bluuebunny/crossref_metadata_2025 huggingface dataset:
The metabolic fate of tridemorph in rats
Authors: Hawkins David R. , Down William H. , Chasseaud Leslie F. , Lewis John D.
Published: November 2006

A single oral dose of [14C]tridemorph was partly, but rapidly absorbed by rats. Most of the radioactivity was excreted with a half‐life of about 15 h. During 5 days, 42.6% was excreted in the urine, 46.7% in the faeces, 1.5% in the expired air and 3.4 % was still retained. 24 % was excreted in the 48 h bile. Sequential wholebody autoradiography indicated that much of the radioactivity was confined to the gastrointestinal tract, liver and kidneys. There was no unexpected uptake of radioactivity. Urinary metabolites were more polar than tridemorph and were also detected in the bile and faeces. The major metabolite in 24 h urine, accounting for 22.3% of the dose appeared to be a side‐chain hydroxylated derivative. Cleavage of the morpholine ring was limited to about 1.5 % of the dose.
Knockdown by pyrethroids: Its role in the intoxication process
Authors: Burt Paul E. , Goodchild Ralph E.
Published: November 2006

Using techniques for treating the insects unanaesthetised, knockdown of aduit Musca domestica by pyrethrin I applied topically to or injected into the thorax was assessed by measuring the ED50s on 13 occasions 1 min‐48 h after treatment. From 1 min to approximately 1 h after treatment, ED50s for topical application decreased quickly with increasing time. During this “knockdown phase” ED50 values were probably determined mainly by rate of penetration of the insecticide into the insect, but the rate of elimination of the insecticide probably determined the increasing ED50 values during the “recovery phase” which followed. ED50s for injected pyrethrin I were initially much smaller than after topical application but increased continuously until 24 h after treatment. From 100 min onwards ED50s by topical application and injection were similar. These results indicate (1) that the site affected during knockdown is within the insect rather than superficial, and (2) that detoxication and excretion processes determine the ultimate toxicity of the insecticide apparently independently of the method of treatment. Additional tests with a strain of flies having the penetration delaying factor and with the cockroach Periplaneta americana L. supported these conclusions.

Speed of knockdown after topical treatment was also affected by the site of application and the solvent in which pyrethrin I was applied.

Bioresmethrin was about as effective as pyrethrin I in knocking down flies when applied topically or when injected, but because the ED50 increased very little during the recovery phase it was ultimately much more toxic.
Time‐dose‐response relationships of pyrethroid insecticides with special reference to knockdown
Authors: Ford Martyn G. , Pert David R.
Published: November 2006

The relationship between incoordination, knockdown and mortality was investigated by following the course of poisoning in Schistocerca gregaria of two synthetic pyrethroids, bioresmethrin and bioallethrin. Kinetics describing theonset of these responses as a function of dose are interpreted in terms of the dynamics of penetration and detoxication. The possibility of the same site of action for knockdown and kill is briefly discussed.
Studies on the possible formation of polychloroazobenzenes in quintozene treated soil
Authors: Buser Hans‐Rudolf , Bosshardt Hans‐Paul
Published: November 2006

Treatment of different soils with quintozene at a level of 1000 parts/106 and incubation for 24 days at 30 °C did not result in the formation of polychloroazobenzenes, although pentachloroaniline was formed. This negative finding is in line with previous work, where it was shown that azobenzenes can only be formed from substituted anilines with at least one free ortho position. Soil activity was demonstrated by incubation of 3,4‐dichloroaniline under similar conditions yielding the expected 3,3′,4,4′‐tetrachloroazobenzene. Mass fragmentography with a quadrupole mass spectrometer was used for the detection of polychloroazobenzenes. Mass spectra for the synthesised reference compounds are presented.
Anti‐fungal and anti‐bacterial activities of some pyrrole, furan‐and thiophen‐sulphonamides and sulphonanilides
Authors: Carter Geoffrey A. , Dawson Glenn W. , Garraway James L.
Published: November 2006

The anti‐fungal and anti‐bacterial activities and phytotoxicity of pyrrole‐ and 5‐nitropyrrole‐2‐sulphonamides are compared with furan and thiophen analogues. Certain compounds of the group have appreciable anti‐bacterial activity consistent with structure‐activity investigations of other anti‐bacterials derived from these heterocycles.
A comparative study of insecticide resistance assays with the German cockroach
Authors: Collins William J.
Published: November 2006

Females of a diazinon‐resistant strain of German cockroach exhibiting cross resistance to propoxur were evaluated for resistance to diazinon and propoxur by six assays: LD50s for topical application and injection; LC50, KT50 and LT50 for deposits on wood and KT50 for deposits on glass. Also investigated were certain variables in the topical application technique and the experimental conditions for topical synergism studies. Among all assays, diazinon resistance ratios (resistant:susceptible) ranged from 3‐ to 145‐fold; propoxur varied from 1‐ to 14‐fold. Resistance ratios based on KT50 data were consistently low (<4x) for both insecticides. Resistance to diazinon was 13x when applied topically and 6x when injected. Resistance to propoxur was 14x by injection compared to 8x for topical application. The LC50 assay exhibited the greatest difference in resistance to the two insecticides: namely, 145x to diazinon and 1x(no resistance) to propoxur. By LT50 analysis, resistance to propoxur was 10x compared with 100x resistance to diazinon. Thus, the method used had a significant effect on the final value of the resistance ratio. Even though resistance ratios may vary widely among different techniques, the final choice of a method depends upon many factors. The LT50 method may provide a more realistic appraisal of resistance in wild populations of German cockroaches especially when experimental residues are similar to those used in control programmes.
Effects of benomyl, carbendazim and thiophanates on respiration and oxidative phosphorylation of Fusarium oxysporum and Saccharomyces cerevisiae
Authors: Decallonne Jacques R. , Genot Monique , Meyer Joseph A.
Published: November 2006

