paper or (morerapidly) on dock leaves. S‐(N‐Ethoxycarbonyl‐N‐methylcarbamoylmethyl) O, O‐diethyl phosphorothioate was detected only in bean plants and then, at a level of less than 0.1 mg kg−1.
Inhibition of ergosterol biosynthesis in Ustilago maydis by the fungicide 1‐[2‐(2, 4‐dichlorophenyl)‐4‐ethyl‐1, 3‐dioxolan‐2‐ylmethyl]‐1H‐1, 2, 4‐triazole
Authors: Henry Matthew J. , Sisler Hugh D.
Published: November 2006

Inhibition of sporidial multiplication in cultures of Ustilago maydis by 1‐[2‐(2, 4‐dichlorophenyl)‐4‐ethyl‐1, 3‐dioxolan‐2‐ylmethyl]‐1H‐1, 2, 4‐triazolea (CGA‐64251), at concentrations of 0.1, 1.0 and 5.0 μg ml−1, increased from about 15% during the first 4 h, to 58–70% during the subsequent 4 to 12‐h period. Sporidia became swollen and highly branched in the presence of the fungicide. Total lipid content as a percentage of the dry weight was not affected after exposure of the sporidia to the fungicide at 0.1 or 5 μg ml−1 for 4 h, but synthesis of ergosterol and other demethyl‐sterols was inhibited by 87–92%. Large quantities of methyl‐sterol precursors of ergosterol and of free fatty acids accumulated in the treated sporidia. Fungitoxicity of CGA‐64251 is attributed to inhibition of ergosterol biosynthesis at the stage of sterol C‐14 demethylation.
Response of five species of stored‐product insects to phosphine in oxygen‐deficient atmospheres
Authors: Kashi Kattera P.
Published: November 2006

Five species of stored‐product insects, [Tribolium castaneum (Herbst), T. confusum (DuVal), Rhyzopertha dominica (F.), Sitophilus oryzae (L.) and S. 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 treatment.
Toxicity of phosphine to five species of stored‐product insects in atmospheres of air and nitrogen
Authors: Kashi Kattera P.
Published: November 2006

The responses of five species of adult stored‐product insects [Tribolium castaneum (Herbst), T. confusum (DuVal), Rhyzopertha dominica (F.), Sitophilus oryzae (L.) and S. granarius (L.)] to various doses of phosphine in atmospheres of air or nitrogen were determined. A few S. oryzae and S. granarius survived phosphine concentrations up to 80 mg litre−1 for 24 h in normal (air) or nitrogen atmospheres. By contrast, T. castaneum, T. confusum and R. dominica could not tolerate more than 0.2 mg phosphine litre−1 in air for 12 h. However, they could tolerate up to 10 mg phosphine litre−1 in 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 unaffected.
Metabolism of diflubenzuron by spider mites and bean plantsa
Authors: Franklin Erasmo J. , Knowles Charles O.
Published: November 2006

Diflubenzuron was absorbed and metabolised relatively slowly by the two‐spotted spider mite Tetrunychus urticae Koch. 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 from mites.
Toxicity of 1,2‐dibromoethane and 1,3‐dichloropropene to microsclerotia of Verticillium dahliae
Authors: Ben‐Yephet Yephet , Letham David , Evans Graeme
Published: November 2006

The toxicity of two fumigants to microsclerotia (MS) of Verticillium dahliae in air and in soil was determined in sealed containers. 1, 2‐Dibromoethane (DBE, ethylene dibromide) at 470 μ ml−1 of air, or at 12.5 μ g−1 of soil, killed 97% of the MS, both after incubation for 16 days. 1, 3‐Dichloropropene (1, 3‐D) at 20 μ ml−1 of air, however, killed 100% of the MS after incubation for 30 h, and at 100 μ g−1 of 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 20–80% of field capacity.
Uptake of benodanil by tobacco seedlings and its relation to the rate of application and control of Rhizoctonia solani
Authors: Cole James S. , Zvenyika Zvenyika
Published: November 2006

