bluuebunny/crossref_metadata_2025 huggingface dataset:
The mode of action of chlomethoxyfen
Authors: Hikawa Masanori
Published: November 2006

Chlomethoxyfen [5‐(2, 4‐dichlorophenoxy)‐2‐nitroanisole] has been widely used as a pre‐emergence herbicide in rice in Japan, where it is known as chlomethoxynil. It is effective against many annual weeds and some perennials, including Eleocharis acicularis and Sagittaria pygmaea. The activity of chlomethoxyfen is only slightly affected by water movement because of its low water‐solubility. It is more toxic to shoots than roots and is rapidly absorbed by roots, with limited translocation to upper parts of the plants. The demethylated derivative, which was presumed to be conjugated with plant materials, was identified as the major metabolite in plants. Several other metabolites were also detected in soils and animals. Chlomethoxyfen increases phenylalanine ammonia‐lyase activity in plants under light conditions, resulting in the accumulation of the biphenyl‐2‐ol content. The biochemical basis of the light requirement of diphenyl ether herbicides is also discussed.
Dibromo addition products of (1R)‐cis‐permethrin and deltamethrin; evidence that debromination is an obligatory requirement for biological activity
Authors: Gammon Derek W. , Ruzo Luis O.
Published: November 2006

3‐Phenoxybenzyl (1R‐)‐cis‐3‐(1,2‐dibromo‐2, 2‐dichloroethyl)‐2, 2‐dimethylcyclopropanecarboxylate [dibromo‐(1R)‐cis‐permethrin] was >100 times less active than (1R)‐cis‐permethrin in causing repetitive firing in a cockroach cereal sensory nerve in vitro, although its toxicity, symptomology and nerve effects in vivo were comparable to the parent compound. Treatment of the in‐vitro preparation with glutathione significantly increased the effectiveness of dibromo‐(1R)‐cis‐permethrin in a concentration‐dependent manner, while having no effect on the action of (1R)‐cis‐permethrin. Topical treatment of the cockroach with dibromo‐(1R)‐cispermethrin gave a similar time of onset of symptoms to that caused by (1R)‐cis‐permethrin (∼2 min). Pretreatment of the cockroach with N‐ethylmaleimide (NEM) significantly (P<0.05) increased dose‐dependently the latency of signs of poisoning caused by dibromo‐(1R)‐cis‐permethrin, but had no significant effect on the latency following (1R)‐cis‐permethrin treatment. Deltamethrin and tralomethrin, applied to the cockroach at LD95 doses of 0.03 and 0.07 m̈g g−1 respectively, also had similar latencies for the development of symptoms. Moreover, pretreatment with NEM delayed the time of onset of symptoms for tralomethrin (P<0.02) but not for deltamethrin. The results strongly suggest that debromination is an obligatory requirement for the biological activity of dibromo‐(1R)‐cis‐permethrin and tralomethrin.
Influence of nitrogen fertilisers on the persistence of carbaryl and carbofuran in flooded soils
Authors: Rajagopal B. S. , Sethunathan N.
Published: November 2006

Ammonium sulphate and urea, but not potassium sulphate, increased the persistence of carbaryl in a flooded laterite soil with a low native nitrogen content (0.04%), but not in an alluvial soil with a higher nitrogen content (0.11%). Thus, NH4+ but not SO42‐, contributed to the increased persistence of carbaryl. Likewise, ammonium sulphate increased the persistence of carbofuran in the laterite soil, but not in the alluvial soil. Significant accumulations of 1‐naphthol and 2,3‐dihydro‐2, 2‐dimethylbenzofuran‐7‐ol (‘carbofuran phenol’), in soils treated with carbaryl or carbofuran, suggested hydrolysis as the major pathway of degradation. Treatment of the two soils with ammonium sulphate, urea or potassium sulphate led to a decrease in soil‐bound residues and an increase in the respective hydrolysis products, compared with untreated soils. Sorption studies indicated that NH4+ and SO42‐ compete with carbaryl, 1‐naphthol and carbofuran for sorption and exchange sites in the complex soil system. Evolution of [14C]carbon dioxide from ring‐14C in carbaryl and carbofuran was negligible. Consequently, after 40 days, more than 50% of the 14C in [14C]carbaryl and [14C]carbofuran remained in the soils as hydrolysis products (1‐naphthol or 2,3‐dihydro‐2,2‐dimethylbenzofuran‐7‐ol) plus soil‐bound residues.
Correlations between three methods for determining the toxicity of chemicals to earthworms
Authors: Heimbach Fred
Published: November 2006

Three different laboratory methods for determining the toxicity of chemicals to earthworms were tested with a variety of pesticides and other chemicals. These methods, proposed by the EEC (Determination of Ecotoxicity of Chemicals), were: the Contact Filter Paper Test, in which the skin contact toxicity is tested by placing the organisms on treated filter paper; the Artificial Soil Test, in which the toxicity by skin and gut uptake is determined by adding the earthworms to an artificial soil made of sand, clay mineral and peat; and the Artisol Test, in which the toxicity by skin and gut uptake is determined by placing the worms in an artificial substrate consisting of silica, water and glass balls. (In the Artisol Test, the earthworms ingest the silica paste as they do soil.) With several chemicals, the Artificial Soil Test was conducted as described in an early guideline of the BBA. This test is similar to that proposed by the EEC. Results from the Contact Filter Paper Test were poorly correlated to those obtained by the other two methods (correlation to the Artificial Soil Test, r=0.55; correlation to the Artisol Test, r=0.48). In contrast, there was a high correlation between the Artificial Soil Test and the Artisol Test (r=0.91). This indicated that the mode of uptake of the chemicals (skin uptake and/or gut uptake) may be the same. As the Artisol Test seems to be readily handled and standardised, it could be useful for obtaining reproducible data on the ecotoxicity of chemicals to earthworms.
Studies on the sorption of organochlorine insecticides by flour stored on or near treated laminated timber or plywood as used in freight containers
Authors: Paton Robert , Luke Barry G. , Roberts Graham
Published: November 2006

