bifenthrin and cypermethrin

Pyrethroid pesticides are commonly used for pest control in agriculture setup, veterinary and home garden. They are now posing increased risks to non-targeted organisms associated to human beings due to their considerable use. The present work deals with the isolation of bacteria with tolerance to high concentrations of bifenthrin and cypermethrin from contaminated soil. Enrichment culture technique (bifenthrin concentration = 50-800 mg/L) was used for bacterial isolation. Bacteria that showed growth on minimal media with bifenthrin were also sub-cultured on minimal media with cypermethrin. Bacteria showing luxurious growth on both the pyrethroid, were screened out based on their morphological, biochemical parameters and by API 20NE Kit. Phylogenetic studies revealed that, one bacterial isolate (MG04) belonging to Acinetobacter lwoffii and other five bacterial isolates (MG06, MG05, MG01, MG03 and MG02) cluster with Pseudomonas aeruginosa, Pseudomonas putida respectively. Isolated members of genera Pseudomonas and Acinetobacter could be used for further detailed degradation studies by using FTIR, HPLC-MS or GC-MS analysis.

Topics: Agriculture; Bacteria; Biodegradation, Environmental; Humans; Phylogeny; Pyrethrins; Soil; Soil Microbiology; Soil Pollutants

The spotted-wing drosophila, Drosophila suzukii (Matsumura), is a global economic pest of berry crops and stone fruit. Since management of this pest primarily relies on calendar insecticide applications, and field-derived resistance to spinosad has already been documented in California caneberry production, there is significant concern for development of resistance to other insecticides. In this study, susceptibility of D. suzukii populations collected from caneberry and strawberry fields to two pyrethroids, zeta-cypermethrin, and bifenthrin, was assessed in 2019 and 2020. Resistance to both pyrethroids were observed in flies from all sampling sites. For flies collected from caneberries in 2019, the LC50 values ranged from 4.5 to 5.2 mg liter-1 with RR50s ranging from 7.5- to 8.7-fold. Our 2020 assays showed that susceptibility of flies to the discriminating dose of zeta-cypermethrin decreased significantly as the season progressed. For flies collected from strawberries in 2020, the LC50s ranged from 19.0 to 36.1 mg liter-1 and from 30.3 to 90.7 mg liter-1 for zeta-cypermethrin and bifenthrin, respectively. The RR50 values varied from 19.0- to 36.1-fold for zeta-cypermethrin and from 15.9- to 47.7-fold for bifenthrin. This study is the first report of field-derived pyrethroid resistance in D. suzukii from two major California berry production areas. Adoption of informed insecticide resistance management practices would be essential to prolong the efficacy of products available to control D. suzukii. Future molecular work is needed to unravel the underlying genetic mechanisms conferring the observed pyrethroid resistance and to develop robust diagnostics that can inform integrated pest management of this pest.

Topics: Animals; Drosophila; Fragaria; Fruit; Insect Control; Insecticides; Pyrethrins

Topics: Acaricides; Animals; Guanidines; Mites; Neonicotinoids; Nitriles; Nitro Compounds; Pesticides; Pyrethrins; Spiders; Tetranychidae; Thiazoles

The neonicotinoid insecticide acetamiprid (ACT) and seven pesticides [abamectin (ABA), emamectin benzoate (EMB), dicrotophos (DIC), bifenthrin (BIF), cypermethrin (CYP), lambda-cyhalothrin (LCY) and tetraconazole (TET)] are widely applied agrochemicals worldwide. Since most previous studies on these pesticides are performed merely based on toxicity tests with individual active ingredients, only finite knowledge is available on the mixture toxicities of these formulated compounds to crop pollinators. In this study, we examined their toxicities of binary, ternary, quaternary, quinquenary, senary, septenary and octonary mixtures to honey bee (Apis mellifera L.) with feeding toxicity test. Results showed that EMB and ABA had the highest toxicities to A. mellifera with LC

Topics: Animals; Bees; Chlorobenzenes; Insecticides; Neonicotinoids; Nitriles; Pesticides; Pollination; Pyrethrins; Toxicity Tests; Triazoles

This study compared four different statistical methods, involving six estimation procedures, for addressing censored left data in measuring temporal trends of eight different pyrethroids measured in sediment from a 10-year data set in a residential California stream (Pleasant Grove Creek). The statistical methods used were: the Kaplan-Meier (km) method; the robust regression on order statistics (ros using normal and log normal distributions rosln); the maximum likelihood estimation (mlen using normal and log normal distributions mleln); and a substitution method (sub) using ½ the detection limit. For five of the eight pyrethroids (bifenthrin, cyfluthrin, cypermethrin, lambda-cyhalothrin, and permethrin), the six statistical methods generally agree, with one exception, that the data set exhibit significant declining trends. In the case of bifenthrin, the slight disagreement among statistical methods only occurred for the mleln estimate that did not show a significant declining trend, whereas the other five methods did. For deltamethrin, esfenvalerate, and fenpropathrin, all six statistical methods were in agreement showing no significant trends. Possible reasons for declining sediment concentrations of pyrethroids in Pleasant Grove Creek are urban label changes effective in 2012-2015 that reduced residential use, variable annual rainfall, and more responsible homeowner use based on outreach/education programs.

