Common consumer residual insecticides lack efficacy against insecticide-susceptible and resistant populations of the German cockroach (Blattodea: Ectobiidae).

The German cockroach, Blattella germanica (L.) (Blattodea: Ectobiidae), is a ubiquitous pest in affordable housing. They represent a major threat to human health due to their contribution of asthma-exacerbating allergens and the potential to transfer pathogenic microorganisms indoors. Despite well-documented pyrethroid resistance, pyrethroid-based broadcast residual insecticide products are often used by residents to control cockroaches in their homes. Additionally, there is little empirical independent testing of these products. Thus, it remains unclear how effective these commonly used do-it-yourself products are at controlling German cockroaches. This study represents a comprehensive examination of the efficacy of these products with direct, limited, and continuous exposure assays on a variety of common household surfaces on field populations of cockroaches with varying levels of pyrethroid resistance. While most products performed well when applied directly to test insects, mortality was substantially lower across all surfaces with limited exposure (30 min). In continuous exposure assays on a nonporous surface, products took at least 24 hr to cause 100% mortality in a field population, with some products taking up to 5 d to achieve 100% mortality. The findings of this study demonstrate a lack of residual efficacy from common pyrethroid-based consumer-use pesticides products. Given that it is not feasible to find and treat every cockroach in a home directly, the residuality of spray-based formulations is critical for products designed to control German cockroaches. Without residual efficacy, as shown in the consumer aerosol and spray products tested, we expect these products to add little to no value to cockroach control.

Ecotoxicological evaluation of an aqueous phytoextract of Melia azedarach L.

Melia azedarach L. is a Meliaceae that has shown important insecticidal activities. However, few researchers have extensively studied the toxicology of aqueous extracts of M. azedarach (MAE). Therefore, the main objective of this study was to characterize the phyto-eco-toxicological profile of MAE. First, a botanical and phytochemical characterization of MAE was performed using a histological, and metabolomic multi-analytical approach. Second, the toxicological effects on pollinating insects (Apis mellifera ligustica) and soil collembola (Folsomia candida) were evaluated. In addition, acute toxicity was evaluated in zebrafish (Danio rerio) to assess effects on aquatic fauna, and toxicity was determined in human neuroblastoma (SH-SY5Y) and fibroblast (FB-21) cell models. Finally, phytotoxic effects on germination of Cucumis sativus L., Brassica rapa L. and Sorghum vulgare L. were considered. Metabolomic analyses revealed the presence of not only limonoids but also numerous alkaloids, flavonoids and terpenoids in MAE. Histological analyses allowed us to better localize the areas of leaf deposition of the identified secondary metabolites. Regarding the ecotoxicological data, no significant toxicity was observed in bees and collembola at all doses tested. In contrast, severe cardiac abnormalities were observed in zebrafish embryos at concentrations as low as 25 µg/mL. In addition, MAE showed toxicity at 1.6 µg/mL and 6.25 µg/mL in FB-21 and SH-SY5Y cells, respectively. Finally, MAE inhibited seed germination with inhibitory concentrations starting from 5.50 µg/mL in B. rapa, 20 µg/mL in S. vulgare, and 31 µg/mL in C. sativus. Although M. azedarach extracts are considered valuable natural insecticides, their ecological impact cannot be underestimated. Even the use of an environmentally friendly solvent (an aqueous solution), for the first time, is not without side effects. Therefore, the data collected in this study show the importance of evaluating the dosages, modes of administration and production methods of M. azedarach phytoextracts in agricultural settings.

Sulfoxaflor residues and exposure risk assessment in grape under Egyptian field conditions.

