Unveiling six novel bacterial strains for fipronil and thiobencarb biodegradation: efficacy, metabolic pathways, and bioaugmentation potential in paddy soil.

Introduction: Soil bacteria offer a promising approach to bioremediate pesticide contamination in agricultural ecosystems. This study investigated the potential of bacteria isolated from rice paddy soil for bioremediating fipronil and thiobencarb, common agricultural pesticides.

Methods: Bacterial isolates capable of degrading fipronil and thiobencarb were enriched in a mineral salt medium.

Efficacy of novel bacterial consortia in degrading fipronil and thiobencarb in paddy soil: a survey for community structure and metabolic pathways.

Introduction: Fipronil (FIP) and thiobencarb (THIO) represent widely utilized pesticides in paddy fields, presenting environmental challenges that necessitate effective remediation approaches. Despite the recognized need, exploring bacterial consortia efficiently degrading FIP and THIO remains limited.

Methods: This study isolated three unique bacterial consortia-FD, TD, and MD-demonstrating the capability to degrade FIP, THIO, and an FIP + THIO mixture within a 10-day timeframe.

Optimizing the QuEChERS method for efficient monitoring of fipronil, thiobencarb, and cartap residues in paddy soils with varying properties.

This study aims to optimize the QuEChERS methodology for extracting three pesticides (fipronil, thiobencarb, and cartap) from two paddy soils with distinct characteristics. Various modifications were explored to enhance extraction efficiency, employing acetonitrile (MeCN) or ethyl acetate (EtOAc) for extraction and primary-secondary amine (PSA) and graphitized carbon black (GCB) for the clean-up. Assessment criteria included accuracy, precision, linearity, detection limits, uncertainty, and matrix effects.

Urinary metabolites of diazinon and chlorpyrifos in sprayer operators and farm workers of a potato farm.

In order to investigate the effect of diazinon and chlorpyrifos on agricultural workers exposed to pesticides, urinary metabolites 2-Isopropyl-6-methyl-4-pyrimidinol (IMPy) and 3,5,6-Trichloro-2-pyridinol (TPCy) in farm workers, sprayer operators, and non-exposed people as a control group were measured. The modified QuEChERS method was applied to extract samples and was measured using a gas chromatograph/nitrogen-phosphorus detector. The obtained results showed that the median concentrations of TCPy were 36.

Physiological Differences Between Seasonal Dimorphs of Agonoscena pistaciae (Hemiptera: Aphalaridae) Elicit Distinct Host Plant Responses, Informing Novel Pest Management Insights.

We examined differences in the physiology and life history between dimorphs of the common pistachio psyllid, Agonoscena pistaciae (Burckhardt and Lauterer) (Hemiptera: Aphalaridae), and how they differ in elicitating host plant production of key metabolites and volatile compounds involved in the recruitment of herbivores and natural enemies. Summer morphs had higher activities of glutathione S-transferase, carboxylesterase, acetylcholinesterase, and cytochrome P450 monooxygenase, superoxide dismutase, catalase, peroxidase, phenoloxidase, and a higher total protein content compared to winter morphs, whereas the latter had higher amounts of lipid, carbohydrate, and glycogen. Winter morphs were heavier, with a higher chitin content and longer preoviposition period, but greater fecundity and longevity than summer morphs.

Salicylic Acid Induced Resistance in Drought-Stressed Pistachio Seedlings Influences Physiological Performance of Agonoscena pistaciae (Hemiptera: Aphalaridae).

Induced host plant resistance is a potential approach to insect and disease management. Salicylic acid (SA) acts as a signal molecule to induce resistance in plants against sap-sucking insects. The effects of salicylic acid-induced resistance against common pistachio psylla, Agonoscena pistaciae Burckhardt and Lauterer, were investigated in well-watered and drought-stressed pistachio, Pistacia vera L.

Evaluation of physiological and biochemical responses of pistachio plants (Pistacia vera L.) exposed to pesticides.

Pesticides may manipulate plant physiology as non-target organisms. In this study, we examined biochemical responses of pistachio plants (Pistacia vera L.) to imidacloprid and phosalone as common pesticides used to control pistachio psyllids.

Physiological responses of plants and mites to salicylic acid improve the efficacy of spirodiclofen for controlling Tetranychus urticae (Acari: Tetranychidae) on greenhouse tomatoes.

Salicylic acid (SA) is a signaling molecule that can induce plant resistance to certain herbivores. Although the role of jasmonic acid in mediating mite-tomato plant interactions has been well studied, the role of salicylic acid has not. This study examined how the application of exogenous SA, via its effects on tomato plant physiology, alters the activity of mite digestive enzymes, mite energy reserves, and mite susceptibility to spirodiclofen.

Micronutrient Fertilization of Greenhouse Cucumbers Mitigates Pirimicarb Resistance in Aphis gossypii (Hemiptera: Aphididae).

The nutritional status of host plants can have direct impacts on herbivore physiology and insect-plant interactions. We investigated the effect of micronutrients, including manganese, iron, zinc, and copper, on cucumber plant physiology, and on the biology and physiology of a strain of Aphis gossypii Glover selected over 12 generations to be resistant to pirimicarb. The micronutrient treatment increased the activity of superoxide dismutase, ascorbate peroxidase, guaiacol peroxidase, polyphenol oxidase, and phenylalanine ammonia-lyase in cucumber plants, and also increased levels of total phenolics, hydrogen peroxide, salicylic acid, and total chlorophyl, whereas malondialdehyde levels were unaffected.

