bluuebunny/crossref_metadata_2025_split huggingface dataset:
New insecticides by replacement of carbon by other Group IV elements
Authors: Sieburth Scott McN. , Lin Sarah Y. , Cullen Thomas G. 
Published: November 2006

AbstractAll of the Group IV elements, C, Si, Ge, Sn and Pb, form four tetrahedrally disposed bonds and could be considered as replacements for each other. Because the atomic radius increases linearly with increasing row number, this replacement can also be considered as a probe of steric effects. The use of silicon, with its high natural abundance and non‐toxic nature, has received the most attention. Examples of silicon‐for‐carbon exchange can be found for all major classes of insecticides, including carbamates, phosphates, pyrethroids, as well as DDT and juvenile hormone analogs. Generally, the silicon analogs retain insecticidal activity. A silicon analog of MTI‐800 (dimethyl‐4‐ethoxyphenyl‐I‐(3‐(4‐fluoro‐3‐phenoxyphenyl)propyl)silane) is a broad spectrum insecticide. This silane was used as a starting point for building new silane analogs as potential insecticides. Two analogs were particularly noteworthy. A silane with a cyclopropyl group was found to be non‐toxic to Trichoplusia ni (cabbage looper) while the corresponding carbon compound was a potent insecticide. An analog containing a silicon‐hydrogen bond, a structural feature reported to be unstable in vivo, was found to be significantly insecticidal both topically and in foliar tests. The latter compound suggests that biologically active silanes can encompass broader structural types than previously anticipated.
Sensitivity of the pear scab fungus (Venturia nashicola) to three ergosterol biosynthesis‐inhibiting fungicides
Authors: Ishii Hideo , Takeda Hiromi , Nagamatsu Yoshinori , Nakashima Hideki 
Published: November 2006

AbstractSensitivity patterns of Venturia nashicola strains to ergosterol biosynthesis inhibitors (EBIs) were explored in order to obtain ‘base‐line’ data. For triflumizole or bitertanol, sensitivity was examined in mycelial growth tests and comparisons were based on EC50 rather than MIC values. It was also indicated that measurements of germ‐tube length rather than observation of conidial germination or septum formation were needed to assess sensitivity to these fungicides as a rapid and simple method. Field trials were carried out to examine how fast EBIs might select for lower sensitivity in field populations of V. nashicola. Results suggested that any shifts to lower EBI sensitivity in this fungus would not proceed very quickly. It might be possible to avoid potential problems of EBI resistance and maintain the long‐term effectiveness of EBI fungicides in orchards by applying them sparingly.
Antimicrobial activity of some N‐(fluorophenyl)maleimides
Authors: Watanabe S. , Igarashi Y. , Yagami K. , Imai R. 
Published: November 2006

AbstractA variety of N‐(fluorophenyl)maleimides were prepared from the reaction of maleic anhydride and fluorophenylamines, and their antimicrobial activities examined. N‐(Monofluorophenyl)maleimides exhibited antibacterial activity against Bacillus subtilis, Staphylococcus aureus and Escherichia coli, and no activity against Pseudomonas aeruginosa. These compounds also showed antifungal activity against Aspergillus niger, Penicillium citrinum, Cladosporium cladosporioides and Aureobasidium pullulans. All N‐(fluorophenyl)maleimides tested showed activity against yeasts.
Lysimeter studies
Authors: Leake Christopher R. 
Published: November 2006

AbstractTraditionally, the potential mobility of agricultural xenobiotics in soil has been assessed under controlled laboratory conditions. This continues to have a role in determining relative movement, but there is an increasing need to be confident that xenobiotics will not reach the groundwater under field conditions. Outdoor lysimeters using intact soil cores provide a more realistic means of assessment than laboratory techniques without the complications and uncertainties of field studies. Two methods of collecting intact lysimeter cores are described, together with a series of experiments involving the degradation and mobility of the radiolabelled herbicide benazolin‐ethvl (ethyl 4‐chloro‐2,3‐dihydro‐2‐oxo‐1,3‐henzothiazol‐3‐ylacetate).
New heterocyclic herbicidal sulphonamides
Authors: Percival Albert 
Published: November 2006