Grapes are among the most popular fruits globally, and insecticides are commonly used on grape farms. Sulfoxaflor, a novel sulfoximine insecticide that works against various insect pests, is extensively used in Egypt. Our field trials assessed the dynamics and final residues of sulfoxaflor in grapes and grape leaves grown in Egyptian environments with different application rates, including worst-case scenarios. A QuEChERS-based method with LC-MS/MS was used to analyze residues of sulfoxaflor in grapes and grape leaves. The limit of quantification (LOQ) was validated at 0.01 mg‧kg-1. Sulfoxaflor residues are degraded in grapes and grape leaves according to a first-order kinetic model, with an estimated half-life (t1/2) of 7.04 and 7.7 days, respectively, and considerable degradation (74.68 and 72.16%, respectively) after 14 days. The final residues in grapes and grape leaves were below the Codex or EU maximum residue limit (MRL) (2 mg‧kg-1) after 3 days of the recommended and high application rates. The findings showed that grapes and leaves treated with sulfoxaflor at the recommended rate are safe for humans 3 days after two or three consecutive treatments with intervals of 14 days. The current study should pave the way for implementing safe and appropriate sulfoxaflor use in grapes and grape leaves in Egypt.

Imidacloprid affects human cells through mitochondrial dysfunction and oxidative stress.

Given their relatively low persistence and mammalian toxicity, neonicotinoid pesticides have been extensively used worldwide and are omnipresent in the environment. Recent studies have shown that neonicotinoids may pose adverse effects on non-target organisms other than the known neurotoxicity, raising emerging concerns that these insecticides might pose human health risk through additional toxicity pathways. In the present study, the mitochondria function, oxidative stress, DNA damages, and genes transcription levels were examined in the human neuroblastoma SH-SY5Y cells after 48-h exposure to imidacloprid at concentrations from 0.05 to 200 µmol/L. Results showed that imidacloprid induced mitochondrial dysfunction with the degradation of adenosine triphosphate (ATP) and mitochondrial membrane potential (MMP) levels. In addition, imidacloprid caused oxidative stress by stimulating the generation of reactive oxygen species (ROS) and hydrogen peroxide (H2O2) via the disruption of calcium ion level and mitochondrial function. Ultimately, the oxidative stress continued to produce DNA damage and apoptosis in SH-SY5Y cells at imidacloprid concentrations above 47.6 µmol/L. Among the evaluated endpoints, ATP was the most sensitive, with a median activity concentration of 0.74 µmol/L. The 5 % hazard concentration of imidacloprid was estimated to be 0.69 µmol/L, which can be used as a threshold for human health risk assessment for imidacloprid. Collectively, our results provide an important support for further research on potential toxicity of neonicotinoids related to mitochondrial toxicity in humans.

Functional Validation of Endogenous Redox Partner Cytochrome P450 Reductase Reveals the Key P450s CYP6P9a/-b as Broad Substrate Metabolizers Conferring Cross-Resistance to Different Insecticide Classes in Anopheles funestus.

The versatility of cytochrome P450 reductase (CPR) in transferring electrons to P450s from other closely related species has been extensively exploited, e.g., by using An. gambiae CPR (AgCPR), as a homologous surrogate, to validate the role of An. funestus P450s in insecticide resistance. However, genomic variation between the AgCPR and An. funestus CPR (AfCPR) suggests that the full metabolism spectrum of An. funestus P450s might be missed when using AgCPR. To test this hypothesis, we expressed AgCPR and AfCPR side-by-side with CYP6P9a and CYP6P9b and functionally validated their role in the detoxification of insecticides from five different classes. Major variations were observed within the FAD- and NADP-binding domains of AgCPR and AfCPR, e.g., the coordinates of the second FAD stacking residue AfCPR-Y456 differ from that of AgCPR-His456. While no significant differences were observed in the cytochrome c reductase activities, when co-expressed with their endogenous AfCPR, the P450s significantly metabolized higher amounts of permethrin and deltamethrin, with CYP6P9b-AfCPR membrane metabolizing α-cypermethrin as well. Only the CYP6P9a-AfCPR membrane significantly metabolized DDT (producing dicofol), bendiocarb, clothianidin, and chlorfenapyr (bioactivation into tralopyril). This demonstrates the broad substrate specificity of An. funestus CYP6P9a/-b, capturing their role in conferring cross-resistance towards unrelated insecticide classes, which can complicate resistance management.

