bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of chitin‐synthesis inhibitors on stored‐product beetles
Authors: Elek Jane A. , Longstaff Barry C. 
Published: November 2006

AbstractThe fecundity of four important coleopteran stored‐grain pests, Rhyzopertha dominica (Fab.), Sitophilus oryzae (L.), Oryzaephilus surinamensis (L.) and Tribolium castaneum (Herbst.) was assessed after exposure to wheat treated with five benzoylphenyl ureas (BPUs), members of the chitin‐synthesis inhibitor group of insect growth regulators (IGRs). Chlorfluazuron was found to control all four species more effectively than triflumuron, teflubenzuron, flufenoxuron or diflubenzuron. Two weeks of exposure of parents to 0.5 mg kg −1 of all the BPUs, except diflubenzuron, inhibited almost all F1 production and all the F2 production of each species. The fecundities of T. castaneum and O. surinamensis recovered almost to their untreated levels after two weeks of exposure to 1 mg kg −1 of BPUs followed by two weeks on untreated wheat, but the effect of the exposure persisted for at least two weeks on untreated wheat in adult S. oryzae and to a lesser extent in R. dominica. The mean F1 response of the four species after two weeks of exposure to four doses showed clearly that the four newer BPUs were all similar in their overall effectiveness and significantly more effective than diflubenzuron, although diflubenzuron was equally effective against S. oryzae. At 0.1 mg kg −1 triflumuron was less effective against O. surinamensis, while teflubenzuron and flufenoxuron were not very effective against the rice weevil, S. oryzae. Chlorfluazuron provided the most effective control of all four stored‐product pest species, including the weevil, S. oryzae. The BPUs show particular potential for use in the stored‐product industry because low dosages will effectively control the rice weevil in addition to the other major pest species.
Metabolism of the pesticide metabolites 4‐nitrophenol and 3,4‐dichloroaniline in carrot (Daucus carota) cell suspension cultures
Authors: Schmidt Burkhard , Thiede Brigitte , Rivero Christiane 
Published: November 2006

AbstractThe metabolism of [ 14 C]‐4‐nitrophenol and [ 14 C]‐3,4‐dichloroaniline (the xenobiotics are degradation products of parathion and propanil, respectively) was studied in cell suspension cultures of carrot (Daucus carota L.). 4‐Nitrophenol was transformed almost quantitatively to water‐soluble conjugates with minor amounts of non‐extractable residues. The conjugates identified were 1‐(O‐β‐D‐glucopyranosyl)‐4‐nitrobenzene and 1‐(6′‐O‐malonyl‐O‐β‐D‐glucopyranosyl)‐4‐nitrobenzene. In addition, two unidentified metabolites were observed, possibly a disaccharide and another malonylated glycoside of 4‐nitrophenol. Time‐course studies demonstrated that 4‐nitrophenol was rapidly taken up and conjugated; all metabolites remained associated with the cells rather than nutrient medium. 3,4‐Dichloroaniline was transformed quantitatively to water‐soluble conjugates and bound residues (3.6%). The water‐soluble metabolites were identified as 6′‐O‐malonyl‐N‐(β‐D‐glucopyranosyl)‐3,4‐dichloroaniline, N‐(β‐D‐glucopyranosyl)‐3,4‐dichloroaniline and N‐malonyl‐3,4‐dichloroaniline. A time‐course study showed that the glucosides were formed initially, then decreased, possibly due to hydrolysis. This decrease was paralleled by an increase of the main metabolite, N‐malonyl‐3,4‐dichloroaniline, which was predominantly recovered from the medium.
Activity of two novel insecticides against permethrin‐resistant Pseudoplusia includens
Authors: Thomas James D. , Mink Jeffrey S. , Boethel David J. , Wier Alan T. , Leonard B. Roger 
Published: November 2006

