bluuebunny/crossref_metadata_2025 huggingface dataset:
Residues of organochlorine insecticides in some fishes and birds in the gezira of Sudan
Authors: El‐Zorgani Gaafer A.
Published: November 2006

Twenty‐eight specimens representing five types of fish and five types of birds from the Gezira Research Farm, Wad Medani, Sudan, were analysed for residues of organochlorine insecticides. All fish muscle samples were found to contain pp′‐DDE, pp′‐TDE and pp′‐DDT in total concentrations ranging from 0.27 to 16.0 mg/kg. In addition to DDT‐type residues, dieldrin (HEOD) was also found in the majority of bird samples. Concentrations in bird breast muscle ranged from 0.07 to 5.5 mg/kg. When bird liver samples were examined they were found to contain higher residues than the breast muscle in nearly all cases.
German cockroach resistance: Propoxur selection induces the same resistance spectrum as diazinon selection
Authors: Collins William J.
Published: November 2006

A resistant laboratory strain of the German cockroach, Blattella germanica, was developed from a normal laboratory strain by selection with propoxur. Resistance to all insecticides except chlordane began increasing after 15 generations of selection and reached a plateau for most insecticides by generation 27. The resistant colony, designated B‐strain, developed significant resistance to carbamates, organophosphorus compounds, pyrethrins and DDT, developed low resistance to gamma‐BHC and no resistance to chlordane. The resistance spectrum, effect of synergists and inheritance of resistance of this propoxur resistant strain are similar to a diazinon resistant strain. Therefore, diazinon and propoxur may select for the same resistance mechanism(s) in this species. The practical implications of this research are discussed.
Poisoning of wild geese by carbophenothion‐treated winter wheat
Authors: Hamilton George A. , Hunter Kenneth , Ritchie Alexander S. , Ruthven Alexander D. , Brown Peter M. , Stanley Peter I.
Published: November 2006

A series of incidents involving greylag goose (Anser anser) casualties in Angus and Perthshire and a single incident involving pink‐footed goose (Anser brachyrhynchus) casualties on Humberside occurred during the winter of 1974/75. The results of post‐mortem examinations and brain esterase studies were consistent with the deaths having resulted from organophosphorus poisoning. Chemical analysis revealed the presence of carbophenothion (S‐4‐chlorophenylthiomethyl OO‐diethyl phosphoro‐dithioate) residues in the gut contents and internal tissues of the casualties. It was concluded that the geese had died from carbophenothion poisoning following the ingestion of treated winter wheat seed and the factors that led to the incidents are discussed.
Benomyl residues in bananas
Authors: Cox John , Pinegar John A.
Published: November 2006

An ultraviolet spsctrophotometric and a microbiological assay were used to determine residues of benomyl and its derivative carbendazim on banana skin and pulp. Two alternative procedures for the purification of pulp extracts are described and recovery values from laboratory‐treated bananas are compared. The average residue determined in the pulp was 6.4 % of the total for the whole fruit.
Structural and physical aspects of pyrethrum chemistry
Authors: Crombie Leslie , Pattenden Gerald , Simmonds Derek J.
Published: November 2006

Recent spectroscopic and X‐ray crystallographic studies of the natural pyrethrins are summarised.
Quantitative structure‐activity correlation of pyrethroids againstMusca domesticaandBlattella germanica
Authors: Lee Hung‐Hee H.
Published: November 2006

Structure‐activity correlations of pyrethroids toMusca domesticaandBlattella germanicawere studied in terms of partition coefficient, electronic effect and conformation. RelativeRfvalues of 12 pyrethroids measured by thin‐layer chromatography were related to the relative partition coefficients and electronic effect. The relative size and shape of six pyrethroids were determined by probabilistic automatic pattern analysis using Corey‐Paulings' molecular models. There is no correlation of knockdown ofM. domesticaand partitioning. The simple correlation, with 0.10<P<0.01 of partitioning, electronic effect and size and shape of pyrethroids to toxicity were 0, 0.2–0.3, 0.7–0.8 respectively while thermodynamic treatment gave corresponding correlations of 0, 0.4, 0.6.
Development of resistance to pyrethroids in field populations of danish houseflies
Authors: Keiding Johannes
Published: November 2006

Houseflies (Musca domestica) on Danish farms have developed high multiresistance to organophosphorus compounds, after successive use of several OPs, mainly dimethoate, in recent years. Topical application tests 1971–73 with flies from many farms showed that the high OP‐resistance did not involve resistance to pyrethroids (± the synergist piperonyl butoxide (pb)) above a level of 3–7 x, unless field pressure with synergised pyrethrum (py/pb) or other pyrethroids was applied. In 1971–72 moderate to high, often heterogeneous, pyrethroid resistance was found on a few trial farms treated frequently with pyrethroid aerosols (mainly py/pb) and in 1973 on most of 23 trial farms treated intensively with aerosols (or space spray) containing py/pb, bioresmethrin ± pb, tetramethrin/pb or tetramethrin/resmethrin. The effect of field pressure with these different pyrethroids on development of pyrethroid resistance is summarised and discussed. Maximum resistance ratios, R/S at LD50‐LD95, were: py/pb (1:5), 40‐>100; bioresmethrin, 191–770; bioresmethrin/pb (1:5), 55–133; tetramethrin/pb (1:5), 171‐>200; tetramethrin/resmethrin (1:5), 78‐>370. The intensity of selection pressure with pyrethroids is believed to be an important factor. Although py/pb has been widely used as a supplementary fly control on Danish non‐trial farms, pyrethroid resistance has only been found on a few of them.
Metabolism and fate of triazophos in rats
Authors: Bock Rudolf , Thier Werner
Published: November 2006