Spatiotemporal distribution, risk levels, and transport variations in neonicotinoids and fipronil and its metabolites cross a river-to-sea continuum.

Neonicotinoids (NEOs) and fipronil are widely used in pest control, but their spatiotemporal distribution and risk levels in the "river-estuary-bay" system remain unclear. Between 2018 and 2021, 148 water samples from rivers to inshore and offshore seawater in Laizhou Bay, China were collected to investigate the presence of eight NEOs and fipronil and its metabolites (FIPs). Significant seasonal variations in NEOs were observed under the influence of different cultivation practices and climatic conditions, with higher levels in the summer than in the spring. The average concentrations of total neonicotinoids (ΣNEOs) and ∑FIPs decreased from rivers (63.64 ng/L, 2.41 ng/L) to inshore (22.62 ng/L, 0.14 ng/L) and offshore (4.48 ng/L, 0.10 ng/L) seawater of Laizhou Bay. The average concentrations of ΣNEOs decreased by 85.3 % from 2018 to 2021. The predominant insecticides in the study area were acetamiprid, thiamethoxam, imidacloprid, and fipronil sulfone, with a gradual shift toward low-toxicity and environmentally friendly species over time. Influenced by agricultural intensity, ∑NEOs were mostly distributed in the Yellow River, Xiaoqing River, and their estuaries, where they pose chronic ecological risks. However, FIP exhibited high risk in certain rivers and sewage treatment plants owing to the use of animal repellents or landscape gardening insecticides. This study provides evidence of the transfer of NEOs and FIPs from rivers to the ocean and also clarifies their transition dynamics and changes in risk levels from rivers to oceans. Additionally, the study offers data support for identifying critical pesticide control areas.

Acetyl-CoA Carboxylase Proteolysis-Targeting Chimeras: Conceptual Design and Application as Insecticides.

Novel approaches for pest control are essential to ensure a sufficient food supply for the growing global population. The development of new insecticides must meet rigorous regulatory requirements for safety and address the resistance issues of existing insecticides. Proteolysis-targeting chimeras (PROTACs), originally developed for human diseases, show promise in agriculture. They offer innovative insecticides tailored to overcome resistance, opening avenues for agricultural applications. In this study, we developed small-molecule degraders by incorporating pomalidomide as an E3 ligand. These degraders were linked to a ligand (spirotetratmat enol) targeting the ACC protein through a flexible chain, aiming to achieve the efficient control of insects. Compounds 9a-9d were designed, synthesized, and evaluated for biological activities and mechanisms. Among them, 9b exhibited superior potency against Aphis craccivora (LC50 = 107.8 µg mL-1) compared to others and effectively degraded ACC proteins through the ubiquitin-proteasome system. These findings highlight the potential of utilizing PROTAC-based approaches in the development of insecticides for efficient pest control.

Fabrication of fluorinated magnetic microporous organic network for selective and efficient extraction of benzoylurea insecticides in tea beverages.

In this work, a novel fluorinated magnetic microporous organic network (Fe3O4@FMON) was exquisitely designed and synthesized for highly efficient and selective magnetic solid phase extraction (MSPE) of fluorinated benzoylurea insecticides (BUs) from complex tea beverage samples. The Fe3O4@FMON exhibited good extraction for BUs via the pre-designed hydrophobic, π-π stacking, hydrogen bonding and specific FF interactions. A sensitive Fe3O4@FMON-based MSPE-HPLC-UV method with wide linear range (0.10-1000 µg L-1, R2 ≥ 0.996), low limits of detection (0.01-0.02 µg L-1), and large enrichment factors (85.6-98.0) for BUs from tea beverage samples was developed. By decorating F elements within MON's networks, the Fe3O4@FMON characterized good hydrophobicity and chemical stability, which could be reused at least 8 times without decrease of recoveries. This work demonstrated the great prospects of Fe3O4@FMON for enriching trace BUs from complex substrates and triggered the potential of FMON for sample pretreatment of fluorinated analytes.