AbstractTwo experimental insecticides, AC 303,630 and MK 244, were tested against a laboratory colony and three field strains of Pseudoplusia includens (Walker). Topical application bioassays indicated that permethrin resistance in the field strains ranged from 3.9 to 489.0‐fold. In leaf dip bioassays, LC50 and LC90 values for AC 303,630 ranged from 6.7 to 15.1 mg litre −1 and 8.7 to 28.2 mg litre −1, respectively, for third‐instar larvae. The Louisiana 1991 field strain was significantly more susceptible to AC 303,630 than the laboratory and other field strains. The LC50 (but not LC90) for the Louisiana 1992 field strain was significantly higher than that of the laboratory strain. However, there was no difference in toxicity of AC 303,630 between the field strain with the highest level of permethrin resistance and the laboratory strain. LC50 and LC90 values for MK 244 in leaf dip bioassays ranged from 0.014 to 0.023 mg litre −1 and 0.079 to 0.174 mg litre −1, respectively. There were no significant differences in LC 50 or LC 90 among any of the strains for MK 244. Field trials in soybean were also conducted in 1991 and 1992 in an area of Louisiana where permethrin efficacy against P. includens has declined. In both years, AC 303,630 at 0.11–0.22 kg ha −1, and MK 244 at 0.0042–0.0084 kg ha −1, provided significantly better control than permethrin at 0.11 kg ha −1, and control equal to the recommended standard, thiodicarb. These studies indicate no cross‐resistance exists between the experimental insecticides and permethrin.
Photochemistry of parathion in the plant cuticle environment: Model reactions in the presence of 2‐propanol and methyl 12‐hydroxystearate
Authors: Schwack Wolfgang , Andlauer Wilfried , Armbruster Wolfgang 
Published: November 2006

AbstractOn UV‐irradiation (λ > 280 nm), photodegradation of parathion dissolved in 2‐propanol took place mainly by reduction of the phenylnitro group. The photoreduction intermediates so formed then combined, yielding primarily azoxyparathion which, upon further irradiation, rearranged into 2‐hydroxyazoparathion.When parathion was irradiated in the presence of the cutin acid 12‐hydroxystearic acid (as the methyl ester), azoparathion, azoxyparathion and 2‐hydroxyazoparathion were the dominant photoproducts if the reaction was performed in thin‐layer films of the 12‐hydroxystearate. Irradiation of parathion dissolved in a solution of the 12‐hydroxystearate in cyclohexane yielded mainly paraoxon.Furthermore, in all experiments, photolysis of the P—O ester bonds of the parent compound as well as of the photoproducts was observed at low levels.
Molecular connectivity and hydrophobicity in the study of antifeedant activity of clerodane diterpenoids
Authors: Luco Juan M. , Sosa Mart A. E. , Cesco Juan C. , Tonn Carlos E. , Giordano Oscar S. 
Published: November 2006

AbstractFeeding deterrent activities of twelve clerodane diterpenoids towards Tenebrio molitor (Coleoptera: Tenebrionidae) larvae have been correlated using molecular connectivity indexes (3χc, 4χc, °ΔX) and hydrophobicity constants (log K′w) obtained by reverse‐phase liquid chromatography (RPLC). The equations obtained suggest that both the degree of branching and the electronic characteristics of the compounds under study have a dominant role in the observed antifeedant activity. The information obtained from the correlations should be useful in designing more potent analogues.
Behavioral responses of red‐winged blackbirds (Agelaius phoeniceus) to viewing a conspecific distressed by 4‐Aminopyridine
Authors: Conover Michael R. 
Published: November 2006

Abstract4‐Aminopyridine (4‐AP) is the only pesticide that can be legally used in the US to reduce bird damage in ripening grain fields. Birds that consume grain baits treated with 4‐AP (‘Avitrol’ FC‐99®) exhibit erratic behavior and emit vocalizations that presumably scare away the rest of the flock. Yet the behavior of 4‐A Pintoxicated birds has not been documented, and we do not know how other birds react when observing these intoxicated birds or what these observers learn from their experience. Hence, we examined the behavior of 15 4‐A Pintoxicated red‐winged blackbirds (Agelaius phoeniceus (L.)) and found that initial signs of intoxication occurred 12.5 min after consumption of the bait, with death following 16.3 min later. During this 16‐min intoxication period, birds gradually lost muscular control, making their movements and vocalizations weaker until hardly perceptible. Other captive red‐winged blackbirds (‘observers’) gave more alarm calls while witnessing a 4‐A P‐intoxicated bird in one room of their cage (treatment period) than they did during the pre‐treatment period. Immediately after the intoxicated bird died and was removed from the room, the observers' behaviour returned to pre‐treatment levels. Broadcasting calls of an intoxicated bird or the placement of an untreated bird in one of the rooms had little effect on the observers' behavior. In another experiment, the placement of a 4‐A Pintoxicated or untreated red‐winged blackbird or the broadcast of calls of an intoxicated bird at a feed station did not affect the number of free‐ranging conspecifics feeding, within sight of, or vocalizing at, these feeder stations. These results suggest that red‐winged blackbirds learn little from witnessing a distressed conspecific.
Solid‐phase extraction of pesticides from surface water using discs, bulk sorbents and supercritical fluid extraction (SFE)
Authors: Bengtsson Staffan , Berglöf Tomas , Granat Sophia , Jonsäll Göran 
Published: November 2006

