Imidacloprid Residues Research Articles

Determination of seven pesticide residues in bamboo shoots by high performance liquid chromatography-tandem mass spectrometry coupled with solid-phase extraction

A simple and efficient method based on solid-phase extraction (SPE) and high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was developed for the determination of butylene fipronil, chlorpyrifos, chlorantraniliprole, fipronil, imidacloprid, indoxacarb and phoxim residues in bamboo shoots. The sample was extracted with acetonitrile and purified by a primary secondary amine (PSA) solid-phase extraction cartridge. The detection of targets was performed by HPLC-MS/MS with multiple reaction monitoring (MRM) mode. All the seven pesticides were completely separated in 15 min with an excellent linear relationship. The limits of detection and the limits of quantification for the seven pesticides were 0.02-0.5 microg/kg and 0.08-1.5 microg/kg, respectively. The recoveries of the seven pesticides spiked in a bamboo shoot sample at the levels of 4, 8, 32 microg/kg were in the range from 76.0% to 102.6% (the RSD < or = 11.0%, n = 3). The method was successfully applied to the real bamboo shoot samples. The method has high accuracy and sensitivity, and is simple and quick. It can meet the requirement of the simultaneous determination of the seven pesticides in bamboo shoots.

Quantification of Pesticide Residues in Vegetables by Different Chromatographic Techniques

Cypermethrin, chlorpyrifos and imidacloprid residues were determined in different vegetables. During 2013, samples were collected from different six major vegetable markets from Lahore. Ethyl acetate was used for extraction, whattman fluted filter and charcoal was used for cleaning procedure. High performance thin layer chromatography was used for detection, as well as quantification of pesticides. Confirmation of results was done by using gas chromatography/mass spectrophotometer. From results, it was concluded that different vegetables contain different concentration of pesticides means adsorption rate is different for each pesticide and vegetable. 79% samples were contaminated with cypermethrin, 70% from imidacloprid and 65% samples were contaminated from chlorpyrifos. Pumpkin, okra, egg plant, cucumber spinach and cabbage were contaminated with pesticides. Peeling of vegetables resulted in less concentration of pesticide.

Multi-analyte enzyme-linked immunosorbent assay for organophosphorus pesticides and neonicotinoid insecticides using a bispecific monoclonal antibody

A bispecific monoclonal antibody (BsMcAb) with antigen-binding sites for two classes of insecticides was used to develop a multi-analyte immunoassay for determination of organophosphorus pesticides and neonicotinoid insecticides. A trioma cell line ON-D6 was produced by fusion of HAT sensitive hybridomas secreting antibody to organophosphorus pesticides with spleen lymphocytes from the BALB/c mice which were immunized by artificial antigens of neonicotinoid insecticides. The broadly selective BsMcAb was raised to recognize eight organophosphorus pesticides (parathion-methyl, parathion, fenitrothion, EPN, paraoxon-ethyl, paraoxon-methyl, fenitrooxon, and cyanophos) and two neonicotinoid insecticides (imidacloprid, and imidaclothiz). A multi-analyte ELISA was established by using the BsMcAb, and several key parameters were optimized to enhance the sensitivity of the immunoassay. The developed immunoassay showed average IC50 values of 114.6 and 129.8 ng mL−1 for eight organophosphorus pesticides and two neonicotinoid insecticides, respectively. The recoveries from the spiked samples ranged between 86.8 and 125.0% for the detection of single pesticide residues of parathion-methyl and imidacloprid in tap water, pond water, grape, cucumber, and soil. ELISA results were validated by comparison with gas chromatography (GC) analyses. The results showed that this multi-analyte ELISA is useful for the determination of neonicotinoid insecticides and organophosphorus pesticides in real samples.