The excretion patterns and tissue residues were determined after single and repeated oral dosing of rats with triazophos‐14C Within 4 days after a single oral dose 76.3 % of the 14C was excreted in the urine and 21.0% in the faeces. After daily application for 12 days 69.5–83.4% of the label was eliminated in urine and 30.9–18.1 % in the faeces. Following prolonged application, however, elimination is distinctly slower. Distribution of radioactive residues in organs and tissue in both test series showed no appreciable or critical concentrations of radioactivity, with the exception of the gastrointestinal tract (contents and walls). Unchanged triazophos and l‐phenyl‐1,2,4‐triazol‐3‐ol‐3‐14C were excreted in the faeces. Renewed release of other metabolites into the gastrointestinal tract apparently does not take place. The following metabolites are detected in the urine: urea‐14C (approx. 85% of the radioactivity excreted with the urine); and three compounds as conjugates with glucuronic acid, i.e. 1‐phenyl‐l,2,4‐triazol‐3‐ol‐3‐14C (approx. 3%), l‐phenylsemicarbazide‐3‐14C (approx. 5%), and semicarbazide‐14C (approx. 5%). Two further metabolites, so far unidentified, occurred in small quantities.
The degradation of (Z)‐ and (E)‐1,3‐dichloropropenes and 1,2‐dichloropropane in soil
Authors: Roberts Terry R. , Stoydin George
Published: November 2006

The degradation in soil of the major constituents of a 1,3‐dichloropropene‐1,2‐dich‐loropropane nematicide has been studied under laboratory and outdoor conditions. In sealed glass containers, ( Z)‐ and ( E)‐1,3‐dichloropene‐ 2‐14C were converted in soil into the corresponding 3‐chloroallyl alcohols and these alcohols were in part strongly bound to the soil. The ( Z)‐ and ( E)‐3‐chloroacrylic acids were also found as minor products. More polar products were detected and these released the chloroacrylic acids in 20–30% yield upon hydrolysis. Although the 1,3‐dichloropropenes were lost by volatilisation from soil stored in open glass jars outdoors, they also underwent degradation to the same products that were detected in sealed containers. There was evidence of only slight degradation of 1,2‐dichloropropane‐ 2‐14C (4 % or less of the applied radioactivity remained unextracted from a loam soil after 5 months). When soil treated with the 1,2‐dichloropropane was stored outdoors in an open glass container, less than 1 % of the original radiolabel remained in the soil after 10 days under these conditions due to volatilisation of the applied material. In a separate experiment potatoes were grown in soil 6 months after treatment with a mixture of both ( Z)‐ and ( E)‐1,3‐dichloropropene‐ 2‐14C and 1,2‐dichloropropane‐ 2‐14C. Although 5 % of the applied radiolabel remained in the soil at potato harvest the potato tubers contained only a very small residue (0.007 mg/kg).
Development of methods for the analysis of crops and soils for residues of benzoylprop‐ethyl and its breakdown products
Authors: Wright A. Neill , Mathews Brian L.
Published: November 2006

Methods are described for the analysis of residues of the herbicide benzoylpropethyl, ethyl (±)‐2‐[ N‐(3,4‐dichlorophenyl)benzamido]propionate, and its breakdown product, (±)‐2‐[ N‐(3,4‐dichlorophenyl)benzamido]propionic acid, in wheat and soil. In wheat the acid degradation product conjugates with plant sugars and the present paper includes methods for determination of these residues either separately or as a combined residue with unconjugated acid. Efficient extraction procedures have been developed together with partition and column chromatographic techniques for purification of extracts. The full analytical procedures are described and the final determinations are by g.1.c. with electron capture detection with blank values for field samples in the range 0.01–0.05 mg/kg. Good recoveries were obtained. Radiochemical techniques have been used to verify the extraction and subsequent procedures in the methods.
Annual beet: Problems and prospects
Authors: Longden Peter C.
Published: November 2006

Annual bolting sugar beets have contaminated fields in England and represent a potential hazard through their seed production capability (up to 150 viable seed/plant), which could make them an important weed in arable crops, and through their pollen production, which could lead to a degeneration in varieties of sugar beet being grown for seed nearby. Although control by rotation and herbicides in other crops are probably the easiest effective control measures, up to 100% reduction in seed production in the sugar beet crop resulted from bolter pulling, topping or treatment with a 100 g a.e./litre glyphosate solution (1 ml/plant) early in July. The glyphosate damaged other plants which it reached. Whichever control method is selected, mechanisation seems possible.
Contact activity of diflubenzuron against Spodoptera littoralis larvae
Authors: Ascher K. R. Simon , Nemny Nadia E.
Published: November 2006

The effect of diflubenzuron as a residue on glass or applied topically to Spodoptera littoralis larvae was investigated. Diflubenzuron was active as a residue on glass against 100 and 200 mg larvae; the toxicity of residues was identical whether a dispersable formulation or a wettable powder or the technical substance were used. By topical application, diflubenzuron had an ED50 for cumulative percentage mortality up to the adult stage of 004 and 0066 μg/larva for 100 and 200mg larvae respectively. Neither the site of the topical application nor whether the larvae were kept singly or in groups of ten after the treatment had an influence on toxicity. The data indicate that diflubenzuron has contact toxicity to at least one insect species as well as the known stomach poison action.
Insecticidal activity of the pyrethrins and related compounds. IX. 5‐benzyl‐3‐furylmethyl 2,2‐dimethylcyciopropanecarboxylates with non‐ethylenic substituents at position 3 on the cyclopropane ring
Authors: Elliott Michael , Farnham Andrew W. , Janes Norman F. , Needham Paul H. , Pulman David A.
Published: November 2006