Diazinon degradation by bacterial endophytes in rice plant (Oryzia sativa L.): A possible reason for reducing the efficiency of diazinon in the control of the rice stem-borer.

It is well known that microorganisms can reduce the effectiveness of organophosphate pesticides after their application. But, little information is available concerning the effect of rice endophytic bacteria on the degradation of diazinon, an organophosphate pesticide used in control of the rice stem-borer, absorbed by the rice plant. Thus, aim of this study was to characterize the endophytic bacterial isolates, isolated from diazinon-treated and non-treated rice plants in paddy fields, in terms of diazinon degradation and to investigate whether potent isolates that degrade diazinon in vitro might have the same effect in the rice plant.

Diazinon dissipation in pesticide-contaminated paddy soil: kinetic modeling and isolation of a degrading mixed bacterial culture.

Dissipation kinetics of diazinon was investigated in soils culled from a paddy field with a long history of the pesticide application. Goodness of fit statistical indices derived from several fitted mono- and bi-exponential kinetic models revealed a bi-phasic pattern of the diazinon dissipation curve at 15 and 150 mg kg spiking levels, which could be described best by the first-order double exponential decay (FODED) model. Parameters obtained from this model were able to describe the enhanced dissipation of diazinon as the result of repeated soil applications, where a larger fraction of the pesticide readily available in the solution phase was dissipated with a fast rate.

Circadian Rhythmicity of Diazinon Susceptibility, Detoxifying Enzymes, and Energy Reserves in Aphis gossypii (Hemiptera: Aphididae).

The daily susceptibility rhythm of the cotton aphid, Aphis gossypii Glover, to diazinon and the corresponding changes in the activity of three xenobiotic detoxifying enzymes-cytochrome P450 monooxygenases (P450), glutathione S-transferases (GSTs), and esterases-were investigated. Bioassays were conducted to estimate the median lethal doses (LD50) of diazinon at six different zeitgeber times (ZT0, 4, 8, 12, 16, and 20) under constant light (LL) and lighting conditions of 16 h of light and 8 h of darkness (LD). The results showed that the highest susceptibility occurred at the onset of night (ZT16) and 4 h before this time point (ZT12) under the LD condition.

The dissipation kinetics of malathion in aqueous extracts of different fruits and vegetables.

The dissipation of malathion in 5% aqueous extracts of some fruits and vegetables including bell pepper, tomato, cucumber, cantaloupe, carrot, and also buffer (control) was investigated at 37 °C for 4 h. The dissipation trend of malathion in the fruit/vegetable samples and buffer followed first-order double-exponential decay (FODED) and simple first-order kinetic (SFOK) models, respectively. The initial dissipation rate of malathion in tomato (DT10=0.

Linear-dendritic copolymers/indoxacarb supramolecular systems: biodegradable and efficient nano-pesticides.

Photodegradable and biocompatible nano-indoxacarb was prepared successfully by encapsulation of indoxacarb with poly(citric acid)-poly(ethylene glycol)-poly(citric acid) (PCA-PEG-PCA) ABA type linear-dendritic copolymers both with (nano-IND/TiO2) and without (nano-IND) TiO2 nanoparticles via supramolecular interactions. Preparation of nano-indoxacarb by both formulae was confirmed using spectroscopy and microscopy analyses. TEM images showed small particles with average sizes of 10 nm for nano-IND and 12 nm for nano-IND/TiO2.

Preparation, characterization and efficiency of nanoencapsulated imidacloprid under laboratory conditions.

In this work, nano-imidacloprid was prepared by direct encapsulation with ABA triblock linear dendritic copolymers composed of poly(citric acid) (PCA) as A block and poly(ethylene glycol) (PEG) as B block. Nanocapsules of imidacloprid were characterized using spectroscopy, microscopy and thermal analysis. The encapsulation process was performed by self-assembly of PCA-PEG-PCA in the presence of imidacloprid in different solvents.

Diazinon residues and degradation kinetics for grapes under field conditions.

The dissipation of diazinon (O,O-diethyl O-2-isopropyl-6-methylpyrimidin-4-yl phosphorothioate) in grapes was investigated to determine its pre-harvest interval (PHI). Diazinon was applied to grapes at the recommended dosage (0.9 g a.

Demographic traits of Tetranychus urticae (Acari: Tetranychidae) on leaf discs and whole leaves.

Life tables of twospotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), were studied on leaf discs and whole leaves of the common bean plant, Phaseolus vulgaris L. Data were analyzed based on the age-stage, two-sex life table theory. Durations of deutonymph stage, total preadult stage, and preoviposition period of mites reared on whole leaves (1.

Dissipation of phosalone and diazinon in fresh and dried alfalfa.

The objectives of this study were to determine the persistence of phosalone (S-6-chloro-2,3-dihydro-2-oxobenzoxazol-3-ylmethyl O, O-diethyl phosphorodithioate) and diazinon (O,O-diethyl O-2-isopropyl-6-methylpyrimidin-4-yl phosphorothioate) residues in fresh and baled alfalfa under field conditions. Plots of alfalfa were sprayed with each insecticide. Fresh alfalfa was sampled up to 20 days after treatment, and dried alfalfa was sampled up to 25 weeks after baling.

Effects of two different formulations of metalaxyl on their residues in cucumber.

Investigations were carried out on the presence of metalaxyl residues in field grown cucumbers. In one experiment, cucumber plants underwent once and twice sprayings by Ridomil-MZ 72 WP at 2.5 g/litre.