bluuebunny/crossref_metadata_2025_split huggingface dataset:
A simple bioassay for detecting and characterising insecticide resistance
Authors: Bloomquist Jeffrey R. , Miller Thomas A. 
Published: November 2006

AbstractA simple and rapid paralysis assay was developed to detect and characterise knockdown resistance in larvae of the house fly and pink bollworm. Pyrethroidtreated larvae unable to perform a stereotypic curling movement when probed with a warm needle, 10 min (house fly) or 60 min (pink bollworm) after treatment, were considered to be paralysed. Responses in a susceptible strain of house fly were compared with those of the pyrethroid‐resistant strains kdr and super‐kdr. In this assay, the kdr strain displayed over 28 fold resistance to deltamethrin, and super‐kdr larvae were unaffected by doses up to 100μg. These results are in good qualitative agreement with previous studies. The assay detected no significant fenvalerate resistance in pink bollworm larvae collected from the field; this was consistent with mortality bioassays performed on wild adult males. The limitations and potential utility of the paralysis bioassay in resistance screening are discussed.
Mode of action of the anthelmintics morantel, pyrantel and levamisole on muscle cell membrane of the nematode Ascaris suum
Authors: Harrow Ian D. , Gration Kenneth A. F. 
Published: November 2006

AbstractIntracellular current and voltage clamp techniques were used to investigate the mode of action of the anthelmintics, morantel, pyrantel and levamisole applied to the bag region of Ascaris suum muscle cells. Microperfusion of the anthelmintics and of O‐acetylcholine (ACh) increased the input conductance and depolarised the membrane potential of the muscle bags. The relative potencies of these drugs were determined from dose–conductance relationships and found to be: morantel = pyrantel > levamisole > ACh. High doses (>10μM) of morantel caused antagonism of ACh responses. ACh‐induced currents were measured under voltage clamp (over the range −80 to +10mV). At membrane potentials between −80 and 0 mV, microperfusion of ACh induced a voltage‐dependent inward current. The current–voltage relationship was linear for membrane potentials in the range −30 to +10mV. The reversal potential was measured directly and found to be about +10mV. The relationship became non‐linear at membrane potentials more negative than −30 mV, and the degree of non‐linearity was dependent upon the concentration of ACh. The current–voltage relationships for morantel, pyrantel and levamisole also possessed both linear (−30 to 0mV) and non‐linear components. The reversal potential for each agonist, determined by extrapolation of the linear component of the current–voltage relationship, was approximately +10mV, indicating the same cation channels were activated both by ACh and the anthelmintics. Evidence for competition between ACh and pyrantel for the same membrane receptor was obtained using iontophoretic delivery of each agonist from a double‐barrelled micropipette. It is concluded that the anthelmintics, morantel, pyrantel and levamisole act as potent agonists at ACh receptors on muscle bag membranes of A. suum.
Physiological interactions between the herbicide EPTC and selected analogues of the antidote naphthalic anhydride on two hybrids of maize
Authors: Hatzios Kriton K. , Zama Paul 
Published: November 2006

AbstractThe efficacies of nine structural analogues of the herbicide antidote naphthalene‐1,8‐dicarboxylic acid anhydride (naphthalic anhydride, NA) for the protection of maize (Zea mays L. cv. DeKalb XL72AA and DeKalb XL67) against injury by the herbicide S‐ethyl dipropyl(thiocarbamate) (EPTC) were elevated under greenhouse conditions. The chemical analogues of NA tested were: acenaphthenequinone (ACQ); 4‐aminonaphthalene‐1,8‐dicarboxylic acid anhydride (NH2NA); 1,8:4,5‐naphthalenetetracarboxylic acid dianhydride (NDiA); naphthalene‐ 1,8‐carboximide (NHNA); 4‐chloronaphthalene‐1,8‐dicarboxylic acid anhydride (C1NA); biphenyl‐2,2′‐dicarboxylic acid anhydride (diphenic anhydride; DA); 2‐phenylglutaric anhydride (PGA); phthalic anhydride (PHA); phenalen‐1‐one (PA). Pre‐plant incorporated applications of EPTC at 2.2, 4.5, 6.7, and 9.0 kg ha−1 were highly toxic to XL67 maize. Appreciable injury to XL72AA maize by EPTC was observed only with the high rates of EPTC (6.7 and 9.0 kg ha−1). Of the analogues tested PGA and PA were very toxic and inhibited germination of both maize hybrids. NA, ACQ, NH2NA, NDiA, NHNA, C1NA, DA, and PHA applied as seed dressings at 5.0 and 10 g per kg of seed offered satisfactory protection to XL72AA maize against EPTC rates higher than 6.7 kg ha−1. The same antidotes significantly antagonised the EPTC activity against XL67 maize but the overall protection obtained was partial and not agronomically important. The presence of the dicarboxylic anhydride group and of at least one aromatic ring attached directly to the anhydride appeared to be essential for the exhibition of protective activity by the structural analogues of NA. NA was slightly toxic to both hybrids of maize and chlorination of NA increased the phytotoxicity of this molecule. A genetic component that is present in the thiocarbamate‐tolerant XL72AA hybrid but absent from the thiocarbamate‐susceptible XL67 hybrid of maize appeared to be important for the phytotoxic activity of EPTC and may be involved in the protective activity of NA and its structural analogues.
Excretion of DDT residues into milk of the Indian buffalo, Bubalus bubalis (L.) after oral and dermal exposure
Authors: Kalra Rajinder L. , Chawla Ram P. , Joia Balbir S. , Tiwana Mewa S. 
Published: November 2006