Benomyl [methyl 1‐(butylcarbamoyl)‐benzimidazol‐2‐ylcarbamate] (350 × 10−6 M) decreased the respiration rate of Fusarium oxysporum conidia by 50% during germination. This inhibition was maintained at least 24 h after the treatment had begun. The treatment did not modify the relation between incubation time and respiration rate. Carbendazim [methyl benzimidazol‐2‐ylcarbamate], thiabendazole[2‐(thiazol‐4‐yl)benzimidazole], thiophanate [1,2‐di‐(3‐ethoxycarbonyl‐2‐thioureido)benzene] and thiophanate‐methyl [1,2‐di‐(3‐methoxycarbonyl‐2‐thioureido)benzene] were assayed using isolated mitochondria of Saccharomyces cerevisiae. These four compounds decreased mitochondrial respiration and oxidative phosphorylation rates to different extents when they were applied at a concentration of 250 × 10−6 M. Thiophanate‐methyl was the most effective since it completely suppressed the mitochondrial respiratory control at 75 × 10−6 M.
Distribution of tridemorph and its metabolites in barley plants grown to maturity
Authors: Waring Rosemary H. , Wolfe Martin S.
Published: November 2006

The distribution of tridemorph residues in previously treated mature barley plants has been determined using a specific g.l.c. method. Tridemorph residues were found in grain, awns, leaves, rachis and stems, the amount of residue in the grain appearing to be variety‐specific.
Iodometric analysis and shelf life of malathion in formulations
Authors: Orth Robert A. , Minett William
Published: November 2006

Using an iodometric method for the determination of malathion in emulsifiable concentrates, values of active ingredient in four commercial formulations and one primary reference standard were within ±0.7% weight/volume (w/v) of the stated concentrations. A standard deviation of 0.42% w/v and 95% confidence limits of ±0.9% w/v for a single determination were calculated for the method. Added moisture and elevated temperature were found to accelerate malathion breakdown in the commercial formulations. The greatest breakdown rate of 5.2% w/v per 100 days occurred with a formulation stored at 27 °C containing 0.5% v/v added moisture.
Selectivity and mode of action of flamprop‐isopropyl, isopropyl (±)‐2‐[N‐(3‐chloro‐4‐fluorophenyl)benzamido]propionate, in the control of Avena fatua in barley
Authors: Jeffcoat Brian , Harries W. Norton
Published: November 2006

The post‐emergence herbicide isopropyl (±)‐2‐[N‐(3‐chloro‐4‐fluorophenyl)benzamido]propionate (flamprop‐isopropyl) showed good activity against wild oat with selectivity in barley. The basis for activity and selectivity was similar to that previously established for benzoylprop‐ethyl, and found to be dependent on its rate of degradation to the biologically active acid flamprop. Flamprop stunted the growth of the oat by inhibiting cell elongation and showed a relatively high rate of movement in the phloem, approximately five times that of benzoylprop. Selectivity of flamprop‐isopropyl was dependent on its relative rate of hydrolysis and the subsequent detoxication of the acid to inactive conjugates. However, although the relative rate of de‐esterification of flamprop‐isopropyl was lower than that of benzoylprop‐ethyl similar quantities of the parent ester gave comparable effects on oat. The inherent activity of flamprop is approximately twice that of benzoylprop. The effect of flamprop‐isopropyl was best seen when the compound was applied during growth stages when the crop could offer the most effective competition to the wild oat. Throughout a range of growth stages the rate of hydrolysis of flamprop‐isopropyl was higher in oat than in barley. The metabolism of the compound was not markedly affected when the plants were under stress.
Use and misuse of calorimetry with special reference to muscle physiology
Authors: Woledge Roger C.
Published: November 2006

Calorimetric experiments, on their own, can be extremely dangerous to biologists, for there are usually several possible, but alternative interpretations. The simplest interpretation is often not correct. The best way to use biological calorimetry on its own is to indicate good targets for biochemical investigations of a tissue. Even when biochemical investigations are carried out in parallel with calorimetry, dangers remain. In particular it is easy to assume that the heat observed is necessarily derived from the biochemical process measured. The way to avoid this error is to make an energy balance study. In most cases such a study requires calorimetric measurements on cell‐free systems of known composition to establish ΔH values for in vivo conditions. Used in this way biological calorimetry is much more than a mere indicator that something is happening; it can lead to the most important statement about what is happening: that we do not yet understand it!
Microcalorimetric studies of tissue cells and bacteria
Authors: Kemp Richard B.
Published: November 2006

Analytical microcalorimetric studies of cultures of Enterobacter aerogenes and Clostridium pasteurianum revealed a complex pattern of heat production. While both organisms gave thermograms which followed the exponential growth curves in the early stages, the later events in the heat effect appeared to reflect deficiencies in the growth medium and induction of “secondary” nutrients. Synchronously dividing Schizosaccharomyces pombe is known to give maxima in oxygen uptake during the cell cycle. These peaks are enhanced by the uncoupling agent, 2‐oxomalononitrile m‐chlorophenylhydrazone (CCCP). The rate of heat production in control cultures pumped through the LKB microcalorimeter increased at a linear rate, doubling over each complete cell cycle. Introduction of CCCP to cultures gave an altered thermogram in which the maxima of heat evolution which occurred corresponded in time to the peaks in oxygen uptake.