Effect of Imidacloprid and Tetraconazole on Various Hematological and Biochemical Parameters in Male Albino Rats (Rattus Norvegious)

This study was carried out to investigate the toxicity of imidacloprid and tetraconazole in male rats given daily oral doses of these pesticides (for 30 days). Which equal to those residues found in and on cucumber fruits after zero time, (24 hour after application) as well as two doses which equal 0.1, 0.125 of the LD50 value for each pesticide? These doses were (0.943, 0.365, 45, 56.25 mg/kg) for imidacloprid, and (0.174, 0.104, 124.8, 156 mg/kg) for tetraconazole, respectively.Results indicated that imidacloprid and tetraconazole residues on and in cucumber fruits after one hour and 24 hour from the last spray did not cause any significant effects on the activities of AST, ALT, GGT, LDH and ALP enzymes. There is no significant difference on the levels of creatinine, uric acid, total protein, albumin and glucose in the serum of treated rats. There is no effect on Packed Cell Volume (PCV), Red Blood Cell Counts (RBC’s), haemoglobin (Hb) and White Blood Cell Counts (WBC’s) in the blood of treated rats. Also doses equal to the residues did not cause any harmful effect on concentrations of AChE, T3, T4, TSH and testosterone hormone. The aforementioned results of this part of study indicated that the neonicotinoid insecticide, imidacloprid, and the fungicide tetraconazole, can induce a variety of alterations in the activities of AST, ALT, GGT, LDH and ALP enzymes and the levels of creatinine, uric acid, total protein, albumin and glucose in the serum of treated rats also the concentrations of AChE, T3, T4, TSH and testosterone hormone at higher doses which equal to 0.125 and 0.1of the LD50value for each pesticide. The severity of their action depends entirely on the level of the given doses and the type of the tested pesticides.

항공살포에 따른 Acetamiprid와 Imidacloprid의 산림환경 중 행적

Fate of acetamiprid and imidacloprid aerially sprayed to control pine wood nematode (Bursaphelenchus xylophilus) were studied in a forest of Haman area. Acetamiprid 20% SL or imidacloprid 20% DC were diluted 100 times and applied two times as rate of 50 L/ha using an aircraft of Bell 206 L helicopter. Average acetamiprid deposits on forest floor ranged from 2 to 4% of standard aerial application rate. Following to the second application, acetamiprid deposits in the pine needle ranged 1.8~8.5 mg/kg and then gradually decreased to 1.2~2.1 mg/kg after 48 days. Deposits on the plant washed off by rainfall and reached to soil surface was ca. 17% of the application rate. All of acetamiprid on the ground resided in the forest floor covering the soil surface, where acetamiprid residues were decreased to a quarter at 48 days after the second application, but they were not detected in soil beneath it. And the only low level of acetamiprid residues, 0.0003 mg/L, was detected in the reservoir nearby the experimental forest on the day of aerial application. The acetamiprid detection was presumably due to spray drift. And average imidacloprid deposits on forest floor ranged from 1 to 3% of standard aerial application rate. Following to the second application, imidacloprid deposits in the pine needle analysed very low concentration of 0.1 mg/kg, but the amount of imidacloprid in wash-off in standard and two-fold treatment were ca. 8% and 4% of the application rate, respectively. Most of imidacloprid on the ground also resided in the forest floor, where imidacloprid residues were decreased to a twentieth at 111 days after the second application, and they were detected below 0.5% of the application rate in sol beneath it. And the low level of imidacloprid, 0.0003~0.0017 mg/L, were detected in the streams in the experimental forest. It was not to the level of contamination concerns.

Persistence Behavior of Imidacloprid and Carbosulfan in Mango (Mangifera indica L.)

Imidacloprid was sprayed on mango cv. Dashehari at 0.3 mL L(-1) of water during pre-bloom stage with 6-8 cm panicle size (first week of March) to control hopper and carbosulfan was sprayed at 2.0 mL L(-1) of water in the trees of mango hybrid (H-1000) during fruit development stage (first week of May) to control leaf webber. Residues of both the insecticides were analysed in peel, pulp and fruit at different stages of fruit development and maturity. The initial residues of imidacloprid, after 30 days of spraying, were 1.21, 0.56 and 1.77 mg kg(-1) in peel, pulp and whole fruit, respectively. The residues persisted in peel for 60 days and in pulp for 50 days and dissipated with a half-life of 38 days. Mature Dashehari fruits at harvest (after 85 days of spraying) were free from imidacloprid residues. Carbosulfan in mango peel dissipated from 5.30 mg kg(-1) (after 1 h of spraying) to 0.05 mg kg(-1) at the time of harvest (after 45 days of spraying). Carbosulfan residue in pulp was very low (0.08 mg kg(-1)) after 1 h of spraying, which increased gradually to 0.90 mg kg(-1) after 10 days and finally came down to 0.04 mg kg(-1) after 26 days of spraying. The insecticide residue was not detected in the pulp at the time of harvest. The residues persisted in pulp for 26 days and in peel for 45 days and degraded with a half-life of 7 days. The dissipation of both imidacloprid and carbosulfan followed first order rate kinetics in whole fruit (peel + pulp). Therefore, the safe pre-harvest intervals were suggested to be 55 days for imidacloprid and 46 days for carbosulfan before consumption of mango fruits after spraying of these insecticides.