AbstractThree groups of buffaloes were fed with 20, 100 and 400 mg of p,p′‐DDT in their daily rations. The DDT residues in the milk fat of the treated animals showed an initial rapid rise but soon attained a dose‐dependent equilibrium. The transfer coefficient of DDT residues in milk at ‘plateau’ levels showed an average value of about 12%. Half‐life values for the rate of decline of DDT residues during the post‐dosing period were computed according to a two‐open‐compartment model. Dermal application of p,p′‐DDT to buffaloes also resulted in excretion of a significant amount of its residues in milk. TDE was the predominant compound present in milk when buffaloes had ingested p,p′‐DDT, whilst p,p′‐DDT itself was present in greater quantity than its metabolites when animals were treated dermally.
Theoretical considerations for the application of aromatic and heterocyclic fluorine compounds as pesticides
Authors: Pavlath Attila E. 
Published: November 2006

AbstractA fluorine atom attached to an aromatic or heterocyclic system is quite stable in many chemical and biochemical reactions. Its size, in contrast to other halogen atoms, is comparable to that of a hydrogen atom and therefore, fluorine substitution does not distort the steric configuration of most compounds involved in biological processes. This can result in the incorporation of fluorinated compounds at some stage into the life cycle of various organisms. The high electronegativity of the fluorine, however, may alter considerably the reaction kinetics and mechanism of such intermediates at a later stage of the cycle causing biological disruption and possible pesticidal effect.
Fluorine‐containing intermediates for pesticides
Authors: Braden Rudolf P. J. , Klauke Erich 
Published: November 2006

AbstractCompounds containing fluoro‐ or fluoroalkyl‐substituents often show interesting biological activities. However, the high cost of introducing fluorine into a molecule may make the manufacture of a compound with excellent biological activity too expensive for commercial viability. The cheapest source of fluorine is hydrogen fluoride but most fluorine substitution reactions described in the literature make use of alkali metal fluorides which, although more convenient to handle in the laboratory, are much more expensive. This paper describes the use of hydrogen fluoride in new synthetic routes to a number of intermediates for the manufacture of commercially useful pesticides. These include compounds containing the dichlorofluoromethylsulphenyl radical, derivatives of perfluoro‐2,5‐diazahexa‐2,4‐diene, various aromatic fluoro compounds and some fluorinated benzodioxoles and benzodioxenes.
Vapour pressure of permethrin
Authors: Wells David , Grayson B. Terence , Langner Eric 
Published: November 2006

AbstractThe vapour pressures of the separate isomers of permethrin have been determined over a range of temperatures by two laboratories using different versions of the gas saturation method. A statistical analysis of the sets of data from the two laboratories shows no significant differences for the cis isomers but a small difference in the 20°C extrapolated values for the trans isomer exists. However, this difference is discounted as arising from experimental error and the mean values of the estimated vapour pressures at 20°C are given as 2.5 μPa (cis) and 1.5 μPa (trans).
The influence of molasses on the physical properties and sprayability of two pesticide formulations
Authors: Abbott Henry A. 
Published: November 2006

