Neonicotinoid Research Articles

Sub-lethal effects of six neonicotinoids on avoidance behavior and reproduction of earthworms (Eisenia fetida)

Avoidance behavior of earthworms (Eisenia fetida) against six neonicotinoids (NEOs) (acetamiprid, dinotefuram, clothianidin, thiacloprid, nitenpyram, imidacloprid) was studied following the protocol of ISO. The results showed obvious avoidance behavior of E. fetida against the tested insecticides, and the medium effective concentration for avoidance behavior (EC50) of the six pesticides was 0.14, 0.55, 0.91, 7.87, 1.32 and 0.77 mg/kg, respectively. Compared to the acute toxicity, avoidance behavior was more sensitive as an indicator of soil contamination with NEOs. Chronic toxicity of above six NEOs to E. fetida was also evaluated; cocoon production, hatchability, cocoon weight and adult weight were all affected in the test. Cocoon production and hatchability were more sensitive than cocoon weight and adult weight. The reproduction of earthworms were significantly reduced with a 56 d half-maximal effective hatchability concentration (EC50) of 0.37, 0.74, 1.30, 3.57, 1.20 and 0.70 mg/kg (acetamiprid, dinotefuram, clothianidin, thiacloprid, nitenpyram, imidacloprid), respectively. Most of the tested NEOs were highly toxic to E. fetida. Avoidance behavior and reproduction damage of E. fetida was observed at very low concentrations. The existing levels of pollution with NEOs in soil frequently exceed the lowest observed adverse effect concentrations, which are likely to have negative biological and ecological impacts on earthworms.

Cholinesterase activity in the cup oyster Saccostrea sp. exposed to chlorpyrifos, imidacloprid, cadmium and copper

In the present study, the sensitivity and concentration dependence of three functionally-defined components of cholinesterase activity (total: T-ChE; eserine-sensitive: Es-ChE; and eserine-resistant: Er-ChE) were quantified in the gill, digestive gland and adductor muscle of the tropical cup oyster Saccostrea sp., following acute (96h) aqueous exposure to commercial formulations of the organophosphate (OP) insecticide chlorpyrifos and the neonicotinoid (NN) imidacloprid (concentration range: 0.1–100mg/L), as well as to dissolved cadmium and copper (concentration range: 1–1000μg/L). Oysters (1.5–5.0cm shell length), field-collected from a boating marina in Santa Marta, Colombia (Caribbean Sea) were exposed in the laboratory to each substance at five concentrations. T-ChE, Es-ChE, and Er-ChE activity were quantified in the three tissues in pools of 5 individuals (3 replicates per concentration), before and after inhibition with the total cholinesterase inhibitor eserine (physostigmine, 100µM). Oysters exposed to chlorpyrifos, imidacloprid and Cd showed reduced T-ChE and Es-ChE activity in gills at highest exposure concentrations, with Es-ChE activity being inhibited proportionally more so than T-ChE, whereas Er-ChE activity showed no significant concentration-response. Digestive gland also showed diminished T-ChE, Es-ChE and Er-ChE activity for highest chlorpyrifos and Cd concentrations relative to controls, but an increase of T-ChE and Er-ChE activity at the highest imidacloprid concentration (100mg/L). For Cu, T-ChE, Es-ChE and Er-ChE activities in gills and digestive gland were elevated relative to controls in oysters exposed to Cu concentrations > 100µg/L. In adductor muscle, T-ChE, Es-ChE and Er-ChE activity showed no apparent pattern for any of the four xenobiotics and concentration levels tested. Although this study confirms acute (96h) concentration-dependent reduction of tissue T-ChE and Es-ChE activity in gills and digestive glands of Saccostrea sp. exposed to high concentrations of chlorpyrifos (100mg/L), significant changes in T-ChE, Es-ChE and Er-ChE were also caused by exposure to Cd and Cu at concentrations > 100µg/L and by exposure to imidacloprid (100mg/L), indicating that cholinesterase activity is not a specific biomarker of organophosphate exposure in this species, but, rather, a biomarker of diverse xenobiotic exposure.

The bitter battle over the world's most popular insecticides.

As regulators consider a ban on neonicotinoids, debate rages over the harm they cause to bees.

When and where neonicotinoids are bad for bees

When and where neonicotinoids are bad for bees

Neonicotinoids found in honey from every continent

Neonicotinoids found in honey from every continent

Largest-ever study of controversial pesticides finds harm to bees

Scientists say the industry-funded work confirms that neonicotinoids are harmful, but manufacturers question its conclusions.