Bio-efficacy of imidacloprid and bifenthrin against mustard aphid (Lipaphis erysimi) on Brassica rapa subsp oleifera

The efficacy, relative toxicity, residual toxicity and dissipation behaviour of imidacloprid and bifenthrin were evaluated against mustard aphid [Lipaphis erysimi (Kalt.)] during 2006-07 and 2007-08. Imidacloprid (RiBo 17.8 SL @ 20, 40 and 60 g ai/ha), bifenthrin (Marker 20 per cent EC @ 60, 80 and 100 g ai/ha) and deltamethrin (as standard check) (Decis 2.8 per cent EC @ 15 g ai/ha) were evaluated against mustard aphid, Lipaphis erysimi (Kalt.) and was found effective in reducing the aphid population in comparision to control. The highest mortality of aphids and marketable yield was registered by imidacloprid @ 60 g ai/ha, while highest cost benefit ratio was found in imidacloprid @ 20 g ai/ha and proved sufficient to optimize the yield. The LC50 values were 0.00017 and 0.00015 for imidacloprid, 0.00152 and 0.00122 for bifenthrin, 0.00199 and 0.00134 for deltamethrin, after 24 and 48 hr of treatment, respectively. Imidacloprid was 8.93 times and bifenthrin 1.10 times more toxic than deltamethrin after 48 hr of treatment. For evaluation of persistence and residual toxicity of imidacloprid the mortality data were taken up to 48 hr, within different exposure periods of 1, 3, 5, 10 and 15 days after application of insecticides. Based on the index of persistence toxicity, the order of effectiveness for the L. erysimi were imidacloprid @ 60 g a.i/ha (1014.23)&gt; imidacloprid @ 40 g a.i/ha (931.37) &gt; imidacloprid @ 20 g a.i/ha (820.41)&gt; deltamethrin 15 g a.i/ha (707.93)&gt; bifenthrin @ 100 g a.i/ha (659.76)&gt; bifenthrin @ 80 g a.i/ha (611.12)&gt;bifenthrin @ 60g a.i/ha (545.25). The dissipation behaviour of imidacloprid under field condition on Brassica rapa L. subsp. oleifera (toria) crop was studied in tender shoots and seeds. The initial deposits of imidacloprid @ 20, 40 and 60 g a.i /ha were 0.830, 1.126 and 1.280, respectively. Imidacloprid residues reached below its detectable level after 5th and 10th day of its application at lower and higher rates. The half life values were 1.44, 1.96, 1.67 days for imidacloprid @ 20, 40 and 60 g a.i/ha, respectively. Based on the observations, a waiting period of at least four days after imidacloprid application @ 20 g a.i/ha is considered safe from point of health hazards due to toxic effect of residues in leaves.

Do residues of imidacloprid in surface water cause honeybee colony losses?