Τhe sublethal impacts of five insecticidal formulations on Oryzaephilus surinamensis behavioral traits.

BACKGROUND: Mortality caused by various pyrethroids, and neonicotinoids has been studied for stored-product insects in the past, yet limited information exists on the sublethal effects they can induce to Oryzaephilus surinamensis. In the current study, the sublethal effects of deltamethrin, λ-cyhalothrin, α-cypermethrin, etofenprox, and the mixture of acetamiprid with d-tetramethrin and piperonyl butoxide on the mobility of O. surinamensis in the presence or the absence of a food source was investigated. RESULTS: Lethal concentrations (LCs) were lower for deltamethrin, α-cypermethrin, and λ-cyhalothrin (LC10 = 0.000233, 0.000211, and 0.000271 mg active ingredient (a.i.) cm-2, LC30 = 0.000413, 0.000398, and 0.000447 mg a.i. cm-2, respectively), followed by etofenprox, and the mixture of acetamiprid with d-tetramethrin and piperonyl butoxide (LC10 = 0.00228 and 0.003267 mg a.i. cm-2, LC30 = 0.00437 and 0.01188 mg a.i. cm-2, respectively). Deltamethrin and λ-cyhalothrin negatively impacted adult walking behavior, increasing stop durations compared to controls. Adults exposed to LC10 and LC30 of λ-cyhalothrin, and LC30 of deltamethrin exhibited prolonged periods on their backs compared to the remaining treatments and the controls. The α-cypermethrin LC30-exposed adults exhibited significantly shorter walking and stopping durations than controls but demonstrated prolonged climbing on the arena walls compared to adults exposed to the remaining a.i. and the control. A similar trend was observed for etofenprox. CONCLUSIONS: Under sublethal concentrations, λ-cyhalothrin and deltamethrin increased stop intervals and reduced the duration of climbing attempts of O. surinamensis versus α-cypermethrin. These findings advance comprehension of the underexplored sublethal impacts of the tested a.i. on O. surinamensis adults, holding potential for leveraging insecticide-induced behavioral effects to enhance warehouse pest management. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Unconventional Strategies for Aphid Management in Sorghum.

Since the invasion of the sorghum aphid Melanaphis sorghi (Theobald), farmers in the sorghum (Sorghum bicolor L. Moench) production region in the Great Plains of the U.S. have faced significant crop damage and reduced yields. One widely used practice to aid in managing sorghum aphids is pest monitoring, which often results in field-level insecticide applications when an economic threshold is reached. However, relying on this traditional management practice includes the application of insecticides to non-infested plants. To reduce insecticide usage in sorghum, we proposed spraying individual plants when aphids are present or absent compared to traditional spraying based on a standard economic threshold using field replicate plots over two summer seasons. The experimental results of this study indicated fewer aphids in plots managed with an economic threshold, followed by randomly sprayed and plant-specific treatments compared with the untreated control treatment. Therefore, compared with traditional management, those treatments can be alternative strategies for managing aphids on sorghum within our field plot study.

Repellency, Toxicity, and Chemical Composition of Plant Essential Oils from Myrtaceae against Asian Citrus Psyllid, Diaphorina citri Kuwayama (Hemiptera Liviidae).

