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Ecotoxicology and Environmental Safety Aug 2021Few studies have been conducted with regard to the effects of insecticides on population dynamics of shrimps and associated groups such as macrophytes, phytoplankton,...
Few studies have been conducted with regard to the effects of insecticides on population dynamics of shrimps and associated groups such as macrophytes, phytoplankton, microorganisms etc. In the present study, effects of a single application of fenoxycarb were tested using indoor freshwater systems dominated by Neocaridina palmata and Ceratophyllum demersum (Dicotyledons: Ceratophyllales). The no observed effect concentration (NOEC) and lowest observed effect concentration (LOEC) for the N. palmata, as scaled by liberated chitobiase, were 6.48 μg/L and 27.76 μg/L, and the dose-related effect lasted for 14 days. Results of principal components analysis (PCA) and that of principal response curves (PRC) method showed that the biomass of C. demersum and concentrations of chlorophyll-a were suppressed, while the concentrations of phycocyanin were promoted. Illumina high-throughput sequencing was adopted to determine the diversity of bacteria and fungi in the media. Result of PCA and PRC showed that the fenoxycarb promoted photosynthetic bacteria (e.g. Cyanobacteria and Rhodobacterales) and suppressed groups involved in nitrogen and sulfur the transformation (e.g. Flavobacterium, hgcI_clade, Cystobasidium, Rhodotorula and Rhizobiales). Promotion in pathogen such as Pseudomonas and Cercozoa and suppression in beneficial taxa such as Novosphingobium and Rhodotorula were also sighted. Result of study suggested a water quality deterioration due to fenoxycarb applications.
Topics: Animals; Biomass; Chlorophyll A; Crustacea; Cyanobacteria; Decapoda; Fresh Water; Insecticides; Magnoliopsida; Nitrogen; Phenylcarbamates; Phytoplankton; Water Pollutants, Chemical; Water Quality
PubMed: 33991935
DOI: 10.1016/j.ecoenv.2021.112304 -
Acta Crystallographica. Section E,... Oct 2012The title compound, C(17)H(19)NO(4), which is a non-toxic insect growth regulator with the common name fenoxycarb, contains two independent and conformationally...
The title compound, C(17)H(19)NO(4), which is a non-toxic insect growth regulator with the common name fenoxycarb, contains two independent and conformationally different mol-ecules in the asymmetric unit. Although the inter-ring dihedral angles are similar [62.21 (15) and 63.00 (14)°], the side-chain orientations differ. In the crystal, the mol-ecules are linked through N-H⋯O hydrogen-bonding associations, giving chains which extend along [110], while intra- and inter-molecular aromatic C-H⋯π inter-actions give sheet structures parallel to [110].
PubMed: 23125640
DOI: 10.1107/S1600536812037105 -
Journal of Pesticide Science Aug 2023Brassinosteroids (BRs) are steroid hormones that regulate plant growth, development, and stress resistance. In this study, we evaluated the effect of agrochemicals on...
Brassinosteroids (BRs) are steroid hormones that regulate plant growth, development, and stress resistance. In this study, we evaluated the effect of agrochemicals on dark-induced hypocotyl elongation, which is regulated by BRs, to identify novel chemicals that regulate BR action. We found that the juvenile hormone agonist fenoxycarb inhibited dark-induced hypocotyl elongation in . Treatment with the same class of juvenile hormone agonist, pyriproxyfen, did not affect hypocotyl elongation. Co-treatment with fenoxycarb and BR partly canceled the fenoxycarb-induced hypocotyl suppression. In addition, gene expression analysis revealed that fenoxycarb altered the BR-responsive gene expression. These results indicate that fenoxycarb is a BR action inhibitor.
PubMed: 37745175
DOI: 10.1584/jpestics.D23-015 -
Ecotoxicology and Environmental Safety Oct 2020To evaluate the aquatic hazards of the insect juvenile hormone analogue fenoxycarb, a single application (0, 48.8, 156.3, 500, 1600, and 5120 μg/L) of it was done in...