More About Bees and Neonicotinoids

More About Bees and Neonicotinoids

Are Neonicotinoids Killing Bees? A Summary of the Recent SCI Conference on Bees and Insecticides

Are Neonicotinoids Killing Bees? A Summary of the Recent SCI Conference on Bees and Insecticides

Design features of a proposed insecticidal sugar trap for biting midges.

Insecticidal sugar baits for mosquitoes and house ies have proven e cacy to reduce insect populations and consequently, disease transmission rates. The new insecticidal sugar trap (IST) is designed speci cally for controlling biting midge disease vector populations around livestock and near larval habitats. The trap operates by combining light-emitting diode (LED) technology with insecticidal sugar baits. The positive photo attraction of Culicoides elicited by the LEDs, draws the insects to the insecticidal sugar bait, which can be made from various commercial insecticide formulations (pyrethroids, neonicotinoids, etc.) or naturally derived formulations (boric acid, garlic oil, etc.) lethal to Culicoides. Insecticidal sugar trap advantages include: customizable LED lights, they can be used with several di erent oral insecticides that have di erent modes of action to help combat the evolution of pesticide resistance, screening on the trap reduces non-target insect feeding (for example bees and butter ies), targets males and females of the species because both must feed on sugar, and low energy LEDs and a solar panel reduce trap maintenance to re lling sugar baits, rather than replacing batteries. This article discusses key components of an IST, which increase the traps e ectiveness for biting midge control.

Exposure characterization of three major insecticide lines in urine of young children in Japan—neonicotinoids, organophosphates, and pyrethroids

The use of neonicotinoid (NEO) insecticides has increased over the past decade not only in Japan but also worldwide, while organophosphate (OP) and pyrethroid (PYR) insecticides are still conventionally used in agriculture and domestic pest control. However, limited data are currently available on the NEO exposure levels, especially in children, who are particularly vulnerable to environmental toxicants. Thus, the purpose of this study was to characterize the exposure to NEOs, as well as OPs and PYRs, in three-year-old Japanese children by assessing the range, distribution, and seasonal differences of the urinary concentrations of seven NEOs (acetamiprid, clothianidin, dinotefuran, thiacloprid, thiamethoxam, imidacloprid, and nitenpyram); four OP metabolites (dialkylphosphates [DAPs]), including dimethylphosphate, dimethylthiophosphate, diethylphosphate, and diethylthiophosphate; and three PYR metabolites (3-phenoxybenzoic acid, trans-chrysanthemumdicarboxylic acid, and 3-(2,2-dichlorovinyl)-2,2- dimethylcyclopropane carboxylic acid). Urine samples were collected from 223 children (108 males and 115 females) in the summer and winter months. The detection rates of NEOs were 58% for dinotefuran, 25% for thiamethoxam, 21% for nitenpyram, and <16% for all other NEOs. The median and maximum concentrations of the sum of the seven NEOs (ΣNEO) were 4.7 and 370.2nmol/g creatinine, respectively. Urinary ΣNEO, dimethylphosphate, and all PYR metabolite concentrations were significantly higher in the summer than in the winter (p<0.05). The creatinine-adjusted concentration of ΣNEO significantly correlated with those of all DAPs (p<0.05) but not with those of the PYR metabolites. Moreover, the NEO-detected group showed higher urinary ΣDAP (sum of four OP metabolites) concentrations than the group without NEO detection. These findings suggest that children in Japan are environmentally exposed to the three major insecticide lines, and that the daily exposure sources of NEOs are common to those of OPs.

Opposition To Neonicotinoids Intensified

Opposition To Neonicotinoids Intensified

Temporal Levels of Urinary Neonicotinoid and Dialkylphosphate Concentrations in Japanese Women Between 1994 and 2011.

Over the last two decades, usage of neonicotinoid (NEO) insecticides has increased due to their high selectivity for insects versus mammals and their effectiveness for extermination of insects resistant to conventional pesticides such as pyrethroids and organophosphates (OPs). However, historical change of the NEO exposure level in humans is poorly understood. The aim of this study is to reveal changes in the levels of NEO and OP exposure in the human body over the last two decades using biomonitoring technique. We quantified urinary concentrations of 7 NEOs (acetamiprid, clothianidin, dinotefuran, imidacloprid, nitenpyram, thiacloprid, and thiamethoxam) and 4 metabolites of OPs (dimethylphosphate, dimethylthiophosphate, diethylphosphate, and diethylthiophosphate) in 95 adult females aged 45-75 in 1994, 2000, 2003, 2009, and 2011 (n = 17-20 different individuals in each year). The results show that the detection rates of urinary NEOs in Japanese women increased significantly between 1994 and 2011, suggesting that intakes of NEOs into the human body rose during that period. In contrast, exposure to OPs having O,O-dimethyl moieties decreased steadily according to a finding that geometric means of urinary dimethylphosphate concentrations kept diminishing considerably. These changes may reflect the amounts of NEOs and OPs used as insecticides in Japan.