The insecticidal activities against houseflies (Musca domestica L.) and mustard beetles (Phaedon cochleariae Fab.) of 29 new 5‐benzyl‐3‐furylmethyl 2,2‐dimethyl‐cyclopropane‐carboxylates are compared with those of the corresponding chrysanthe‐mate (bioresmethrin) to assess the influence of non‐ethylenic and isobutenyl substituents at position 3 of the cyclopropane ring. Of the new groups investigated, only 3‐methoxyiminomethyl gives equal or enhanced activity; 3‐(2‐furyl) esters are moderately effective, but 3‐phenyl and 3‐alkoxycarbonyl compounds show weak activity. A 3‐(2,2,2‐trihaloethyl) compound was more active than compounds with other saturated groups, such as isobutyl.
Determination of residues of isofenphos and its phosphoramidate analogue
Authors: Brown Marilyn J. , Williams Ian H.
Published: November 2006

A method is described for the gas chromatographic determination of residues of isofenphos (BAY 92114, O‐ethyl O‐2‐isopropoxycarbonylphenyl isopropylphosphor‐amidothioate) and its phosphoramidate which is a potential metabolite. When potato, cabbage, rapeseed and a sandy loam soil were fortified with 0.01, 0.1 and 1.0 mg/kg and analysed by the method described, the recoveries ranged from 76 to 98%. The limits of detection of the method were 0.5 and 1.0 ng for isofenphos and isofenphos oxygen analogue respectively. Degradation under field conditions of isofenphos to its oxygen analogue was demonstrated in a sample of field‐treated potatoes.
Fonofos residues in an organic soil and vegetable crops following treatment of the soil with the insecticide
Authors: Khan Shahamat U. , Hamilton Herman A. , Hogue Eugene J.
Published: November 2006

Fonofos (O‐ethyl S‐phenyl ethylphosphonodithioate) was applied to an organic soil as band treatment at the rates of 1.12 and 2.24 kg/ha. The persistence of the insecticide and its translocation into onions and two rotation crops (lettuces and carrots) was studied under field conditions. Proportionally more residues persisted in the soil from the higher rate of application. In autumn, 4 months after soil treatment, about 40‐48 % of the initially recovered levels of fonofos remained in soil. However, the amount of fonofos present at the harvest time, during the second growing season was only 16–26% of the insecticide concentration found in spring. Onions harvested 4 months after application of fonofos had no detectable residue (> 0.005 mg/kg) whereas lettuces and carrots grown in the following year contained fonofos in various amounts. At the lower rate of application the insecticide residues in lettuces and carrots were < 0.005 and 0.025 mg/kg, respectively, and those from the higher application rate were 0.012 and 0.036 mg/kg. About 72–80% of the residue could be removed by peeling the carrots. No residue of the oxygen analogue, O‐ethyl S‐phenyl ethylphos‐phonothioate (I) was detected in any soil or crop samples.
The use of synthetic sex pheromones for pest management in stored‐product situations
Authors: Haines Christopher P.
Published: November 2006

In spite of the obvious advantages of storage systems for pheromone use, few attempts have been made to investigate the practical effectiveness of pheromones in such systems. The sex pheromone complex of Ephestia cautella (Walker) is described, and the possible natural functions of the components are suggested. Trials with the synthetic pheromones show that mating frequency of the moth can be reduced by slow release of the materials in a warehouse. The prospects for the use of pheromones in pest management in stores are discussed.
The basis of selectivity of 4‐(2, 6‐dichlorobenzyloxymethyl)‐4‐ethyl‐2, 2‐dimethyl‐1, 3‐dioxolan (WL 29, 226), a new pre‐emergence herbicide for use in cereals
Authors: Jeffcoat Brian
Published: November 2006

A series of pot experiments were undertaken to assess the selectivity of the pre‐emergence herbicide 4‐(2, 6‐dichlorobenzyloxymethyl)‐4‐ethyl‐2, 2, ‐dimethyl‐1, 3‐dioxolan (WL 29,226) against a number of annual weeds in wheat. When applied at dose rates of 0.5–2 kg/ha it gave good control of a number of annual monocotyledonous weeds, including Alopecurus myosuroides (blackgrass), without any adverse effects on the crop. WL 29,226 is relatively immobile in soil, remaining at the soil surface and thus favouring uptake via the emerging shoot. Since WL 29,226 is transported predominantly via the xylem, to reach its site of action in the regions of cell division, and hence to be effective, the compound has to penetrate the shoot either at or below the stem apex. The roots are inhibited only when these come into direct contact with the compound. Selectivity of the herbicide is dependent upon the relative anatomical positions of the stem apices of the weeds and the crop with respect to the soil surface. Mesocotyl elongation in many of the weed species was such that the meristematic tissue was raised to the soil surface and into contact with the compound during the emergence of the shoot. In contrast, the stem apex of wheat remained some distance below the soil surface until considerably later, by which time the leaf sheaths offered protection to the meristematic tissue from direct contact with the herbicide. Selectivity is further enhanced in the field as a result of both the depth of planting for wheat and the tendency of many annual weed species to germinate more readily when near the soil surface. Tolerance of the wheat is lost where it germinates in direct contact with the herbicide, due to the lack of any biochemical selectivity. Under field conditions WL 29,226 gives good control of many dicotyledonous species. In pot experiments, however, these exhibit some tolerance to the compound. Radio‐tracer studies indicate that the tolerance shown by the shoots of these plants is due to limited transport of the herbicide from the shoot to its site of action at the apex. This suggests that control of broad‐leaved weeds occurs predominantly through an inhibition of root growth. However, in species such as sugar‐beet, soyabean and cotton a rapid rate of root elongation confers increased tolerance to the compound. Availability of WL 29,226 for uptake by young seedlings is favoured by soil moisture. Low temperatures further improve performance by reducing the rate of shoot emergence and hence prolonging contact with the compound at the most sensitive stage of growth. After emergence uptake of the compound via the shoot becomes a less efficient mode of entry.
Ion concentration variations at short distances downwind of continuous and quasi‐instantaneous point sources
Authors: Jones Christopher D.
Published: November 2006