AbstractExtraction of pesticides from river water samples using the classical liquid‐liquid extraction (LLE) approach is a labour‐intensive procedure that requires relatively large volumes of solvent. With the solid‐phase extraction (SPE) technique using membranes, the volumes of solvent are reduced. However, it is necessary to pre‐filter and often also to acidify the river water to pH < 2 to prevent plugging of the capillary pores. This low pH may decompose some pesticides and therefore a fast and inexpensive technique with bulk sorbent and without prefiltration and acidification was developed.To reduce the solvent volumes further, extractions of discs and bulk sorbent were performed with supercritical fluids (SF). Seven pesticides with different polarities were studied. Mean recoveries from the bulk sorbent and the discs were of the same order (61%). However, recoveries from the latter improved to 82% with SFE of the discs, providing results comparable to LLE (94%) recovery.
Fungicidal activity of the synthetic putrescine analogue, (E)‐l,4‐diaminobut‐2‐ene, and derivatives
Authors: Havis Neil D. , Walters Dale R. , Foster Sally A. , Martin William P. , Cook Fiona M. , Robins David J. 
Published: November 2006

AbstractThe putrescine analogue. (E)‐1,4‐diaminobut‐2‐ene (E‐BED), synthesized as the dihydrochloride salt, controlled five economically important crop pathogens, Erysiphe qraminis DC f.sp. hordei Marchal. Uromyces viciae‐fabae (Pers.) Schroet, Botrytis fabae Sardina, Podosphaera leucotricha (Ell. & Ev.) Salm. and Phytophthora infestans (Mont) De Bary. The Z‐isomer. Z‐BED. was also fungicidal, although less so than E‐BED. Post‐inoculation treatment with E‐BED gave greater control of powdery mildew infection on barley and rust and chocolate spot on broad bean than did pre‐inoculation application. It was also effective in vitro against Botrytis cinerea Pers. ex Fr., Pyricularia oxyzae Br. & Cav. and Pyrenophora avenae Ito & Karibay. When P. avenae was grown in the presence of E‐BED dihydrochloride at 81·5 mg litre−1, growth was reduced by 58% and there were significant reductions in soluble ornithine decarboxylase (ODC) and S‐adenosylmethionine decarboxylase (AdoMetDC) activity. These changes were accompanied by a sevenfold increase in putrescine concentration, a 60% increase in spermine concentration and a 32% reduction in spermidine concentration within the fungal tissue.
Selectivity of SMY 1500 (4‐amino‐6‐tert‐butyl‐3‐ethylthio‐l,2,4,triazin‐5(4H)‐one) in Triticum durum
Authors: García‐Valcárcel Ana , Villarroya Mercedes , Chueca Ma Cristina , Tadeo José Luis , García‐Baudin José María 
Published: November 2006

AbstractSusceptibility to SMY 1500 (4‐amino‐6‐tert‐butyl‐3‐ethylthio‐1.2.4‐triazin‐5(4H)‐one) was studied in durum wheat (Triticum durum Desf.) cultivars in growth‐chamber assays. Weight reduction, photosynthesis inhibition and herbicide levels were determined at various times after a 24‐h herbicide treatment in two cultivars of durum wheat, one cultivar of spring wheat (Triticum aestivum L). and in the weed Bromus diandrus (Roth). Measurements of weight reduction distinguished between plants tolerant and plants susceptible to SMY 1500. Tolerant cultivars showed a lower herbicide content and photosynthesis inhibition than susceptible plants after the 24‐h treatment. Thereafter, herbicide levels and photosystem II inhibition decreased faster in tolerant plants. Comparison with previous work showed that plants tolerated doses of SMY 1500 about four times higher than of its analogue, metribuzin. Herbicide content in leaves just after treatment, and rate of detoxification may explain the selectivity of SMY 1500 in these cereals.
Root absorption and translocation of 5‐substituted analogs of the imidazolinone herbicide, imazapyr
Authors: Little Desiree L. , Shaner Dale L. , Ladner David W. , Tecle Berhane , Ilnicki Richard D. 
Published: November 2006

