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Frank H. Arthur - One of the best experts on this subject based on the ideXlab platform.

  • Variation in Susceptibility of Field Strains of Three Stored Grain Insect Species to Spinosad and Chlorpyrifos-Methyl Plus Deltamethrin on Hard Red Winter Wheat
    Journal of Economic Entomology, 2013
    Co-Authors: Blossom Sehgal, Frank H. Arthur, Bhadriraju Subramanyam, Bikram S. Gill
    Abstract:

    ABSTRACT Spinosad and Chlorpyrifos-Methyl plus deltamethrin efficacy at labeled rates on hard red winter wheat were evaluated against 11 field strains of the red flour beetle, Tribolium castaneum (Herbst); six strains of the sawtoothed grain beetle, Oryzaephilus surinamensis (L.); and two strains of the lesser grain borer, Rhyzopedha dominica (F.), collected mostly from farm-stored grain in Kansas. Adults were exposed to wheat treated with spinosad at 1 mg(active ingredient)/kg or chlorpyrifosmethyl plus deltamethrin at three plus 0.5 mg(active ingredient) /kg. Adult mortality was assessed after 7 and 14 d and progeny production after 42 d. Spinosad did not provide complete mortality or progeny suppression of T. castaneum and O. surinamensis field strains, but was effective against R. dominica strains. Chlorpyrifos-Methyl plus deltamethrin produced complete mortality and progeny suppression of field strains all three species. The two least susceptible T. castaneum and O. surinamensis strains and the two R...

  • Variation in susceptibility of laboratory and field strains of three stored-grain insect species to β-cyfluthrin and Chlorpyrifos-Methyl plus deltamethrin applied to concrete surfaces
    Pest Management Science, 2013
    Co-Authors: Blossom Sehgal, Frank H. Arthur, Bhadriraju Subramanyam, Bikram S. Gill
    Abstract:

    BACKGROUND: The efficacy of commercial formulations of β-cyfluthrin and Chlorpyrifos-Methyl plus deltamethrin applied to clean, concrete surfaces similar to that of empty bins against field strains of stored-grain insects is unknown. We exposed adults of 16 strains of the red flour beetle, Tribolium castaneum (Herbst); eight strains of the sawtoothed grain beetle, Oryzaephilus surinamensis (L.); and two strains of the lesser grain borer, Rhyzopertha dominica (F.), collected mainly from farm-stored grain in Kansas, USA, to β-cyfluthrin and Chlorpyrifos-Methyl plus deltamethrin applied to concrete surfaces and determined knockdown and mortality. RESULTS: Knockdown and mortality differences among species and strains to the insecticides tested were significant. Mortality of all species was less than that of knockdown, suggesting recovery when placed on food after insecticide exposure. β-Cyfluthrin was effective against R. dominica but ineffective against T. castaneum and O. surinamensis field strains. Chlorpyrifos-Methyl plus deltamethrin was only partially effective against field strains of the three species. CONCLUSION: Reduced susceptibility in field strains may be due to inherent formulation deficiency and low levels of tolerance or resistance to β-cyfluthrin. No single insecticide provided adequate control of the three species tested.

  • Degradation and Efficacy of Deltamethrin + Chlorpyrifosmethyl and Cyfluthrin + Chlorpyrifos-Methyl as Protectants of Wheat Stored in Southeast Georgia1
    Journal of Entomological Science, 1995
    Co-Authors: Frank H. Arthur
    Abstract:

    Soft red winter wheat (27.27 kg replicates) treated with combinations of deltamethrin + Chlorpyrifos-Methyl, with and without piperonyl butoxide, and cyfluthrin, applied alone or with either chlorp...

  • Cyfluthrin Applied with and without Piperonyl Butoxide and Piperonyl Butoxide Plus Chlorpyrifos-Methyl for Protection of Stored Wheat
    Journal of Economic Entomology, 1994
    Co-Authors: Frank H. Arthur
    Abstract:

    Soft red winter wheat treated with 0.5, 1.0, 1.5, or 2.0 ppm cyfluthrin, all rates + 8.0 ppm piperonyl butoxide, and all rates with piperonyl butoxide + 6.0 ppm Chlorpyrifos-Methyl was stored for 10 mo at ambient conditions in southern Georgia. Samples of wheat were bioassayed with lesser grain borer, Rhyzopertha dominica (F.), and rice weevil, Sitophilus oryzae (L.), every 2 mo. Lesser grain borer survival on wheat treated with cyfluthrin alone ranged from 0-37.0%, whereas survival in the cyfluthrin + piperonyl butoxide and cyfluthrin + piperonyl butoxide + Chlorpyrifos-Methyl combinations ranged from 0 to 16.0%. No F1 adults or ground flour (dockage) was present in incubated samples. Rice weevil survival on wheat treated with 0.5 and 1.0 ppm cyfluthrin steadily increased to a maximum of 94.5 and 43.5%, respectively, after 10 mo. Survival was reduced on wheat treated with 1.5 and 2.0 ppm cyfluthrin, and beetles did not survive in the piperonyl butoxide-Chlorpyrifos-Methyl combinations. The number of F1 rice weevils and the amount of dockage were greatest in the two lowest rates of cyfluthrin. F1 adults and dockage weight were positively correlated with initial.