When suspensions of muscle fibroblasts from 9 day old chick embryos were pumped through the aeration vessel, they produced heat at a rate which was proportional to cell concentration. Inhibitors of respiration decreased heat evolution by similar percentages to their effect on oxygen uptake. Cells of the same type in monolayer gave slightly lower levels of heat production. The thermogram was characterised by maxima over 4 h, which may be a reflection of temporal changes in intracellular ATP levels. When muscle fibroblasts were mixed with excess (zero order kinetics) ATP and pumped through the gold vessel of the microcalorimeter, the rate of heat production was proportional to cell concentration, the latter representing the hydrolysing enzyme. 4,4′‐Dithiodi(nicotinic acid), a sulphydryl inhibitor which does not enter cells, depressed the calorimetric response vs cell concentration curve by 78%, indicating that a sulphydryl enzyme was present at the cell surface. Batch calorimetric experiments to determine the heat of interaction of antibodies with cells gave thermograms which differed in form and value, the latter changing in sign and magnitude. The results illustrate the need for careful model experiments to disect this complex system. The present results underline the value of microcalorimetry in giving analytical data on growth and respiration in cells and organisms and illustrates the potential of the technique in studies of surface‐localised reactions.
Surfactants for the control of apple mildew
Authors: Clifford Derek R. , Hislop Eric C.
Published: November 2006

Reduction of the overwintering powdery mildew fungus Podosphaera leucotricha resulted from one application of a variety of surfactants (at 50 g/litre a.i.) to apple trees during the dormant season. Examples of non‐ionic, anionic and cationic materials were tested and some gave promising control. Successful treatments delayed bud burst during the following spring and caused some loss in fruit yield.
Surfactants and the uptake and movement of paraquat in plants
Authors: Bland Peter D. , Brian Robert C.
Published: November 2006

Surfactants are still considered to be agents which either increase spray coverage of leaves with herbicidal solutions and/or increase herbicide penetration into the leaves. Experiments where the method of application largely eliminates leaf wetting as a factor in paraquat uptake show that this is an over‐simplification. Its efficiency in the plant is influenced by penetration and most of all by the degree of movement down the plant into untreated leaves. Results on the uptake, movement and biological activity of paraquat are reported using cocksfoot and wheat. A relation is found between paraquat movement and the hydrophilic nature of the surfactant. It moves most when the number of ethylene oxide residues is less than six and it is minimal when the number is 10 to 15. Leaf penetration, however, is at a maximum when movement under the influence of surfactant is least. Partition studies in which surfactants are distributed between leaf wax and water are described. There is a direct correlation between the degree of partition of the surfactant into the wax and the degree of movement of paraquat in cocksfoot and wheat. Surfactants are essential components of a paraquat formulation to wet the leaf surface and increase penetration but, when the surfactant also penetrates into the leaf, it reduces the mobility of paraquat and hence its efficiency.
Biological implications of the use of surfactants in medicines: and the biphasic effects of surfactants in biological systems
Authors: Florence Alexander T. , Gillan James M. N.
Published: November 2006

A survey of the biological effects of surface‐active agents reveals that their affinity for membranes and in particular their ability to penetrate and increase the permeability of membranes is of prime importance. An increase in drug absorption from the gastrointestinal tract, from muscle, from the rectum and from topical preparations is frequently a result of an increase in membrane permeability; the effect of surfactants on enzyme activity can be also the result of changes in organelle permeability or to surfactant‐induced changes in protein conformation. As anionic surfactants and cationic surfactants tend to exhibit too high a degree of toxicity, non‐ionic agents are most commonly used in pharmaceuticals. Experiments to elucidate the mode of action of a range of commercially available non‐ionic surfactants on the increase in drug absorption in model systems employing goldfish (Carassius auratus) are described. Emphasis is placed on the biphasic effects of the surfactants whereby an increase in membrane permeability is observed at low concentrations (frequently below the critical micelle concentration of the surfactant) and a decrease in overall absorption is found at higher concentration. Such biphasic effects are frequently encountered in the literature on surfactant effects in biological systems.
Effect of substituted pyrazoles and related compounds on geotropism in cress seedlings
Authors: Geissler Art E. , Huppatz John L. , Katekar Gerard F.
Published: November 2006

The effects on root geotropism of three series of compounds related to 2‐phenyl‐8H‐pyrazolo[5,1‐a]isoindol‐8‐one (IV), its 3,3a‐dihydro derivative (V) and 5‐(2‐carboxyphenyl)‐3‐phenylpyrazole (VI) have been assessed using cress seedlings. Compounds (IV) and (VI), and their derivatives, are highly active, destroying geotropism at concentrations of 10−7‐10−9M. Substitution with various functional groups and increased molecular size resulted in only minor variation in the level of activity.
Insecticidal activity of the pyrethrins and related compounds. VII. Insecticidal dihalovinyl analogues of cis and trans chrysanthemates
Authors: Elliott Michael , Farnham Andrew W. , Janes Norman F. , Needham Paul H. , Pulman David A.
Published: November 2006