AbstractThe effects of molasses on some of the physicochemical properties and on the sprayability of a carbaryl wettable powder (w.p.) and triazophos emulsifiable concentrate (e.c.) were studied in the laboratory and the field. When sprayed in the laboratory on bean leaves, the deposit obtained from either formulation decreased as the percentage of molasses was increased. In an aerial application field trial on cotton, 10% molasses gave a smaller deposit of active ingredient than obtained in the absence of additive, while 20% molasses gave a greater deposit, with either formulation. Molasses had an adverse effect on some properties of the spray mixtures, which resulted in lower deposits when spraying was done at high humidity in the laboratory. This effect was offset when spraying was done at lower humidity in the field, because molasses improved the impaction of droplets by increasing their density and by preventing the complete evaporation of small droplets.
The in‐vivo metabolism of propetamphos by insecticide‐resistant and susceptible strains of the housefly, Musca domestica
Authors: Wells David S. , Motoyama Naoki , Dauterman Walter C. 
Published: November 2006

AbstractThe metabolism of propetamphos by insecticide‐resistant and susceptible houseflies, in vivo, was investigated. Two major pathways of propetamphos degradation were found. The first is the major route of detoxification for both resistant and susceptible strains at low doses and involves a hydrolysis of the P–O‐vinyl bond, ultimately resulting in the formation of carbon dioxide. The second major pathway involves conjugation. As the dose increases, so does the importance of this pathway. Those strains of houseflies with greater conjugative capacity are able to tolerate greater doses of propetamphos than those strains with lesser conjugative capacity. The properties exhibited by this conjugate are consistent with those of glutathione conjugates. This is further supported by a parallel between reported values of glutathione S‐transferase activity in the houseflies tested and tolerance to propetamphos.
Teratogenic effects of the fungicide benomyl on posterior segmental regeneration in the earthworm, Eisenia fetida
Authors: Zoran Mark J. , Heppner Thomas J. , Drewes Charles D. 
Published: November 2006

AbstractEarthworms, Eisenia fetida, were treated by surface exposure to the fungicide benomyl at various stages of posterior segmental regeneration. Teratogenic effects of benomyl were observed when worms were treated 7–11 days after amputation (i.e. during the normal period of segmental replication), but not during days 1–5, 13–17, or 19–23. Teratogenic effects included a reduction in the number of regenerated segments, an increased frequency of segmental groove anomalies, and a variety of monstrosities. The effects of benomyl treatment on the number of regenerated segments and frequency of anomalies were dose‐dependent within a narrow concentration range (approximately 0.2–5.0 mg litre−1); at higher concentrations (e.g. 25 mg litre−1) teratogenic effects were less frequent because the onset of segmental delineation was delayed until well after exposure. Non‐invasive electrophysiological recordings from treated worms indicated that functional integrity of giant nerve fibre conduction pathways was established in all anomalously regenerated tail segments, except in a two‐tailed monstrosity. The evidence supports the hypothesis that these teratogenic effects derive from an antimitotic mode of action of benomyl on segmental regeneration.
Fungicidal activity of 2‐(1‐alkenyl)‐3‐hydroxy‐1,4‐naphthoquinones and related compounds
Authors: Jacobsen Niels , Wengel Anita 
Published: November 2006

AbstractThe fungicidal activity of a series of 2‐(1‐alkenyl)‐3‐hydroxy‐1,4‐naphthoquinones and their acetates has been assessed against various fungi in vitro and against others, notably powdery mildews, in vivo, and the activity compared with that of analogous compounds bearing saturated side chains. Several of the compounds demonstrated a broad spectrum of activity in vitro. Whereas the presence of α‐unsaturation in the side chain is essential for the in‐vitro activity against the non‐obligate fungi tested, it is of virtually no importance for the curative effect against Erysiphe graminis on barley. Only the corresponding acetates had activity against the latter pathogen.
Residues of dalapon and TCA in sediments and irrigation water
Authors: Bowmer Kathleen H. 
Published: November 2006

