Application Of Imidacloprid Research Articles

Imidacloprid Uptake and Accumulation in Lettuce Plant (Lactuca sativa L. var. longipolia) and Its Effects on Abundance of Microbial Communities in Cultivated and Non-Cultivated Arid Soil.

Systemic plant protection products, such as neonicotinoids (NIs), are capable of being translocated throughout a plant. Although NIs are less toxic to mammals, fish, and birds, their impact on microbial and non-target insects is of concern. This study investigates the uptake, translocation, and accumulation of the NI, imidacloprid (IMI), in romaine lettuce (Lactuca sativa L. var. longipolia). Exposing 15-day-old seedlings to "10 mg/L" of IMI, the effects on microbial communities in both cultivated (CS) and non-cultivated soil (NCS) were studied along with IMI translocation within plant tissues. The concentrations of IMI in soil varied temporally and between soil types after initial application, with a decrease from 2.0 and 7.7 mg/kg on the first day of sampling to 0.5 and 2.6 mg/kg on the final sampling day (day 35) for CS and NCS, respectively. The half-life of IMI soil was 10.7 and 72.5 days in CS and NCS, respectively, indicating that IMI degraded more quickly in CS, possibly due to smaller grain size, aeration, microbial degradation, and water flow. The accumulated concentrations of IMI in lettuce tissues ranged from 12.4 ± 0.2 and 18.7± 0.9 mg/kg in CS and NCS, respectively. The highest concentration of IMI was found in the shoots, followed by the roots, whereas the soil showed the lowest IMI residuals at the end of the trial. Soil bacteria and fungi were altered by the application of IMI, with a lower abundance index within the bacterial community, indicating a negative impact on the distribution of bacteria in the soil.

Effects of the insecticide imidacloprid on aquatic invertebrate communities of the Ecuadorian Amazon

Imidacloprid is a neonicotinoid insecticide that has received particular attention due to its widespread use and potential adverse effects for aquatic and terrestrial ecosystems. Its toxicity to aquatic organisms has been evaluated in central and southern Europe as well as in (sub-)tropical regions of Africa and Asia, showing high toxic potential for some aquatic insects and zooplankton taxa. However, its toxicity to aquatic organisms representative of tropical regions of Latin America has never been evaluated. To fill this knowledge gap, we carried out a mesocosm experiment to assess the short- and long-term effects of imidacloprid on freshwater invertebrate communities representative of the Ecuadorian Amazon. A mesocosm experiment was conducted with five weekly applications of imidacloprid at four nominal concentrations (0.01 μg/L, 0.1 μg/L, 1 μg/L and 10 μg/L). Toxic effects were evaluated on zooplankton and macroinvertebrate populations and communities, as well as on water quality parameters for 70 days. Given the climatic conditions prevailing in the study area, characterized by a high solar radiation and abundant rainfall that resulted in mesocosm overflow, there was a rapid dissipation of the test compound from the water column (half-life: 4 days). The macroinvertebrate taxa Callibaetis pictus (Ephemeroptera), Chironomus sp. (Diptera), and the zooplankton taxon Macrocyclops sp., showed population declines caused by the imidacloprid treatment, with a 21-d Time Weighted Average No Observed Effect Concentrations (21-d TWA NOEC) of 0.46 μg/L, except for C. pictus which presented a 21-d TWA NOEC of 0.05 μg/L. In general terms, the sensitivity of these taxa to imidacloprid was greater than that reported for surrogate taxa in temperate zones and similar to that reported in other (sub-)tropical regions. These results confirm the high sensitivity of tropical aquatic invertebrates to this compound and suggest the need to establish regulations for the control of imidacloprid contamination in Amazonian freshwater ecosystems.