AbstractIn preparation for assessing quantitative structure‐activity relationships (QSAR) for root absorption and translocation of imidazolinones herbicides, 13 radiolabeled analogs of imazapyr (2‐(4‐isopropyl–4‐methy1–5‐oxo‐2‐imidazolin‐2‐yl) nicotinic acid) substituted in the 5‐position of the pyridine ring were evaluated in corn (Zea mays L.) and sunflower (Helianthus annuus L.). The compounds (10 μm) were supplied to the roots through a hydroponic solution for 8 h and, following harvest, plant tissues were either combusted to measure total uptake of radiolabeled material or were extracted for determination of the extent of degradation of the parent compound. Root absorption in both species varied by two orders of magnitude among analogs while translocation, expressed as a percentage of absorption, varied by only three‐ or four‐fold. Few differences were observed for translocation of radioactivity from sunflower stems to leaves. Although six of the analogs were partially metabolized in corn, little metabolism of the imidazolinone analogs occurred in sunflower. These data indicate that meaningful models of root absorption and subsequent translocation to shoots may be developed for 5‐substituted analogs of imazapyr, particularly when applied to sunflower.
Key chemical inputs to new herbicides: Intermediates, processes and mechanistic investigations
Authors: Dingwall John G. 
Published: November 2006

AbstractThe key chemical inputs that led to the discovery of the three herbicides CGA 215684 (a cyclohexanedione), CGA 244126 (a substituted pyridine) and CGA 152005 (sulfonylurea) and the plant‐growth regulant CGA 163935 (a cyclohexanedione) are described.
Nuclear DNA analysis of maize seedlings treated with the triazole fungicide, triticonazole
Authors: Biradar Digambareppa P. , Pedersen Wayne L. , Rayburn A. Lane 
Published: November 2006

AbstractMaize kernels were treated with the fungicide triticonazole (RP‐727), belonging to the triazole family. The nuclear DNA content was analyzed in various maize plant organs by using flow cytometry. Two fluorochromes with different DNA binding mechanisms were used for probing nuclear DNA and chromatin structure. Results indicated nuclear alterations with the use of triticonazole and the alterations observed were different in the various tissues analyzed. Active meristematic plant organs, such as root tip, did not show any significant change in nuclear DNA, but chromatin structure was altered with increasing concentrations of fungicide. Stem and mesocotyl showed both DNA and chromatin condensation changes with triticonazole concentration, but the trends observed in these two plant organs were opposite. The magnitude of the alterations was minute in the different plant organs studied. These alterations do not appear to be deleterious for normal plant development.
Growth‐linked and cometabolic biodegradation: Possible reason for occurrence or absence of accelerated pesticide biodegradation
Authors: Robertson Boakai K. , Alexander Martin 
Published: November 2006

AbstractA study was conducted to relate the occurrence of accelerated pesticide biodegradation to the susceptibility of the pesticides to growth‐linked degradation or cometabolism. The mineralization of 2,4‐D was initially slow but then became rapid, and a second application was mineralized with no acclimation phase and more rapidly than the first. The numbers of 2,4‐D‐degrading micro‐organisms increased markedly following its first application and then declined, but the population size increased after a second addition. Glyphosate was rapidly and extensively mineralized following the first and second applications to soil, and the abundance of organisms able to degrade it rose after the first addition and remained high before and following the second application. Propham (IPC) mineralization was detected only 15 days after its application but the degradation was rapid thereafter, and the second addition was rapidly and extensively mineralized with no acclimation phase. The population of propham‐degrading micro‐organisms was initially small, but increased markedy 10 days after the initial herbicide addition and was still large at the time of the second application. The rate of carbofuran biodegradation in the test soil was the same following the first and second applications, and the abundance of carbofuran‐metabolizing microorganisms did not change appreciably as a result of soil treatment with the insecticide. Simazine mineralization was slow, although the rate was higher following the second addition; however, the number of simazine‐degrading organisms did not increase appreciably. From 10 to 12% of the14C from radiolabeled 2,4‐D, propham, glyphosate or glucose was usually incorporated into the microbial biomass of soil but 0.82% or less of the14C from simazine or ring‐ or carbonyl‐labeled carbofuran was converted to biomass. It is suggested that pesticides that support microbial growth may be subject to accelerated biodegradation if the population remains large until the pesticide is applied again. Pesticides that do not support growth may not be subject to accelerated biodegradation.
Selection of compounds acting as aphid development and reproduction regulators: Laboratory screening
Authors: Kuldova Jelena , Hrdy Ivan , Wimmer Zdeně 
Published: November 2006