Topics: Animals; California; Environmental Monitoring; Insecticides; Nitriles; Permethrin; Pyrethrins; Rivers; Water Pollutants, Chemical

The Kanzawa spider mite, Tetranychus kanzawai Kishida, is a major pest in tea fields [Camellia sinensis (L.) O. Kuntze] in Japan. However, recently, there have been some instances where acaricides are no longer applied as a result of the low occurrence of T. kanzawai in tea fields in Japan. In the period of 2015-2017, surveys of predatory mites in the study tea field detected Amblyseius eharai Amitai and Swirski, Phytoseiulus persimilis Athias-Henriot, Euseius sojaensis (Ehara), Amblyseius obtuserellus Wainstein and Begljarov, and Typhlodromus vulgaris Ehara in tea fields, but not Neoseiulus womersleyi (Schicha), indicating that a major change in the composition of the phytoseiid mite population had occurred. In laboratory studies, we confirmed the ability to avoid synthetic pyrethroid insecticides of the major beneficial mites in tea fields, A. eharai and P. persimilis, but not of E. sojaensis, a predatory mite whose population declined heavily after pesticide application. Attempts are made in this study to associate the decrease in T. kanzawai frequency in Japan with changes in pesticide used, method of spraying, and composition of the phytoseiid mite population. By continuing the method of pesticide spraying ('partial surface'), which leaves refugia in the leaf layer with sub-lethal dosages of pesticide, phytoseiid mites are aided to evade pesticides, resulting in maintenance of the composition of the phytoseiid mite populations in terms of diversity and abundance. Maintaining the diversity and abundance of Phytoseiidae may have contributed to the stabilization of the T. kanzawai population at low densities in Japanese tea fields.

Topics: Acaricides; Animals; Avoidance Learning; Female; Mites; Permethrin; Predatory Behavior; Pyrethrins; Species Specificity

One method for controlling the Asian citrus psyllid (ACP) Diaphorina citri Kuwayama, the vector of the putative causal agent of Huanglongbing, uses the parasitoid Tamarixia radiata (Waterston). However, the general intensive use of insecticides has reduced the numbers of this parasitoid. This study evaluated the effect of the residual action of 24 insecticides on T. radiata and also determined the differential toxicity of insecticides to D. citri and T. radiata, using three bioassays. In the first, when adults of the parasitoid were exposed to residues of the 24 insecticides, ten were considered short-life (class 1), six slightly persistent (class 2), five moderately persistent (class 3), and three insecticides were considered persistent (class 4), under the IOBC/WPRS classification system. The second bioassay evaluated the sublethal concentrations of the persistent insecticides (formetanate, dimethoate, spinosad). Increasing the concentrations of the insecticides increased the number that were classified as persistent. In the third bioassay, evaluation of the differential toxicity of eight insecticides to the ACP and the parasitoid showed that chlorpyrifos and bifenthrin were more harmful to T. radiata. Therefore, these two insecticides are not recommended for application at the time of parasitoid release. Cypermethrin, imidacloprid, and dimethoate caused higher mortality of D. citri and are most often recommended in IPM programs. The choice of an insecticide for the control of citrus pests must be made with care, aiming to preserve the natural enemies in the ecosystem, and thereby contribute to the success of biological control.

Topics: Animals; Biological Control Agents; Carbamates; Chlorpyrifos; Dimethoate; Hemiptera; Hymenoptera; Insecticides; Neonicotinoids; Nitro Compounds; Pyrethrins

Twenty-nine pesticide residues in nut-planted soils from China were investigated. One organophosphate (chlorpyrifos) was detected in 5.3% soils, and the residue levels of 7.2 μg/kg to 77.2 μg/kg. The concentrations of six organochlorines (DDT, HCH, endosulfan, quintozene, aldrin and dieldrin) detected in 78.9% soils were 0.6 μg/kg to 90.1 μg/kg. The residue levels of six pyrethroids (bifenthrin, fenpropathrin, cyhalothrin, cypermethrin, fenvalerate and deltamethrin) detected in 65.8% soils were 1.5 μg/kg to 884.3 μg/kg. Triadimefon and buprofezin were found in 71.1% and 52.6% samples, respectively, with the corresponding concentrations of 9.8 μg/kg to 193.7 μg/kg and 87.9 μg/kg to 807.4 μg/kg. The multiple residues were found in 76.3% soils. A significant correlation between pesticide residues in nuts and soils was observed, with the correlation coefficient (r) 0.83 (P < 0.001). In addition, the bioconcentration factor (BCF) values for the explanation of pesticides from soils into nuts were ranged from 0.8 to 16.5. The results showed that some pesticides could accumulate in nut by the uptake effect from soil.