Wood preservatives containing a number of organochlorine insecticides, including aldrin, dieldrin, chlordane and lindane, have been approved in Australia for treating timber used as structural components in cargo containers. Studies on the migration of these insecticides from treated laminated timber and plywood, using commercial containers and in the laboratory, are reported here. The highest insecticide residue levels were found in flour samples stored on newly treated laminated sawn timber. Physical pick‐up of insecticide from the surface of the floor was considered to be the major source of contamination. Sorption of insecticides from the atmosphere of the container was the most likely source of contamination in samples stored on or near treated plywood.
Synergistic antifungal interactions of zinc or copper with anilazine
Authors: Goss Veronica , Marshall William D.
Published: November 2006

Two isolates of Botrytis cinerea and one of Colletotrichum coccodes were used to test for synergistic or antagonistic interactions (a) between pairs of 11 common fungicides and (b) between mixtures of individual fungicides with components of foliar fertilisers. Two screening assays monitored the effects with time of inhibitor combinations on spore germination and subsequent mycelial growth. The combinations that gave positive results for interaction in the screening assays were further investigated by a third quantitative assay, which compared the observed inhibition of mycelial growth with the net inhibition predicted by a non‐interaction model. This model assumed that the components of a combination of substances each inhibited the test fungus independently of one another. Only mixtures of anilazine with zinc or copper resulted in appreciable deviation from the predicted behaviour based on a non‐interaction model. The inhibition of mycelial growth by combinations of anilazine with Zn2+ (inorganic salt or formulated with urea) was consistently greater than predicted for each of three fungi on either of the two test media. Similar effects were observed with Cu2+, although the synergism was less marked.
Phosphonic analogues of morphactins. Part III: Peptides containing p‐terminal 9‐aminofluoren‐9‐ylphosphonic acid
Authors: Lejczak Barbara , Kafarski Pawel , Gancarz Roman , Jaskulska Elzbieta , Mastalerz Przemyslaw , Wieczorek Jan Sylwester , Król Marta
Published: November 2006

Peptides of 9‐aminofluoren‐9‐ylphosphonic or 1‐aminocyclohexylphosphonic acids were synthesised and found to have typical morphactin activity when tested on Lepidium sativum and Triticum vulgare. The observed effects included root elongation with simultaneous stem shortening. The results obtained indicate that these phosphonic acid derivatives of cyclohexylamine and fluoren‐9‐ylamine may have a similar mechanism of action.
Bioassays using detached tobacco leaves to determine the sensitivity of Peronospora tabacina to fungicides
Authors: Reuveni Moshe , Siegel Malcolm R. , Nesmith William C.
Published: November 2006

Two bioassay methods are described which use detached tobacco leaves to measure the sensitivity of Peronospora tabacina to systemic fungicides. Tobacco leaves (13–15 cm2), treated with fungicides before or after detachment from the plant, were inoculated with sporangia in water drops and, after incubation in beakers and Petri plates, the disease severity and/or production of sporangia was determined 4–7 days after treatment with the fungicides. Of 15 systemic fungicides applied to detached leaves, eight N‐phenylamides at 0.066−1.0 μg ml−1 controlled blue mould; metalaxyl was the most effective fungicide. Isolates of P. tabacina, collected in the field from tobacco plants grown in soil treated with metalaxyl, were not resistant to the fungicide applied to detached leaves prior to inoculation. The fungicide, applied to leaves before detachment, was used to measure the efficacy of five systemic N‐phenylamide fungicides sprayed on the basal and unsprayed distal portions of the leaves. Blue mould was controlled on the basal portion of the leaf by all the fungicides at 0.66−1.0 μg ml−1, but it required the application of 3–30 times more chemical on the basal portion to achieve comparable blue mould control on the distal part of the leaf.
Uptake and distribution of [14C]metalaxyl by detached tobacco leaves
Authors: Reuveni Moshe , Siegel Malcolm R. , Nesmith William C.
Published: November 2006

When the petioles of detached tobacco leaves (10–17 cm2) were incubated in aqueous solutions containing [14C]metalaxyl, uptake of the fungicide was dependent on the temperature and photoperiod. Detached leaves took up 78% more [14C]metalaxyl at 26°C than at 16°C. The rate of uptake in the light at 21°C was linear, but after an additional 20h in the dark, there was only twice as much fungicide in the leaves. Different sized leaves contained the same amount of fungicide per cm2 area. Uptake by detached leaves of the 14C‐labelled anilide lactones ofurace and RE‐26940 [2‐methoxy‐N‐(tetrahydro‐2‐oxo‐3‐thienyl)acet‐2′,6′‐xylidide] was similar to that of metalaxyl. At the concentration of metalaxyl (66 ng ml−1) that controlled blue mould (Peronospora tabacina) on detached tobacco leaves, the amount of fungicide in the leaves was found to be 7.25 ng. Autoradiography showed that the distribution of [14C]metalaxyl in detached leaves after incubation for 23h was uniform, although higher concentrations of the label were present in the smaller veins of the leaves.
Detection of halogenated biphenyls from sunlight photolysis of chlorinated herbicides in aqueous solution
Authors: Tanaka Fred S. , Hoffer Barry L. , Wien Ronald G.
Published: November 2006