AbstractThe sulphonylurea structures and their relationships with the 1,2,4‐triazolo[1,5‐a]pyrimidinesulphonamides are first discussed. Three novel examples of heterocyclic sulphonamides, pyrazolo[1,5‐a]pyrimidine‐2‐sulphonamides, thiazolo[3,2‐b][1,2,4]triazole‐2‐sulphonamides and 1,2,4‐triazole‐3‐sulphonamides are highlighted and their synthesis, biological activity and soil behaviour are described.
The toxicity of deltamethrin to pine beauty moth Panolis flammea schiff. and its parasitoids Barichneumon bilunulatus grav. and Rictichneumon pachymerus katz
Authors: Glowacka Barbara , Malinowski Henryk 
Published: November 2006

AbstractThe toxicity of deltamethrin to larvae of the pine beauty moth, Panolis flammea Schiff., and its two parasitoid species, Barichneumon bilunulatus Grav. and Rictichneumon pachymerus Katz., was evaluated. Two methods, exposure of insects on treated filter paper and topical application of insecticide, were used. Results showed that larvae of the pest were many times more susceptible to deltamethrin than imagines of either of the two parasitoid species.
Herbicidal activity and mode of action of vulgamycin
Authors: Babczinski Peter , Dorgerloh Michael , Löbberding Antonius , Santel Hans‐Joachim , Schmidt Robert R. , Schmitt Peter , Wünsche Christian 
Published: November 2006

AbstractThe antibiotic vulgamycin was isolated from a new strain of Streptomyces. Vulgamycin shows herbicidal activity when applied post‐emergence. It controls dicotyledonous weeds and grasses such as Setaria sp. at dosages between 125 and 500 g ha−1. Crops such as cotton, barley and maize tolerate vulgamycin very well. Biochemical mode‐of‐action studies indicate some effect of vulgamycin on an isoleucine‐dependent step within the cell cycle, so‐called GI‐arrest.
Comparative measurements of resistance to insecticides in three closely‐related old and new world bollworm species
Authors: Ernst Gert H. , Dittrich Volker 
Published: November 2006

AbstractToxicity measurements were made with three closely‐related Bollworm species, Heliothis virescens F., Helicoverpa zea (Boddie), and Helicoverpa armigera (Huebner) using insecticides of 3 different chemical classes. Tests were carried out by a leaf‐dip method using neonate larval stages, a topical application test on 3rd larvae, and a topical test with imagines. H. armigera populations from Ivory Coast, Turkey, Thailand, and India were obtained and investigated. H. virescens originated from the USA and Colombia, and H. zea from Guatemala and Nicaragua. Resistance was expressed in all species, the sensitive reference strains having similar LC50s in tests with monocrotophos, profenofos, thiodicarb, and methomyl. Since resistance appeared not to be a quality related to species but rather a feature common to all of the samples investigated, its origin must be connected with the type of cotton culture and the selection pressure they were subjected to in their respective agro‐ecosystem. Resistance was highest for monocrotophos and cypermethrin in Central American countries, differences in the treatment regime being reflected by the resistance levels attained. In all stages tested, resistance was sufficiently well expressed to make a monitoring system based on neonate larvae, the 3rd larval stage, or imagines of the species possible. The final decision as to which should be used for a general, comparative monitoring system, therefore, should be governed by the technical parameters of the testing process.
Development and validation of residue methods for the determination of the pyrethroids lambda‐cyhalothrin and cypermethrin in natural waters
Authors: Hadfield Stephen T. , Sadler Jill K. , Bolygo Elek , Hill Ian R. 
Published: November 2006

AbstractThis paper describes the development of methods suitable for the sampling and analysis of the pyrethroid insecticides lambda‐cyhalothrin and cypermethrin in natural waters. A solid‐phase water‐sampling method which avoids the requirement for transport and storage of large volumes of water is described. This method is shown to be capable of extracting trace levels (ng litre−‐1) of the title compounds from natural waters with efficiencies of at least 80%. Chromatographic analysis of processed samples by gas chromatography–electron capture detection enables determination of residues at levels of 1–2 ng litre−‐1 in water.
Inheritance of fenvalerate and carbofuran resistance in colorado beetles—Leptinotarsa decemlineata (Say)—from North Carolina
Authors: Heim D. Craig , Kennedy George G. , Gould Fred L. , Van Duyn John W. 
Published: November 2006