AbstractWhen dalapon and TCA are used for the management of aquatic weeds in irrigation distribution systems, they are often applied to established stands of Typha spp. and Phragmites australis in autumn or early winter, after draining water from the system. It has been assumed that the herbicides would dissipate from the sediments within 6 weeks, so that water supplies could be safely restored. In field experiments the decay of dalapon and TCA in sediments followed the classical pattern for a microbially mediated process, with a slow lag‐phase, followed by a rapid phase of decline, but not to completion. Particularly for TCA, there was a final slow phase in which residues were sufficient to contaminate eluting water at concentrations much greater than the legally prescribed tolerance, even when the interval between herbicide treatment and water re‐supply was more than 6 weeks. Although the overall pattern of dissipation in the sediment was similar for the two herbicides, concentrations of TCA were higher than those of dalapon in the elution water, probably reflecting differences in herbicide mobility and elution efficiency. Dye tracers were used in three field experiments to investigate the efficiency of herbicide elution and carryover of contaminated water when canals were filled to capacity, drained and refilled. Together with the rate of dissipation from sediments, canal topography and draining efficiency determined the safety of the elution process in removing surplus residues before re‐supply of water for irrigation. In large‐scale management operations, where the dissipation interval was only 17‐19 days, the TCA was eluted from the sediment into flowing water in proportion to the square root of time, giving average concentrations over 3 days of discharge of more than 0.4gm−3. Ideally, the interval between spraying and water re‐supply should be extended beyond 6 weeks. Alternatively, herbicide use should be restricted, or provision made for elution of surplus residues and disposal of contaminated water to waste, or onto tolerant crops or fallow land.
A note on the bimodal concentration response of Pythium aphanidermatum to carboxin and carbendazim
Authors: Panwar Roopali , Singh Rama S. , Singh Uma S. 
Published: November 2006

AbstractThe concentration/respone curve for carboxin and carbendazim against mycelial growth of Pythium aphanidermatum measured in vitro is bimodal, suggesting the involvement of more than one concentration‐dependent site of action.
High resolution g.l.c. specifications for plant spray oils
Authors: Furness Geoffrey O. , Walker David A. , Johnson Paul G. , Riehl Louis A. 
Published: November 2006

AbstractHigh resolution g.l.c. chromatograms of a series of reference plant‐spraying oils were used for the development of proposed g.l.c standards for spraying oils in Australia. The mean size and size‐range of molecules in the oils have been specified in relation to carbon number positions for reference n‐paraffins. Problems with reproducibility and precision with reduced pressure distillation (10 mm Hg) of plant‐spraying oils have been demonstrated and discussed.
Synthesis and insecticidal activity of lipophilic amides. Part 6: 6‐(disubstituted‐phenyl)hexa‐2,4‐dienamides
Authors: Elliott Michael , Farnham Andrew W. , Janes Norman F. , Johnson Diana M. , Pulman David A. 
Published: November 2006

AbstractBy using a phosphonate containing an N‐(2,2‐dimethylpropyl) instead of an N‐(2‐methylpropyl) group, rearrangement during the Wadsworth‐Emmons condensation step was restricted to an acceptable level even with products from disubstituted phenylacetaldehydes. Previous results had shown that this change in N‐group did not alter insecticidal activity drastically, so structure‐activity relationship conclusions could be drawn from both series in combination. The presence of methyl groups on the phenyl lowered activity, confirming results in the mono‐substituted series, so attention was directed primarily to the numerous possible di‐halo combinations. Many were active, especialty those with 3,4 or 3,5 substitution patterns, but beyond this no simple correlations could be detected relating position or nature of substituents to activity. Varying both the phenyl substituents and amine group gave results approximately in agreement with additivity principles.
Permethrin treatments in canadian forests. Part 1: Impact on stream fish
Authors: Kingsbury Peter D. , Kreutzweiser David P. 
Published: November 2006

AbstractThe effects of permethrin on native and caged fish when aerially applied directly to forest streams at dosages between 8.8 and 70 g ha−1 were studied between 1976 and 1981. None of the applications caused mortality of caged or native fish in streams. Trout and salmon diets were altered by the treatments due to effects on fish food organisms. The duration of the effects varied from several months to over a year with increasing dosage. Reductions in salmonid growth rates and reductions in fish densities in treated areas, presumably due to emigration, were documented following severe impacts on aquatic invertebrates in salmon nursery streams. Growth rates and population densities both recovered within four months after treatment.
The photodegradation of parathion and chlormephos
Authors: Buckland Simon J. , Davidson R. Stephen 
Published: November 2006