Eighteen esters of resolved cis‐ and trans‐3‐(2,2‐difluoro, ‐dichloro or ‐dibromovinyl)‐2,2‐dimethylcyclopropanecarboxylic acids with 5‐benzyl‐3‐furylmethyl, 3‐phenoxybenzyl and α‐cyano‐3‐phenoxybenzyl alcohols were prepared and evaluated for insecticidal activity against Musca domestica L. and Phaedon cochleariae Fab. Chlorine and bromine substituted esters are more active, in general, than those with fluorine, and in the most active esters, the cis isomer is more effective than the trans.
Resistance to some organophosphorus insecticides in field populations of Myzus persicae from sugar beet in 1974
Authors: Needham Paul H. , Devonshire Alan L.
Published: November 2006

Following the failure of insecticides to control Myzus persicae on sugar beet, populations from the field were examined for susceptibility to dimethoate. Topical application of discriminating doses of dimethoate showed a 30‐fold variation in susceptibility between different populations. After this preliminary screening, clones were established from some populations and their resistance determined by both topical application and a systemic bioassay. This confirmed resistance to dimethoate and demonstrated resistance to demeton‐S‐methyl. There was no resistance to some other compounds tested. In all populations tested, resistance was associated with increased carboxylesterase activity.
Inactivation of triforine by u.v. and sunlight on glass and on leaves of bean plants
Authors: Buchenauer Heinrich
Published: November 2006

Triforine is sensitive to u.v. and sunlight. The photochemical inactivation rate was higher in aqueous solution than in the solid state. In aqueous solution 50% of triforine was inactivated after 3 h irradiation with u.v. light and after 30 h exposure to sunlight. Eighty hours were necessary to decompose 25% of triforine in the solid state with sunlight on glass. The half life of triforine residues on the leaves of bean plants was about 60 h when exposed to solar irradiation. The inactivation of triforine by u.v. light and sunlight was accelerated in the presence of the sensitising chemicals riboflavin and xanthene; however, rhodamine B (C.I. 45170) showed only a small photosensitising activity.
Interstitial air movement in model grain silos
Authors: Berck Ben
Published: November 2006

Sulphur hexafluoride, SF6, was used as a gaseous tracer to determine the rate of unassisted air movement in the microclimate of grain stored in steel bins. The airspeeds were influenced by the nature of the stored products, the size and geometrical shape of the kernels and the storage temperature. Air movement rates varied from 3 to 108 in/h depending on the temperature gradients. This is the first quantitative evidence of the ultraslow speed of air movement in stored grain.
Inhibitors of choline acetyltransferase as potential insecticides
Authors: Baillie Alister C. , Corbett John R. , Dowsett John R. , Sattelle David B. , Callec Jean‐Jacques
Published: November 2006

Choline acetyltransferase (E.C.2.3.1.6) catalyses the synthesis of acetylcholine and is therefore a target for a new insecticide. We have prepared a variety of compounds, mainly choline analogues, as inhibitors of this enzyme. One of these, 2‐isothiocyanatoethyltrimethylammonium iodide, has a Ki of 0.06 μM (Km for choline is 150 μM) and is apparently the most powerful inhibitor known for this enzyme. Although some of our compounds are insecticidal we believe, on the basis of electrophysiological studies, that they act, not on choline acetyltransferase, but on the acetylcholine receptor of the insect.
Penetration of bean leaves by asulam as influenced by adjuvants and humidity
Authors: Babiker Abdel G. T. , Duncan Henry J.
Published: November 2006

Penetration of bean (Vicia faba var. Maris Bead) foliage by asulam was found to be affected differently by different surfactants. Some anionic and non‐ionic surfactants brought about a significant increase compared with the aqueous control, others were similar to the aqueous control and one caused a significant reduction. High humidity increased asulam uptake and the effect was still further enhanced in the presence of Tween 20. High humidity was also found to influence asulam penetration in the presence of glycerol. With urea, uptake was greater under high humidity conditions and in the presence of Tween 20. A similar enhancement of penetration was found with potassium ethyl xanthate at lower concentrations (0–0.20%) in the presence of Tween 20. On the other hand, reduced uptake resulted at higher concentrations (0.40–1.00%). Tributyl phosphate brought about an increase in penetration at concentrations greater than 0.75%. However, both potassium ethyl xanthate and tributyl phosphate were shown to damage the leaf surface.
Some chemical and physical properties of epronaz, a new herbicide
Authors: Brookes Robert F. , Copping Leonard G.
Published: November 2006

A brief account is given of the work leading up to the synthesis of epronaz (BTS 30 843), 1‐(N‐ethyl‐N‐propylcarbamoyl)‐3‐propylsulphonyl‐1,2,4‐triazole, a new pre‐ and early post‐emergence herbicide for annual grasses. The synthesis is described, together with the occurrence and isolation of all three possible positional isomers in the final (carbamoylation) stage. The evidence for the structure assigned to epronaz is presented together with that for the other two isomers, and their interconversion is described. Some chemical properties of epronaz are described, with particular reference to its hydrolysis and its ability to function as a carbamoylating agent, in relation to persistence in the environment and to mode of action respectively. Some physical properties are also reported, including vapour pressure, solubility, and spectra. The mass spectral fragmentation pattern is also discussed.
Spray deposit cover and fungicide distribution obtained by low and ultralow volume spraying of intensive apple trees
Authors: Cooke Barry K. , Herrington Pamela J. , Jones Kenneth G. , Morgan Norman G.
Published: November 2006