AbstractProgeny from reciprocal F1 crosses and F1 backcrosses between fenvalerate‐resistant and fenvalerate‐susceptible Colorado beetles, Leptinotarsa decemlineata (Say), and between carbofuran‐resistant and carbofuran‐susceptible Colorado beetles were bioassayed to investigate the mode of inheritance of resistance to these chemicals. Bioassays of progeny from these crosses indicate that resistance to fenvalerate is inherited in a semi‐recessive, sex‐linked manner and carbofuran resistance is inherited in a partially dominant autosomal fashion. Log concentration/probit mortality lines and chi‐square tests, however, indicate that multiple genes may be involved in resistance to both insecticides.
In‐vitro systems for studying phytotoxicity and metabolic fate of pesticides and xenobiotics in plants
Authors: Harms Hans H. 
Published: November 2006

AbstractPlant cell cultures have been used for an ecotoxicological evaluation of pesticides and xenobiotics and results are compared with those using intact plants grown under aseptic conditions. Both plant test systems were able to metabolize the compounds by common metabolic pathways. Qualitatively, the metabolites were the same in both systems. However, using cell suspension cultures, the results may be obtained more quickly with less analytical expense. Such cultures are therefore useful systems for obtaining rapid evidence of the ecotoxicological behaviour of chemicals in plants.
Effects of Sterol Biosynthesis Inhibitor Fungicides on Growth and Sterol Composition of Ustilago maydis, Botrytis cinerea and Pyrenophora teres
Authors: Loeffler R. S. Thomas , Hayes Ann L. 
Published: November 2006

AbstractThe effects of the sterol biosynthesis inhibitor (SBI) fungicides fenarimol, fenpropimorph, imazalil, prochloraz, propiconazole and triadimenol on growth and sterol composition of Ustilago maydis, Botrytis cinerea and Pyrenophora teres, grown from spores or sporidia in liquid culture, were determined. Growth of U. maydis was only slightly inhibited by SBI fungicides at concentrations which caused considerable changes in both sterol content and composition. Conversely, in B. cinerea and P. teres, growth was strongly inhibited under conditions where ergosterol was still the predominant sterol, suggesting that, in these two fungi, growth may be more sensitive to SBI fungicides than overall sterol production. Demethylase inhibitor fungicides behaved as a homogeneous group in their effects on growth and on sterol profiles of the three fungi studied.
Structure and general properties of mineral and vegetable oils used as spray adjuvants
Authors: Hamilton Richard J. 
Published: November 2006

AbstractThe abiogenic and biosynthetic origins of mineral and vegetable oils are contrasted and the importance of soybean, palm, rape seed and sunflower as the major source of fatty acids is highlighted. The cheaper oils derived from animal sources also provide fatty acids. The extraction and refining processes for vegetable oils are explained, the composition of typical vegetable oils is discussed and the importance of the glyceride structure to the physical properties of the oils is emphasised. Stability, volatility and viscosity of vegetable oils are considered.Production of fatty acids by fat‐splitting methods and the formation of methyl esters by inter‐esterification are outlined. Mineral oil compositions are detailed and their properties explained.
Use and mode of action of adjuvants for herbicides: A review of some current work
Authors: Kirkwood Ralph C. 
Published: November 2006

AbstractThe use of surfactants, mineral and vegetable oils, emulsifiers and fertiliser salts, such as ammonium sulfate, can greatly enhance the activity of foliage‐applied herbicides. Adjuvant‐herbicide interactions are reviewed with particular reference to the benefits, including dose reduction, enhanced and more consistent herbicide activity, and the nature of underlying mechanisms; the use and role of surfactants receive particular attention. Surfactants are used as activators in commercial formulations of many herbicides to improve their foliar absorption and ultimate biological activity. Current views on their influence are considered in relation to surface phenomena, solubilisation of non‐polar active ingredients, wax dissolution, cuticle penetration, preferential sites of penetration, membrane permeability and possible systemicity. The importance of a number of moderating factors (plant, chemical and environmental) is discussed in the light of current work, with particular regard to herbicide polarity, surfactant type, Hydrophile‐Lipophile Balance and critical micelle concentration. Current studies on the influence of nonionic polyoxyethylene surfactants of differing ethylene oxide (EO) content have underlined the importance of EO number to their activity.
Topical and oral activities of imidacloprid and cyfluthrin against susceptible laboratory strains of Heliothis virescens and Spodoptera littoralis
Authors: Lagadic Laurent , Bernard Ludovic , Leicht Wolfgang 
Published: November 2006