Topics: China; Chlorpyrifos; Dieldrin; Endosulfan; Environmental Monitoring; Hydrocarbons, Chlorinated; Nitriles; Nuts; Pesticide Residues; Pesticides; Pyrethrins; Soil; Soil Pollutants

Pyrethroids are insecticides widely used to control pests and disease vectors in residential areas and agricultural lands. Pyrethroids are emerging pollutants, and their use is a growing concern because of their toxicity potential to aquatic organisms. Todos Santos Bay and the Punta Banda estuary, 2 coastal bodies located to the south of the Southern California Bight, were studied to establish a baseline of the current conditions of pollution by pyrethroids and fipronil. Eight pyrethroids, along with fipronil and its 2 metabolites, were determined in effluents from wastewater-treatment plants (n = 3), surface sediments (n = 32), and 3 locations with mussels (Mytilus californianus, n = 9). Bifenthrin, permethrin, and cypermethrin were the most common pyrethroids found in the study areas and were widespread in sediments, mussels, and wastewater-treated effluents. Fipronil and its metabolites were detected in mussels and wastewater-treated effluents only. Total pyrethroid concentrations in sediments ranged from 0.04 to 1.95 ng/g dry weight in the Punta Banda estuary (n = 13) and from 0.07 to 6.62 ng/g dry weight in Todos Santos Bay (n = 19). Moreover, total pyrethroids in mussels ranged from 1.19 to 6.15 ng/g wet weight. Based on the toxic unit data calculated for pyrethroids and fipronil for Eohaustorius estuarius and Hyalella azteca, little to no impact is expected to the benthic population structure. Environ Toxicol Chem 2017;36:3057-3064. © 2017 SETAC.

Topics: Amphipoda; Animals; Bays; Estuaries; Geologic Sediments; Insecticides; Mexico; Permethrin; Pesticide Residues; Pyrazoles; Pyrethrins; Wastewater; Water Pollutants, Chemical

Topics: Animals; Brazil; Chickens; Diet; Eggs; Environmental Exposure; Farms; Gas Chromatography-Mass Spectrometry; Humans; Insecticides; Nitriles; Permethrin; Pyrethrins

Extreme and uncontrolled usage of pesticides produces a number of problems for vegetation and human health. In this study, the existence of organophosphates (OPs), organochlorines (OCs), pyrethroids (PYs) and fungicides (FUs) were investigated in persimmons/jujubes and their planted soils, which were collected from China. One OP (dimethoate), three OCs (DDT, quintozene and aldrin), six PYs (bifenthrin, fenpropathrin, cyhalothrin, cypermethrin, fenvalerate and deltamethrin) and two FUs (triadimefon and buprofezin) were found in 36.4% of persimmons and 70.8% of jujubes, with concentrations from 1.0 μg/kg to 2945.0 μg/kg. The most frequently detected pesticides in the two fruits were fenpropathrin in persimmons and cypermethrin in jujubes, with the detection frequencies of 30.0% and 22.7%, respectively. The residues of 4.5% (persimmon) and 25.0% (jujube) of samples were higher than the maximum residue limits (MRLs) of China. Compared with the fruits, more types of pesticides and higher residues were observed in their planted soils. The most frequently detected pesticides were HCH in persimmon soil and DDT in jujube soil, with the detection frequencies of 10.9% and 12.7%, respectively. For the tested samples, 39.1% of fruit samples and 63.0% of soil samples with multiple residues (containing more than two pesticides) were noted, even up to 8 residues in fruits and 14 residues in soils. Except for cyhalothrin, the other short-term risks for the tested pesticides in the fruits were below 10%, and the highest long-term risk was 14.13% for aldrin and dieldrin. There was no significant health risk for consumers via consumption of the two fruits.

Topics: Agriculture; China; Dieldrin; Diospyros; Environmental Monitoring; Food Contamination; Fruit; Hydrocarbons, Chlorinated; Nitriles; Pesticide Residues; Pyrethrins; Risk Assessment; Soil; Soil Pollutants; Ziziphus

A resistant strain of the Aphis glycines Matsumura (CRR) has developed 76.67-fold resistance to lambda-cyhalothrin compared with the susceptible (CSS) strain. Synergists piperonyl butoxide (PBO), S,S,S-Tributyltrithiophosphate (DEF) and triphenyl phosphate (TPP) dramatically increased the toxicity of lambda-cyhalothrin to the resistant strain. Bioassay results indicated that the CRR strain had developed high levels of cross-resistance to chlorpyrifos (11.66-fold), acephate (8.20-fold), cypermethrin (53.24-fold), esfenvalerate (13.83-fold), cyfluthrin (9.64-fold), carbofuran (14.60-fold), methomyl (9.32-fold) and bifenthrin (4.81-fold), but did not have cross-resistance to chlorfenapyr, imidacloprid, diafenthiuron, abamectin. The transcriptional levels of CYP6A2-like, CYP6A14-like and cytochrome b-c1 complex subunit 9-like increased significantly in the resistant strain than that in the susceptible. Similar trend were observed in the transcripts and DNA copy number of CarE and E4 esterase. Overall, these results demonstrate that increased esterase hydrolysis activity, combined with elevated cytochrome P450 monooxygenase detoxicatication, plays an important role in the high levels of lambda-cyhalothrin resistance and can cause cross-resistance to other insecticides in the CRR strain.