Damage to the underground part of the stems of tobacco seedlings, drenched with benodanil in the seedbeds and transplanted into field soil containing Rhizoctonia solani Kühn, was negatively correlated with log(amount of benodanil applied). During the first 3 weeks of growth, the dry mass per seedling was positively correlated with the rate of benodanil applied and negatively correlated with stem damage. Concentrations of the fungicide extractable from roots, stems and leaves at transplanting and after 21 days were positively correlated with the rates of application; in 21 days they decreased by 94% in stems and roots. Stem damage at 21 days after planting was negatively correlated with log(benodanil concentration) at planting and 21 days later.
Further studies of the degradation of the pyrethroid insecticide cypermethrin in soils
Authors: Roberts Terry R. , Standen Mervyn E.
Published: November 2006

Studies of the degradation of the pyrethroid insecticide cypermethrin (NRDC 149) and its cis‐ and trans‐isomers (NRDC 160 and NRDC 159, respectively), have been extended. In soils stored in the laboratory for up to 52 weeks, cypermethrin continued to be degraded by hydrolysis and oxidation. A previously unidentified product has now been identified as the dicarboxylic acid 3‐(2, 2‐dichlorovinyl)‐1‐methylcyclopropane‐1, 2‐dicarboxylic acid. Comparative experiments carried out under indoor and outdoor conditions showed that essentially the same products were formed under these different conditions. However, α‐carboxy‐3‐phenoxybenzyl 3‐(2, 2‐dichlorovinyl)‐2, 2‐dimethyl‐cyclopropanecarboxylate was one minor product detected only under outdoor conditions. Evidence is presented for the further degradation of bound residues arising in soil from cypermethrin treatments. There was limited uptake of the radiolabel into wheat grown in soil containing radiolabelled bound residues.
Variations among field isolates of Botrytis cinerea in their sensitivity to antifungal compounds
Authors: Grindle Morris
Published: November 2006

Seventeen field isolates of Botrytis cinerea were compared by determining their radial growth on synthetic media containing various amounts of 21 antifungal compounds. Twelve of these compounds were fungicides that are recommended for the control of Botrytis infections. There were marked differences between the isolates in their sensitivity to the compounds. Individual isolates displayed high levels of resistance to some of the fungicides, including benomyl, carbendazim, iprodione, thiabendazole, thiophanate‐methyl, vinclozolin and zineb. The most potent growth inhibitors were benomyl and carbendazim (ED95 values for most isolates <0.1 μg fungicide ml−1 media), dichlofluanid, iprodione, nystatin, thiabendazole, thiophanatemethyl and vinclozolin (ED95 values for most isolates < 1.0 μg ml−1), and captan, chlorothalonil, dicloran and thiram (ED95 values for most isolates < 6.0 μg ml−1). Zineb was much less potent than the other recommended anti‐Botrytis fungicides; it was no more effective than carboxin, dinocap and mancozeb (ED95 values for most isolates > 25 μg ml−1).
High‐pressure liquid chromatographic determination of sec‐butylamine residues in potatoes
Authors: Hunter Kenneth , Lindsay David
Published: November 2006

Fluorescamine, 4‐phenylspiro[furan‐2(3H), 1′(3′H)‐isobenzofuran]‐3,3′‐dione, derivatives of primary aliphatic amines were separated by high‐pressure liquid chromatography using a reverse‐phase system with fluorescence detection. This technique was applied to the determination of residues of the fungicide sec‐butylamine in potato tubers; the limit of detection was 0.36 pmol, equivalent to a residue of 0.1 mg kg−1 in potato samples. A second amine, phenethylamine, was identified in extracts from artificially rotted potato flesh but this did not interfere with the analysis of sec‐butylamine residues.
Metabolism of the cis‐ and trans‐isomers of cypermethrin in mice
Authors: Hutson David H. , Gaughan Loretta C. , Casida John E.
Published: November 2006