Honeybee colony mortality is a problem at a world wide scale. Insecticides in agriculture and horticulture might contribute, especially the neonicotinoid imidacloprid, which is a commonly used systemic insecticide that might induce several effects at sublethal concentrations. Furthermore it is very persistent in soil and water. At several locations in the Netherlands imidacloprid was found in the surface water in relatively high concentrations. The exceeding of the acceptable levels was suggested to be causally related to honeybee colony losses, and several groups in society are concerned. The aim of this study is to determine whether concentrations of imidacloprid in surface water influence honeybee mortality in the Netherlands. Therefore monitoring data of honeybee mortality from 2005, 2006, 2007 and 2009 and several covariates are used. Data of honeybee mortality are linked to maximum values of imidacloprid concentrations in surface water. For a realistic risk valuation, three foraging distances are used, i.e. 1000 meters, 3000 meters and 7500 meters. Peak concentrations of imidacloprid within a radius of 7500 meters around the colonies appeared negatively correlated with honeybee mortality. However, imidacloprid was aliased with the factor beekeeper, so the earlier shown correlation is possibly a disguised beekeepers effect. A negative effect of imidacloprid in surface water on honeybee colony survival in the Netherlands is therefore not shown in this study. Although it can not be proven that imidacloprid has no influence on honeybee mortality, it seems unlikely that imidacloprid in surface water as a single factor is relevant to the current problem. Possible interactions between imidacloprid and factors that undermine the vitality of colonies are not taken into account in this study.

Quantitation of neonicotinoid insecticide residues in experimentally poisoned honey bees

Background: In cases of poisoning incidents, the standard procedures consider the sampling of dead honeybees to define the active ingredients (a.i.) involved and to determine if the quantity of the residue present can be considered responsible of the death. However one should verify the loss of residues in the period from the discovery of the dead honeybees to their analysis. Since honey bee mortalities due to neonicotinoid insecticides have been recently reported, thiametoxam, clothianidin, imidacloprid residues were determined in experimentally poisoned honey bees. Results: Oral and indirect contact trials were carried out for each pesticide, using commercial formulations. Honey bees that died during the trials were stored at -18 °C and analyzed through a LCMS/ MS analytical procedure adapted from AOAC methods. The quantity of insecticide residues that were detected resulted much lower than the administered residues. Honey bees that did not die within six hours from the trial start were also analyzed and the quantities of insecticide residues resulted much lower than those found in the dead honey bees. Conclusion: On the basis of these results, the determination of the Subsequent Residue Level or of a similar index should be required during the normal procedures of authorization for the use of pesticides. Keywords: poisoning incidents, clothianidin, imidacloprid, thiametoxam

Rapid and Sensitive Analytical Method for Simultaneous Determination of Imidacloprid and Thiamethoxam Residues in Soils of Sugarcane Ecosystem by Reversed-Phase HPLC

A rapid, simple, sensitive and cost-effective analytical method has been standardised to determine the residues of imidacloprid and thiamethoxam in soil. This method does not require any cleanup with costly sorbents. The recoveries of imidacloprid and thiamethoxam obtained in this no-cleanup method were on par with the protocol involving primary–secondary amine-based cleanup. This method requires less volume of solvent (20 mL of acetonitrile/sample) and is suitable for high throughput analyses involving large number of samples. The limit of quantification of the method was 0.01 μg/g. Dissipation kinetics of imidacloprid and thiamethoxam in the soils of sugarcane ecosystem was studied by adopting this rapid method. The half-life of imidacloprid and thiamethoxam was 9.07 and 6.22 days when applied at 70 and 100 g a.i./ha, respectively. The dissipation of both the neonicotinoids followed first-order kinetics with good fit.

Residue Dynamics of Spirotetramat and Imidacloprid in/on Mango and Soil

Spirotetramat is a unique insecticide having both phloem and xylem mobility and imidacloprid, a neonicotinoid insecticide, is one of the most widely used in the world. The combination formulation is very effective against sucking pests of mango. Residue dynamics of spirotetramat and imidacloprid in/on mango and soil was studied following application of the combination formulation, spirotetramat 12% + imidacloprid 12% (240 SC) at 90 and 180 g a.i. ha(-1). Spirotetramat residues in/on mango fruits were 0.327 and 0.483 mg kg(-1) after giving 3 applications at 90 and 180 g a.i. ha(-1), respectively. The residues remained on mango fruits for 7 days and dissipated with the half-life of 3.3 and 5.2 days, respectively. Residues of spirotetramat-enol, the major metabolite of spirotetramat in plant, were not detected in mango fruits. Initial residues of imidacloprid on mango fruits from the two treatments were 0.329 and 0.536 mg kg(-1), respectively. Imidacloprid residues remained on mango fruits beyond 15 days and dissipated with the half-life of 5.2 and 8.2 days. The residues of spirotetramat, spirotetramat-enol and imidacloprid were found below quantifiable limit of 0.05 mg kg(-1) in mature mango fruits and field soil at harvest.