An improved experimental technique is described which enables the fine structure of the ion concentration variations downwind of both continuous and instantaneous point sources to be examined. The method, which involves the use of ionised air, permits resolution of features within diffusing clouds of the order of centimetres since the detector response time is about ten milliseconds. The success of the method can be attributed to the fact that the measurements are entirely electrical in nature, thereby eliminating certain defects inherent in most other sensing techniques. However, the method does possess disadvantages and these are critically examined. Experimental results are presented which show clearly the presence of considerable fine structure hitherto suspected, but not quantitatively observed, in diffusing plumes, i.e. from continuous sources, and puffs, i.e. from instantaneous sources. The implications of these data are considered briefly.
Estimation of acid dissociation constants from potentiometric titration curves
Authors: Farrington John A.
Published: November 2006

A computer program has been developed for fitting theoretical curves to data points obtained in pH titrations of weak acids or bases. The logarithm of the acid dissociation constant ( — pKa) and end point are optimised by the program and any strong acid or base which may be present as an impurity is allowed for. Activity coefficient corrections are included. It is applicable to mono‐, di‐ and tri‐basic acids, including those with overlapping ionisation regions. The choice of concentration at which to carry out the titration in order to obtain a reliable pKa is discussed.
Co‐inheritance of increased carboxylesterase activity and resistance to organophosphorus insecticides in Myzus persicae (sulzer)
Authors: Blackman Roger L. , Devonshire Alan L. , Sawicki Roman M.
Published: November 2006

Levels of carboxylesterase activity and resistance to dimethoate were assessed in F1 clones of Myzus persicae obtained by crossing sexuales from a resistant, high esterase clone (R) with those from three susceptible, low esterase clones. The progeny of the most successful cross fell into two distinct groups, intermediate between the parent clones with respect to both carboxylesterase activity and resistance. The first group averaged 74% of the total carboxylesterase activity, 79% of the esterase band‐4 activity, and 86% of the resistance of R. The second group averaged 43% of the total carboxylesterase activity, 33% of the esterase band‐4 activity and 17% of the resistance of R. The results indicate that R may be heterozygous for two alleles coding for increased esterase levels and associated resistance.
Absorption, metabolism and excretion of the fungicide triforine in the rat
Authors: Darda Siegfried
Published: November 2006

Eighty per cent of orally administered triforine is absorbed by the rat. Maximum blood levels are reached 4 h after administration. After complete metabolic conversion has occurred, the fungicide absorbed is excreted mainly in the urine as a metabolite, N‐[2,2,2‐trichloro‐1‐(piperazin‐1‐yl)ethyl]formamide. Elimination is complete with most of the compound being excreted during the first 24 h following administration.
Control of insects in cotton crops in africa with some pyrethroid
Authors: Lhoste Jean , Piédallu Christian
Published: November 2006

Cotton yield results are presented for trials in Senegal, the Ivory Coast, Chad and Morocco in which the pyrethroids permethrin, biopermethrin, 3‐phenoxybenzyl (1R,cis)‐3‐(2,2‐dichlorovinyl)‐2, 2‐dimethylcyclopropanecarboxylate (NRDC 167) and (S)‐α‐cyano‐3‐phenoxybenzyl (1R,1 S)‐cis,trans‐3‐(2,2‐dibromovinyl‐2, 2‐dimethylcy‐clopropanecarboxylate (NRDC 156) were compared with the compounds currently used for insect control. NRDC 156 gave marked yield increases at rates as low as 12.5 g.a.i./ha, the other pyrethroids needing higher rates to give comparable results. Control of mites, Hemitarsonemus lata and Tetranychus urticae was not satisfactory, however.
Mothproofing with permethrin
Authors: Duffield Peter A.
Published: November 2006

The new pyrethroid, permethrin, previously shown to have high activity against textile pests, was successfully applied to wool from a conventional dye bath. The stability of permethrin to boiling aqueous conditions and to some textile testing regimes was shown to be satisfactory, although some loss on prolonged boiling did occur. Industrial trials made on both wool and wool/nylon blends are described.
A field trial with permethrin against bodylice, pediculm humanus humanus in Egypt, 1976
Authors: Nassif Moufida , Kamel Osman
Published: November 2006

Populations of bodylice, Pediculus humanus humanus L., in Egypt have become resistant to DDT and BHC, but not to malathion. A single dust application of permethrin (1 % a.i.; cis: trans‐ratio 25:75) rendered 98.9% of the treated population louse‐free. Thirty‐seven days after dusting 91.3% and at the end of the 98‐day observation period 64.6% of the population were free of infestation; during the same period the proportion of infested individuals rose by 12.3% in a similar untreated village. Permethrin is ovicidal against bodylice, affects the population of the human flea, PulexirritansL., and ishighly effective against the rat flea, Xenopsyllacheopis(Rothsch.).
The synthesis and insecticidal activity of indole‐derived carbamates
Authors: Wright Brian J. , Baillie Alister C. , Dowsett John R.
Published: November 2006