Metabolism in mice of the separated cis‐ and trans‐isomers of the pyrethroid insecticide cypermethrin (NRDC 149), (RS)‐α‐cyano‐3‐phenoxybenzyl (1RS)‐cis, trans‐3‐(2,2‐dichlorovinyl)‐2,2‐dimethylcyclopropanecarboxylate, was investigated in each case with preparations that were 14C‐labelled in the benzyl and cyclopropyl moieties. Radioactivity from the trans‐isomer was mainly excreted in the urine and that from the cis‐isomer in the faeces. Elimination of both isomers was rapid except for a small portion (approximately 2%) of the cis‐isomer which was released from the fat with a half‐life of approximately 13 days. Metabolism of cypermethrin occurred mainly by ester cleavage and elimination of the cis‐ and trans‐3‐(2,2‐dichlorovinyl)‐2,2‐dimethyl‐ cyclopropanecarboxylic acid moieties as glucuronide conjugates. The α‐cyano‐3‐phenoxybenzyl alcohol released by ester cleavage was mainly converted to 3‐phenoxy‐benzoic acid which was partly eliminated unchanged, partly conjugated with aminoacids (mainly taurine) and glucuronic acid, and partly oxidised to 3‐(4‐hydroxyphenoxy) benzoic acid which was excreted as the sulphate conjugate. Metabolites retaining the ester linkage were formed by hydroxylation at various sites in the molecule with more hydroxylation of the cis‐ than of the trans‐isomer occurring.
The metabolism of the pyrethroid insecticide cypermethrin in rats; excreted metabolites
Authors: Crawford Maureen J. , Croucher Andrew , Hutson David H.
Published: November 2006

The metabolism of the pyrethroid insecticide cypermethrin has been studied in rats using three forms of 14C‐labelling (benzyl‐, cyclopropyl‐ and cyano‐) and separate cis‐ and trans‐ isomers. The proportion of the dose absorbed from the intestines (50–70% at 2–3 mg kg−1) is rapidly metabolised and eliminated. The major reaction is cleavage of the ester bond to afford the constituent cis‐ and trans‐ acids which are conjugated with glucuronic acid and eliminated in the urine. The 3‐phenoxybenzyl portion of the molecule is probably released as the α‐hydroxynitrile, which is converted via the aldehyde into 3‐phenoxybenzoic acid. This compound is then largely hydroxylated and eliminated as a sulphate conjugate. The cyanide ion is metabolised via predictable routes, for instance, as thiocyanate. Cypermethrin is hydroxylated to some extent before hydrolysis. Most of this hydroxylation occurs at the methyl group trans to the cyclopropane carboxyl group, and at the 4‐position of the phenoxy group. cis‐ Cypermethrin is slightly more stable than the trans‐isomer.
Repellent action of permethrin, cypermethrin and resmethrin against black flies (Simulium spp.) attacking cattle
Authors: Shemanchuk Joseph A.
Published: November 2006

Permethrin, cypermethrin, and resmethrin were tested under field conditions as repellents to protect cattle from black flies (Simulium spp.). The chemicals were applied topically to the entire body surface of steers. Ethanolic solutions of technical permethrin, at doses of 1, 2, 4 and 6 mg a. i. kg−1 of body weight, effectively repelled black flies by preventing at least 70% of the flies present from taking a blood meal for up to 8 days, and for at least 11 days at a dose of 12 mg a. i. kg−1. Aqueous mixtures of a 20% permethrin emulsifiable concentrate (e. c.), at doses of 1, 2 and 6 mg a. i. kg−1, effectivelyrepelled black flies for 2, 10 and 11 days, respectively. Aready‐to‐use 5% permethrin dust, at doses of 1, 2, and 4 mg a. i. kg−1, effectively repelled black flies for 4, 5 and 8 days, respectively. Ethanolic solutions of technical cypermethrin, at doses of 1 and 2 mg a. i. kg−1, repelled black flies for 3 and 4 days, respectively. Aqueous mixtures of a 40% cypermethrin e. c., at doses of 2 and 4 mg a. i. kg−1, repelled black flies for at least 5 days. Ethanolic solutions of technical resmethrin, at doses of 2 and 6 mg a. i. kg−1, repelled black flies for 1 and 2 days, respectively.
A method of analysis for the determination of binapacryl, bupirimate and diflubenzuron on apple foliage and fruit, and its application to persistence studies
Authors: Austin Douglas J. , Hall Kathleen J.
Published: November 2006