Determination of nicotinyl pesticide residues in vegetables by micellar electrokinetic capillary chromatography with quantum dot indirect laser‐induced fluorescence

A new assay was developed by use of micellar electrokinetic capillary chromatography with indirect LIF fluorescence for the determination of thiamethoxam, acetamiprid, and imidacloprid residues in vegetables, in which the cadmium telluride quantum dots (QDs) synthesized in aqueous phase were used as fluorescent background substance and their excitation and emission wavelengths matched with LIF detector by engineering their size. The factors that affected the peak height and the resolution were optimized. The running buffer was composed of 4.4 μM cadmium telluride QDs as fluorescent background substance, 40 mM borate and 60 mM SDS, and its pH was adjusted to 8.0. The separation voltage was 25 kV. Under the optimum conditions, the detection limits were 0.05, 0.01, and 0.009 mg/kg; the linear dynamic ranges were 0.5-30, 0.1-30, and 0.1-30 mg/L; and the average recoveries of spiked samples were 72.0-101.2, 74.0-106.7, and 77.8-105.1% for thiamethoxam, acetamiprid, and imidacloprid, respectively. The assay can meet the requirement of maximum residue limits to these three pesticides in the regulations of European Union and Japan, and has been applied for determining their residues in vegetables.

Deposition and residues of azoxystrobin and imidacloprid on greenhouse lettuce with implications for human consumption

Lettuce greenhouse experiments were carried out from March to June 2011 in order to analyze how pesticides behave from the time of application until their intake via human consumption taking into account the primary distribution of pesticides, field dissipation, and post-harvest processing. In addition, experimental conditions were used to evaluate a new dynamic plant uptake model comparing its results with the experimentally derived residues. One application of imidacloprid and two of azoxystrobin were conducted. For evaluating primary pesticide distribution, two approaches based on leaf area index and vegetation cover were used and results were compared with those obtained from a tracer test. High influence of lettuce density, growth stage and type of sprayer was observed in primary distribution showing that low densities or early growth stages implied high losses of pesticides on soil. Washed and unwashed samples of lettuce were taken and analyzed from application to harvest to evaluate removal of pesticides by food processing. Results show that residues found on the Spanish preharvest interval days were in all cases below officially set maximum residue limits, although it was observed that time between application and harvest is as important for residues as application amounts. An overall reduction of 40–60% of pesticides residues was obtained from washing lettuce. Experimentally derived residues were compared with modeled residues and deviate from 1.2 to 1.4 for imidacloprid and azoxystrobin, respectively, presenting good model predictions. Resulting human intake fractions range from 0.045kgintakekgapplied-1 for imidacloprid to 0.14kgintakekgapplied-1 for azoxystrobin.

Statement on the findings in recent studies investigating sub‐lethal effects in bees of some neonicotinoids in consideration of the uses currently authorised in Europe

The European Food Safety Authority was requested to perform a comparison between the doses of several neonicotinoids tested in the studies from Henry et al. (honeybees, thiamethoxam) and Whitehorn et al., (bumblebees, imidacloprid) published in Science (2012) with exposure of bees, following the actual use of these neonicotinoids. A third study investigating sub-lethal effects on honeybees for clothianidin and imidacloprid was also considered (Schneider et al., 2012). Data of uses authorised in EU and data on residues in pollen and nectar were collected to compare the actual exposure of bees with the investigated doses. The residue data were limited and available only for some crops; therefore, the extrapolation to other crops was not considered appropriate. In the studies on honeybees, the highest residue levels of thiamethoxam, clothianidin and imidacloprid in nectar were compared with the actual concentrations tested. The results indicated that the tested concentrations were higher than the concentrations found in nectar. The residue intake was estimated using different exposure scenarios. The results indicated that the doses tested in these publications were lower for clothianidin and for thiamethoxam than the estimated exposure. For imidacloprid the doses tested were higher in all the scenarios. In the studies on honeybees, the total amount of active substance was consumed by honeybees within a relatively short period instead of being not administrated over a longer period i.e a day. In the study on bumblebees the tested concentrations were in the range of the highest residues of imidacloprid in pollen and nectar. However, the relevance of the exposure period in the study is unknown. The comparison between the doses tested in the studies with the actual doses with the exposure of bees was considered feasible only for the seed treatment uses to maize, sunflower, oilseed rape and alfalfa. Further data would be necessary before drawing a definite conclusion on the behavioural effects regarding sub-lethal exposure of foragers exposed to actual doses of neonicotinoids