Diaphorina citri Kuwayama (D. citri) is one of the major pests in the citrus industry, which spreads Citrus Huanglongbing disease. It has developed resistance to chemical insecticides. Therefore, searching for greener solutions for pest management is critically important. The main aim of this study was to evaluate the repellent and insecticidal efficacy of essential oils (EOs) from four species of Myrtaceae plants: Psidium guajava (PG), Eucalyptus robusta (ER), Eucalyptus tereticornis (ET), and Baeckea frutescens (BF) against D. citri and to analyze their chemical compositions. GC-MS analysis was performed, and the results indicated that the EOs of PG, ER, ET, and BF were rich in terpenoids, ketones, esters, and alcohol compounds. The repellent rate of all four EOs showed that it decreased with exposure time but increased with the concentration of EOs from 80.50% to 100.00% after treating D. citri for 6 h with four EOs at 100% concentration and decreased to 67.71% to 85.49% after 24 h of exposure. Among the compounds from the EOs tested, eucalyptol had the strongest repellent activity, with a 24 h repellency rate of 100%. The contact toxicity bioassay results showed that all EOs have insecticidal toxicity to D. citri; the LC50 for nymphs was 36.47-93.15 mL/L, and for adults, it was 60.72-111.00 mL/L. These results show that when PG is used as the reference material, the ER, ET, and BF EOs have strong biological activity against D. citri, which provides a scientific basis for the further development of plant-derived agrochemicals.

Associations between DEET, Organophosphorus Insecticides, and Handgrip Strength in Diabetes: An NHANES Analysis.

INTRODUCTION: Sarcopenia and diabetes mellitus (DM) have been shown to be related. It has been demonstrated that pesticides/insecticides are linked to various health issues, including DM. This study investigated the relationships between exposure to pesticides/insecticides and muscle strength among community-dwelling DM patients in a national sample of the United States (US). METHODS: Data from the 2011-2012 and 2013-2014 U.S. National Health and Nutrition Examination Survey (NHANES) on people aged 20 years with diabetes were retrieved. A digital dynamometer was used to quantify handgrip strength, and urine pesticide concentrations were determined through laboratory testing. Regression models were used to investigate the relationship between pesticide/insecticide exposure and handgrip strength. RESULTS: After weighting, the data from 412 NHANES participants represented 6,696,865 U.S. inhabitants. The mean age of the participants was 58.8 years. High para-nitrophenol levels (tertile 3 vs. tertile 1) were shown to be associated with lower handgrip strength in both males (aBeta = -7.25, 95% CI: -11.25, -3.25) and females (aBeta = -3.73, 95% CI: -6.89, -0.56). Further, females with elevated 2-isopropyl-4-methyl-pyrimidinol had decreased handgrip strength. Desethyl hydroxy N, N-diethyl-m-toluamide (DEET) was inversely related to handgrip strength in men aged ≥60 years. DEET acid and para-nitrophenol were inversely correlated to handgrip strength in women over 60 years. CONCLUSIONS: This study has linked certain pesticides/insecticides to decreased muscle strength in people with diabetes. Para-nitrophenol, in particular, is negatively related to muscular strength in both males and females, and 2-isopropyl-4-methyl-pyrimidinol is inversely related to muscle strength in females.

Development and Validation of a High-Performance Liquid Chromatography Diode Array Detector Method to Measure Seven Neonicotinoids in Wheat.

Neonicotinoids (NEOs), used as insecticides against aphids, whiteflies, lepidopterans, and beetles, have numerous detrimental impacts on human health, including chronic illnesses, cancer, infertility, and birth anomalies. Monitoring the residues in food products is necessary to guarantee public health and ecological balance. The present work validated a new method to measure seven neonicotinoid insecticides (acetamiprid ACT, clothianidin CLT, dinotefuran DNT, imidacloprid IMD, nitenpyram NTP, thiacloprid TCP, and thiamethoxan THT) in wheat. The analytical procedure was based on simple and fast wheat sample cleanup using solid-phase extraction (SPE) to remove interferents and enrich the NEOs, alongside the NEOs' separation and quantification by reverse-phase chromatography coupled with a diode array detector (DAD). The validation process was validated using the accuracy profile strategy, a straightforward decision tool based on the measure of the total error (bias plus standard deviation) of the method. Our results proved that, in the future, at least 95% of the results obtained with the proposed method would fall within the ±15% acceptance limits. The test's cost-effectiveness, rapidity, and simplicity suggest its use for determining the levels of acetamiprid, clothianidin, dinotefuran, imidacloprid, nitenpyram, thiacloprid, and thiamethoxam in routine analyses of wheat.