Topics: Animals; Aphids; Cytochrome P-450 Enzyme System; Esterases; Insect Proteins; Insecticide Resistance; Insecticides; Nitriles; Pyrethrins

Hyalella azteca are epibenthic invertebrates that are widely used for toxicity studies. They are reported to be more sensitive to pyrethroid insecticides than most other test species, which has prompted considerable use of this species in toxicity testing of ambient surface waters where the presence of pyrethroids is suspected. However, resident H. azteca have been found in some ambient water bodies reported to contain surface water and/or sediment pyrethroid concentrations that are toxic to laboratory reared H. azteca. This observation suggests differences in the sensitivities of laboratory reared and field populations of H. azteca to pyrethroids. The goal of the present study was to determine the sensitivities of laboratory reared and field populations of H. azteca to the pyrethroids bifenthrin and cypermethrin. Specimens of H. azteca were collected from resident populations at field sites that are subject to varied land-use activities as well as from laboratory populations. These organisms were exposed to bifenthrin- or cypermethrin-spiked water in 96-h water-only toxicity tests. The resulting data demonstrated that: 1) field-collected populations in urban and agricultural settings can be >2 orders of magnitude less sensitive to the pyrethroids than laboratory reared organisms; 2) field-collected organisms varied in their sensitivity (possibly based on land-use activities), with organisms collected from undeveloped sites exhibiting sensitivities similar to laboratory reared organisms; and 3) the sensitivity of field-collected "tolerant" organisms increased in subsequent generations reared under laboratory conditions. Potential mechanisms for these differences are discussed.

Topics: Amphipoda; Animals; Insecticides; Laboratories; Pyrethrins; Toxicity Tests, Acute; Water Pollutants, Chemical

The dynamic flux of an organophosphate and four pyrethroid pesticides was determined in an air-(soil)-water-sediment system based on monitoring data from Guangzhou, China. The total air-water flux, including air-water gaseous exchange and atmospheric deposition, showed deposition from air to water for chlorpyrifos, bifenthrin and cypermethrin, but volatilization for lambda-cyhalothrin and permethrin. The transport of the pesticides from overlying water to sediment suggested that sediment acted as a sink for the pesticides. Additionally, distinct annual atmospheric depositional fluxes between legacy and current-use pesticides suggested the role of consumer usage in their transport throughout the system. Finally, pesticide toxicity was estimated from annual air-water-sediment flux within an urban stream in Guangzhou. A dynamic flux-based risk assessment indicated that inter-compartmental transport of chlorpyrifos decreased its atmospheric exposure, but had little influence on its aquatic toxicity. Instead, water-to-sediment transport of pyrethroids increased their sediment toxicity, which was supported by previously reported toxicity data.

Topics: China; Environmental Monitoring; Geologic Sediments; Nitriles; Organophosphates; Pesticides; Pyrethrins; Risk Assessment; Rivers; Water Pollutants, Chemical

House flies, Musca domestica L., are important pests of dairy operations worldwide, with the ability to adapt wide range of environmental conditions. There are a number of insecticides used for their management, but development of resistance is a serious problem. Insecticide mixtures could enhance the toxicity of insecticides in resistant insect pests, thus resulting as a potential resistance management tool. The toxicity of bifenthrin, cypermethrin, deltamethrin, chlorpyrifos, profenofos, emamectin benzoate and fipronil were assessed separately, and in mixtures against house flies. A field-collected population was significantly resistant to all the insecticides under investigation when compared with a laboratory susceptible strain. Most of the insecticide mixtures like one pyrethroid with other compounds evaluated under two conditions (1∶1-"A" and LC50: LC50-"B") significantly increased the toxicity of pyrethroids in the field population. Under both conditions, the combination indices of pyrethroids with other compounds, in most of the cases, were significantly below 1, suggesting synergism. The enzyme inhibitors, PBO and DEF, when used in combination with insecticides against the resistant population, toxicities of bifenthrin, cypermethrin, deltamethrin and emamectin were significantly increased, suggesting esterase and monooxygenase based resistance mechanism. The toxicities of bifenthrin, cypermethrin and deltamethrin in the resistant population of house flies could be enhanced by the combination with chlorpyrifos, profenofos, emamectin and fipronil. The findings of the present study might have practical significance for resistance management in house flies.

Topics: Animals; Chlorpyrifos; Disaccharides; Drug Combinations; Houseflies; Insecticide Resistance; Insecticides; Ivermectin; Nitriles; Pyrazoles; Pyrethrins

Pyrethroids are widely used insecticides, but minimal information has been published on their presence in municipal wastewater in the United States. Pyrethroids in wastewater from the Sacramento, California, USA, area consisted of permethrin, bifenthrin, cypermethrin, and cyhalothrin, with a combined concentration of 200 ng/L to 500 ng/L. Sampling within the wastewater collection system leading to the treatment plant suggested pyrethroids did not originate primarily from urban runoff, but could be from any of several drain disposal practices. Wastewater from residential areas was similar in pyrethroid composition and concentration to that from the larger metropolitan area as a whole. Secondary treatment removed approximately 90% of pyrethroids, but those remaining exceeded concentrations acutely toxic to sensitive species. Toxicity to the amphipod, Hyalella azteca, was consistently evident in the final effluent. The large river into which this particular plant discharged provided sufficient dilution such that pyrethroids were undetected in the river, and there was only slight toxicity of unknown cause in 1 river sample, but effects in receiving waters elsewhere will be site-specific.