ネオニコチノイド系農薬の使用規制でミツバチを救えるか

ネオニコチノイド系農薬の使用規制でミツバチを救えるか

Biological monitoring method for urinary neonicotinoid insecticides using LC-MS/MS and its application to Japanese adults.

Agricultural use of neonicotinoid (NEO) insecticides has been increasing in recent years, but their biological monitoring methods have been scarcely reported. In this study, we developed and validated a rapid and sensitive method for quantifying urinary NEO concentrations using high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS). After phosphate-induced acidification of a urine sample, urinary NEOs were trapped by a solid-phase extraction column and eluted with methanol for acetamiprid, imidacloprid, thiacloprid, thiamethoxam, clothianidin and dinotefuran and with an acetonitrile and methanol solution (1:1, v/v) containing 5% NH3 for nitenpyram. A separation analysis was performed by LC-MS/MS within 10 minutes for the sample. This method was applied to first morning urine obtained from 52 Japanese (40.9 ± 10.5 years old, mean ± standard deviation) without occupational NEO exposure. The linear dynamic ranges and their limit of quantification (LOQ, signal to noise ratio=10) levels were 0.3-20 or 50 µg/l (r=0.998-0.999) and 0.05-0.36 µg/l, respectively. The absolute recovery was 64-95%, and the intra- and inter-day precisions were less than 16.4% (relative standard deviation, %RSD). This method was successfully applied for analysis of NEOs in human urine samples obtained from 52 adults. The frequencies of individuals who showed more than LOD levels was above 90% for imidacloprid, thiamethoxam, clothianidin and dinotefuran, more than 50% for acetamiprid and thiacloprid and 29% for nitenpyram. These results indicated that our new method could be applied to biological monitoring of NEO exposure even at environmental exposure levels in Japanese adults without occupational spraying histories.

Quantitation of neonicotinoid metabolites in human urine using GC-MS

A rapid and sensitive analytical method using gas chromatography-mass spectrometry (GC-MS) was developed for the measurement of neonicotinoid (NEO) metabolites 6-chloronicotinic acid (6CN), 2-chloro-1,3-thiazole-5-carboxylic acid (2CTCA) and 3-furoic acid (3FA) from human urine. After acid hydrolysis, the metabolites were extracted using solid phase extraction (SPE) column (Bond Elute Plexa PCX) and eluted with methanol. N,O-bis (trimethylsilyl) trifluoroacetamide with 1% trimethylchlorosilane (BSTFA-TMCS, 99:1) was used for the derivatization of metabolites and analyzed by GC-MS with the electron ionization mode. The elution solvent, derivatization reagent and its conditions were mainly optimized for improved detection and quantitation of the metabolites based on signal-to-noise ratio, recoveries and reproducibility. Our present method offered a sufficiently low limit of detection (0.1μg/L for each metabolite) with satisfactory within-run and between-day accuracy and precision (variability less than 12.3%, R.S.D). This method is simple, sensitive and precise, and has been successfully applied to quantify low concentrations of urinary 6CN, 2CTCA and 3FA for the occupational NEO exposures survey.

Neonicotinoids and Bees

Neonicotinoids and Bees

Receptor based insecicide resistance and prospects—The case for neonicotinoids—

Receptor based insecicide resistance and prospects—The case for neonicotinoids—

Susceptibility of third instar Melolontha spp. white grubs to the contact action of neonicotinoid insecticides

Wrażliwość trzeciego stadium pędraków chrabąszczy (Melolontha spp.) na kontaktowe działanie insektycydów neonikotynoidowych

Response of adult large pine weevils (Hylobius abietis L.) to neonicotinoids (chloronicotinyls) and fenylpirazoles insecticides

Reakcja chrząszczy szeliniaka sosnowca (Hylobius abietisL.) na insektycydy z grupy neonikotynoidów (chloronikotynyli) i fenylopirazoli

Toxicity of Eco-Friendly Chemicals to Coccinellid Predators on Okra

Field experiments were carried out to study the relative toxicity of different groups of chemicals viz., dichlorvos, Nimbecidine, B.t. (Delfin), novaluron (lGR), spinosad and imidacloprid (neonicotinoid) and combination of dichlorvos, spinosad and imidacloprid with novaluron and B.t. against predatory coccinellid beetles Cheilomelles Sexmaculata (Fahricius) and Micraspis ullivittata (Hope). The results indicated that dichlorvos and imidaclollrid alone were found to be toxic compared to their combination with cco-friendly chemicals. The treatments B.t. and nimbecidine were found to be relatively safe to coccinellids.