To evaluate the aquatic hazards of the insect juvenile hormone analogue fenoxycarb, a single application (0, 48.8, 156.3, 500, 1600, and 5120 μg/L) of it was done in indoor freshwater systems dominated by Daphnia carinata (daphnid) and Dolerocypris sinensis (ostracoda). The responses of zooplankton (counted by abundance and the activity and immuno-reactive content of free N-Acetyl-β-D-glucosaminidase (NAGase)), phytoplankton (counted by chlorophyll and phycocyanin), planktonic bacteria and fungi, and some water quality parameters were investigated in a period of 35 d. Results of the study showed that the ostracoda was more sensitive than daphnid, with time-weighted average (TWA)-based no observed effect concentrations (NOECs) to be 8.45 and 12.66 μg/L in systems without humic acid addition (HA-) and to be 6.37 and 9.54 μg/L in systems with humic acid addition (HA+). The duration of treatment-related effects in the ostracoda population was longer than the daphnid population (21 vs. 14 days). Besides, the data analysis indicated that the toxicity of fenoxycarb was significantly enhanced in the HA+ systems. Owing to the reduced grazing pressure, the concentrations of chlorophyll and phycocyanin increased in the two highest treatments. The increase in photosynthesis along with a reduced animal excretion led to an increase in pH and a decrease in nutrient contents. These changes seemed to have an effect on the microbial communities. For example, the abundances of some opportunistic pathogens of aquatic animals (e.g. Aeromonas and Cladosporium) and organic-pollutant-degrading microorganisms (e.g. Ancylobacter and Azospirillum) increased significantly in microbial communities, but the abundances of Pedobacter, Candidatus Planktoluna, and Rhodobacter (photosynthetic bacteria) markedly decreased. This study provides useful information to understand the ecotoxicological impacts of fenoxycarb at the population and community levels while integrating the effects of HA on toxicity.
Topics: Animals; Crustacea; Daphnia; Ecotoxicology; Fresh Water; Humic Substances; Microbiota; Phenylcarbamates; Phytoplankton; Water Pollutants, Chemical; Zooplankton
PubMed: 32888608
DOI: 10.1016/j.ecoenv.2020.111022 -
Environmental Pollution (Barking, Essex... Apr 2020After exposure of soils to anthropogenic organic chemicals non-extractable residues (NER) can be formed. The quantitative proportion of a compound which remains...
After exposure of soils to anthropogenic organic chemicals non-extractable residues (NER) can be formed. The quantitative proportion of a compound which remains non-extractable is operationally defined by the extraction procedure employed and can be quantified only when using isotope labelled compounds (e.g. C or C). In Germany and the EU, there is no standardised procedure, how to determine NER, especially when different legal regulations apply. Consequently, the comparability of NER data is low. Hence, a major task of this study was the development of a general approach for the quantification of non-extractable residues (NER) in soils using radiotracer analysis. For that, extraction efficiencies were determined for 42 non-labelled organic chemicals spiked onto 3 soils applying a number of extraction techniques and conditions, developing an extraction procedure which provides high extraction efficiencies and a low variability for a broad spectrum of analytes. Additionally, NER generated within soil transformation studies according to OECD 307 using C-triclosan, C-fenoxycarb and C-acetaminophen were analysed using sequential batch extraction and pressurised liquid extraction (PLE). Depending on the extraction procedure used, the NER fraction related to C-triclosan in a soil varied greatly between 96% and 28%. In this study a widely universal extraction procedure was developed to improve the comparability of the NER data and limit overestimation of NER, which can be of enormous consequence for the assessment of persistence and environmental risk of organic chemicals. Furthermore, silylation, EDTA-extraction and HCl-treatment were compared regarding a further analysis of NER using radiotracer analysis.