Topics: Amphipoda; Animals; California; Insecticides; Nitriles; Permethrin; Pyrethrins; Rivers; Wastewater; Water Pollutants, Chemical

Eight pesticide residues in tomato samples collected in the area of Souss Massa Valley (Southern Morocco) were analyzed. The detected residue levels ranged from 0.001 to 0.400 mg kg(-1) for dicofol, from 0.003 to 0.170 mg kg(-1) for procymidone, from 0.001 to 0.250 mg kg(-1) for chlorothalonil, from 0.050 to 0.500 mg kg(-1) for bifenthrin, from 0.001 to 0.010 mg kg(-1) for λ-cyhalothrin, from 0.001 to 0.300 mg kg(-1) for cypermethrin, from 0.010 to 1 mg kg(-1) for deltamethrin and from 0.003 to 1.123 mg kg(-1) for endosulfan. European MRL for endosulfan in tomatoes set in 0.500 mg kg(-1), was exceeded in 8 samples, and MRL for deltamethrin set in 0.300 mg kg(-1) for tomatoes was exceeded in 2 samples.

Topics: Bridged Bicyclo Compounds; Dicofol; Endosulfan; Environmental Monitoring; Gardening; Morocco; Nitriles; Pesticide Residues; Pyrethrins; Solanum lycopersicum

Pyrethroid insecticides are hydrophobic compounds that partition to streambed sediments and have been shown to cause toxicity to non-target organisms; their occurrence is well documented in parts of California, but there have been limited studies in other urban and agricultural areas across the United States. To broaden geographic understanding of pyrethroid distributions, bed sediment samples were collected and analyzed from 36 streams in 25 states, with about 2/3 of the sites in urban areas and 1/3 in agricultural areas. At least one pyrethroid (of the 14 included in the analysis) was detected in 78% of samples. Seven pyrethroids were detected in one or more samples. Bifenthrin was the most frequently detected (58% of samples), followed by permethrin (31%), resmethrin (17%), and cyfluthrin (14%). The other three detected pyrethroids (cyhalothrin, cypermethrin and delta/tralomethrin) were found in two or fewer of the samples. Concentrations ranged from 0.3 to 180 ng g(-1) dry weight. The number of pyrethroids detected were higher in the urban samples than in the agricultural samples, but the highest concentrations of individual pyrethroids were split between urban and agricultural sites. The pyrethroids detected in the agricultural areas generally followed use patterns. Predicted toxicity was greater for urban areas and attributed to bifenthrin, cyfluthrin and cypermethrin, while in agricultural areas the toxicity was mainly attributed to bifenthrin.

Topics: Agriculture; Cities; Environmental Monitoring; Geologic Sediments; Insecticides; Nitriles; Permethrin; Pyrethrins; Rivers; United States; Water Pollutants, Chemical; Water Pollution, Chemical

Contact and noncontact behavioral actions of wild-caught Anopheles dirus in response to the operational field dose of three synthetic pyrethroids (bifenthrin, α-cypermethrin and λ-cyhalothrin) were evaluated using an exito-repellency test chamber. DEET was used as the repellency standard for comparison with the other three synthetic pyrethroids. Results showed that test specimens rapidly escaped from the test chamber when exposed to direct contact with a surface treated with each of the three synthetic pyrethroids and DEET. Alpha-cypermethrin demonstrated the strongest irritant action (84.9% escape), followed by DEET (77.0%), λ-cyhalothrin (68.6%) and bifenthrin (68.3%). In the noncontact configuration, fewer mosquitoes escaped from the test chambers as compared to contact trials, although a significant escape response was still observed as compared to the controls (P<0.05). We conclude that An. dirus exhibits both irritant and repellent actions in response the three pyrethroids testing in this study. The information obtained will allow us to better understand the behavioral responses of vectors to various chemicals and provide guidance when designing control strategies for targeting specific disease vectors.