A survey study was conducted to determine the generality of chlorinated biphenyl formation from the photolysis of chlorine‐containing herbicides in aqueous solution. Seven herbicides from the phenylurea, anilide and carbamate classes were examined. In this study, the photoreaction under investigation proceeded via the coupling of two herbicide molecules to yield a chlorinated biphenyl with concomitant loss of hydrogen chloride. In preliminary studies using ultraviolet lamps, 4‐chlorophenyl methylcarbamate (PPG‐124) gave a chlorinated biphenyl with only one carbamate side chain, and chlorpropham gave no chlorinated biphenyl, but rather a hydroxylated biphenyl. Employing ultraviolet lamps or natural sunlight, photolyses of monuron, diuron, linuron, metobromuron and propanil produced halogenated biphenyls according to the photocoupling reaction under investigation. All yields of chlorinated biphenyls from sunlight photolysis were approximately 1% or lower.
Recent progress in the field of N‐acylalanines as systemic fungicides
Authors: Gozzo Franco , Garlaschelli Luigi , Boschi Pier M. , Zagni Angela , Overeem Jean C. , de Vries Lambertus
Published: November 2006

The influence of structural variations in compounds of the N‐acylalanine type, on their fungicidal activity towards Peronosporales, was examined. Within a series of methyl N‐(acyl)‐N‐(2,6‐xylyl)alaninates (I), a quantitative structure‐activity relationship was given for the curative action against Plasmopara viticola, through a Hansch‐type equation. A deviation from this equation is discussed with reference to benalaxyl (I; acyl=phenylacetyl). Syntheses and qualitative indications of activity are reported for structural changes in the xylyl and in the alanine moieties. Progress in the latter approach is briefly outlined.
Excretion and residues of the pyrethroid insecticide cypermethrin in lactating cows
Authors: Croucher Andrew , Hutson David H. , Stoydin George
Published: November 2006

Two radiolabelled forms of racemic [14C]cypermethrin (14C at the benzylic carbon or at C‐1 of the cyclopropane ring) were separately administered twice daily to lactating cows in portions of the feed. The amounts dosed were equivalent to 0.2, 5 and 10 μg of cypermethrin per g of feed. The radioactivity eliminated in the milk indicated that the ingestion and elimination of radioactivity were in balance at about day 4 after the start of dosing. Urine and faeces were equally the major routes of elimination, and only a fraction of a percent of the dose appeared in the milk. The residue in the milk was unchanged cypermethrin and was found at a concentration that was proportional to the dose. At the high cypermethrin intake of 10 μg g−1 of diet, the residue in the milk was 0.03 μg g−1. Concentrations of residues in the tissues, measured after 7, 20 or 21 days of treatment, were low and in the order: liver>kidney>renal fat>subcutaneous fat>blood>muscle>brain. The major residue in the liver and kidney of a cow that received 10 μg of cypermethrin per g of diet was N‐(3‐phenoxybenzoyl)glutamic acid. Other conjugates of 3‐phenoxybenzoic acid and of 3‐(4‐hydroxyphenoxy)benzoic acid (unidentified, with the exception of the glycine conjugate) were also present. The residue in fat (about 0.1 μg g−1 from an intake of 10 μg g−1 of feed) consisted mainly of cypermethrin.
The toxicity of two pyrethroids to Encarsia formosa and its host Trialeurodes vaporariorum; Prospecting for a resistant strain of the parasite
Authors: Delorme Robert , Berthier Andrée , Augé Danielle
Published: November 2006

The toxicity of bioresmethrin and deltamethrin has been studied on the host‐parasite couple Trialeurodes vaporariorum‐Encarsia formosa. Long term trials were used under laboratory conditions. The insecticides were applied to the plant at all stages of host and parasite development. The two products studied showed some toxicity to E. formosa. Bioresmethrin, a poorly persistent insecticide, could be used with care in integrated control; deltamethrin, a highly persistent product, must be excluded. Attempts to obtain strains of E. formosa resistant to deltamethrin were made. The selection pressure applied during 21 successive generations failed to produce a significant and stable resistance level.
Inactivation of seed‐treatment fungicides by Rhizobium
Authors: Kataria Hans R. , Yadav Jaipal S. , Garg Faquir C. , Grover Rajendra K.
Published: November 2006

2‐Methoxyethylmercury chloride (MEMC) applied to cowpea seeds with Rhizobium provided little or no control of seedling rot caused by Rhizoctonia solani; similar treatment, but without Rhizobium, gave >40% control of disease. Treating seeds with quintozene and then with Rhizobium rendered the fungicide completely ineffective against R. solani infections; disease control was >70% when seeds were treated with quintozene only, and >60% when seeds were coated first with Rhizobium and then with quintozene; treatment with quintozene+Rhizobium gave about 25% control. Simultaneous treatment with Rhizobium considerably reduced the efficacy of captafol, chloroneb, carbendazim and thiophanate‐methyl. Disease control by carboxin, benomyl and thiabendazole remained unaltered in the presence of Rhizobium, but only thiabendazole gave good control. Seeds treated with MEMC and Rhizobium produced seedlings without root nodules; nodulation was also decreased by captafol and by carboxin but six other fungicides had no effect. The implications of Rhizobium‐fungicides interactions are discussed in the context of fungicidal control of root diseases.
The effect of the annual use of pesticides on soil microorganisms, pesticide residues in the soil and barley yields
Authors: Heinonen‐Tanski Helvi , Rosenberg Christina , Siltanen Hilkka , Kilpi Sisko , Simojoki Paavo
Published: November 2006