Topics: Environmental Monitoring; Germany; Soil; Soil Microbiology; Soil Pollutants; Triclosan
PubMed: 31887596
DOI: 10.1016/j.envpol.2019.113826 -
Aquatic Toxicology (Amsterdam,... Feb 2015Although Daphnia magna is a key species in many lentic freshwater ecosystems and is commonly used as model organism in ecology and ecotoxicology, very little is known...
Although Daphnia magna is a key species in many lentic freshwater ecosystems and is commonly used as model organism in ecology and ecotoxicology, very little is known about the effects of chemicals on their dormant life stages. Dormant eggs (ephippia) are produced when environmental conditions deteriorate, and Daphnia switch from clonal to sexual reproduction. Ephippia produced over different growing seasons can accumulate in the sediment of ponds and lakes, where they can be exposed to pesticides and other (anthropogenic) stressors. In the present study, we have investigated the effects of pesticide exposure on dormant eggs at different embryonic developmental stages and evaluated the degree of protection against pollution provided by the ephippial case. We therefore conducted a hatching experiment in which decapsulated and encapsulated dormant eggs were exposed to an insect growth regulator (fenoxycarb) at different stages during their development, both before and after activation of the eggs. In addition, we developed an analytical method to measure fenoxycarb concentrations in the dormant eggs. Fenoxycarb negatively affected development and hatching success and changed the timing of hatching in activated and in dormant eggs. Hatching characteristics as well as fenoxycarb concentrations inside the eggs differed significantly between exposure treatments. Final stages of embryonic development were most sensitive to pesticide exposure and had the highest tissue concentrations of fenoxycarb. Tissue concentrations did not differ significantly between decapsulated and encapsulated eggs, suggesting that the ephippial case offers limited or no direct protection against pesticide exposure. With this study we provide new evidence showing that pesticides can bioconcentrate in and affect D. magna dormant eggs. The severity of the effects on developing embryos depends on the timing of pesticide exposure. Our results stress the importance of considering the full life-cycle of model organisms used in ecotoxicological studies, since these are ultimately aimed at assessing risks of chemical exposure on natural aquatic ecosystems.
Topics: Animals; Daphnia; Pesticides; Phenylcarbamates; Time Factors; Water Pollutants, Chemical
PubMed: 25546008
DOI: 10.1016/j.aquatox.2014.12.016 -
Journal of Insect Science (Online) 2015The effects of fenoxycarb, a Juvenile hormone analogue, at sublethal concentrations were tested on some biological parameters of Plutella xylostella (L.) in two...
The effects of fenoxycarb, a Juvenile hormone analogue, at sublethal concentrations were tested on some biological parameters of Plutella xylostella (L.) in two consecutive generations. The calculated LC10, LC25, and LC50 values of the insecticide were 21.58, 43.25, and 93.62 mg/liter on third-instar larvae, respectively. Fenoxycarb significantly reduced pupal weight and oviposition period in parent generation. In addition, the fecundity of treated groups (LC10 = 71.06, LC25 = 40.60 eggs per female) in parents was significantly lower than control (169.40 eggs per female). Although fenoxycarb could not affect gross reproductive rate and death rate, it decreased net reproductive rate, intrinsic rate of increase, finite rate of increase, and birth rate in offspring generation. Also, mean generation time and doubling time of treated insects was significantly longer than control at LC10 level. Therefore, the data from this study suggested that fenoxycarb could adversely cause population decline in the subsequent generation.
Topics: Animals; Female; Insecticides; Juvenile Hormones; Larva; Male; Moths; Phenylcarbamates; Pupa; Reproduction
PubMed: 26136495
DOI: 10.1093/jisesa/iev064 -
International Journal of Environmental... Jun 2008Use of Juvenile Hormone Analogues (JHA) in sericulture practices has been shown to boost good cocoon yield; their effect has been determined to be dose-dependent. We...