Association between organophosphorus insecticides exposure and osteoarthritis in patients with arteriosclerotic cardiovascular disease.

BACKGROUND: Organic phosphorus insecticides (OPPs) are a class of environmental pollutants widely used worldwide with potential human health risks. We aimed to assess the association between exposure to OPPs and osteoarthritis (OA) particularly in participants with atherosclerotic cardiovascular disease (ASCVD). METHODS: Participants' information was obtained from data in the National Health and Nutrition Examination (NHANES). Weighted logistic regression models were utilized to detect associations between OPPs metabolites and OA. Restricted cubic spline plots (RCS) were drawn to visualize the dose-response relationship between each metabolite and OA prevalence. Weighted quantile sum (WQS) regression and Bayesian kernel-machine regression (BKMR), were applied to investigate the joint effect of mixtures of OPPs on OA. RESULTS: A total of 6871 samples were included in our study, no significant associations between OPPs exposure and OA incidence were found in whole population. However, in a subset of 475 individuals with ASCVD, significant associations between DMP (odds ratio [OR] as a continuous variable = 1.22, 95% confidence interval [CI]: 1.07,1.28), DEP ((odds ratio [OR] of the highest tertile compared to the lowest = 2.43, 95% confidence interval [CI]: 1.21,4.86), and OA were observed. DMP and DEP showed an increasing dose-response relationship to the prevalence of OA, while DMTP, DETP, DMDTP and DEDTP showed a nonlinear relationship. Multi-contamination modeling revealed a 1.34-fold (95% confidence intervals:0.80, 2.26) higher prevalence of OA in participants with high co-exposure to OPPs compared to those with low co-exposure, with a preponderant weighting (0.87) for the dimethyl dialkyl phosphate metabolites (DMAPs). The BKMR also showed that co-exposure of mixed OPPs was associated with an increased prevalence of OA, with DMP showing a significant dose-response relationship. CONCLUSION: High levels of urine dialkyl phosphate metabolites (DAP) of multiple OPPs are associated with an increased prevalence of OA in patients with ASCVD, suggesting the need to prevent exposure to OPPs in ASCVD patients to avoid triggering OA and further avoid the occurrence of cardiovascular events caused by OA.

Effects of Essential Oils on Biological Characteristics and Potential Molecular Targets in Spodoptera frugiperda.

Spodoptera frugiperda control methods have proved to be inefficient, which justifies the search for new control measures. In this search for botanical insecticides for controlling S. frugiperda, the following were evaluated: (i) the toxicity of essential oils (EOs) from Cinnamodendron dinisii, Eugenia uniflora, and Melaleuca armillaris; (ii) the effect of EOs on life table parameters against S. frugiperda; (iii) the chemical characterization of EOs; and (iv) the in silico interaction of the chemical constituents present in the three EOs with the molecular targets of S. frugiperda. The EO from E. uniflora had the lowest LD50 (1.19 µg of EO/caterpillar). The major compounds bicyclogermacrene (18.64%) in C. dinisii and terpinolene (57.75%) in M. armillaris are highly predicted to interact with the octopamine receptor (OctpR). The compound 1,8-cineole (21.81%) in M. armillaris interacts mainly with a tolerant methoprene receptor (MET) and curzerene (41.22%) in E. uniflora, which acts on the OctpR receptor. Minor compounds, such as nerolidol in C. dinisii and ß-elemene in E. uniflora, are highly ranked for multiple targets: AChE, MET, OctpR, and 5-HT1. It was concluded that the EO from E. uniflora negatively affects several biological parameters of S. frugiperda development and is promising as an active ingredient in formulations for controlling this insect pest.

L-carnitine: A novel approach in management of acute cholinesterase inhibitor insecticide poisoning.