A study has been made of the influence of pesticides used annually on soil microorganisms and crop yields. The persistence of these pesticides in the soil was also investigated. The herbicides MCPA, glyphosate, maleic hydrazide and tri‐allate, and the insecticide parathion, were applied on experimental plots on which barley was grown during the years 1973‐1981. The fungicide 2‐methoxyethylmercury chloride was used every year for dressing the seeds grown in pesticide‐treated plots. The pesticide treatments did not affect significantly the numbers of several groups of soil microorganisms. A slight increase was, however, observed in the nitrification activity in the soil. The barley yields were on average higher on pesticide‐treated plots than on controls because of successful weed control. Pesticide residues in the soil were generally very low; for example, for parathion they were below 0.02 mg kg−1 within 11 days, and for MCPA 0.06 mg kg−1 within 7 days. However, the glyphosate residue was 1.6 mg kg−1 in the autumn 2 days after the treatment, and the residue settled to a level of 0.2 mg kg−1 during the following summer. No clear dependence was observed between the residue level and the time between treatment and sampling.
Surfaces and other factors modifying the effectiveness of pyrethroids against insects in public health
Authors: Chadwick Peter R.
Published: November 2006

Features of the evolution of synthetic pyrethroid insecticides are reviewed and related to the target function in control. The factors affecting residual activity are discussed and related to the surfaces to which different formulations are applied. Many insecticide/formulation/surface combinations lose effectiveness rapidly. The consequence of this in relation to the recovery of cockroach populations are discussed using mathematical models and field observations.
Gamma‐HCH in rape seedlings grown from treated seeds
Authors: Westcott Neil D.
Published: November 2006

Rape seedlings grown from seeds treated with a gamma‐HCH seed dressing at a dose rate of 15.7 g kg−1 had a maximum gamma‐HCH concentration of 380 mg kg−1 in seedlings collected 1 day after emergence. The mean gamma‐HCH concentration in the seedlings decreased to 2.6 and to 0.9 mg kg−1 by 7 and 15 days after emergence, respectively. Gamma‐HCH was chemically detected in true leaves, at concentrations up to 1.9 mg kg−1, indicating translocation of gamma‐HCH in young plants.
A rapid bioassay for the detection of photosynthesis inhibitors in water
Authors: Saltzman Sarina , Heuer Bruria
Published: November 2006

A modified leaf disc buoyancy procedure for the detection of photosynthesis‐inhibiting residues in water is described. The modifications proposed, mainly the presence of sodium hydrogen carbonate in the infiltration solution, increased the sensitivity of the method and reduced the time required. The substituted urea and 1,3,5‐triazine herbicides diuron, linuron, monuron, atrazine, ametryn and atraton were detected below 0.7 mg litre−1 using cucumber (Cucumis sativus L., cv. ‘Dalia’) leaf discs. A concentration as low as 0.09 mg diuron litre−1 could be detected. Although bean (Phaseolus vulgaris L., cv. ‘Bulgarian’) leaf tissue was less sensitive in this bioassay than cucumber, 0.3 mg diuron litre−1 could still be detected. The test, being very rapid (less than 30 min per determination) and relatively sensitive, could be used for the detection of photosynthesis inhibitors in recycled water used for irrigation.
Effects of the pyrethroids bioallethrin, deltamethrin and RU‐15525 on the electrical activity of a cuticular mechanoreceptor of the cockroach Periplaneta americana
Authors: Roche Michel , Guillet Jean C.
Published: November 2006

A study has been made of the effects of bioallethrin, RU‐15525 [5‐benzyl‐3‐furylmethyl (1R)‐cis‐2,2‐dimethyl‐3‐(tetrahydro‐2‐oxo‐3‐thienylidenemethyl)‐cyclopropanecarboxylate, ‘Kadethrin’], and deltamethrin on the electrical activity, measured in vivo, of a cuticular mechanoreceptor of Periplaneta americana. The modifications induced by these pyrethroids on the membrane excitability can be classified into two groups: Type I effects (bioallethrin) are characterised by a substantial increase in the number of action potentials triggered at the initiation site by a given mechanical stimulation, by an electrical activity persisting after mechanical stimulus has been stopped (repetitive activity), and possibly, by an inhibition of excitability of the cell membrane. Type II effects (RU‐15525 and deltamethrin), are characterised by an inhibition of the excitability of the initiation site. In the case of RU‐15525, there was a transient spontaneous electrical activity. Both types of effects have been linked to an action on the sodium channel, particularly at the initiation site. The preparation studied, which possessed no synapses, was shown to be more sensitive to deltamethrin (which is also the most insecticidal of the three pyrethroids) than to either allethrin or RU‐15525. These results suggest that it is unnecessary to envisage a main target (sodium channel) that is different for the two types of pyrethroid.
Multifactorial resistance to transpermethrin in field‐collected strains of the tobacco budworm Heliothis virescens F.
Authors: Nicholson Russell A. , Miller Thomas A.
Published: November 2006

The penetration, degradation and excretion of [3H]transpermethrin were examined in susceptible and field‐collected pyrethroid‐resistant strains of the tobacco budworm Heliothis virescens. No consistent differences in labelled materials excreted or recovered in cuticle rinses were found between the resistant (R) and susceptible (S) larvae. Considerably lower levels of the parent compound were present internally in R compared with S larvae after 24h (P <0.01), clearly identifying a metabolic resistance mechanism in Meloland and Westmorland larvae. Moderate levels of absorbed permethrin accompanied by an absence of poisoning symptoms were observed in certain individuals of both R strains, suggesting a second resistance mechanism. Neurobioassays of R larvae showed a consistently lower sensitivity of the neuromuscular system to pyrethroids when compared with the S larvae, thus confirming the indication from metabolic studies of the additional (site‐insensitive) mechanism. Toxicity values suggest a cross‐resistance to other pyrethroids.
Actions of pyrethroid insecticides on insect axonal sodium channels
Authors: Laufer Jerome , Pelhate Marcel , Sattelle David B.
Published: November 2006