Thirty‐seven novel 3H‐indolyl and indolinyl carbamates were synthesised as potential insecticides. They were generally found to be good inhibitors of acetylcholinesterase in vitro, but although several compounds were highly insecticidal no correlation was found between their in vitro activity and their in vivo performance. Experimental evidence suggested that the insecticidal activity of the compounds was governed by a combination of their relative rates of penetration into insects and subsequent metabolic breakdown.
The uptake of the molluscicide, 4′‐chloronicotinanilide into Biomphalaria glabrata (Say) in a flowing water system
Authors: Duncan John , Brown Nicolette , Dunlop Robert W.
Published: November 2006

A system is described for the exposure of freshwater snails to pesticides in flowing water. The method allows groups of seven snails to be confined in about 20 ml of water under constant conditions of pesticide concentration, oxygen tension and temperature for up to 5 days. The uptake rate of 4′‐chloronicotinanilide into the planorbid snail, Biomphalaria glabrata (Say), has been measured using this method with liquid scintillation counting techniques. The necessity for an acclimatisation period prior to exposure and the possible influence of activity on uptake is demonstrated. The advantages of the flowing system over exposure in static solutions are discussed and the use of the apparatus in deciding whether relative uptake rates can account for interspecific differences in susceptibility or contribute to the improvement of molluscicide specificity, is indicated.
Persistence of the herbicide AC 92,553, N‐(1‐ethylpropyl)‐2,6‐dinitro‐3,4‐xylidine, in soils
Authors: Walker Allan , Bond William
Published: November 2006

The effects of soil temperature and soil moisture content on the rate of loss of N‐(1‐ethylpropyl)‐2,6‐dinitro‐3,4‐xylidine (I, AC 92,553) were measured under controlled conditions. The time for 50% disappearance in a sandy loam soil at 75% of field capacity was inversely related to temperature (98 days at 30°; 409 days at 10°). At 25°, the half‐life increased with decreasing soil moisture content (122 days at 75% of field capacity; 563 days at 12.5%). In seven soils with different properties there was a trend towards a slower rate of loss as the organic matter content of the soils increased and the half‐life varied from 72 to 172 days, first‐order kinetics being obeyed. The herbicide was lost rapidly from an inert surface and 97% loss was recorded after 28 days at 25°. Losses from soil surfaces occurred more slowly and were greater from wet compared with dry soil. In the field, it was more persistent when incorporated than when applied to the soil surface. More than 60% of I incorporated in April 1975 could be detected the following September, but when applied to the soil surface, only about 20% of the applied dose remained by this time. Residues measured by gasliquid chromatography using a thermionic nitrogen detector closely paralleled those measured by a bioassay based on the root growth of buckwheat.
Models and designs for agricultural vaccine trials
Authors: Ross Gavin J. S.
Published: November 2006

Agricultural vaccine trials are costly, and it is important that they should provide the maximum amount of information. The traditional probit model often fails to provide a reliable estimate of median protective dilution. The complementary loglog transformation is to be preferred because it provides a probabilistic basis for fixing one of the parameters, thereby increasing the precision of estimation.
Meeting the requirements of probit analysis for evaluating chemicals against storage insects
Authors: Howe Robert W. , Prickett Anthony J.
Published: November 2006

When probit methods are used to estimate the toxicity of fumigants or insecticides to a stored product species, it is desirable to use several doses of poison over a similar time range of at least seven periods. Then the validity of the concentration × time (ct) principle can be examined. In each experiment, either the populations must be homogeneous or, if insecticide resistance is suspected, the nature of the heterogeneity should be known. The individuals must be shared between doses in a manner that guarantees randomisation. The experimental results must be examined for evidence of curvature of probit lines, especially if these lines are to be used as a guide to the practical doses required to eradicate a population. In these circumstances, all survivors from the higher doses should be kept and their ability to produce offspring examined, because the adverse influence of poisoning is often revealed in some later stage of the life cycle.
A quantitative study of asulam persistence in soil
Authors: Smith Allan E. , Walker Allan
Published: November 2006

The persistence of the herbicide asulam was studied at different controlled temperature and moisture levels in Regina heavy clay. Degradation was rapid, approximating to first‐order kinetics with a half‐life of about 7 days, at temperatures in the range 20–35° and at moistures of above 50% of field capacity. At lower soil temperature and/or moisture regimes, breakdown was slower. The laboratory data were used in conjunction with the appropriate meteorological records in a computer program to simulate the degradation pattern for asulam in six separate microplot field studies carried out during May to November 1976. In three of the six experiments there was close correspondence between observed and predicted residue levels, but in the other three experiments, the model underestimated rates of loss.
Degradation of S‐2‐di‐isopropylaminoethyl O‐ethyl methylphosphonothioate in soil. Sulphur‐containing products
Authors: Kaaijk Joke , Frijlink Carel
Published: November 2006

The degradation of [35S]‐labelled and [32P]‐labelled S‐2‐di‐isopropylaminoethyl O‐ethyl methylphosphonothioate has been studied in humic sand, humic loam and clayey peat under laboratory conditions. Radioactivity, which proved to be tightly bound to the soil, was extracted by alkaline methanol. N,N'‐Dithiodiethylenebis(di‐isopropylamine) was identified as the only sulphur‐containing product in the extract.
Effect of soil application of chloroxuron, metobromuron and fluometuron on nodulation, growth and nitrogen fixation by Centrosema pubescens and Vigna sinensis
Authors: Amakiri Mildred A. , Odu Clifford T. I.
Published: November 2006