Spray deposit assessments were made on the leaf surfaces in the top, middle and base zones of intensively grown dessert apple trees sprayed by a conventional high volume automatic mast method applying 2250 litres/ha, an experimental low and ulfralow volume tractor mist blower, applying 225 litres/ha at normal dilution, 45 litres/ha at five times normal concentration or 22.5 litres/ha at ten times normal concentration, and a modified proprietary hand‐directed fan‐disc sprayer applying 225 or 22.5 litres/ha. Fluorescent tracer assessments showed that the high volume method gave heavy cover on upper and lower surfaces of the leaves in all zones, the tractor mist method gave lighter but uniform cover and the fan‐disc sprayer gave sparse cover on the upper surfaces at the top and on the lower surfaces at the base zone. The hand‐directed low and ultralow volume methods, applying one‐tenth of the amounts of copper fungicide/ha, gave deposit levels 5–30 % of those of the high volume method and the tractor mist applications gave 0.8–5.2%. The corresponding captan deposits from 5–6 applications were 12–50% and 10–20%: residual deposits from the ultralow volume applications of the concentrated captan were greater than the low volume applications of the same quantities in dilute form. In general, the order of pest and disease control obtained by the three methods was high volume automatic, fan‐disc and experimental mist, and this was related to the order of deposit levels: the order of control by the three volume rates was 2250, 225 and 22.5 litres/ha, and this could be related to the degree of spray cover.
Simulation of herbicide persistence in soil .III. Propyzamide in different soil types
Authors: Walker Allan
Published: November 2006

The effects of soil temperature and soil moisture content on the rate of degradation of propyzamide in five soils were examined under controlled laboratory conditions. Half‐lives in soils incubated at field capacity varied from 23 to 42 days at 25°C and from 63 to 112 days at 15°C. The variation in half‐life at 25°C and 50% of field capacity was from 56 to 94 days. When the laboratory data were used in conjunction with the relevant meteorological records and soil properties in a computer simulation program, predicted degradation curves for propyzamide in four of the soils in micro‐plots were in close agreement with those observed. Use of the program to predict residues of propyzamide in the fifth soil at crop maturity in a series of field experiments concerned with continuity of lettuce production gave values fairly close to those observed when appropriate corrections were made for initial recoveries.
The control in vitro of Ceratocystis ulmi by amine cations
Authors: Clifford Derek R. , Cooke Louise R. , Davies Susan M.
Published: November 2006

Of 60 amine cations tested in vitro for activity against Ceratocystis ulmi, that of methyl benzimidazol‐2‐ylcarbamate (carbendazim) showed the highest activity, this being constant with three different associated anions. Some guanidines, 2‐nitro‐morpholine and 2‐(thiazol‐4‐yl)benzimidazole (thiabendazole) showed considerable activity but a large group of alkylamines, 1‐methylalkylamines and poly‐amines were relatively inactive.
Uptake, distribution and metabolic fate of 3H‐triforine in plants .I. Short‐term experiments
Authors: Fuchs Adriaan , De Vries Frits W. , Aalbers André M. J.
Published: November 2006

Most of the label, present in the roots of bean, tomato and barley seedlings after short‐term root‐treatment with 3H‐triforine, appeared only weakly adsorbed on to the root tissue and was desorbed after transplanting in fungicide‐free soil. Label taken up accumulated almost exclusively in the leaves present at the time of treatment; all leaves expanding after termination of the treatment remained virtually devoid of radioactivity. In “adult” plants label was usually present in a concentration gradient from roots to youngest leaves; in tomato plants, however, distribution of label was rather irregular. Time‐course studies with bean and barley plants revealed that the aerial parts were gradually supplied with label, from old to youngest leaves, the maximum relative accumulation of radioactivity slowly moving acropetally. Under the experimental conditions chosen, triforine was converted nearly quantitatively to one metabolite, which almost certainly is different from any known non‐enzymic breakdown product of the fungicide.
Metabolism of the insecticide SD 8280, 2‐chloro‐1‐(2,4‐dichlorophenyl)vinyl dimethyl phosphate, following its application to rice
Authors: Roberts Terry R. , Stoydin George
Published: November 2006

The metabolism of the insecticide SD 8280 [2‐chloro‐1‐(2,4‐dichlorophenyl)vinyl dimethyl phosphate] in rice plants has been examined. When rice seedlings were treated with [14C]‐SD 8280 the major metabolite was 1‐(2,4‐dichlorophenyl)ethanol which was present mainly conjugated with plant carbohydrates. This compound was also the major metabolite present in grain and straw from rice treated with [14C]‐SD 8280 and grown to maturity under paddy conditions both in the glasshouse and in an outdoor enclosure. Other metabolites detected in the mature plants included 2‐chloro‐1‐(2,4‐dichlorophenyl)vinyl methyl hydrogen phosphate and 2,4‐dichloro‐benzoic acid, both of which occurred in free and conjugated forms. Paddy water was sampled at intervals after the application of [14C]‐SD 8280 and the total residue in the water fell from initial levels of 0.28–1.1 μg/ml (expressed as SD 8280 equivalent) immediately after treatment to <0.01 μg/ml after 2–3 weeks. The total residues in the soil from these experiments were low and did not exceed 0.20 mg/kg (SD 8280 equivalents) through the 0–15 cm profile.
Photodecomposition of natural pyrethrins and related compounds
Authors: Bullivant Michael J. , Pattenden Gerald
Published: November 2006