  • Efficacy of Cyfluthrin, Cyfluthrin + Piperonyl Butoxide, and Cyfluthrin + Piperonyl Butoxide + Chlorpyrifos-Methyl as Protectants of Stored Peanuts1
    Peanut Science, 1994
    Co-Authors: Frank H. Arthur
    Abstract:

    Abstract Inshell peanuts were treated with 0.5, 1.0, 2.0, and 4.0 ppm cyfluthrin, each rate of cyfluthrin + 8.0 ppm piperonyl butoxide, and each rate of cyfluthrin + piperonyl butoxide + 25 ppm Chlorpyrifos-Methyl. After 10 months red flour beetle, Tribolium castaneum (Herbst), populations in peanuts treated with 0.5 and 1.0 ppm cyfluthrin averaged 89.5 and 34.2 adults per 12.7 kg peanuts; populations in peanuts treated with 1.0 and 1.5 ppm cyfluthrin + piperonyl butoxide averaged 72.0 amd 41.5 adults per 12.7 kg peanuts. Populations in the remaining 8 treatments ranged from 0.5 to 7.2 adults. Indianmeal moth, Plodia interpunctella (Hubner), and almond moth, Cadra cautella (Walker), populations remained low in all treatments. At 10 months the percentage of insectdamaged kernels from cracked pods ranged from 8.7 to 28.8% in the cyfluthrin and cyfluthrin + piperonyl butoxide treatments, while the percentage of damaged kernels was 4.4 to 6.1% in the 4 treatments with Chlorpyrifos-Methyl.

Adrienne S Ettinger - One of the best experts on this subject based on the ideXlab platform.

  • urinary 3 5 6 trichloro 2 pyridinol tcpy in pregnant women from mexico city distribution temporal variability and relationship with child attention and hyperactivity
    International Journal of Hygiene and Environmental Health, 2014
    Co-Authors: Gamola Z Fortenberry, John D Meeker, Brisa N Sanchez, Dana B Barr, Parinya Panuwet, David C Bellinger, Lourdes Schnaas, Maritsa Solanogonzalez, Adrienne S Ettinger
    Abstract:

    Abstract Attention Deficit Hyperactivity Disorder (ADHD) is the most commonly diagnosed and studied cognitive and behavioral disorder in school-age children. The etiology of ADHD and ADHD-related behavior is unclear, but genetic and environmental factors, such as pesticides, have been hypothesized. The objective of this study was to investigate the relationship between in utero exposure to chlorpyrifos, Chlorpyrifos-Methyl, and/or 3,5,6-trichloro-2-pyridinol (TCPY) and ADHD in school-age Mexican children using TCPY as a biomarker of exposure. The temporal reliability of repeated maternal urinary TCPY concentrations across trimesters was also explored ( N  = 21). To explore associations with ADHD-related outcomes in children, third trimester urinary TCPY concentrations in were measured in 187 mother-child pairs from a prospective birth cohort. Child neurodevelopment in children 6–11 years of age was assessed using Conners’ Parental Rating Scales-Revised (CRS-R), Conners’ Continuous Performance Test (CPT), and Behavior Assessment System for Children-2 (BASC-2). Multivariable linear regression models were used to test relationships for all children combined and also stratified by sex. Intraclass correlation coefficients (ICC) calculations were based on a random effects model. The ICC was 0.41 for uncorrected TCPY, and ranged from 0.29 to 0.32 for specific gravity-corrected TCPY. We did not observe any statistically significant associations between tertiles of maternal TCPY concentrations and ADHD-related outcomes in children. However, compared to the lowest tertile we found suggestive evidence for increased ADHD index in the highest TCPY tertile in boys ( β  = 5.55 points; 95% CI (−0.19, 11.3); p  = 0.06) and increased attention problems for the middle tertile in girls ( β  = 5.81 points; 95% CI (−0.75, 12.4); p  = 0.08). Considering the continued widespread agricultural and possible residential use of chlorpyrifos and Chlorpyrifos-Methyl in Mexico and the educational implications of cognitive and behavior deficits, these relationships deserve further study.

Jurgen Angerer - One of the best experts on this subject based on the ideXlab platform.