The actions of pyrethroid insecticides were tested on isolated giant axons of the cockroach Periplaneta americana, using oil‐gap, single‐fibre recording techniques. Current‐clamp and voltage‐clamp experiments were used to determine the actions of pyrethroids on axonal membrane potentials and ionic currents. Treatment with deltamethrin at micromolar concentrations caused gradual depolarisation of the axon accompanied by a reduction in amplitude of the action potential. This depolarisation was enhanced by an increase in stimulation frequency. Other synthetic pyrethroids: 3,4,5,6‐tetrahydrophthalimidomethyl (1RS)‐cis‐3‐[(RS)‐2,2‐dimethylcyclopropyl]‐2,2‐dimethylcyclopropanecarboxylate, biopermethrin and its (1S)‐enantiomer, (1R)‐tetramethrin, S‐bioallethrin, bioresmethrin and its (1S)‐enantiomer, cismethrin, and 5‐benzyl‐3‐furylmethyl (E)‐(1R)‐cis‐2,2‐dimethyl‐3‐(2‐oxothiolan‐3‐ylidenemethyl)cyclopropanecarboxylate (RU‐15525, ‘Kadethrin’) were investigated. The (1S)‐enantiomers were inactive, but all the other pyrethroids tested, apart from deltamethrin, induced prolonged negative (depolarising) after‐potentials.

All the treatments with the active pyrethroids resulted in the appearance of a voltage and time‐dependent ‘maintained’ sodium conductance. The duration of this ‘slow’ conductance varied considerably depending on the pyrethroid under test. Clearly, the effectiveness of pyrethroids on whole insects is not determined only by the degree to which they directly modify the properties of sodium channels. Nevertheless, voltage‐clamp experiments on isolated axons readily permit direct comparison of the actions of different pyrethroids on the sodium channels of insect neurones.
Molecular modifications of benzylphenol and benzyl‐1,3‐benzodioxole types of insect chemosterilants
Authors: Matolcsy György , Feyereisen René , Van Mellaert Herman , Pál Ágnes , Varjas László , Bélai Iván , Kulcsár Péter
Published: November 2006

Rationally planned structural modifications were carried out on benzylphenols and benzyl‐1,3‐benzodioxoles described as fly chemosterilants and as anti‐juvenile hormones. The introduction of a prop‐2‐ynyloxy group at various sites of the molecule resulted in compounds with a moderate inhibitory action on cytochrome P‐450 mono‐oxygenases, as measured by aldrin epoxidation. One compound, 5‐(4‐methoxybenzyl)‐6‐prop‐2‐ynyloxy‐1,3‐benzodioxole, revealed chemosterilant activity on Phormia regina, but its activity was less than that of the parent compounds. 2,4‐Di‐tert‐butyl‐6‐[4‐(3‐methoxy‐3‐methylbutoxy)benzyl]phenol, which possessed a juvenoid structure, revealed no juvenile hormone (JH) activity but showed a high sterilant effect against Dysdercus cingulatus. In contrast to the parent substances, none of the tested compounds showed a detectable anti‐JH effect in the Galleria assay. 8‐Methoxy‐2,3‐methylenedioxydibenz[b,e]oxepine, a hitherto undescribed fused heterocyclic ring system, was devoid of activity, indicating the importance of free rotation and/or molecular flexibility. In spite of the moderate activities of these compounds, the manifold biological potential of the quinone‐methide mechanism justifies further research on these lines.
Relationships between chemical structure and phloem mobility in Ricinus communis var. Gibsonii with reference to a series of ω‐(1‐naphthoxy)alkanoic acids
Authors: Chamberlain Keith , Butcher Dennis N. , White Jean C.
Published: November 2006

The phloem translocation of an homologous series of ω‐(1‐[1‐4C]naphthoxy)alkanoic acids relative to that of applied [6,6′‐3H] sucrose was measured in Ricinus communis var. Gibsonii. Relative phloem mobility decreased with increase in octan‐l‐ol/water partition coefficients. However, non‐ionisable compounds with partition coefficients similar to the readily translocated acids were not phloem mobile. These results are explained in terms of an ion‐trap mechanism subject to limitations on the partition coefficients of the acids and possibly their anions.
The foliar uptake of isoproturon by wheat and Alopecurus myosuroides huds
Authors: Achhireddy Nagi R. , Kirkwood Ralph C.
Published: November 2006

The uptake and translocation of 14C‐isoproturon (3‐p‐cumenyl‐1‐1,‐dimethylurea) in wheat (tolerant) and backgrass (sensitive) following foliar treatment under controlled environmental conditions were examined. The amount of 14C‐isoproturon translocated through the xylem was about 10 times that translocated through the phloem in both wheat and blackgrass. However, 25.5% of the applied 14C‐isoproturon was translocated in the xylem in blackgrass, compared with 8.9% in wheat. 14C‐isoproturon did not respond significantly to induced sink‐demand in either species. Leaf‐disc autoradiograms revealed the absorption of 14C‐isoproturon by the minor veins and translocation into the cut vein endings. No significant differences were found in between wheat and blackgrass in this respect.
Further studies of the deposition and persistence of binapacryl, bupirimate and diflubenzuron on apple foliage and fruit
Authors: Austin Douglas J. , Carter Kathleen J.
Published: November 2006

In an extension of previous work, deposits and residues of binapacryl, bupirimate and diflubenzuron on mature foliage and the peel of developing fruit of Worcester and Cox apple trees were monitored throughout the 1980 season following applications by mistblower sprayer. The three compounds were applied as commercial formulations in trials to compare integrated pest management with routine farm spray programmes. In contrast to previous results, all three compounds persisted on foliage until leaf‐fall and were detected on the peel of harvested fruit. The mean residue of diflubenzuron on harvested Worcester fruit was 0.05 mg kg−1 fresh weight and on harvested Cox fruit was 0.02 mg kg−1 fresh weight. Binapacryl and bupirimate were present on harvested fruit of both cultivars. The unexpectedly long persistence of these chemicals in 1980 remains unexplained, but may be due to climatic factors.
Glyphosate–sediment interactions and phytotoxicity in turbid water
Authors: Bowmer Kathleen H. , Michael P. , Boulton D. , Short David L. , Higgins M. Leith
Published: November 2006