Lethal effect of imidacloprid on the coccinellid predator Serangium japonicum and sublethal effects on predator voracity and on functional response to the whitefly Bemisia tabaci

Neonicotinoid insecticides are widely used for controlling sucking pests, and sublethal effects can be expected in beneficial arthropods like natural enemies. Serangium japonicum is an important predator in many agricultural systems in China, and a potential biological control agent against Bemisia tabaci. We evaluated the toxicity of imidacloprid to S. japonicum and its impact on the functional response to B. tabaci eggs. S. japonicum adults exposed through contact to dried residues of imidacloprid at the recommended field rate on cotton against B. tabaci (4 g active ingredient per 100 l, i.e. 40 ppm [part per million]), and reduced rates (25, 20, 15 and 10 ppm) for 24 h showed high mortality rates. The mortality induced by a lowest rate, 5 ppm, was not significantly different than the control group and thus it was considered as a sublethal rate. The lethal rate 50 and hazard quotient (HQ) were estimated to be 11.54 ppm and 3.47 respectively, indicating a risk for S. japonicum in treated fields (HQ > 2). When exposed to dried residues of imidacloprid at the sublethal rate (5 ppm) on cotton leaves, functional response of S. japonicum to B. tabaci eggs was affected with an increase in handling time and a reduction in peak consumption of eggs. Imidacloprid residues also disturbed predator voracity, the number of B. tabaci eggs consumed on treated leaves being significantly lower than on untreated leaves. All effects disappeared within a few hours after transfer to untreated cotton leaves. Imidacloprid systemically applied at the recommended field rate (for cotton) showed no toxicity to S. japonicum, nor affected the functional response of the predator. Sublethal effects of imidacloprid on S. japonicum observed in our study likely negatively affect S. japonicum development and reproductive capacity and may ultimately reduce predator population growth. These results hint at the importance of assessing potential effects of imidacloprid on S. japonicum for developing effective integrated pest management programs of B. tabaci in China.

Degradation of Imidacloprid in Chrysanthemi Flos and Soil

Degradation of imidacloprid in chrysanthemi flos and cultivated soil was studied. The half-lives of imidacloprid were 3.55-5.17 days (soil), 2.10-3.98 days (fresh buds and flowers), 22.14 days (dry flowers, 5°C) and 13.08 days (dry flower, 20°C), separately. The temperature can affect imidacloprid degradation in soil and dry chrysanthemum buds and flowers. Imidacloprid residues in chrysanthemum flowers were more stable during store stage than growing one. Few imidacloprid residues would be dissolved into chrysanthemum tea liquor when the residue in dry buds or dry flowers was below 0.8 mg/kg.

Evaluation of neonicotinoid, organophosphate and avermectin trunk injections for the management of avocado thrips in California avocado groves

Trunk injections of systemic insecticides were evaluated for the management of avocado thrips. Insecticide residues were quantified in leaves to determine when after treatment, and for how long, toxic concentrations of the insecticides were present. Residues in fruit were quantified to determine whether trunk injection of insecticides might present a greater risk than traditional application methods for contaminating fruit. Residues of imidacloprid and dinotefuran were at least tenfold higher in leaves when trees were treated via trunk injection compared with soil application. Dinotefuran uptake was more rapid than imidacloprid, and no residues were detected within fruit. Acephate was also mobilized very rapidly and gave good control of thrips in bioassays; however, residues of acephate and its insecticidal metabolite methamidophos were detected in the fruit for up to 4 weeks after injection. Avermectin uptake was very slow, and it was ineffective against avocado thrips. Trunk injections of acephate and dinotefuran permitted rapid uptake into avocados, and they are strong candidates as control methods for avocado thrips. However, residues of organophosphates in fruit could necessitate increased preharvest intervals. Residues of neonicotinoids were below detection limits in fruit, suggesting that neonicotinoids may be the more suitable control option of the two chemical classes.