Present knowledge of the photochemistry of the pyrethrins, and of the alcohols and acids from which they are constituted is summarised.
Insecticidal activity of the pyrethrins and related compounds VIII. Relation of polarity with activity in pyrethroids
Authors: Briggs Geoffrey G. , Elliott Michael , Farnham Andrew W. , Janes Norman F. , Needham Paul H. , Pulman David A. , Young Stephen R.
Published: November 2006

Comparing insecticidal activities of a wide range of pyrethroids with polarities measured by reversed phase, thin‐layer chromatography suggests that there are optimum polarities for potency in both Musca domestica and Phaedon cochleariae, and that these optima have closely similar values. The significance of these conclusions is discussed.
1‐alkylcyclopropanecarboxylates: An extension of pyrethroid structure—activity relationships
Authors: Bolton Roge R. G.
Published: November 2006

1‐Alkylcyclopropanecarboxylic acids are synthesised by thermolysis of 1‐pyrazolines prepared by 1,3‐dipolarcycloadditions of diazoalkanes. The insecticidal and acaricidal activities of 14 pyrethroid esters of these acids are considered in relation to the influence of steric and metabolic factors on activity. 1‐Alkyl compounds are less active than esters with no alkyl group at position 1, contrary to expectations, and also less active than the corresponding 2‐alkyl esters.
Nerve membrane as a target of pyrethroids
Authors: Narahashi Toshio
Published: November 2006

Nerve membrane is one of the most important target sites of pyrethroids. Changes in excitability of nerve fibres caused by allethrin can be satisfactorily accounted for in terms of ionic permeabilities of the membrane. Temperature has a profound effect on the allethrin‐induced permeability changes.
Development of resistance to pyrethroids in insects resistant to other insecticides
Authors: Farnham Andrew W. , Sawicki Roman M.
Published: November 2006

Resistance to pyrethroids in insects is rare, but its recent rapid development in the field suggests that this resistance may be facilitated by previous exposure to or by resistance to insecticides of unrelated groups. To test this houseflies of strain 49r2b, originally resistant to dimethoate in the field, were selected eight times during ten generations with either pyrethrum extract or bioresmethrin with or without piperonyl butoxide or with dimethoate. Selecting with any of the pyrethroids led to resistance to these insecticides and in particular to pyrethrum/piperonyl butoxide. Selecting with pyrethrum/piperonyl butoxide resulted in strongest resistance to the pyrethroids tested, whereas selecting with bioresmethrin/piperonyl butoxide resulted in least resistance. These results show that dimethoate‐resistant flies selected with pyrethroids can readily develop resistance to these insecticides, but development of resistance can be minimised by using bioresmethrin/piperonyl butoxide. The implications of these findings on the sequential use of insecticides are discussed.
Distribution and loss of phorate residues in the foliage of broad bean plants following root uptake of 14C‐labelled phorate
Authors: Galley D. John , Foerster Luis A.
Published: November 2006

14C‐Methylene labelled phorate was added to nutrient solutions supplying the roots of young broad bean plants and after 24 h absorption, fresh nutrient was substituted. The radiolabel accumulated at the leaf margins was initially associated with solvent‐soluble toxic metabolites. Radiolabel extracted from foliage which developed after the treatment was mainly in water‐soluble form. The maximum concentration of toxic material occurred in the marginal areas of the leaves after 5 or 6 days and in the central portions after 2 days. The concentrations declined to half of their peak values in 4–6 days from leaf‐margin tissue and in 2 days from the central tissues. Water‐soluble label did not accumulate to any significant extent. Most was found in the marginal areas but concentrations built up slowly reaching a maximum after about 2 weeks, declining slowly thereafter.
Measurement of herbicide spray deposits on foliage by fluorescence I. Paraquat deposits on Vicia faba
Authors: Sharp Rex B.
Published: November 2006

An investigation revealed a paraquat‐compatible fluorochrome that fluoresces at 600 nm where the herbicide fluorescence is negligible. Acceptable amounts of this fluorochrome are recoverable from dry spray deposits of paraquat + fluorochrome mixture sprayed on various broad‐leaf weeds and bean leaves but care must be taken if a wetting agent is used for extraction purposes because the fluorescent intensity of the fluorochrome is affected by wetting agents. A procedure is given for extracting and measuring the fluorochrome from spray deposits on foliage.
Uptake of some volatile alkyl methylphosphonofluoridates from the vapour phase by wheat plants
Authors: Howells David J. , Hambrook Joy L. , Allenby Eleanor A.
Published: November 2006

The uptake of cyclohexyl, isopropyl and 1,2,2‐trimethylpropyl methylphosphonofluoridates from the vapour phase by growing wheat plants was studied. The compounds were absorbed through the leaves of the plants and were degraded in a manner similar to that following their uptake through the roots from hydroponic culture solution. The levels of the methylphosphonic acid derivatives in the plant extracts were influenced by the vapour concentration of the methylphosphonofluoridate, the period of exposure to the vapour and the state of illumination of the plants, but were not markedly influenced by the chemical nature of the compounds. Likely mechanisms for the uptake are discussed and it is concluded that the main route of absorption involves the stomata. The studies suggest that growing plants can absorb and possibly have a “sink effect” for atmospheric organophosphorus contamination.
Diazinon poisoning in large white butterfly larvae and the influence of sesamex and piperonyl butoxide
Authors: Wahla Mahmud A. , Gibbs R. Geoffrey , Ford John B.
Published: November 2006