AbstractIrradiation (∼350 nm) of oxygenated acetonitrile solutions of parathion containing sensitisers such as benzoin and α‐dicarbonyl compounds leads to oxidative desulphurisation at phosphorus, producing paraoxon in reasonable yield. Other degradation reactions also occur, probably as a result of the presence of the 4‐nitrophenyl group in parathion. Under similar irradiation conditions, chlormephos is desulphurised at both the thionate and thiolate moiety. The reactions are rationalised as occurring via peroxy radicals which are generated from the sensitisers. Reaction was not observed when dyes, e.g. rose bengal, were used as sensitisers, which accords with the view that thionates and thiolates are not reactive towards singlet oxygen.
Physico‐chemical factors affecting uptake by roots and translocation to shoots of weak acids in barley
Authors: Briggs Geoffrey G. , Rigitano Renê L. O. , Bromilow Richard H. 
Published: November 2006

AbstractThe uptake from solution of maleic hydrazide, flamprop and a series of phenoxyacetic acids by roots, and their subsequent translocation to shoots, was measured in barley. Both uptake and translocation increased as the pH of the solution decreased, the magnitude of the change varying amongst the chemicals tested. Uptake by roots could be accounted for by the ion‐trap mechanism, which assumes that entry of the chemicals occurs largely by passive diffusion of the undissociated form of the acids, with passage of the anions across the cell membranes being very slow. The ratio of the permeability of the cell membranes to the undissociated and dissociated forms of the acids was estimated from the accumulation in roots, and in the phenoxyacetic acid series this ratio was maximal (4×105) for compounds of intermediate lipophilicity. Maleic hydrazide and flamprop had much lower ratios, 1.8×102 and 103 respectively; the value for flamprop was much less than for phenoxyacetic acids of similar lipophilicity, such as 2, 4‐ dichlorophenoxyacetic acid, indicating that lipophilicity may not be the sole factor determining the behaviour of weak acids in plants. Translocation to shoots was approximately proportional to the chemical concentrations in the roots.
Characterization of the structure‐activity relationship of kdr and two variants of super‐kdr to pyrethroids in the housefly (Musca domestica L.)
Authors: Farnham Andrew W. , Murray Alistair W. A. , Sawicki Roman M. , Denholm Ian , White Jean C. 
Published: November 2006

AbstractStructure‐activity relationships (SARs) for 10 pyrethroids against susceptible, kdr and super‐kdr strains of houseflies (Musca domestica L.) were investigated by Principal Components Analysis. In the three strains with kdrLatina' all only slightly to moderately (2.6 to 26‐fold) resistant to pyrethroids, no correlation between the structure and Levels of resistance could be discerned. In flies with super‐kdr, SARs were influenced by the nature of the alcoholic portion of the ester. Resistance was strongest to esters of a‐cyano‐3‐phenoxybenzyl alcohol (74 to 430‐fold) and to permethrin (48 to 55‐fold). It was weak (6.2 to 11‐fold) to cyclopentenone derivatives, being barely stronger than for flies with kdr (2‐6 to 6.3‐fold). Two variants of super‐kdr (3D and A2) were distinguished on the basis of their differential response to esters of 5‐benzyl‐3‐furylmethanol. It is presumed that kdrLatina, super‐kdrA2 and super‐kdr3D form an allelic series in which kdrLatina represents ground level insensitivity, and the two super‐kdrs the progressive extension of strong resistance to more types of ester. The strong differences in resistance to different pyrethroid esters by super‐kdr flies provides scope for improving management of resistance to pyrethroid insecticides and for modifying the SAR of pyrethroids to favour weak resistance.
Determination and persistence of imazalil in post‐harvest‐treated apples during cold storage
Authors: Cano Maria P. , De la Plaza Josê L. , Muñoz‐Delgado Luis 
Published: November 2006

AbstractA method to determine imazalil (allyl 1 ‐(2, 4‐dichlorophenyl)‐2‐imidazol‐ 1‐ylethyl ether) on apples using high performance liquid chromatography is described. After harvest, fruits were immersed in an aqueous suspension (1 g litre‐1) and cold stored (0‐2°C) at 85‐90% r.h. Samples were taken monthly and imazalil was determined in the peel, outer pulp, inner pulp and on whole fruit. Residues were 3.8‐4.9 mg imazalil kg‐1 and decreased during storage. Most imazalil was found on the peel and amounts in the pulp decreased toward the core.