In aquatic situations it was expected that adsorption by sediments and suspended solids would influence the movement of glyphosate away from the application zone and attenuate its phytotoxicity. However, the results of two experiments showed that only a minor proportion of glyphosate was adsorbed onto suspended solids, even in turbid irrigation water. Phytotoxicity, as measured by the effect on the root growth of safflower (Carthamus tinctorius L.), was not significantly reduced. Where glyphosate was intentionally injected into flowing water of contrasting quality to simulate incidental contamination of water during foliage treatment, adsorption by benthic sediments attenuated loads of glyphosate only slowly. The attenuation was 13–27% for each kilometre of travel downstream, as compared to 31% observed previously. However, when glyphosate was sprayed onto the sediment exposed after channel draining, less than 7% of the glyphosate applied was subsequently eluted. Consequently, draining before treatment should be an effective strategy for minimising the contamination of irrigation water.
Degradation of dicarboximidic fungicides in wine. Part II: Isolation and identification of the major breakdown products of chlozolinate, vinclozolin and procymidone
Authors: Pirisi Filippo M. , Meloni Marco , Cabras Paolo , Bionducci Maria R. , Serra Adriana
Published: November 2006

The main degradation products formed from the dicarboximidic fungicides chlozolinate, vinclozolin and procymidone in wine have been isolated and identified using spectroscopic and chromatographic methods. The fungicides were added to wine after fermentation. Chlozolinate underwent a rapid hydrolytic loss of the ethoxy‐carbonyl substituent, to give an oxazolidine that underwent hydrolytic cleavage to give 3′,5′‐dichloro‐2‐hydroxypropanilide. The oxazolidine ring of vinclozolin underwent a similar hydrolysis to give the corresponding anilide 3′,5′‐dichloro‐2‐hydroxy‐2‐methylbut‐3‐enanilide. Both these anilides were stable in wine for 150 days. A different degradation behaviour was observed with procymidone and led to the formation of 3,5‐dichloroaniline (3,5‐DCA), which, in turn, broke down but the derivatives could not be isolated. After consideration of the different behaviours of the fungicides on degradation in wine and in aqueous ethanol at pH4, together with their kinetic data, breakdown pathways are proposed.
Behavioural and electrophysiological investigation of 1‐(7‐ethoxygeranyl)‐2‐methylbenzimidazole on the house fly Musca domestica
Authors: Bradfisch Gregory A. , Miller Thomas A.
Published: November 2006

The insecticidal properties of 1‐(7‐ethoxygeranyl)‐2‐methylbenzimidazole (EGMB) were investigated on larval and adult house flies. Unsynergised EGMB gave topical LD50 values of 0.53 μg per female fly on NAIDM strain house flies. When flies were pretreated with 5.2 μg piperonyl butoxide, susceptibility was increased (LD50 0.12 μg per female fly). House fly larvae were less susceptible to EGMB (LD50 2.2 μg). Poisoning with EGMB resulted in a rapid reduction in locomotor activity of both larval and adult house flies. This reduction in locomotion was progressive and led to complete paralysis. Various parameters of larval nervous system function were investigated in larvae during these early phases of poisoning. As early as 15 min after dosing larvae with LD95 doses of EGMB, sensory nerves were less responsive. Over a somewhat longer time (2–4 h), neurally evoked contractures were adversely affected by EGMB. In some cases, this effect appeared to be due to reduced postsynaptic potential amplitude; in other instances, it appeared to be due to an effect independent of neuromuscular transmission. The close temporal correlation between behavioural and electrophysiological observations suggests that the nervous and muscular systems are important sites of action of EGMB.
Antagonism of iprodione toxicity to Botrytis cinerea by mixed function oxidase inhibitors
Authors: Gullino M. Lodovica , Sisler Hugh D.
Published: November 2006

The fungitoxicity of iprodione to a sensitive strain of Botrytis cinerea was antagonised by a variety of cytochrome P‐450 mixed function oxidase inhibitors. Piperonyl butoxide, metyrapone and N‐(2‐ethylhexyl)‐8,9,10‐trinorborn‐5‐ene‐2,3‐dicarboximide (MGK‐264) at non‐fungitoxic concentrations were strongly antagonistic, whereas sesamex, nuarimol, fenarimol, etaconazole and 6‐nitro or 6‐methoxy 1,2,3‐benzothiadiazole were moderately antagonistic. Phenobarbital and 2‐diethylaminoethyl 2,2‐diphenylvalerate (SKF 525‐A) were slightly antagonistic. The results suggest that fungitoxicity of iprodione may be dependent on an activation catalysed by a cytochrome P‐450 mixed function oxidase.
Residues of synthetic pyrethroid insecticides on horticultural crops
Authors: McEwen Freeman L. , Braun Heinz E. , Ritcey Gwen M. , Frank Richard
Published: November 2006

Foliar applications of synthetic pyrethroids were made to several crops to determine residue levels at various intervals after application. On onions, residues of cypermethrin, permethrin and fenvalerate were negligible > 0.1 mg kg−1, 7 days after application. On lettuce, residues of fenvalerate and permethrin were 0.8 mg kg−1. On celery, residues of fenvalerate did not decline and ranged from 0.12 to 0.25 mg kg−1 during the 14‐day period. On green bush‐beans, residues of permethrin and cypermethrin did not decline during the 14‐day period and ranged from 0.1 to 0.6 mg kg−1. By day 7, residues of cyfluthrin, cypermethrin, deltamethrin, fenvalerate and permethrin on strawberries were less than the acceptable maximum tolerance of 0.1 mg kg−1 with the exception of cypermethrin, applied at the rate of 0.14 kg a.i. ha−1 which gave a residue of 0.14 mg kg−1.
Properties and inhibition of Sclerotium rolfsii chitin synthetase
Authors: Cohen Ephraim , Elster Iris , Chet Ilan
Published: November 2006