The effect of soil applications of three phenylurea herbicides on the growth, nodulation and nitrogen fixation by Centrosema pubescens and Vigna sinensis under two plantings in pots were investigated under glasshouse conditions. Toxicity increased in the order chloroxuron < metobromuron < fluometuron with both legumes. C. pubescens was more susceptible to the effects of the herbicides than V. sinensis. The effects during cropping of C. pubescens and V. sinensis immediately after herbicide application and 9 months later was observed on nodule formation, plant growth and the proportion and quantity of nitrogen in the soil and in dry matter in the plant roots and tops. The levels at which the applied herbicides controlled weeds without any injurious effects on the legumes were for chloroxuron 0.5–2.0 mg/kg and for metobromuron 0.5–1.0 mg/kg but fluometuron killed weeds and was toxic to the legumes at the lowest concentration used (0.25 mg/kg).
Insecticidal activity of the pyrethrins and related compounds. Part XI. Relative potencies of isomeric cyano‐substituted 3‐phenoxybenzyl esters
Authors: Elliott Michael , Farnham Andrew W. , Janes Norman F. , Soderlund David M.
Published: November 2006

The insecticidal activities to Musca domestica L. and Phaedon cochleariae Fab. of a series of 3‐phenoxybenzyl pyrethroid esters with a cyano substituent at the 2‐, 6‐. (R)‐α‐, or (S)‐α‐position are compared with those of the unsubstituted analogues. Only an (S)‐α‐substituent enhances activity; others diminish or almost eliminate it. (RS)‐α‐mixtures are generally less active than would be predicted from the potencies of their separate constituents.
Residues of carbofuran and 2,3‐dihydro‐3‐hydroxy‐ 2,2‐dimethylbenzofuran‐7‐yl methylcarbamate in the mushroom, agaricus bisporus, cultivated in casing soils treated with the insecticide
Authors: Kalberer Peter , Vogel Elsbeth
Published: November 2006

Residues of carbofuran (1) and 2,3‐dihydro‐3‐hydroxy‐2,2‐dimethylbenzofuran‐7‐yl methylcarbamate (2) in and on mushrooms, cultivated on casing soils containing added carbofuran granular insecticide, were determined. The quantitative estimations in cleaned mushroom extracts were done on thin‐layer plates using a cholinesterase inhibition method. Samples were analysed, which had been harvested at different times from cultures, to which different amounts of carbofuran were added. Residues in washed and unwashed mushroom samples were compared. Residues did not exceed 0.5 mg (carbofuran) kg−1 and 0.25 mg (compound 2) kg−1 for fresh unwashed mushrooms grown on casing soil treated with carbofuran granules 1 g (a.i.) m−2.
Potentiation of malathion by other insecticides against Musca domestica
Authors: Gera Ramesh , Gupta Dalip S.
Published: November 2006

Twenty‐seven insecticides, including organochlorine, organophosphorus compounds and carbamates were tried for potentiation of the toxic effect of malathion. Carbaryl, diazinon, fenthion, gamma‐BHC, parathion and tetrachlorvinphos potentiated the action of malathion. Fourteen insecticides gave additive effects while seven proved antagonistic. Insecticides which showed potentiation, were further tested by mixing with malathion in the ratios of 1:9, 3:7, 5:5, 7:3 and 9:1. All the five combinations in the six mixtures gave potentiating effects. Maximum potentiation of 17.6 times was observed in 1:9 combination of malathion and gamma‐BHC. The proportions in which the insecticides were mixed had a pronounced effect on the toxic effect of malathion.
Decision factors in barley mildew control in South‐East Scotland
Authors: Gilmour James
Published: November 2006

The use of a mildew‐susceptible barley variety, Golden Promise, has drawn attention to the problem of mildew in south‐east Scotland. The increased intensity of disease has also influenced the potential value of the more resistant varieties. Whilst it is not possible to evaluate all the significant factors which result in severe mildew situations, the recommendation that winter barley should not be grown is thought to reduce the overwintering levels of disease. Trials have shown the benefits to be derived from using fungicidal seed treatments on a susceptible variety, although similar effects have also been found with single sprays. In this case, however, problems of timing and damage caused by wheelings have to be considered. In economic terms the many factors associated with barley mildew lead one to the view that blanket recommendations are inappropriate. Risk analyses are being considered as an aid to the decision making.
Uptake and translocation of ethofumesate in sugar‐beet plants
Authors: Eshel Jacob , Zimdahl Robert L. , Schweizer Edward E.
Published: November 2006

The uptake and translocation of 14C‐labelled ethofumesate [(±)‐2‐ethoxy‐2,3‐dihydro‐3,3‐dimethylbenzofuran‐5‐yl methanesulphonate] was studied in sugar‐beet seedlings following soil and foliar applications. After soil applications, the roots absorbed and translocated to the foliage more ethofumesate or its metabolites than did the emerging hypocotyls. Ethofumesate or its metabolites did not accumulate in either roots or hypocotyls after exposure to treated soil. When sugar‐beet leaves were treated with the herbicide at the two‐leaf stage, acropetal translocation was rapid but there was no translocation out of the treated leaves. Furthermore, ethofumesate or its metabolites were not translocated basipetally after either soil or foliar application.
Ultraviolet spectrophotometric determination of the purity of technical pyrazon
Authors: Šustek Ján , Livař Milan
Published: November 2006

A method for the analysis of technical samples of the herbicide pyrazon is described. A double‐beam recording spectrophotometer with digital data recording accessory was used in the analysis of the multicomponent mixtures. The absorbances were measured in the u.v. region between 346 and 282 nm. Two alternative u.v. spectrophotometric methods are presented which allow the determination of all three components in technical products of pyrazon without any preliminary separation.
Practical considerations in the control of bioavailability
Authors: Marrs Gordon J. , Seaman David
Published: November 2006