The toxicity of diazinon and diazoxon to fourth instar Pieris brassicae larvae was determined, with or without modifying chemicals. Piperonyl butoxide and sesamex antagonised diazinon but synergised diazoxon. The penetration, excretion and internal concentration of diazinon were measured following topical application. Penetration of diazinon followed first order kinetics and was considerably slower after pretreatment with sesamex and piperonyl butoxide. Pretreatment with piperonyl butoxide increased the internal concentration of diazinon, but the onset of symptoms of poisoning was delayed, presumably because of inhibition of diazinon activation.
Accumulation patterns and fungicidal effect of carbendazim and thiabendazole in peanut plants after soil injection
Authors: Aharonson Nadav , Solel Zvi
Published: November 2006

Carbendazim and thiabendazole applied to the rhizosphere of peanut plants by injection into the soil at doses of 0.1, 0.5 and 2.5 g per 1 m row, accumulated in the leaves during the first week after treatment, the concentrations being related to the doses applied. Two weeks after treatment the concentrations of both fungicides dropped sharply. During the rest of the season, whilst the concentration of carbendazim in the high‐dose treatment was 0.1 mg/kg fresh weight, the concentration of thiabendazole increased from 0.1 to 2.0 mg/kg and remained at this level until harvest. At the end of the growing season treated plants were less infected with Cercospora leaf spot (Cercospora per sonata) than the untreated control, thiabendazole affording better protection than carbendazim. Plants treated with the highest dose of thiabendazole were the only ones that did not wilt, even though infected. Laboratory studies of the adsorption of these fungicides on soil revealed that carbendazim is less adsorbed and also less persistent than thiabendazole.
Dosage values obtained following pre‐plant fumigation for perennials II. Using special methods of applying methyl bromide and 1,3‐dichloropropene nematicides
Authors: McKenry M. V. , Thomason I. J.
Published: November 2006

The movement of 1,3‐dichloropropene and methyl bromide was monitored in various field situations involving fumigant application coupled with contemporary soil profile modification techniques. The soil moisture, temperature, texture and profile differences are reported in each case. A combination of soil modification and soil fumigation may provide for better plant response than either treatment alone. Spot and strip treatments may provide an efficient method of applying certain pre‐plant fumigants to protect young perennials.
The mode of action of insecticides: Accelerated water loss and reduced respiration in insecticide‐treated Musca domestica L.
Authors: Gerolt Philip
Published: November 2006

Contact with organophosphorus, carbamate, organochlorine and pyrethroid insecticides caused accelerated water loss from all major parts of the integument of the housefly. The response appeared to be specific in that only insecticides, and not their truly non‐toxic analogues, had this effect, specificity being also reflected in resistance and in synergistic and antagonistic responses. As an insecticide dispersed laterally in the integument the effect spread to more distant parts, including the intestinal and tracheal systems, its arrival in the tracheal system coinciding with a reduction in the rate of respiration. It is suggested that this reaction of the integument to contact with insecticides is the primary cause of eventual death. Interference with the water balance in the tracheal system affects the normal exchange of the respiratory gases and thus proper respiratory control, to which the insect reacts with symptoms of excitation and paralyses. Degeneration of vital tissues following the loss of water is probably ultimately responsible for the death of the insect.
Effects of fungal and plant esterases on the fungicidal activity of nitrophenyl esters
Authors: Clifford Derek R. , Hislop Eric C. , Shellis Claire
Published: November 2006

Aryl esterases, present within leaves and fungal spores and on their surfaces, hydrolysed 2‐naphthyl, 4‐nitrophenyl and 4‐(1‐substituted alkyl)‐2, 6‐dinitrophenyl esters at rates which appeared to be determined by the nature of the ester group and by the alkyl substituents in the molecule. No simple relationship was found between partitioning (as measured by Rm values from reverse‐phase t.l.c.) and susceptibility to hydrolysis by esterases. The most readily hydrolysed alkyldinitrophenyl esters are not those derived from parent nitrophenols with the greatest fungitoxicity in vivo or in vitro and the highly active 4‐(1‐cyclobutylalkyl)‐2, 6‐dinitrophenyl crotonates are amongst the least easily hydrolysed. It is suggested that alkyldinitrophenyl esters may have their own mode of action as powdery mildew fungicides which complements, and may even supplant, that resulting from hydrolysis to the parent alkyldinitrophenol. The proposed mechanism is disruption of the fungal cell membrane (as a result of surfactant properties) leading to leakage of essential cell components.
The biological target
Authors: Matthews Graham A.
Published: November 2006

If transfer of pesticide from the spray nozzle to the target is to be more efficient, a clearer definition is required of the sites which droplets should reach. Such biological targets are examined on both macro and micro scales in this paper.
Deposition and drift of ulv and vlv insecticide sprays applied to cotton by hand applicator in northern nigeria
Authors: Johnstone Donald R. , Huntington Kathryn A.
Published: November 2006

Experiments have been carried out in northern Nigeria to study the deposition and drift of the small spray droplets (70–130 μ v.m.d.), utilised in the application of carbaryl plus an indicating dye, to cotton, at very low volume rates (6–12 litre/ha) using water‐based formulations and at ultralow volume rates (3 litre/ha) using waterless formulations. The character of the deposition and extent of drift have been shown to relate to spray droplet size, formulation and a combination of meteorological factors. Practical recommendations have been evolved for very low volume and ultralow volume techniques in which the time of application is restricted to those periods of the day which favour high recovery.
Penetration of bean leaves by aminotriazole as influenced by adjuvants and humidity
Authors: Cook Gordon T. , Babiker Abdel G. T. , Duncan Henry J.
Published: November 2006