A rapid, sensitive and specific high‐pressure liquid chromatographic method was developed to analyse residues of binapacryl, bupirimate and diflubenzuron on mature foliage and fruit at intervals after application of the compounds to Worcester and Cox apple trees. The three compounds were applied as commercial formulations in trials to compare integrated pest management with routine farm spray‐programmes. The identities of the residues were confirmed by a combination of thin‐layer chromatography, ultraviolet spectrometry and gas chromatography/mass spectrometry. Only diflubenzuron persisted on foliage until leaf‐fall. None of the applied compounds was detectable on harvested fruit, the minimum quantifiable residue levels being 1, 5 and 2.5 μg kg−1 fresh weight for binapacryl, bupirimate and diflubenzuron, respectively.
Factors affecting the sequential acquisition by Danish houseflies (musca domestica L.) of resistance to organophosphorus insecticides
Authors: Sawicki Roman M. , Keiding Johannes
Published: November 2006

The prolonged use of dimethoate, introduced into Denmark to control houseflies (Musca domestica L.) that had become resistant to parathion and diazinon, resulted ultimately in dimethoate resistance. Selection with dimethoate led to the disappearance of the hydrolytic phosphatase, a major mechanism of resistance to parathion and diazinon, and its replacement by the acetylcholinesterase AChER with somewhat decreased sensitivity to inhibition by organophosphorus (OP) insecticides. The hydrolytic phosphatase probably disappeared because low substrate turn‐over made it ineffective against dimethoxon (O, O‐dimethyl S‐methylcarbamoylmethyl phosphorothioate, also known as omethoate). which accumulates at higher concentrations than paraoxon (diethyl4‐nitrophenyl phosphate) in the haemolymph. Dimethoate selected AChER preferentially because it improved the chances of houseflies surviving against the relatively poor AChE inhibitor dimethoxon, whereas its relatively small insensitivity to OP insecticides, unimportant against good inhibitors such as paraoxon, prevented its selection by parathion.
The phytotoxicity of narrow distillation range petroleum spraying oils to valencia orange trees in South Australia. Part II: The influence of distillation temperature and spray timing on fruit quality
Authors: Furness Geoffrey O.
Published: November 2006

Petroleum oils sprays are used as pesticides on citrus in South Australia to control California red scale (Aonidiella aurantii Maskell), but may have phytotoxic effects on trees and fruit. As part of a programme to establish improved specifications for spray oils for South Australia, three oils with different 50 %‐distillation temperatures were applied to trees each month from October to May for two seasons in order to observe their effects on fruit quality. The 50 %‐distillation temperatures of the three oils were 211, 224 and 240°C at 10 mmHg (in order of increasing molecular weight) and the oils are subsequently referred to as the 211, 224 and 240 oils. The 224 and 240 oils significantly reduced the amounts of sugar and acid in the juice, and delayed and inhibited colouring. These effects increased in severity, the closer to harvest the trees were sprayed and the higher the distillation temperature of the oil. The 240 oil prevented full colour development, and caused ‘re‐greening’ if sprayed later than February. Oil sprays applied to the same trees in the following season caused similar effects. However, if oil sprays were omitted in the following season, there was no residual effect, of the previous season's spray, on the sugar and acid contents or the colour of the fruit. Individual fruit weight was not affected in the first spraying season, but there was an increase in the average individual fruit weight in the second season, regardless of whether a second spray was applied that season or not. The effect was more severe, the closer to harvest the trees were sprayed and the greater the distillation temperature of the oil. The effects on yield resulted from a change in the number of fruit per tree.
The metabolism of the carbamate insecticide bendiocarb in the rat and in man
Authors: Challis Iain R. , Adcock John W.
Published: November 2006