The nature of the deposits of conventional pesticide formulations affect their bioavailability and loss. Modification of these formulations and special formulations, in particular microencapsulation, are discussed together with examples. The case for testing of controlled release formulations as part of a biological programme is examined.
Metabolism of [3H]triforine in barley grown in the field: The unbound radioactive residue
Authors: Rouchaud Jean , Moons Chantal , Decallonne Jacques R. , Meyer Joseph A.
Published: November 2006

Barley was sown and grown normally in an experimental field. At the growth stage J,

Growth stage J: during the stem extension stage; second node of stem formed and next‐to‐last leaf just visible.

the aerial part of the plants was sprayed with an aqueous emulsion of a mixture of triforine and [3H]triforine (uniformly labelled in the piperazine ring) using the recommended dose rate of about 240g triforine ha−1. The barley was harvested when ripe and the straw and grain were analysed separately. The total radioactivity concentration was 20 times higher in straw than in grain. In straw and grain, 12 and 25% respectively of the total incorporated radioactivity in each of these tissues was methanol soluble. The composition of the methanol‐soluble radioactive residue was investigated and was shown to contain triforine and its metabolites which were free and unbound in barley straw and grain. No radioactive piperazine was observed, in spite of the high detection sensitivity for radioactivity. The concentrations of triforine and its identified metabolites in straw and grain respectively (mg kg−1, relative to the fresh weight of tissue) were: triforine, 0.034 and 0.0018; N‐[(2,2,2‐trichloro‐1‐(piperazin‐1‐yl)ethyl]formamide), 0.009 and 0.0006; iminodiacetic acid, 0.021 and 0.001; glycine, 0.043 and 0.0033. Other radioactive water‐soluble and very polar, unidentified compounds were observed, corresponding to advanced metabolic products of triforine.
Relationships between acidity/alkalinity and pH and their importance to pesticide specifications
Authors: Niessen Heinz J.
Published: November 2006

In current national and international specifications, acidity and alkalinity on the one hand and pH on the other, are being used as quality criteria for pesticides. These two criteria are by no means interchangeable and the choice must be made on a product‐specific basis. The experimental results clearly show that acidity limits are suitable quality criteria for active ingredients that form acidic decomposition products, and for their emulsifiable concentrates. For powder formulations the nature of the fillers used may seriously influence acidity figures, so that their value may be questionable. It is suggested that acidity limits be deleted for neutral active ingredients which do not form acid decomposition products. A suitable quality criterion for aqueous salt solutions of, for example, phenoxyalkanoic acids, is pH but it may also be used where active ingredients are known to decompose in certain pH ranges.
Absorption and metabolism of permethrin and cypermethrin in the cockroach and the cotton‐leafworm larvae
Authors: Holden J. Stuart
Published: November 2006

Permethrin was metabolised by attack at the ester bond, in vivo by adult cockroaches, Periplaneta americana and in vitro by esterase preparations. Metabolites retaining the ester linkage could not be detected. In all cases, the (1RS)‐trans‐isomer (transpermethrin) was more labile than the (1RS)‐cis‐isomer. Cypermethrin was metabolised at one‐fifth the rate for permethrin. In‐vitro and in‐vivo studies with synergists indicated that cleavage of the ester bond in permethrin can be both oxidative for the (1RS)‐cis‐isomer and hydrolytic for the (1RS)‐trans‐isomer. The penetration of permethrin through the cuticle of the cockroach was significantly greater than that of cypermethrin. The penetration and metabolism of permethrin and cypermethrin in sixth‐instar larvae of susceptible and resistant strains of the Egyptian cotton‐leafworm, Spodoptera littoralis, were studied as possible factors in resistance. No significant differences were found. It is suggested that the major resistance factor to permethrin in S. littoralis is probably non‐metabolic.
The development of a screening method to estimate contact toxicity of pyrethroids against wood‐boring marine crustacea, Limnoria spp.
Authors: Rutherford Donald , Reay Richard C. , Ford Martyn G.
Published: November 2006

A bioassay method has been developed for the screening of pyrethroids for contact toxicity against Limnoria species which should prove suitable for insecticides with low water‐solubility. Less than 1% of a topically applied dose of cypermethrin (4.8 ng per isopod) was lost to the sea‐water from the body surface; the pharmacokinetics of cypermethrin in the isopod accounted for the fate of the remainder. LD50 parameter estimates obtained by this method represent measurements of absolute toxicity; NRDC 161b proved the most effective of three pyrethroids tested.
Performance and uptake of some carbendazim‐producing fungicides applied as seed treatments to spring barley, in relation to their physicochemical properties
Authors: Graham‐Bryce Ian J. , Nicholls Peter H. , Williams Ian H.
Published: November 2006

The performance of carbendazim and its chemical precursors benomyl, thiophanatemethyl and methyl 4‐(2‐aminophenyl)‐3‐thioallophanate (I) ( “NF48” ) as systemic fungicidal seed treatments on barley was investigated. In field trials all treatments significantly decreased smut (Ustilago nuda) at 3.2 g kg‐1 of seed; the order of effectiveness was I > benomyl > thiophanate‐methyl > carbendazim. Control of barley mildew (Erysiphe graminis) followed a similar pattern but results were less clear‐cut. Measurements of uptake and translocation from seeds, treated with radiolabelled fungicide and planted in pots of Woburn soil in a controlled environment room, showed that seedlings accumulated much more I than the other compounds over 28 days. This substantial early uptake into leaves could explain why I was particularly effective against smut in the field trials. Comparisons of amounts taken up. with solubility in water, octanol/water partition coefficient, extent of adsorption on soil and pKa values suggested that the effects of these properties on availability in the soil solution may be more important than their influence on penetration into the root in determining relative uptake and disease control in the case of localised applications such as seed treatments.
Structure—activity relationship for some substituted dialkyl vinyl phosphates
Authors: Fulde Stefan , Kroczynaski Józef , Malinowski Henryk
Published: November 2006