Topics: Animals; Anopheles; Behavior, Animal; Insect Vectors; Malaria; Nitriles; Pyrethrins; Thailand

There is an assumption that pyrethroid pesticides are converted to non-toxic metabolites by hydrolysis in mammals. However, some recent works have shown their bioaccumulation in human breast milk collected in areas where pyrethroids have been widely used for agriculture or malaria control. In this work, thirteen pyrethroids have been studied in human breast milk samples coming from areas without pyrethroid use for malaria control, such as Brazil, Colombia and Spain. The concentrations of pyrethroids ranged from 1.45 to 24.2 ng g⁻¹ lw. Cypermethrin, λ-cyhalothrin, permethrin and esfenvalerate/fenvalerate were present in all the studied samples. The composition of pyrethroid mixture depended on the country of origin of the samples, bifenthrin being the most abundant in Brazilian samples, λ-cyhalothrin in Colombian and permethrin in Spanish ones. When the pyrethroid concentrations were confronted against the number of gestations, an exponential decay was observed. Moreover, a time trend study was carried out in Brazil, where additional archived pool samples were analyzed, corresponding to years when pyrethroids were applied for dengue epidemic control. In these cases, total pyrethroid levels reached up to 128 ng g⁻¹ lw, and concentrations decreased when massive use was not allowed. Finally, daily intake estimation of nursing infants was calculated in each country and compared to acceptable WHO levels. The estimated daily intakes for nursing infants were always below the acceptable daily intake levels, nevertheless in certain samples the detected concentrations were very close to the maximum acceptable levels.

Topics: Adolescent; Adult; Agriculture; Brazil; Breast Feeding; Colombia; Environmental Exposure; Environmental Pollutants; Environmental Pollution; Female; Humans; Infant; Insecticides; Milk, Human; Mosquito Control; Nitriles; Permethrin; Pyrethrins; Spain; Young Adult

This paper presents the development of a highly precise and accurate analytical method for the determination of three matrix-bound pyrethroids, namely, cypermethrin, permethrin, and bifenthrin, using an isotope dilution gas chromatography/mass spectrometry technique. Identification of the analytes was confirmed under selective ion monitoring mode by the presence of two dominant ion fragments within specific time windows and matching of relative ion intensities of the ions concerned in samples and calibration standards. Quantitation was based on the measurement of concentration ratios of the natural and isotope analogues in the sample and calibration blends. Intraday and interday repeatabilities of replicate analyses of the pyethroids in an apple juice sample were below 0.5%. The expanded relative uncertainty ranged from 3 to 6%, which was significantly lower than the range obtained using internal or external calibration methods. As a labeled analogue is not available for bifenthrin, bifenthrin was determined using labeled cis-permethrin as the internal standard. The results were counterchecked by a gas chromatography-electron capture detection technique using PCB 209 as the internal standard. The method developed was applied to a recent pilot study organized by CCQM and the results were consistent with those of other participants.

Topics: Beverages; Calibration; Food Analysis; Gas Chromatography-Mass Spectrometry; Malus; Molecular Structure; Permethrin; Pyrethrins; Quality Control; Radioisotope Dilution Technique; Solid Phase Extraction

Pyrethroid pesticides occur in urban creek sediments at concentrations acutely toxic to sensitive aquatic life. To better understand the source of these residues, runoff from residential neighborhoods around Sacramento, California was monitored over the course of a year. Pyrethroids were present in every sample. Bifenthrin, found at up to 73 ng/L in the water and 1211 ng/g on suspended sediment, was the pyrethroid of greatest toxicological concern, with cypermethrin and cyfluthrin of secondary concern. The bifenthrin could have originated either from use by consumers or professional pest controllers, though the seasonal pattern of discharge from the drain was more consistent with professional use as the dominant source. Stormwater runoff was more important than dry season irrigation runoff in transporting pyrethroids to urban creeks. A single intense storm was capable of discharging as much bifenthrin to an urban creek in 3h as that discharged over 6 months of irrigation runoff.

Topics: Animals; California; Cities; Environmental Monitoring; Geologic Sediments; Humans; Nitriles; Particulate Matter; Pesticides; Pyrethrins; Rain; Rivers; Seasons; Toxicity Tests, Acute; Water Pollutants, Chemical

By incubation experiment, the bacterial strain labeled as M6R9 was isolated from the tame sludge in water course of Pesticide Factory of Hangzhou, and was identified as Enterobacter aerogenes, which had highly efficient degradation for Bifenthrin, Fenpropathrin and Cypermethrin. By investigating the physiological characteristics of the strain, the results show that the bacterium is a gram-negative aerobe bacilli, size is (0.8-1.9) microm x (0.5-1.0) microm, and is capable of utilizing Bifenthrin, Fenpropathrin and Cypermethrin as sole carbon source. Under the condition of ventilation, (25-30) degrees C, inoculated amount at D(415 nm) 0.2, pH 7.0, pesticide concentration 100 mg x L(-1) and vibrational speed 180 r x min(-1), the degradation efficiencies to Bifenthrin, Fenpropathrin and Cypermethrin are the highest by strain M6R9. Under such condition, in the mixture culture medium with 100 mg x L(-1) Bifenthrin, Fenpropathrin and Cypermethrin, the degradation ratios are 55.74%, 55.11% and 55.96% after culturing 3 d, respectively, the degradation processes are fitted for first-order kinetic equation and the half lives (t(1/2)) are 65.4,70.7 and 68.6 h respectively. The degradation ability of Enterobacter aerogenes M6R9 on Bifenthrin, Fenpropathrin and Cypermethrin is positively correlated to inoculated amount,vibrational speed and ventilation.