AbstractActivity of the newly developed nitroguanidine insecticide imidacloprid against fourth‐instar larvae of insecticide‐susceptible strains of the tobacco budworm, Heliothis virescens F., and the Egyptian cotton leafworm, Spodoptera littoralis (Boisd.) was determined from topical application and oral ingestion tests. The activity of imidacloprid was compared to that of cyfluthrin. The LD50 at 48 h of topically applied imidacloprid was estimated as 7.7 and 36.7 μg larva−1 for H. virescens and S. littoralis, respectively. In oral tests, the LC50 at 48 h of imidacloprid incorporated into artificial diet was estimated at 821.0 and 17.7 μg (g food)−1 for H. virescens and S. littoradis larvae, respectively. Imidacloprid showed lower contact and oral toxicities to both species than cyfluthrin, but the difference was much less important in ingestion tests. Mortality caused by both insecticides occurred more slowly in dietary exposures than in topical applications, but imidacloprid acted much more rapidly than cyfluthrin in ingestion tests. When incorporated into the diet, imidacloprid did not produce feeding deterrence, in contrast to cyfluthrin which exhibited a slight repulsive/antifeedant effect. Though cyfluthrin was the more active compound against both H. virescens and S. littoralis larvae, imidacloprid acted much more rapidly in ingestion bioassays. However, the level of activity of the compound is not high enough to provide efficient control of cotton insect pest populations in the field.
The dietary toxicity of deltamethrin to the carabid,Nebria brevicollis(F.)
Authors: Wiles John A. , Jepson Paul C. 
Published: November 2006

AbstractBatches of adultNebria brevicollis(F.) (Coleoptera: Carabidae) were provided with freeze‐killed aphids,Metopolophium dirhodum(Walk.) (Homoptera: Aphididae), that had been treated topically with 30 ng a.i. deltamethrin. Beetles in different hunger states were found to consume contaminated aphids, but they consumed significantly fewer aphids than control beetles. The mean numbers of contaminated aphids eaten increased with hunger‐level, from 2.5 aphids per beetle for those provided with food 24 h before exposure, to 4.5 aphids per beetle for those provided with food 120 h prior to exposure. The highest mortality that occurred over the following six days after consumption of contaminated aphids was 27% for the beetles that had been fed 120 h before exposure and the lowest was 13% for the beetles that had been fed 24 and 48 h prior to exposure. A regurgitation response was observed in 53–80% of the beetles that had consumed deltamethrin‐treated aphids. The beetles that survived consumption of treated aphids showed a short‐term reduction in mean numbers of untreated aphids consumed relative to the control beetles. Dietary and topical dose‐response data for deltamethrin andN. brevicolliswere compared by probit analysis and maximum likelihood procedures. The dietary exposure probit line had a significantly steeper slope than the topical exposure probit line but the two lines occupied similar positions along the dose axis. The steepness of the dietary exposure probit line may be partly explained by the regurgitation response shown by the beetles, which causes water loss and may amplify toxic effects. The results indicated that the consumption of deltamethrin‐contaminated prey may be an important cause of predator mortality soon after pesticide application.
Mobility of fomesafen and atrazine in soil columns under saturated‐ and unsaturated‐flow conditions
Authors: Weber Jerome B. , Strek Harry J. , Sartori Jose L. 
Published: November 2006

AbstractThe relative mobilities of14C‐labeled fomesafen and atrazine in Norfolk sandy loam (Typic Paleudult), Drummer silt loam (Typic Haplaquoll). Cape Fear sandy loam, (Typic Umbraquult), and a Brazilian Oxisol clay (Typic Acrustox) were studied using 50 cm of water applied to 30–5‐cm soil columns under unsaturated‐ and saturated‐flow conditions. Both herbicides were more mobile in Norfolk sandy loam than in Oxisol clay, Drummer silt loam, or Cape Fear sandy loam. Herbicide mobility was inversely related to organic and humic contents of the soils. Mobility of fomesafen was highly correlated with that of atrazine in the soils. Fomesafen was generally less mobile that atrazine under unsaturated‐flow conditions and more mobile under saturated‐flow conditions. Liming a Norfolk sandy loam increased, and oven drying decreased, fomesafen mobility.
Microbial fungicides—the natural choice
Authors: Lange Lene , Breinholt Jens , Rasmussen Frank W. , Nielsen Ruby I. 
Published: November 2006