A chitin synthetase (CS) preparation was obtained from mycelium of the plant pathogen Sclerotium rolfsii and partially characterised. The CS activity was stimulated by N‐acetyl‐D‐glucosamine and magnesium cations with an optimum temperature of 30°C and an optimum pH of 6.4. The enzyme required proteolytic activation and so apparently existed in a zymogenic form. The fungal CS was strongly inhibited by the nucleoside‐peptide antibiotics polyoxin‐D and nikkomycin, and weakly inhibited by the terpenoyl benzimidazole, 1‐geranyl‐2‐methylbenzimidazole. It was insensitive to captan and to insecticidal benzoylphenyl ureas. Disrupted chitin formation caused by polyoxin‐D showed as swollen hyphae containing numerous depressions. The antibiotic also reduced formation of sclerotia and the few that did form were large, irregular in shape and light coloured.
The properties of RH 3866, a new triazole fungicide
Authors: Quinn James A. , Fujimoto Ted T. , Egan Anne R. , Shaber Steven H.
Published: November 2006

2‐Butyl‐2‐(4 chlorophenyl)‐3‐(1H‐1,2,4‐triazol‐1‐yl)propanenitrile, RH 3866, a new broad‐spectrum fungicide was particularly effective against fungi in the subclass loculoascomycetidae and against powdery mildews and rusts. Some activity against fungi in the genera Fusarium, Monilinia and Rhizoctonia was also observed. The compound was translocated upwards when applied as a soil drench to control wheat‐leaf rust caused by Puccinia recondita f.sp. tritici. Fenarimol‐resistant Aspergillus nidulans was cross‐resistant to RH 3866. Using a cell‐free yeast enzyme extract RH 3866 strongly inhibited desmethyl sterol production.
Determination of phosphine residues in fumigated cereals and other foodstuffs
Authors: Scudamore Keith A. , Goodship Gwen
Published: November 2006

An improved method for the determination of phosphine residues in a range of stored foodstuffs with a limit of detection better than 0.1, μg kg−1 is described. The method has been used to obtain data on the amount of phosphine which remains in these commodities after treatment at typical dosage levels and on its persistence during storage. Results show that in cereal grains and nuts residues fall quickly to below internationally recommended levels although trace amounts of phosphine could be detected several months after treatment in all commodities examined.
Fluorinated sterols, hormones and pheromones: Enzyme‐targeted disruptants in insects
Authors: Prestwich Glenn D.
Published: November 2006

Substitution of fluorine for hydrogen in essential sterols, juvenile hormones, and pheromones can lead to materials that interfere with insect growth, development, or communication, in novel and potentially useful ways. Examples have been drawn from work in these areas to illustrate (a) fluorocitrate generation via dealkylation of 29‐fluorophytosterols; (b) fluoroacetate release by β‐oxidation of fatty alcohols and acids; (c) inhibition of juvenile hormone esterase by trifluoromethyl ketones; (d) inhibition of antennal esterases that hydrolyse acetate pheromones; and (e) sensory disruption by acyl fluorides that mimic aldehyde pheromones.
A note on the effects of fluorine substituents on the biological activity and environmental chemistry of benzoylphenylureas
Authors: Luteijn Jan M. , Tipker Jacobus
Published: November 2006

Halogen‐substituted benzoyl ureas have been shown to possess interesting activity against insect larvae, preventing their development by interfering with the formation of cuticular tissue. Certain fluorinated compounds are particularly active. Activity can be related to certain characteristics, notably the spatial structure of the compound, so that those of optimum activity can be predicted.
A note on the synthesis and biological activity of polyfluorobenzyl pyrethroid esters
Authors: McDonald Edward , Punja Nazim
Published: November 2006

The pentaflurobenzyl esters of acids related to chrysanthemic acid are active insecticides. Formal substitution of one or more of the fluorines in pentafluoro‐benzyl alcohol has led to a new series of insecticidal compounds. The synthesis of these esters has some novel aspects. Key factors contributing to the insecticidal activity of these esters in soil, particularly against corn root worm, are discussed, including rates of degradation and vapour pressure.
The photochemical decomposition of the herbicide isoproturon
Authors: Kulshrestha Gita , Mukerjee Sunil Kumar
Published: November 2006

The photochemical degradation of the herbicide isoproturon in aqueous and non‐aqueous solutions and in soils has been investigated. Four new photometabolites were formed in non‐aqueous solution and three in soil. These were characterised by spectroscopic methods and identified by comparison with authentic synthetic samples such as 3‐(4‐isopropylphenyl)‐1‐methylurea; 3‐(4‐isopropylphenyl)urea; 4,4′‐diisopropylazobenzene and 4,4′‐diisopropylazoxybenzene. The pathway of formation of these photo products is depicted.
Laboratory selected resistance to diflubenzuron in larvae of aedes aegypti
Authors: Walker Alastair L. , Wood Roger J.
Published: November 2006

The variation in tolerance to diflubenzuron [1‐(4‐chlorophenyl)‐3‐(2,6‐difluorobenzoyl)urea] was examined in fourth instar larvae of seven strains of Aedes aegypti, some of which were resistant to DDT and permethrin. The difference between the least and the most tolerant to diflubenzuron was approximately two‐fold. There was no correlation with resistance to the other insecticides. A DDT‐resistant strain (T8) was selected 10 times (during 12 generations) with diflubenzuron. The LC50 to diflubenzuron had increased 3.3 times by the S8 generation but there was no further increase in later generations despite further selection. Associated with this increase, a marked decrease in resistance to DDT was observed but no change in permethrin tolerance. A genetically enriched strain (Hotchpotch) was synthesised from 35 strains of different geographic origin and crossed to the selected T8 strain before subsequent generations were selected five times with diflubenzuron. This procedure resulted in an 8 to 12‐fold increase in the LC50 value over that for unselected T8, accompanied by a decrease in the slope of the log dose against probit mortality line.
Physiological factors affecting product yield in plant cell cultures
Authors: Fowler Michael W.
Published: November 2006