Topics: Biodegradation, Environmental; Enterobacter aerogenes; Insecticides; Pesticide Residues; Pyrethrins

Pyrethroid resistance in Helicoverpa armigera (Hübner) field populations was investigated in Benin over several years by using third- and fourth-instar larval topicalbioassays. H. armigera was resistant to pyrethroids tested as cypermethrin, deltamethrin, bifenthrin, and fenvalerate. Pretreatment with piperonyl butoxide significantly decreased the LD50 value of cypermethrin and deltamethrin, and the resistance suppression by this synergist effect was observed. No significant decrease in the LD50 value was obtained when S,S,S-tributyl phosphoro-trithioate was applied before deltamethrin. In the field, cypermethrin's LD50 value varied, and the highest LD50 values were observed during the rainy season, the cotton, Gossypium hirsutum L., crop period, when pyrethroids are extensively used. In the dry season when there was no cotton cultivation, the lowest LD50 values were obtained. However, reversion was never total in the field; resistance did not revert to the level we observed in the susceptible strain. In the laboratory, when field populations were reared in insecticide-free conditions, resistance decreased and total reversion was observed. Results are discussed with regard to insecticide resistance fitness cost and resistance management strategies.

Topics: Animals; Benin; Drug Resistance; Gossypium; Insecta; Insecticides; Lethal Dose 50; Nitriles; Pest Control; Pyrethrins; Solanum lycopersicum

A series of dose-response experiments was conducted to compare the relative sensitivities of toxicity test protocols using the amphipods Ampelisca abdita and Eohaustorius estuarius. A. abdita is one of the dominant infaunal species in the San Francisco Estuary, and E. estuarius is the primary sediment toxicity species used in the San Francisco Estuary Regional Monitoring Program. Experiments were conducted with a formulated sediment spiked with copper, fluoranthene, chlorpyrifos, and the three pyrethroid pesticides permethrin, bifenthrin, and cypermethrin, all chemicals of concern in this Estuary. The results showed that the protocol with A. abdita was more sensitive to fluoranthene and much more sensitive to copper, while E. estuarius was more sensitive to chlorpyrifos, and much more sensitive to the pyrethroid pesticides. These results, considered in conjunction with those from previous spiking studies [Weston, D.P., 1995. Further development of a chronic Ampelisca abdita bioassay as an indicator of sediment toxicity: summary and conclusions. In: Regional Monitoring Program for Trace Substances Annual Report. San Francisco Estuary Institute, Oakland, CA, pp 108-115; DeWitt, T.E., Swartz, R.C., Lamberson, J.O., 1989. Measuring the acute toxicity of estuarine sediments. Environ. Toxicol. Chem. 8: 1035-1048; DeWitt, T.H.E., Pinza, M.R., Niewolny, L.A., Cullinan, V.I., Gruendell, B.D., 1997. Development and evaluation of a standard marine/estuarine chronic sediment toxicity method using Leptocheirus plumulosus. Draft report prepared for the US Environmental Protection Agency, Office of Science and Technology, Washington DC, under contract DE-AC06-76RLO 1830 by Batelle Marine Science Laboratory, Battelle Memorial Institute, Pacific Northwest Division, Richland, WA], suggest that, in general, A. abdita is more sensitive to metals, E. estuarius is more sensitive to pesticides, and both protocols have roughly comparable sensitivities to hydrocarbons. The preponderance of evidence from previous field studies indicate that E. estuarius is considerably more responsive to ambient sediment samples [Bay, S.M., Gries, T.H., Anderson, B.S., Phillips, B.M., Field, J.L., Moore, D.W., Greenstein, D.J., 2005. Comparison of marine amphipod test species responsiveness to contaminated sediments. In: Conference Proceeding: Annual Meeting of the Society of Environmental Toxicology and Chemistry. SETAC, Baltimore, Maryland; Anderson, B.S., Hunt, B.M., Thompson, B., Lowe, S., Tab

Topics: Amphipoda; Animals; Chlorpyrifos; Copper; Dose-Response Relationship, Drug; Environmental Monitoring; Enzyme Inhibitors; Fluorenes; Geologic Sediments; Insecticides; Permethrin; Pyrethrins; Sensitivity and Specificity; Toxicity Tests; Water; Water Pollutants, Chemical

A previously described bioassay was modified to assess the response of the poultry red mite, an important ectoparasite of fowl, to a selected group of acaricides. The adapted bioassay is simple to use, escape-proof and provides data that can be subjected to probit analysis. The reproducibility of the method was assessed by three tests with alpha-cypermethrin against a reference strain, which produced dose-response lines that did not differ significantly (chi(2)=1.39, 2 d.f., p=0.50), and had a derived common slope of 1.89. In addition, a limited evaluation study enabled assessment of response to commercial formulations of bifenthrin, bifenthrin+malathion and cypermethrin by field populations of the poultry red mite.

