Search results for "Insecticide"
showing 10 items of 211 documents
Highly Efficient Removal of Neonicotinoid Insecticides by Thioether-Based (Multivariate) Metal–Organic Frameworks
2021
Circumventing the impact of agrochemicals on aquatic environments has become a necessity for health and ecological reasons. Herein, we report the use of a family of five eco-friendly water-stable isoreticular metal-organic frameworks (MOFs), prepared from amino acids, as adsorbents for the removal of neonicotinoid insecticides (thiamethoxam, clothianidin, imidacloprid, acetamiprid, and thiacloprid) from water. Among them, the three MOFs containing thioether-based residues show remarkable removal efficiency. In particular, the novel multivariate MOF {SrIICuII6[(S,S)-methox]1.5[(S,S)-Mecysmox]1.50(OH)2(H2O)}·36H2O (5), featuring narrow functional channels decorated with both -CH2SCH3 and -CH2…
Bioproduction of an extract from Penicillium funiculosum Thom with activity against Ceratitis capitata and Tetranychus urticae
1993
The bioproduction conditions of a crude extract from a strain of Penicillium funiculosum Thom, which shows activity against Ceratitis capitata and Tetranychus urticae, have been optimized. The efficacy degree was 95% (C. capitata) and 100% (T. urticae), according to Abbot. This is the first report on the pesticide activity of an extract from P. funiculosum against these species. The best yields were obtained when P. funiculosum was grown in Raulin-Thom medium at pH 6.5 with sucrose candy as the carbon source and ammonium sulphate and phosphate as the nitrogen source. Other favourable conditions were static cultures, at 28 degrees C, and in the dark.
Relationship between esterase activity and acrinathrin and methiocarb resistance in field populations of western flower thrips, Frankliniella occiden…
2006
The western flower thrips, Frankliniella occidentalis (Pergande), is a serious pest in the south-east of Spain owing to its direct feeding on crops, transmission of the tomato spotted wilt virus and its very high level of resistance to insecticides. Mechanisms of resistance were examined using field populations of F. occidentalis with different susceptibilities to acrinathrin, methiocarb (selective insecticides), endosulfan, metamidophos and deltamethrin (broad-spectrum insecticides). Esterase activity towards alpha-naphthyl acetate and p-nitrophenyl acetate in resistant strains was significantly higher than in the reference strain (MLFOM) for both model substrates. This higher activity was…
Proteolytic processing of Bacillus thuringiensis Vip3A proteins by two Spodoptera species
2014
Abstract Vip3 proteins have been described to be secreted by Bacillus thuringiensis during the vegetative growth phase and to display a broad insecticidal spectrum against lepidopteran larvae. Vip3Aa protoxin has been reported to be significantly more toxic to Spodoptera frugiperda than to Spodoptera exigua and differences in the midgut processing have been proposed to be responsible. In contrast, we have found that Vip3Ae is essentially equally toxic against these two species. Proteolysis experiments were performed to study the stability of Vip3A proteins to peptidase digestion and to see whether the differences found could explain differences in toxicity against these two Spodoptera speci…
Target vs non-target analysis to determine pesticide residues in fruits from Saudi Arabia and influence in potential risk associated with exposure
2017
The occurrence of pesticide residues in fruits was determined by a target method for 62 analytes and a wide scope screening method against a database of 500 pesticides. Limits of quantification (LOQs) were from 0.5 to 6.3 μg kg−1 for the target method and from 0.5 to 119 μg kg−1 for the non-target. Thirty samples: dates, apples, oranges, tangerines, lemons and grapefruits were selected because their high consumption, except lemons and grapefruits that were to cover all citrus fruits. Using the target method, 15 compounds (mostly insecticides and fungicides) out of 62 pesticides (organophosphorus, carbamates, pyrethroids, chloroacetanilides, triazines, triazoles, imidazoles, etc.) were detec…
Uptake and bioavailability of persistant organic pollutants by plants grown in contaminated soil
2005
This paper assesses the uptake of persistent organic pollutants (POP's) into plants. In particular, uptake of alpha-endosulfan, beta-endosulfan and endosulfan sulfate from lettuce. The lettuce plants were grown on compost that had previously been contaminated at 10 and 50 microg g(-1) per POP. The soil was slurry spiked by adding the appropriate amount of POP in acetone in an approximate ratio of 1 ratio 2, w/v soil ratio solvent. The solvent was left to evaporate at ambient temperature for 24 hours. Lettuce plants were grown under artificial daylight for 12 hours a day. The influence of soil ageing on the recovery of POP's from spiked soil samples was also assessed. The average recovery of…
Assessment of Organochlorine Pesticide Residues in West African City Farms: Banjul and Dakar Case Study
2003
Validated analytical procedures for the determination of 21 organochlorine pesticides have been applied to 74 water samples, 76 soil samples, and 160 vegetable samples from nine Sene-Gambian farms. Mean pesticide residue levels found were compared to the results of other studies. The main contaminants were DDTs in water (231.9 ng/L), in soil (71.4 ng/g), and in vegetables (5.03 ng/g). The distribution of pesticide residues in water and neighboring soils and the soil-plant transfer of these pesticides is briefly discussed. Different bioconcentration factors for sum HCHs, sum DDTs, and sum endosulfans obtained in this study allow us to confirm the complex processes already reported in the lit…
Fragmentations and reactions of the organophosphate insecticide Diazinon and its oxygen analog Diazoxon studied by electrospray ionization ion trap m…
2005
The fragmentations and reactions of Diazinon and related compounds have been studied by electrospray ionization ion trap mass spectrometry. Several novel fragmentation and rearrangements have been observed, including an intramolecular thiono-thiolo rearrangement. The stability, in the gas-phase, of the protomers of 2-isopropyl-4-methyl-6-pyrimidinol has been demonstrated. The complexity of the gas phase ion processes observed suggest that, at present, caution Should be exercised in using this approach for the analysis of environmental and other samples until our understanding of these processes increases considerably. (J Am Soc Mass Spectrom 2005, 16, 515-523) (c) 2005 American Society for …
Confirmation of Fenthion Metabolites in Oranges by IT-MS and QqTOF-MS
2007
14 pages, 4 figures, 4 tables.-- PMID: 18020315 [PubMed].-- Printed version published Dec 15, 2007.
Temperature–Time Relationship in Collembolan Response to Chemical Exposure
1999
Abstract Effects of temperature on chemical toxicity to a collembolan, Folsomia candida , in relation to time were studied in this experiment. Field soil was used as a test substrate. Collembolans were incubated at three different temperatures (+13, +16, and +19°C) and in two different dimethoate concentrations (1 and 3 mg/kg), clean soil serving as the control. Four destructive samplings were done at 2-week intervals. Dimethoate degradation was also analyzed. Dimethoate 1 mg/kg had a slight effect on both adult growth and reproduction, whereas 3 mg/kg was fatal to F. candida in the soil used. Toxic effects tended to last longer at low temperature than at high temperature, but the differenc…