Use of Juvenile Hormone Analogues (JHA) in sericulture practices has been shown to boost good cocoon yield; their effect has been determined to be dose-dependent. We studied the impact of low doses of JHA compounds such as methoprene and fenoxycarb on selected key enzymatic activities of the silkworm Bombyx mori. Methoprene and fenoxycarb at doses of 1.0 microg and 3.0 fg/larvae/48 hours showed enhancement of the 5th instar B. mori larval muscle and silkgland protease, aspartate aminotransaminase (AAT) and alanine aminotransaminase (ALAT), adenosine triphosphate synthase (ATPase) and cytochrome-c-oxidase (CCO) activity levels, indicating an upsurge in the overall oxidative metabolism of the B.mori larval tissues.
Topics: Adenosine Triphosphatases; Alanine Transaminase; Animals; Aspartate Aminotransferases; Bombyx; Dose-Response Relationship, Drug; Electron Transport Complex IV; Energy Metabolism; Gene Expression Regulation, Developmental; Juvenile Hormones; Larva; Metamorphosis, Biological; Methoprene; Phenylcarbamates
PubMed: 18678927
DOI: 10.3390/ijerph5020120 -
Journal of Pesticide Science Feb 2021Juvenile hormone (JH) is an insect-specific hormone that regulates molting and metamorphosis. Hence, JH signaling inhibitors (JHSIs) and activators (JHSAs) can be used...
Juvenile hormone (JH) is an insect-specific hormone that regulates molting and metamorphosis. Hence, JH signaling inhibitors (JHSIs) and activators (JHSAs) can be used as effective insect growth regulators (IGRs) for pest management. In our previous study, we established a high-throughput screening (HTS) system for exploration of novel JHSIs and JHSAs using a cell line (BmN_JF&AR cells) and succeeded in identifying novel JHSIs from a chemical library. Here, we searched for novel JHSAs using this system. The four-step HTS yielded 10 compounds as candidate JHSAs; some of these compounds showed novel basic structures, whereas the others were composed of a 4-phenoxyphenoxymethyl skeleton, the basic structure of several existing JH analogs (pyriproxyfen and fenoxycarb). Topical application of seven compounds to larvae significantly prolonged the larval period, suggesting that the identified JHSAs may be promising IGRs targeting the JH signaling pathway.
PubMed: 33746546
DOI: 10.1584/jpestics.D20-070 -
PloS One 2018Insect growth regulator insecticides mimic the action of hormones on the growth and development of insect pests. However, they can affect the development of non-target...
Insect growth regulator insecticides mimic the action of hormones on the growth and development of insect pests. However, they can affect the development of non-target arthropods. In the present study, we tested the effects of the growth regulator insecticide fenoxycarb on several endpoints in the freshwater crustacean Gammarus fossarum (Amphipoda). Females carrying embryos in their open brood pouch were exposed to 50 μg L-1 fenoxycarb throughout the entire oogenesis (i.e. 21 days). After exposure, newborn individuals from exposed embryos were removed from the maternal open brood pouch for lipidomic analysis, while males were added to assess the reproductive success. After fertilization, the lipid profile, energy reserve content (lipids, proteins and glycogen), and activity of phenoloxidase - an enzyme involved in the immune response - were measured in females. No significant effect of fenoxycarb exposure was observed on the lipid profile of both newborn individuals and females, while reproductive success was severely impaired in exposed females. Particularly, precopulatory behavior was significantly reduced and fertilized eggs were unviable. This study highlighted the deleterious effects of the insect growth regulator fenoxycarb on gammarid reproduction, which could have severe repercussions on population dynamics.
Topics: Amphipoda; Animals; Embryo, Nonmammalian; Environmental Exposure; Female; Fresh Water; Glycogen; Hormones; Immune System; Insecticides; Lipids; Male; Monophenol Monooxygenase; Oocytes; Oogenesis; Phenylcarbamates; Population Dynamics; Proteins; Reproduction; Water Pollutants, Chemical; Zygote
PubMed: 29702662
DOI: 10.1371/journal.pone.0196461