The metabolism of the carbamate insecticide bendiocarb (2,2‐dimethylbenzo‐1, 3‐dioxol‐4‐yl methylcarbamate) has been investigated in male and female rats and in a male human volunteer using radiolabelled material. The compound was rapidly and extensively absorbed and completely metabolised following oral administration. In man, absorption was complete, >99% of the dose being excreted in the urine within 22 h. In the rat, > 86% of the radiolabel was excreted in the urine within the first 24 h. Faecal excretion from the rat was minor (3–8% of dose) and a small amount of the compound (1–3%) was metabolised and excreted as [14C]carbon dioxide. The major metabolic pathway in both species involved cleavage of the carbamate ester group to yield the phenol,2,2‐dimethylbenzo‐1, 3‐dioxol‐4‐ol (I). This metabolite, occurring as sulphate and glucuronide conjugates, accounted for more than 95% of the dose excreted by the human volunteer. In man, small amounts of conjugates of 2, 2‐dimethylbenzo‐1, 3‐dioxol‐4‐yl N‐(hydroxymethyl)carbamate (II) were also found in early samples. In the rat, the metabolism was more complex with the formation of small amounts of conjugates of II and several minor metabolites, thought to be ring‐hydroxylated derivatives of bendiocarb and I.
Deposits of the mildew fungicide binapacryl on the leaves of apple trees of differing sizes after mist blower spraying
Authors: Warman Timothy M. , Hunter Laurence D.
Published: November 2006

Trials in 1975 and 1976 showed that deposit levels of the fungicide binapacryl, on the leaves of bush trees of Cox's Orange Pippin (Cox) after mist blower spraying, varied inversely with tree spread. Deposit levels were measured on young mildew‐susceptible leaves from a well‐sprayed zone around the periphery of the tree canopy at a height of 1.5 m. Low deposit levels in large, dense trees were associated with poor mildew control. Leaves from the smallest trees had deposit levels considerably greater than those found for larger trees (in another nearby orchard) which had adequate mildew control. Fungicide deposit levels on leaves from up to five different zones of trees of three different sizes (the largest trees were of the variety Bramley's Seedling) were measured in 1977. The smallest trees had significantly higher deposit levels than the larger trees in the lower centre and lower outside zones of the trees, whereas both orchards of Cox had the same (commercially acceptable) level of mildew infection at the end of the season. Leaves from zones less accessible to spray had lowerdeposit levels than those nearer the sprayer.
Changes in membrane phospholipids, identified by Arrhenius plots of acetylcholinesterase and associated with pyrethroid resistance (kdr) in houseflies (Musca domestica)
Authors: Chialiang Chiang , Devonshire Alan L.
Published: November 2006

Membrane‐bound acetylcholinesterase (AChE), extracted from the heads of susceptible and knockdown‐resistant (kdr) houseflies, was assayed at a range of temperatures between 5 and 35°C. Arrhenius plots using the results showed discontinuities commonly associated with membrane‐bound enzymes and generally attributed to an abrupt change in the viscosity of the lipids as they undergo a phase change at a temperature characteristic of their chemical composition. The enzyme from susceptible flies had a transition temperature of 14°C compared with 19°C and 21°C for the enzymes from kdr and super‐kdr strains, respectively. This variation was associated with a progressive decrease in activation energies, both above and below the transition temperature, with increasing resistance. The enzyme from a hybrid between susceptible and super‐kdr flies had the same properties as that from susceptible flies, corresponding with the genetically fully‐recessive behaviour of this resistance mechanism in toxicological studies. After digestion with phospholipase A2, the AChE from super‐kdr flies gave unchanged Arrhenius plots, whereas with the susceptible enzyme, both transition temperature and activation energies changed markedly to resemble more closely the enzyme from kdr flies. These results are discussed in relation to the likely changes in phospholipid composition and its effect on the conformation of the, as yet unidentified, target(s) of pyrethroids and DDT.
Transfer of insecticide residues to food stored on or near plywood impregnated with organochlorine insecticides
Authors: Fishwick F. Bernard , Rutter Irene
Published: November 2006