AbstractNewly synthesized compounds were examined in screening tests with the pea aphid, Acyrthosiphon pisum (Harris) for juvenilizing effects. usign the spray‐residue method. Two derivatives of 2‐(4‐hydroxvbenzyl)eyclohexanone bearing a carbamate or an ether group were found to be the most active inhibitors of development and reproduction. Tests with the hop aphid, Phorodon humuli (Schrank) of insecticide‐susceptible and multi‐resistant biotypes and with the green peach aphid, Myzus persicae (Sulzer) confirmed their biological activity. Cross‐resistance between conventional insecticides and juvenoids was not indicated. The formation of supernumerary larvae, where retention of larval cauda and corresponding larval characters were observed and reproduction was entirely suppressed, was recognized as the critical result of the juvenilizing effect. The production of viable progeny was not affected in those aphids which survived treatment and developed normal adult external genitalia.
The trapping of spray droplets by insects
Authors: Bache David H. 
Published: November 2006

AbstractThe paper describes a methodology for specifying the deposition of spray droplets on flying insects and insects at rest on a quantitative basis. Processes of deposition by sedimentation and inertial impaction are viewed in terms of a deposition velocity defined by vg = vsax + Eiuaz, in which vs is the droplet settling velocity, u the air speed relative to the insect, Ei a collection efficiency associated with inertial impaction and ax, az signify horizontal and vertical projections of a representative trapping area. Published data on the deposition of small droplets (diameter < 20μm) on mosquitoes show that the trapping efficiency is dominated by inertial impaction and it is assumed that the collection efficiency is specified by Ei = St2/(St + 0.2)2 in which St is the Stokes number. Analysis of a second data set regarding the deposition of larger drops on flying locusts shows that the dependence of the observed collection efficiency on droplet size can be explained satisfactorily by this simplified approach. Further, it is demonstrated that a characteristic length which forms an essential component of the Stokes number is matched to the general size of the insect. The paper concludes with an analysis of a further data set concerning the deposition of small drops onto resting tsetse flies; this provides insight into the effective air speed controlling the deposition process.
Supercritical fluid chromatography—finding a place in the chromatographers' arsenal?
Authors: Bond Paul M. 
Published: November 2006

AbstractIn the mid‐ to late 1980s, supercritical fluid chromatography (SFC) was ‘reborn’ as a technique for the 1990s. Supercritical fluids have physical properties (viscosity, diffusivity and density) intermediate between those of licuids and gases. Analyte solubilities are similar to those in some liquid chromatography solvents and the gas‐like properties of supercritical fluids make higher resolution or shorter analysis times possible.Applications and experience with a home‐built SFC system, as well as methods developed elsewhere, are described. The successes and limitations of the technique are reviewed together with details of the instrumentation.Areas in which SFC may become the procedure of choice include multi‐residue methods, non‐polar analyses, micro‐preparative uses and for difficult extractions. The advances in GC and HPLC technology, however, lead us to believe that SFC will remain a specialist technique, appealing only to a minority of analysts.
Influence of application methods on the degradation of permethrin in laboratory, soil aerobic metabolism studies
Authors: Skidmore Michael W. , Kirkpatrick David , Shaw David 
Published: November 2006

AbstractThe effects of application rate, volume, solvent and soil moisture content on the kinetics of mineralization and degradation, of [14C] permethrin have been studied in a sandy loam soil under standard laboratory conditions. During the incubation period, up to 32 days, the temperature and moisture level of the soil were controlled. Apart from the effects of application rate, which have been widely reported, application volume had the most significant effect on mineralization rate and T1/2. [14C]Permethrin, at a level of a 1 mg kg−1 in the soil, applied in 100 μl of methanol, resulted in the evolution of 14% of the applied radiochemical as [14C] carbon dioxide over 30 days. The same level applied in 1000 μl mineralized at a faster rate, with 30% [14C]carbon dioxide evolved over 30 days.The test chemical applied to soil in methanol mineralized at a significantly faster rate than a similar concentration applied in ethanol. There was no significant difference when comparing applications made using acetonitrile with those using methanol or ethanol. The addition of formulation ingredients resulted in little or no variation in mineralisation rate compared to an equivalent application volume of methanol/water.