Cholinesterase inhibitors (ChEIs) insecticide poisoning is a serious global health concern that results in hundreds of thousands of fatalities each year. Although inhibition of the cholinesterase enzyme is the main mechanism of ChEI poisoning, oxidative stress is considered the mechanism underlying the related complications. The study aimed to assess the oxidative status of the patients with ChEI insecticide poisoning and the role of L-carnitine as adjuvant therapy in their management. Human studies on the efficacy and safety of L-carnitine in treating insecticide poisoning are limited despite its growing research interest as a safe antioxidant. This prospective study was conducted on eighty patients with acute ChEIs insecticide poisoning admitted to Alexandria Poison Center, Alexandria Main University Hospital, Egypt. Patients were allocated into two equal groups randomly. The L-carnitine (LC) group received the conventional treatment (atropine & toxogonin) and LC and the standard treatment (ST) group received the standard treatment only. Outcome measures were fatality rate, the total administered dose of atropine & toxogonin, length of hospital stay, and the requirement for ICU admission or mechanical ventilation. The study results revealed that malondialdehyde (MDA) significantly decreased in the LC group. Cholinesterase enzyme levels increased significantly after treatment in the LC group than in the ST group. The LC group needed lower dosages of atropine and toxogonin than the ST group. Also, the LC group showed no need for ICU admission or mechanical ventilation. The study concluded that LC can be considered a promising adjuvant antioxidant treatment in acute ChEIs pesticide poisoning.

Cell Painting unravels insecticidal modes of action on Spodoptera frugiperda insect cells.

The "Cell Painting" technology utilizes multiplexed fluorescent staining of various cell organelles, to produce high-content microscopy images of cells for multidimensional phenotype assessment. The phenotypic profiles extracted from those images can be analyzed upon perturbations with biologically active molecules to annotate the mode of action or biological activity by comparison with reference profiles of already known mechanisms of action, ultimately enabling the determination of on-target and off-target effects. This approach is already described in various human cell cultures, the most commonly used being the U2OS cell line, yet allows broad applications in additional areas of chemical-biological research. Here we describe for the first time the application and adaptation of Cell Painting to an insect cell line, the Sf9 cells from Spodoptera frugiperda. By adjusting image acquisition and analysis models, specific phenotypic profiles were obtained in a dose-dependent manner for 20 reference compounds, including representatives for the most relevant insecticidal modes of action categories (nerve & muscle, respiration and growth & development). Through a dimensionality-reduction method, both calculations of phenotypic half maximal inhibition concentration (IC50) values as well as similarity analysis of the obtained profiles by hierarchical clustering were performed. By Cell Painting effects on the phenotype could be obtained at higher sensitivity than in other assay formats, such as cytotoxicity assessments. More importantly, these analyses provide insight into mechanistic determinants of biological activity. Compounds with similar modes of action showed a high degree of proximity in a hierarchical clustering analysis while being distinct from actives with an unrelated mode of action. In essence, we provide strong evidence on the impact of Cell Painting mechanistic understanding of insecticides with regards to determinants of efficacy and safety utilizing an insect cell model system.

Comparative transcriptome profiling of two pesticides, Acephate and Chlorantraniliprole in non-targeted insect model, Drosophila melanogaster.

Acephate and chlorantraniliprole are two insecticides widely used in agricultural applications. Several studies were focused on the mode of action and related biological and cellular level expressions. However, the sub-lethal dose and related molecular expression level of acephate and chlorantraniliprole have not been evaluated or studied to the same degree. In this study, we investigated the sub-lethal toxicity of acephate and chlorantraniliprole in Drosophila melanogaster. The EC50 value was recorded with high difference, and is found to be 1.9 µg/ml and 0.029 µg/ml respectively for acephate and chlorantraniliprole, the difference is simply because of the different modes of action. The 1/5th EC50 concentration was selected for studying the pesticide induced transcriptomics in D. melanogaster. Both pesticides significantly altered the expression profile of several transcripts which are involved in proteolysis, detoxification, chromosome associated proteins and immune response genes and so on. The effect of both pesticides on D. melanogaster was further explored by screening the genes involved in toxicity, which were analyzed using, GO and KEGG pathways. The results revealed that the sub-lethal exposure of both pesticides caused significant changes in the global gene transcription profiles and each pesticide had their unique mode of alteration in the D. melanogaster.