AbstractFungicidally active secondary metabolites have been found throughout the microbial system, with major new discoveries especially from Actinomycetes and Basidiomycetes. New and interesting modes of action have been revealed (e.g. the unique way in which strobilurin inhibits mitochondrial respiration, or trehalase inhibition by validamycin). These new compounds have been used either directly as microbially produced fungicides (e.g. kasugamycin against rice blast) or as lead molecules for chemical synthesis of novel chemistry (e.g. pyrrolnitrin used as a fungicidal seed dressing).However, a real breakthrough, resulting in a major new group of fungicides based on naturally occurring metabolites is yet to come. Three new fungicidal fungal metabolites are described and one is highlighted in detail in order to illustrate the entire process from isolation of antagonistic microorganisms to structure elucidation of the active molecule.
Metabolism of EPTC by a pure bacterial culture isolated from thiocarbamate‐treated soil
Authors: Tal Abraham , Rubin Baruch 
Published: November 2006

AbstractA bacterial strain has been isolated from an enhanced thiocarbamate degradation soil and identified as Corynebacterium sp. The strain was capable of rapidly metabolizing EPTC in a liquid culture where the herbicide was the sole source of carbon. Evolution of high quantities of [14C]carbon dioxide was coupled with a rapid decline of [14C]EPTC in the medium; after 12 h incubation these accounted for, respectively, 60% and 0% of the recoverable radioactivity. Radioactivity in the polar extract increased gradually up to 20% after 6 h of incubation and then declined slowly. TLC analysis and identification based on comparison to reference compounds showed that the polar extract consisted of EPTC sulfoxide and two conjugates, EPTC‐GSH and EPTC‐cysteine (1·8%, 3·4%, and 16%, respectively). Piperonyl butoxide and tetcyclasis, but not tridiphane, were found to be effective inhibitors of EPTC metabolism in the bacterial culture, suggesting that the breakdown of EPTC might be carried out by a cytochrome P‐450 monooxygenase‐type activity. The thiocarbamate extender, dietholate, also strongly inhibited the metabolism of EPTC in bacterial culture. Based on these results it was postulated that the bacteria metabolize EPTC mainly by hydroxylation of the α‐propyl carbon finally to release [14C]carbon dioxide, while EPTC sulfoxidation appears to be a minor route.
Herbicidal selectivity of (E)‐3‐(2,4‐dichlorophenoxy)acrylates: QSAR study with molecular connectivity indices
Authors: Šoškić Milan , Sabljić Aleksandar 
Published: November 2006

AbstractThe aim of this study was to generate a quantitative model of the herbicidal selectivity of (E)‐3‐(2,4‐dichlorophenoxy)acrylates against barnyard grass and rice. Molecular connectivity indices and other topological quantities were used as molecular descriptors. A solid and sound correlation (r = 0·91) was obtained between the selectivity index ΔpI50 (defined as logarithmic ratio of biological activities observed in the two tested plant species) and the three topological quantities: the first‐order molecular connectivity index, the valence fifth‐order path/cluster molecular connectivity index, and the presence of a cyclic alcohol moiety. Our QSAR analysis revealed that the size of a molecule accounts for a large part of the variation in the ΔI50 data. However, the degree of branching and the presence of a cyclic group in the alcohol moiety have a significant influence on the selectivity of (E)‐3‐(2,4‐dichlorophenoxy)acrylates. The derived selectivity model, when compared with the corresponding empirical model, based on the 1‐octanol/water partition coefficient and Taft's polar constant, shows a far superior performance in accuracy.
Modeling environmental effects on enhanced carbofuran degradation
Authors: Parkin Timothy B. , Shelton Daniel R. 
Published: November 2006

AbstractPrediction of the fate of pesticides in soil is of interest from an environmental (pollution) as well as an agricultural (efficacy, carryover) viewpoint. Two environmental parameters that control microbial degradation of pesticides in soil are moisture and temperature. This study was designed to quantify the impact of soil water content and temperature on microbial degradation rates of the insecticide carbofuran (2, 3‐dihydro‐2, 2‐dimethylbenzofuran‐7‐yl methyl‐carbamate). Carbofuran degradation was determined by monitoring the [ 14 C] carbondioxide production from soils amended with [carbonyl‐ 14 C]carbofuran. Soils were incubated at seven soil‐water tensions over the range of 0–03 to 1–5 MPa, and at five temperatures (10°C to 30°C). The sigmoidal degradation kinetics observed from these incubations were modeled using a general saturation model. For the moisture experiments, maximum rate of hydrolysis and half‐life (DT50) were accurately modeled by an exponential relationship. The response of carbofuran degradation to temperature was also well described by an exponential relationship, from which it was estimated that the Q10 associated with the maximum rate was 1.68, and the Q10 for DT50 was 1–89.