Penetration of bean leaves (Phaseolus vulgaris var. Canadian Wonder) by aminotriazole (3‐amino‐1,2,4‐triazole) was greatly enhanced under high humidity conditions (ca 10% in 17 h at the low humidity level (LHL) compared with ca 80% in 2 h at the high humidity level (HHL)). The addition of polyoxyethylene 20 sorbitan monolaurate (polysorbate 20) to the spray fluid increased penetration on all occasions at the LHL. The increase obtained was found to be dependent on the concentration of polysorbate 20. The inclusion of polysorbate 20 at the HHL resulted in an increase in aminotriazole penetration at low polysorbate 20 concentrations 0.2–12.8 g/litre and a non‐significant decrease over the aqueous control at a concentration of 40 g/litre. With additions of glycerol to the spray fluid, aminotriazole penetration was increased on all occasions at the LHL while at the HHL no concentration of glycerol was found to enhance penetration. The addition of polysorbate 20 (< 0.1 to 40 g/litre) to a spray solution containing glycerol (0.3 ml/litre) enhanced penetration at the HHL compared with the aqueous and glycerol controls. A polysorbate 20 plus glycerol combination (6.4 g+0.6 ml/litre) gave the same order of penetration (98.4 and 94.0%) at the HHL and LHL respectively. In both cases penetration exceeded that obtained with the corresponding polysorbate 20 and glycerol controls. Some of the practical implications of these findings are discussed.
Analytical method for traces of hexachlorobenzene in formulations of other pesticides
Authors: Alam Mumtaz
Published: November 2006

A method is described for the analysis of trace levels of hexachlorobenzene in pesticide formulations. The method involves the conversion of hexachlorobenzene to pentachlorophenol which is converted to the acetate and analysed on a gas chromatograph using microcoulometric detection. This technique allows separation of hexachlorobenzene from most constituents of the pesticide formulations.
Hydrolysis and photolysis of the fungicide triforine
Authors: Darda Siegfried , Darskus Rolf L. , Eichler Dietrich , Ost Walter , Wotschokowsky Manfred
Published: November 2006

The main decomposition products formed from triforine by hydrolysis in solution and by photolysis were isolated and identified. In aqueous solution at 21°, hydrolysis proceeds rapidly by formation of chloride ions and, through several intermediates, 1‐(dihydroxyacetyl)piperazine and piperazine. Photolysis by ultraviolet light in the absence of water leads preferentially to the removal of one side chain, the second side chain being attacked more slowly. In aqueous solution, triforine is rapidly destroyed by ultraviolet light. N‐(2,2‐Dichlorovinyl)formamide was isolated as an intermediate photodecomposition product.
Toxicity of pyrethroids to larvae of the egyptian cotton leafworm, Spodoptera littoralis (Boisd.). I. Relative toxicities and knockdown activities of benzyl, and 5‐benzyl‐3‐furylmethyl, cyclopropanecarboxylates
Authors: Ford Martyn G. , Reay Richard C. , Pert David , Ellis Peggy E. , McVeigh Lawrence J.
Published: November 2006

The contact toxicity of ten pyrethroids to larvae of Spodoptera littoralis (Boisd.) was investigated by topical application, and symptoms observed for different combinations of dose and time. Several compounds were sufficiently active to suggest that they may prove useful for the control of populations in the field. Structure and activity are discussed with particular reference to time‐dose‐response relationships: speed of action is related to both chemical structure and applied dose.
Stability of thiophanate‐methyl in aqueous dispersion
Authors: Courtney Graham F.
Published: November 2006

This paper reports chemical evidence on the fate of the systemic fungicide thio‐phanate‐methyl dissolved in methanol, chloroform and ethyl acetate0, and in aqueous dispersions from pH 1 to pH 13. It is shown that thiophanate‐methyl is unstable when dissolved in ethyl acetate and that it is stable in aqueous dispersions from pH 1 to pH 9.
Plant growth substances and flower development
Authors: Morgan Dyfrig G.
Published: November 2006

The development of flowers in some varieties of french beans and barley is controlled by daylength and the effects of photoperiod appear to be mediated through changes in the levels of plant growth substances in the leaves and buds. In oil seed rape hormonal and assimilatory factors interact to control flower development.
The effectiveness of pyrethroid seed treatments against soil pests of cereals
Authors: Griffiths David C.
Published: November 2006

Results are summarised of tests of seed dressings with synthetic pyrethroids against wheat bulb fly (Delia coarctata) and wireworms (Agriotes spp.).
Transparent emulsions of pyrethroids
Authors: Brown Bernard B. , Jaus Joseph B. , Calsetta Douglas R.
Published: November 2006

When the absence of organic solvents or halogenated/hydrocarbon propellants are desirable or mandatory in applying pyrethroids for typical institutional or household disinsection, emulsifiable concentrates are available that permit aqueous dilution in all proportions to provide transparent, indefinitely stable compositions suitable for non‐pressurised delivery. The system is equally applicable to synergised natural pyrethrins and typical synthetic pyrethroids. The compositions can accommodate additives to provide economic residual action against crawling insects when desirable. Typical products registered in the United States will be discussed as will development activities on the new long residual pyrethroids.