Residue and bio-efficacy evaluation of controlled release formulations of imidacloprid against pests in soybean (Glycine max)

Controlled release (CR) formulations of imidacloprid (1-(6 chloro-3-pyridinyl methyl)-N- nitro imidazolidin-2- ylideneamine) were prepared using novel amphiphilic polymers synthesized from polyethylene glycol and aliphatic diacids employing encapsulation technique. The bioefficacy of the prepared CR formulations was evaluated against major pests of soybean, namely stem fly, Melanagromyza sojae Zehntmer and white fly, Bemisia tabaci Gennadius along with a commercial formulation at the experimental farm of Indian Agricultural Research Institute (IARI), New Delhi during kharif 2009 and 2010. Most of the CR formulations of imidacloprid gave significantly better control of the pests compare to its commercial formulations, however the CR formulations, Poly [poly (oxyethylene-1000)-oxy suberoyl] amphiphilic polymer based formulation performed better over others for controlling of both stem fly incidence and Yellow Mosaic Virus (YMV) infestation transmitted by white fly. Some of the developed CR formulations recorded higher yield over commercial formulation and control. Nodulation pattern of soybean was not affected due to treatment of CR and commercial formulations of imidacloprid. Also the residues of imidacloprid in seed and soil at harvest were not detectable for both CR and commercial formulations.

Treatment Strategies Using Imidacloprid in Hemlock Woolly Adelgid (Adelges tsugae Annand) Infested Eastern Hemlock (Tsuga canadensis Carrière) Trees

Due to the widespread establishment of hemlock woolly adelgid (Adelges tsugae Annand) (HWA) across the range of eastern hemlock (Tsuga canadensis Carriere), woodland trees may be infested for many years before treatment is made. Symptoms of prolonged infestation include extensive dieback and thinned canopies. Imidacloprid, a systemic neonicotinoid insecticide, is a useful and effective tool to manage HWA. In this study, mature, large diameter trees in poor condition were treated with imidacloprid. Trees were treated once by trunk and/or soil injection in Asheville, North Carolina, U.S. Following application, changes in tree growth, HWA density and imidacloprid residues were measured for three years. Trees treated with imidacloprid recovered, whereas the untreated trees continued to struggle. Trees injected with imidacloprid accumulated compound in the canopy, facilitating refoliation and the imidacloprid persisted for three years. This extended activity of trunk-injected imidacloprid was attributed in part to slow upward movement through the restrictive tracheid vascular system and to perennial needle retention. The imidacloprid soil injection was slower to act systemically, but has potential for longer-term activity. Researchers suggest the combination of tree and soil injection for immediate and long-term (4+ years) activity as an effective and economic strategy to protect high-value trees.

Extraction, Cleanup, and Chromatographic Determination of Imidacloprid Residues in Wheat

This study presents an improved method for quantitative analysis of imidacloprid residues in wheat grain using high performance liquid chromatography. The study used chromatographic response (in terms of peak height) as a quantitative tool for determination instead of peak area. The peak height of imidacloprid showed a very good linear correlation (R(2)=0.999) when compared with absolute values at six different concentrations. The limit of detection was found to be 0.01μg/mL. The recovery of imidacloprid residues in spiked wheat grain at three levels (0.03, 0.05, and 0.1μg/g) was in the range of 79%-88% with %RSD 5.72 at 0.05μg/g (w/w) and between 87% and 93% with %RSD 3.55 at 0.1μg/g (w/w). At 0.03μg/g (w/w) level, recovery was not within the recommended range of 70%-110%. Therefore, the lowest limit of quantification for this method was found to be 0.05μg/g.