Multiresidues of pesticides in the particulate matter (PM10) emitted by rural soils of the semiarid pampas, Argentina. A potential source of air pollution.

The aim of this work was to evaluate the presence of 40 pesticides in the PM10 emitted by rural soils of the semiarid region of Argentina. Six agricultural soils for grain production under no till and with high use of pesticides (AG), 5 agricultural soils for forage and grain production under conventional tillage (AFG) and 5 unpaved rural roads (RR) were sampled. The PM10 was generated using the Easy Dust Generator and it was collected with an electrostatic precipitator. The presence of 20 herbicides, 14 insecticides and 6 fungicides was analyzed in the soil and in the PM10. More than 70% of the pesticides analyzed were detected in the soil and in the PM10. All agricultural soils and 87% of RR soils showed at least one residue of pesticides. Multiresidues of pesticides were found in the 100% of PM10 emitted by rural soils. The mean number of pesticides was higher in the PM10 (7) than in the soil (5). Some pesticides were not detected in the soils but they were detected in the PM10 (triticonazole, carbofuran, metsulfuron methyl) and vice versa. In general, the concentrations of herbicides were higher in the PM10 than in the soil, while the concentrations of insecticides and fungicides were lower in the PM10 than in the soil. These results suggest that the concentrations of pesticide in the PM10 (inhalable fraction) should be used instead the concentrations of pesticide in the soil to calculate the exposure factor to pesticides by dust inhalation. This study provides the initial evidence of the presence of multiple pesticide residues in PM10 emitted by rural soils under different land management. Also confirms that the PM10 is a potential source of air contamination with pesticides. Future studies should be driven to measure the concentrations of pesticides and their dynamics in the PM10.

Ecotoxicity threshold values for 4-hydroxychlorothalonil, carbendazim, dimethoate and methoxyfenozide in fresh and marine waters: Part 1. Derivation of threshold values.

Pesticide active ingredients are frequently detected in the rivers, creeks, wetlands, estuaries, and marine waters of the Great Barrier Reef (GBR) region and are one of the main contributors to poor water quality. Pesticide concentrations detected in the environment through water quality monitoring programs can be compared against estimates of ecologically "safe" concentrations (i.e., water quality guidelines) to assess the potential hazard and risk posed to aquatic ecosystems. Water quality guidelines are also required to estimate the aquatic risk posed by pesticide mixtures, which is used for the Reef 2050 Water Quality Improvement Plan pesticide target. Seventy-four pesticide active ingredients and their degradates are frequently detected in GBR catchment waterways, however many do not have water quality guidelines in the Australian and New Zealand Guidelines for Fresh and Marine Water Quality. The current study derives ecotoxicity threshold values (ETVs) as unendorsed guideline values for active ingredients in two fungicides (4-hydroxychlorothalonil (fungicide degradate) and carbendazim) and two insecticides (dimethoate and methoxyfenozide) that are commonly detected in GBR catchment waterways. The proposed ETVs have been derived using species sensitivity distributions, as recommended in the Australian and New Zealand nationally endorsed method for deriving water quality guidelines for aquatic ecosystem protection. Four ETVs were derived for each chemical with values that should theoretically protect 99, 95, 90 and 80 % of species (i.e., PC99, PC95, PC90, PC80, respectively). The PC99 and PC95 values for 4-hydroxychlorothalonil, carbendazim, dimethoate and methoxyfenozide were 0.49 µg/L and 4 µg/L, 0.029 µg/L and 0.45 µg/L, 0.11 µg/L and 5.8 µg/L and 0.19 µg/L and 2 µg/L, respectively. The ETVs will be used in an ecological hazard and risk assessment across GBR waterways in part two of this study. The ETVs can also be used to assess potential risk across Australia and internationally where monitoring data are available.