Formulations of aldrin and dieldrin have been used for a number of years to treat exposed timber components used in the construction of freight containers. The extent to which these insecticides migrate to foodstuffs stored on or near treated plywood has been examined under laboratory conditions and is reported here. A limited survey of organochlorine insecticide residues in samples of foodstuffs, taken from commercial loads carried in freight containers, indicated that residue levels are unlikely to present a health hazard.
Determination of the vapour pressure of pesticides
Authors: Grayson B. Terence , Fosbraey Lynda A.
Published: November 2006

An instrument for measuring the vapour pressures of pesticides has been constructed using a suitably adapted gas chromatographic oven. Using this apparatus and a method involving gas saturation, followed by chromatographic analysis of the trapped pesticide vapour, the vapour pressures of a number of pesticides and non‐pesticides have been determined. It has been demonstrated that this procedure gives repeatable and accurate values by statistical comparison of the results obtained with data abstracted from the literature.
The rational design of the optically active wild oat herbicide L‐flamprop‐isopropyl
Authors: Venis Michael A.
Published: November 2006

An esterase, that has been partially purified from oat tissues, catalyses the hydrolysis of the wild oat herbicide benzoylprop‐ethyl and of the related esters of N‐benzoyl‐N‐(3‐chloro‐4‐fluorophenyl)‐DL‐alanine, including flamprop‐methyl and flampropisopropyl. The enzyme is virtually stereospecific for the L‐isomers in the racemic mixtures. Hydrolysis of flamprop‐methyl in oat tissues shows similar enantiomeric discrimination, but the ethyl and isopropyl ester analogues are converted in vivo to the free acid with very little overall stereoselectivity. Oat tissues must, therefore, contain another enzyme, labile to isolation, that acts on the D‐isomers of the higher esters. This was confirmed by showing that it is possible to manipulate the stereoselectivity of the de‐esterification of the ethyl ester in vivo by selective inhibition of either the L‐isomer pathway with paraoxon (diethyl 4‐nitrophenyl phosphate), or the D‐isomer route with piperonyl butoxide. The relationship of these findings to the superior herbicidal performance of the L‐isomers of these esters, relative to their racemates, is discussed.
Insecticidal activity of the pyrethrins and related compounds. Part XII: α‐substituted‐3‐phenoxybenzyl esters
Authors: Elliott Michael , Farnham Andrew W. , Janes Norman F. , Khambay Bhupinder P. S.
Published: November 2006

Seventy‐three α‐substituted 3‐phenoxybenzyl esters were synthesised, mostly using one of two general routes, based on the Grignard and related reactions. Esters with simpler (smaller and more polar) α‐substituents were generally more insecticidally active; correlations based on substituent volume and substituent polarity parameters were about equally significant.
Insecticidal activity of N,N‐diethyl‐, N,N‐dipropyl‐, N,n‐di‐isopropyl‐, and n,n‐di‐isobutylalkanamides against mosquito larvae
Authors: Hwang Yih‐Shen , Mulla Mir S. , Pope Mary Mistrot , Rodriguez Cesar
Published: November 2006

N,N‐Diethyl‐, N,N‐dipropyl‐, N,N‐di‐isopropyl, and N,N‐di‐isobutylalkanamides in which the acyl moiety ranged from C8 to C21 were synthesised, and their larvicidal activity was determined against the first‐instar larvae of the southern house mosquito Culex quinquefasciatus Say. The four homologous series of amides generally showed an increase in their larvicidal activity as the carbon number in the acyl moiety of the amides increased, until the activity reached a maximum. Subsequently, an increment of carbon number resulted in declining activity in the higher homologues, until the activity disappeared. N,N‐Diethyltetradecanamide, N,N‐dipropylundecanamide, N,N‐di‐isopropylundecanamide, and N,N‐di‐isobutlynonanamide or ‐dodecanamide were the most active compounds in their respective homologous series of amides; however, they were less active than their analogous N,N‐dimethylalkanamides previously studied.
Synthesis and antifungal activity of new nitro‐alcohol derivatives
Authors: Mikite Gyula , Jakucs Erzsébet , Kis‐Tamás Attila , Darvas Ferenc , Lopata Antal
Published: November 2006