Topics: Animals; Biological Assay; Dose-Response Relationship, Drug; Insecticides; Malathion; Mites; Pyrethrins

The redlegged earth mite (Halotydeus destructor Tucker) is an important pest of field crops and pastures. Control of this pest relies heavily on chemicals, with few genuine alternatives presently available. Pesticide responses of H. destructor from the field with reported chemical control failures were compared with mites from susceptible 'control' populations. Toxicology bioassays were conducted on adult mites across multiple generations.. Very high levels of resistance to two synthetic pyrethroids, bifenthrin and alpha-cypermethrin, were detected in this species for the first time. For bifenthrin, LC(50) estimates showed a difference in resistance of greater than 240 000-fold. Resistance to alpha-cypermethrin was almost 60 000-fold. This resistance was shown to be heritable, persisting after several generations of culturing. There was no evidence that resistance to organophosphorus chemicals had evolved, which is likely to be a direct consequence of the history of chemical applications these mites have experienced.. These results highlight the need for more judicious management decisions in order to control pest species in a sustainable manner. The implications of these findings in regard to the management and future research of the redlegged earth mite are discussed.

Topics: Animals; Australia; Insecticide Resistance; Insecticides; Mites; Organophosphorus Compounds; Pest Control; Pyrethrins

Synthetic pyrethroid insecticides are chiral compounds with multiple asymmetric positions. In this study, isomers of four commonly used pyrethroids were separated at the enantiomeric level by enantioselective high-performance liquid chromatography (HPLC), and differences between enantiomers in aquatic toxicity were characterized using individual isomers. Isomers of cis-bifenthrin and permethrin were completely resolved on a Sumichiral OA-2500-I column. All eight isomers of cypermethrin and cyfluthrin were completely separated on two chained Chirex 00G-3019-DO columns. Great differences were found between enantiomers in the acute toxicity to aquatic invertebrates Ceriodaphnia dubia or Daphnia magna. In cis-bifenthrin (cis-BF) and cis-permethrin (cis-PM), the 1R-cis isomer was 15-38 times more active than the 1S-cis enantiomer, while in trans-PM, the 1R-trans isomer was substantially more toxic than the 1S-trans enantiomer. In cypermethrin or cyfluthrin, two of the eight isomers, 1R-cis-alphaS and 1R-trans-alphaS, contributed for almost all the toxicity in the racemate, while the other six enantiomers were inactive. These results suggest that significant enantioselectivity occurs for pyrethroids in aquatic toxicity, and such enantiomeric differences must be considered when evaluating ecological effects of pyrethroid insecticides.

Topics: Animals; Chromatography, High Pressure Liquid; Cladocera; Daphnia; Ecosystem; Insecticides; Molecular Structure; Nitriles; Permethrin; Pyrethrins; Stereoisomerism; Water Pollutants, Chemical

The European Union Baby Food Directive (1999/39/EC), which came into force on 1 July 2002, set legal maximum residue levels at 0.01 mg kg(-1) for all pesticides in baby foods. The combination of large volume-difficult matrix introduction (LV-DMI) with gas chromatography-time of flight-mass spectrometry (GC-TOF-MS), described herein, provides the analyst with a simple but rapid alternative GC-MS technique for the multiresidue analysis of pesticides in fruit-based baby foods. Samples were extracted with ethyl acetate in the presence of Na2SO4 and NaHCO3 and the crude extracts were analysed directly using LV-DMI-GC-TOF-MS. The best overall results (98 pesticides quantified satisfactorily at a spiking level of 0.01 mg kg(-1)) were obtained by analysis of concentrated extracts (2.5 g crop ml(-1)) using a 30-m column, with a chromatographic run time of 25 min. A good signal-to-noise ratio was obtained at the lowest calibrated level (0.0125 microg ml(-1)), with excellent linearity achieved over the range 0.0125-0.25 microg ml(-1) (equivalent to 0.005-0.1 mg kg(-1)). Average recoveries for the analysis of five replicate determinations at a spiking level of 0.01 mg kg(-1) were between 79 and 114% with relative standard derivations generally less than 20%.

Topics: Calibration; Food Contamination; Fruit; Fungicides, Industrial; Hexachlorobenzene; Humans; Hydrogen-Ion Concentration; Infant; Infant Food; Organothiophosphates; Organothiophosphorus Compounds; Pesticides; Pyrethrins; Reproducibility of Results

The fruit fly Dacus ciliatus Loew is a pest of the fruits of many cucurbit species. We studied the effect of organaophosphate and pyrethroid compounds on the adult flies by using surface contact and oral administration. In contrast to other fruit flies, we found that organophosphates were ineffective against D. ciliatus. This was supported by the insignificant decrease of head acetylcholinesterase activity. All tested pyrethroids showed satisfactory killing ability, rapid and massive knockdown effect, and prevention of oviposition. Piperonyl butoxide considerably increased the toxicity of pyrethroids, which can be explained by oxidase detoxification of these compounds in D. ciliatus. It can be concluded that pyrethroids have high potential for controlling D. ciliatus.

Topics: Acetylcholinesterase; Animals; Biological Assay; Dimethoate; Diptera; Female; Fertility; Insect Control; Insecticides; Malathion; Male; Monocrotophos; Organothiophosphorus Compounds; Phosphoramides; Pyrethrins