While the first commercial process systems for plant cell cultures are now operational, important questions still face the technology. Key amongst these is the need to raise and maintain product yields in a large number of cell lines. However, approaches to raising product yield are still largely empirical and suffer from a great lack of knowledge of the pathways and control systems for secondary metabolite synthesis in plants. This review examines some of the factors that have been found to affect product yield in plant cell cultures and assesses their potential for future development.
The biological activity of polyhydroxyalkaloids from plants
Authors: Fellows Linda E.
Published: November 2006

Polyhydroxy derivatives of octahydroindolizine, piperidine and pyrrolidine have been isolated from plants and microorganisms. Many have proved to be potent and specific inhibitors of glycosidase enzymes from a variety of organisms: as such they have potential application in several areas of agricultural and medical research.
Comparative histopathology of the chitin synthesis inhibitors nikkomycin X/Z, nikkomycin Z and polyoxin D. I: Effects on moulting, reproduction and digestion in the spider mite Tetranychus urticae
Authors: Mothes‐Wagner Ursula
Published: November 2006

The effects of the closely related chitin synthesis inhibitors, the nucleoside peptidyl antibiotics nikkomycin X/Z, nikkomycin Z and polyoxin D on the two‐spotted spider mite, Tetranychus urticae, have been studied by electron microscopy. The application of all three compounds, nikkomycin X/Z (95% active ingredient, ratio of components unknown), nikkomycin Z (pure component) and polyoxin D (pure component) disrupted cuticle, eggshell and yolk synthesis and influenced the silk and salivary glands. Ultrahistological patterns indicated differences in the mode of action of the three compounds which were especially evident in an alteration of the nuclear ultrastructure in the mid‐gut cells, which was only caused by polyoxin D. Mechanisms of action and their consequences on function, based on previously published information on the action of these compounds, are discussed.
Synthesis and confirmation of structure of four mammalian metabolites of dieldrin and endrin
Authors: Bedford Colin T. , Crane Anthony E. , Harrod Rosina K.
Published: November 2006

The first syntheses of syn‐12‐hydroxydieldrin, syn‐12‐hydroxyendrin and anti‐12‐hydroxyendrin have been accomplished by debenzoylation and epoxidation of three isomeric adduction products of hexachlorocyclopentadiene and 1,7,7‐trinorborna‐2,5‐dien‐7‐yl benzoate. A third known metabolite of endrin, 12‐ketoendrin, and a putative metabolite of dieldrin, 12‐ketodieldrin, were prepared from the corresponding alcohols by oxidation with chromium trioxide. Characterisation of the three debenzoylated intermediates as syn‐12‐hydroxyaldrin, and syn‐ and anti‐12‐hydroxyisodrin constitutes the first syntheses of these three possible metabolites of aldrin and isodrin.
Forecasting the efficiency of the sequential aerosol technique for tsetse fly control
Authors: Johnstone Donald R. , Cooper Jeremy F.
Published: November 2006

An attempt has been made to link the results of laboratory toxicological studies on tsetse flies to the specification of application requirements for control or eradication of tsetse flies in the field. Relevant parameters have been identified and a consideration of their physical interactions has provided the basis for predicting the effect of changes in the operational variables on the efficiency of kill. Some implications for future developments in application techniques and for requirements in research and development have been recognised.
Studies on the mode of action of asulam, aminotriazole and glyphosate in Equisetum arvense L. (field horsetail). II: The metabolism of [14C]asulam, [14C]aminotriazole and [14C]glyphosate
Authors: Marshall George , Kirkwood Ralph C. , Martin David J.
Published: November 2006

The metabolism of [14C]asulam (methyl 4‐aminophenylsulphonylcarbamate), [14C] aminotriazole (1H‐1,2,4‐triazol‐3‐ylamine) and [14C]glyphosate (N‐(phosphonomethyl)glycine) were assessed in Equisetum arvense L. (field horsetail). Following application of the test herbicides (4mg⋍0.3 °Ci herbicide/shoot) to the shoots of 2‐year‐old pot‐grown plants, the total recovery of 14C‐label after 1 week and 8 weeks was high for all three herbicides (>80‐0% of applied radioactivity). Asulam was persistent (>69‐7% of recovered radioactivity) in both shoots and rhizomes. Sulphanilamide, a hydrolysis product of asulam, accounted for the remainder of the recovered radioactivity. Aminotriazole showed evidence of conjugation in shoots and rhizomes. The principal 14C‐labelled component in shoots was composed of high proportions of aminotriazole (>76‐3%) together with the metabolites: X (ninhydrin positive), β‐(3‐amino‐1,2,4‐triazolyl‐1‐)α‐alanine, Y (diazotization positive) and various unidentified compounds. Rhizomes generally contained lower proportions of intact aminotriazole (>59.4%) together with the metabolites X,Y and unidentified compounds. The proportion of aminotriazole did not decrease with time in shoots or rhizomes; however, the ratio of metabolite X: Y moved in favour of Y as the interval after treatment increased. Glyphosate was extensively metabolised in shoots and rhizomes to yield aminomethylphosphonic acid (AMPA) and various unidentified compounds. Differential metabolism appears to be one of the factors which may govern the persistence and toxicity of the test herbicides in E. arvense.