Thirty‐six new nitro‐alcohol derivatives were synthesised. Tested in vitro against Helminthosporium sativum, the compounds had high antifungal activities; the EC50 values varied between 10−2 and 10−6 M, and for the majority of the compounds between 10−4 and 10−6 M. The EC50 values were calculated by probit analysis, except for the compounds with low activity, for which the values were estimated. Interesting relationships between the structure and antifungal action of the compounds were established.
Photo‐induced fungicidal activity elicited by naturally occurring thiophene derivatives
Authors: DiCosmo Frank , Towers G. H. Neil , Lam JØrgen
Published: November 2006

Photo‐induced fungitoxicity was observed inAlternaria alternata, Aspergillus niger, Cladosporium variabile, Colletotrichumsp.,Rhizopus nigricans, Pythium aphanidermatum, andSaprolegniasp., elicited by 5‐(but‐3‐en‐l‐ynyl)‐2,2′‐bithienyl, 2,2′: 5′,2″‐terthienyl, and 2‐chloro‐4‐[5‐(penta‐1,3‐diynyl)‐2‐thienyl]but‐3‐ynyl acetate in the presence of near ultraviolet (u.v.) radiation (320–380 nm). Conidiogenesis inA. niger, and sporangiosporogenesis inR. nigricanswere depressed on media treated with 2,2′: 5′,2″‐terthienyl and irradiated with near u.v. light. Radial growth of mycelia of all fungi tested was dramatically reduced by all three compounds in the presence of near u.v. light. The viability of conidia ofA. niger, andR. nigricanswas unaffected by 2,2′: 5′,2″‐terthienyl, both in the dark and in near u.v. light. Newly emergent germ‐tubes were most sensitive to toxicity mediated by u.v. light. The oomycetous fungi tested were the most sensitive to the photo‐activated toxicity generated by the three compounds used. The results indicate that ED50values are dependent upon the species and the presence or absence of near u.v. light. Dramatically lowered ED50values were always observed in all systems treated with near u.v. light. The dose of near u.v. light used had no effect on the radial growth of fungi in the absence of the three compounds.
Comparisons of simulated with measured transport and transformation of methyl bromide gas in soils
Authors: Rolston Dennis E. , Glauz Robert D.
Published: November 2006

A simulation model is described for the transport of the fumigant, methyl bromide gas, away from injection chisels within the field. The injected methyl bromide is assumed to form cylindrical, parallel sources at the depth of injection. Transport of the methyl bromide is described by radial diffusion from the injection cylinders. The dissolution‐distillation of methyl bromide gas in the soil water and on soil particles is accounted for by a first‐order reversible kinetic equation or by an equilibrium relationship. The hydrolysis of methyl bromide gas to bromide anion is considered to occur according to a first‐order irreversible equation. The model considers cases where the soil surface is and is not covered with an impermeable barrier to the diffusion of the gas. Simulated methyl bromide concentrations in the soil air, and bromide concentrations in the soil, compared reasonably well with measured values from several field sites. Comparison of the results of calculations, with and without plastic barriers at the soil surface, with experimental data, indicate that plastic barriers are ineffective in preventing diffusion of gas from the soil to the atmosphere. Calculations of mass balances show that as much as 70% of the applied methyl bromide had escaped to the atmosphere by 14 days after fumigation.
Control of potato late blight using controlled‐release granules containing ofurace
Authors: Cooke Louise R. , Clifford Derek R. , Deas Adrian H. R. , Holgate Margaret E.
Published: November 2006