The biological activity against the house fly, Musca domestica L., is reported for a series of dialkyl 2‐bromo‐1‐(2,4‐dichlorophenyl)vinyl phosphates. Maximum activity and the lowest degree of synergism with piperonyl butoxide were found with the dimethyl ester. Good activity was also shown by the diethyl ester. Both these compounds, used at the same dose, inhibited fly‐head acetylcholinesterase. Compounds with longer alkyl chains were less effective and did not inhibit acetylcholinesterase.
Chlorpyrifos‐methyl plus bioresmethrin; Methacrifos; Pirimiphos‐methyl plus bioresmethrin; and synergised bioresmethrin as grain protectants for wheat
Authors: Bengston Mervyn , Connell Meville , Davies Richard A. H. , Desmarchelier James M. , Elder W. Brian , Hart Richard J. , Phillips Mervyn P. , Ridley Edward G. , Ripp B. Eric , Snelson John T. , Sticka Rex
Published: November 2006

Field trials with various pesticide combinations were carried out on bulk wheat in commercial silos in Queensland, South Australia and Western Australia. Laboratory bioassays on samples of treated grain at intervals over 8 months using malathion‐susceptible and malathion‐resistant strains established the following orders of efficacy: against Sitophilus oryzae (L.), chlorpyrifos‐methyl 10 mg kg−1 + bioresmethrin 1 mg kg−1 = methacrifos 15 mg kg−1 in aerated storage > pirimiphos‐methyl 4 or 6 mg kg−1 + bioresmethrin 1 mg kg−1 = bioresmethrin 4 mg kg−1 + piperonyl butoxide 16 mg kg−1; against Rhyzopertha dominica (F.), bioresmethrin 4 mg kg−1 + piperonyl butoxide 16 mg kg−1 > methacrifos 15 mg kg−1 > chlorpyrifos‐methyl 10 mg kg−1 + bioresmethrin 1 mg kg−1 = pirimiphos‐methyl 4 or 6 mg kg−1 + bioresmethrin 1 mg kg−1. All treatments completely prevented production of progeny in Sitophilus granarius (L.), Tribolium castaneum (Herbst), T. confusum Jackquelin du Val and Oryzaephilus surinamensis (L.). The biological efficacy of methacrifos was greater and the rate of degradation lower in aerated than in non‐aerated storage. Residue levels of all compounds were determined chemically and were below proposed international residue levels to be considered by the Codex Alimentarius Commission.
Chemistry and biosynthesis of natural pyrethrins
Authors: Crombie Leslie
Published: November 2006

A short account is given of the occurrence, separation, and properties of the insecticidal ester pyrethrins from Chrysanthemum cinerariaefolium. Methods for the synthesis of the two component acids, chrysanthemic and 'chrysanthemumdicarboxylic acid' [3‐(2‐carboxyprop‐1‐enyl)‐2,2‐dimethylcyclopropanecarboxylic acid], and the alcohols (rethrolones) are surveyed, and brief consideration is given to the limited knowledge of the biosynthesis of this group of compounds.
A new synthesis of natural pyrethrins
Authors: Székely Istvan , Lovász‐Gáspár Marianna , Kovács Gábor
Published: November 2006

A synthesis route, based on a by‐product of a prostaglandin synthesis, provides access to rethrolones and rethrins with the same stereochemistry at the ring C‐4 position as the natural compounds. For cinerin I, the overall yield is good and the product is a mixture of side‐chain E and Z isomers. The Z:E ratio varies from 3:1 to 10:1 depending on the conditions employed.
The optical isomers of α‐cyano‐3‐phenoxybenzyl 3‐(1,2‐dibromo‐2,2‐dichloroethyl)‐2,2‐dimethylcyclo‐propanecarboxylate and their insecticidal activities
Authors: Ackermann Peter , Bourgeois François , Drabek Jozef
Published: November 2006

Bromination of the dichlorovinyl group of cypermethrin yielded a new compound which is a highly potent insecticide. This dibromo adduct has four asymmetric centres and therefore can exist as a mixture of 16 stereoisomers. To establish the influence of the absolute configuration at the chiral centres on the biological activities of these isomers, each of the isomers was isolated; their insecticidal activities against larvae of Heliothis virescens, and adult Calliphora erythrocephala and Blattella germanica were then determined and compared with those of (S)‐α‐cyano‐3‐phenoxybenzyl (1R)‐cis‐3‐(2,2‐dibromovinyl)‐2,2‐dimethylcyclopropanecarboxylate (deltamethrin NRDC 161), of fenvalerate, and of the eight stereoisomers of cyper methrin.
The degradation of aldicarb and oxamyl in soil
Authors: Bromilow Richard H. , Baker Robert J. , Freeman Martin A. H. , Görög Katrina
Published: November 2006

The breakdown of oxamyl was studied in three downland chalk soils, a peat loam, a sandy loam, and the same sandy loam modified by adding peat. The kinetics of aldicarb degradation via its sulphoxide and aldoxycarb (aldicarb sulphone) were also studied in these two sandy loam soils. All the reactions followed first‐order kinetics, the reaction being faster in the original than in the modified sandy loam. Rates of reaction were slower at low moisture contents, and decreased markedly when the temperature was reduced from 10 to 5°C though less so than from 15 to 10°C.