  • biological monitoring of exposure of the general population to the organophosphorus pesticides chlorpyrifos and chlorpyrifos methyl by determination of their specific metabolite 3 5 6 trichloro 2 pyridinol
    International Journal of Hygiene and Environmental Health, 2001
    Co-Authors: Holger M Koch, Jochen Hardt, Jurgen Angerer
    Abstract:

    Abstract In this study we determined the concentrations of 3,5,6-trichloro-2-pyridinol (TCPyr) in urine samples from the general population. TCPyr is a specific metabolite of the organophosphorus pesticides chlorpyrifos and Chlorpyrifos-Methyl. By the introduction of a new sensitive analytical method a limit of quantification (LOQ) of 0.1μg per litre urine could be achieved, a tenfold improvement of recent methods. Extraction of TCPyr from the urine and the clean up process were carried out by automatic steam distillation. Separation and quantitative analysis were performed using capillary gas chromatography and mass selective detection in selected ion monitoring mode. The excretion of TCPyr was studied by analysing spontaneous urine samples from 5 women and 45 men between the ages of 22 and 57 (median: 40 years) living in Mecklenburg-Vorpommern (Germany) who were not occupationally exposed to organophosporus pesticides. TCPyr was detected in all specimens and the concentrations were quantified. The median excretion was 1.4μg/l (range: 0.12 to 124.8μg/l), the 95th percentile 11.3μg/l. Under the worst case assumption that all TCPyr measured in urine originated from the intake of intact pesticides and not (less toxic) breakdown products, a TCPyr concentration of 1.4μg/l urine corresponds to a daily intake of approximately 2.5μg chlorpyrifos/Chlorpyrifos-Methyl. The intake at the 95th percentile would be about 23μg chlorpyrifos/Chlorpyrifos-Methyl per day. According to FAO/WHO the acceptable daily intake (ADI) is 10μg per kg bodyweight and day for both chlorpyrifos and Chlorpyrifos-Methyl.

Jeanne A Itak - One of the best experts on this subject based on the ideXlab platform.

  • practical immunochemical method for determination of 3 5 6 trichloro 2 pyridinol in human urine applications and considerations for exposure assessment
    Journal of Agricultural and Food Chemistry, 1999
    Co-Authors: Darcy D Shackelford, Debra L Young, Charles A Mihaliak, Brad A Shurdut, Jeanne A Itak
    Abstract:

    An analytical method is described for the quantitative determination of 3,5,6-trichloro-2-pyridinol (3,5,6-TCP) in human urine. This is the primary analyte found in urine as a result of exposure to chlorpyrifos, Chlorpyrifos-Methyl, triclopyr, or 3,5,6-TCP. Conjugates of 3,5,6-TCP are released from urine by acid hydrolysis. The free 3,5,6-TCP is purified using C18 solid-phase extraction, eluting the analyte with 1-chlorobutane. An aliquot of 1-chlorobutane is placed in a vial containing Trichloropyridinol Sample Diluent and evaporated, leaving the 3,5,6-TCP in the aqueous sample diluent. The samples are assayed using the Trichloropyridinol RaPID Assay immunoassay test kit. Final results are calculated using a standard curve constructed by linear regression after a ln/Logit data transformation is performed of the concentration and the absorbance readings, respectively. The calculated lower limit of quantitation for 3,5,6-TCP in fortified control urine samples is 2.96 ng/mL (2.96 ppb). Residues of 3,5,6-TCP...

Angel Montoya - One of the best experts on this subject based on the ideXlab platform.

  • development of an enzyme linked immunosorbent assay for 3 5 6 trichloro 2 pyridinol 1 production and characterization of monoclonal antibodies
    Journal of Agricultural and Food Chemistry, 1996
    Co-Authors: Juan J Manclus, Angel Montoya
    Abstract:

    3,5,6-Trichloro-2-pyridinol (TCP) is the major degradation product of both the widely used chlorpyrifos and Chlorpyrifos-Methyl insecticides and the herbicide triclopyr. In this paper we describe the development of immunoassays for the detection of this metabolite. With this aim, two types of haptens were synthesized, with spacer attachment either through the 6-position of the pyridyl ring or through the hydroxyl group. Protein conjugates of these haptens were used for the immunization of mice to produce monoclonal antibodies (MAbs). From haptens of the former type, a panel of MAbs displaying 50% inhibition (I50) for TCP in the range 1−10 nM was obtained. Characterization of these MAbs showed their high affinity and specificity for TCP. The best MAbs were used in various assay formats in combination with homologous and heterologous assay haptens. Several immunoassays with I50 lower than 1 nM were developed. These immunoassays are potentially very valuable analytical tools for the determination of TCP in f...