In an attempt to reduce or eliminate the need for spraying to control potato late blight caused by Phytophthora infestans, investigations were made on the use of controlled‐release granules containing the systemic fungicide ofurace. The granules when mixed with sand and buried in soil released the fungitoxicant for about 100 days. When the granules were applied in furrows at planting, protection of potato plants (cv. Maris Bard), assessed by inoculation of detached leaflets with P. infestans, lasted for between 85 and 100 days. Application of the granules when the plants were earthed up 48 days after planting did not result in better late‐season protection, possibly due to poorer uptake of the fungitoxicant by the plants at this time. Chemical analysis of leaves from plants that had received in‐furrow treatment indicated that ofurace at 0.2–0.5 μg g−1 fresh weight was needed to confer protection from late blight.
The pyrethrins and related compounds. Part XXVI. Analogues of fenvalerate from acyclic‐substituted 3‐methylbutyric and related acids
Authors: Elliott Michael , Farnham Andrew W. , Janes Norman F. , Khambay Bhupinder P. S. , Pulman David A.
Published: November 2006

3‐Methylbutyric and 3‐methylbut‐3‐enoic acids were prepared and esterified with pyrethroidal alcohols. The insecticidal activities of 46 esters, analogues of fenvalerate in which non‐aryl substituents replaced the 4‐chlorophenyl group, were determined to establish the structural requirements for activity in this part of the molecule.
The use of [3H] permethrin to investigate the mechanisms underlying its differential toxicity to adult and larval stages of the sheen blowfly Lucilia sericata
Authors: Nicholson Russell A. , Botham Roger P. , Collins Chrystal
Published: November 2006

Observations suggest that more than one mechanism is responsible for the increased tolerance to permethrin in the larval stage of Lucilia sericata. While the penetration rate of permethrin was much reduced in larvae, they remained more tolerant than adults when this compound was injected. Following the injection of sublethal amounts of [3H]‐(1 RS)‐trans‐permethrin, a substantial proportion of the dose was accumulated and retained in the larval fat body. In adults, less permethrin was absorbed and retained in the tissues. However, compared to the larvae, detoxication was faster, haemoplasm levels were lower, and substantially more breakdown products were excreted. The injection of sublethal amounts of permethrin into the larva led to severe disruption of sensory function. These findings suggest that an important difference may exist between adults and larvae in either the sensitivity of vital sites within the nervous system, or in the sequence of events which follow nervous system disruption and lead to death.
Some observations on pest damage to grassland and some possible control measures
Authors: Clements Robert O. , Henderson Ian F.
Published: November 2006

Grassland pests often cause obvious damage at the establishment phase, but it is rare for established swards to be visibly affected. Despite this, insidious damage to established grass is widespread and there are several reasons why it is not easily detected. Insidious pest damage is particularly prevalent in sown ryegrass‐dominant swards in the lowlands. Permanent pastures, in the uplands at least, appear to suffer less from pest damage. In one experiment, established legumes did not suffer markedly from pest damage. Sward damage varies considerably from year to year, during the season, with location, with sward age and with botanical composition.

Much of the blame for damage to established swards and to those being established can be attributed to stem‐boring Dipterans, such as the frit fly (Oscinella frit L.). Certain non‐persistent insecticides can be used to control the pest, but are unlikely to be cost‐effective except when used at the establishment stage or, possibly, on efficiently utilised lowland ryegrass swards. Alterations in management practice do not seem feasible in controlling frit fly. However, large differences have been found between the varieties of perennial and Italian ryegrass, in the level of susceptibility to pests (especially frit fly), and it may be possible to develop resistant varieties.
Synthesis and insecticidal properties of derivatives of propane‐1, 3‐dithiol (analogues of the insecticidal derivatives of dithiolane and trithiane from the alga Chara globularis Thuillier)
Authors: Jacobsen Niels , Pedersen Lars‐Erik K.
Published: November 2006

Functional derivatives of 2‐(methylthio)propane‐1, 3‐dithiol (open chain analogues of the insecticidal 4‐methyithio‐1, 2‐dithiolane and 5‐methylthio‐1, 2, 3‐trithiane from the alga Chara globularis) possess insecticidal properties similar to those of the structurally related nereistoxin. Some derivatives of propane‐1, 3‐dithiol, bearing 2‐substituents different from the methylthio group, have also been shown to have insecticidal pioperties.