Dissipation and residues of imidacloprid in amaranth under greenhouse and open field cultivations

Despite the extensive exposure to imidacloprid residues in food plants, there has been little research on imidacloprid residues in amaranth. The dissipation trend and residue behavior of imidacloprid were evaluated to provide guidelines for imidacloprid application on amaranth under open field and greenhouse. The dissipation rate of imidacloprid in amaranth conformed to the first-order kinetic equation, and the half-lives of imidacloprid in amaranth ranged from 0.29 days in open field to 1.29 days in the greenhouse. After 7 and 14 days from the application of imidacloprid (pesticide dosage, 45 or 67.5 g a.i./ha), the amaranth under the open field and greenhouse growth could be consumed safely with average residues of 0.19 and 0.38 mg/kg, respectively. This result demonstrated that the cultivation has the dominant influence on imidacloprid residue, and the residue of imidacloprid in amaranth planting on open field was much lower than that in the greenhouse, indicating a significant difference in the pesticide residues between the two cultivations with a p-value less than 0.05.

COMPARATIVE EFFICACY OF NEEM OIL DERIVATIVES WITH IMIDACLOPRID AGAINST OKRA JASSID, AMRASCA BIGUTTULA (ISHIDA)

The present research study was conducted at the experimental field condition of Pakistan Agricultural Research Council, Southern Zone Agricultural Research Centre, University of Karachi, to compare the field performance of different neem oil derivatives doses with Imidacloprid, sprayed on okra crop against the jassid population. The experiments were carried out RCBD with the application of four treatments, including three different concentrations of neem oils at (2%, 1.5%, and 1%) with the comparison of Imidacloprid pesticide and control. Neem oil was selected as a natural pesticide against jassid population reduction on okra crop. All the treatments were sprayed twice and data were recorded before 24h of pre-treatment and post-treatment at 48h, 72h, and 144h, respectively. The overall maximum reduction % after the application of Imidacloprid against the jassid population was calculated (61.51%) in 1st spray and (58.25%) 2nd spray, followed by (43.01%), (39.75%) at 2%, consequent to (32.50%), (29.75%), at 1.5% and (25.55%), (24.52%) at 1%, respectively. The maximum efficacy in neem oil concentration was recorded at 2% followed by 1.5%, and 1% but all neem oil concentrations including Imidacloprid observed effective from the 1st day up to the 6th post-spray days. All neem oil concentrations after 24h, 48h, 72h, and 144h of post-spray found significantly different at (P< 0.05). The application of neem oil, 2% caused the phytotoxicity reduction in okra plants. Thus, it is recommended that the bio-pesticide should be applied at 1.5% neem oil concentration against the jassid pest population.

Imidacloprid Uptake and Leaching in the Critical Root Zone of a Florida Entisol

Imidacloprid (IDP) products are applied via soil drenching in the citrus critical root zone (CCRZ) at 0–60 cm soil depth. This study aimed to determine the uptake and leaching of IDP in the CCRZ of a Florida Entisol. The treatments include: (1) a control with no IDP applied, (2) 1.6 g of active ingredient (a.i.) per tree (×2), and (3) 3.2 g a.i. per tree of IDP (×4). The treatments were applied to two trees within each experiment unit, replicated five times, and completely randomized. The IDP concentration in the Entisol was affected by the amount of water received within the sampling intervals. IDP movement in the Entisol was evident for the field trials in Fall 2021 and 2022, irrespective of the treatment. A total of 10 mm of daily irrigation was the major driver of IDP movement in Fall 2021 (September–December 2021), while 11.7 cm of cumulative rainfall plus 10 mm of daily irrigation were the major drivers for IDP in Fall 2022 (November–December 2022). The IDP uptake level by leaves was relatively low probably because of the relatively low temperature and humidity. More applications of IDP did not result in its higher uptake by citrus leaves in the Entisol. Given the persistence of IDP, there is a possibility of leaching, which could potentially contaminate the groundwater, surface water, and non-target organisms. Therefore, it is crucial to carefully manage the use of IDP in citrus production systems to mitigate the unintended environmental impacts.

Dissipation and residues of 18% imidacloprid + buprofezin SC in citrus and soil

ABSTRACT Eighteen per cent imidacloprid + buprofezin suspension concentrate (SC) has been registered for the control of scale insect on citrus trees, but the dissipation of this pesticide mixture on citrus is still a research blank area. In order to fill the gaps and ensure the safe application of mixture formulation, field trials were conducted in Guangdong, Guangxi and Hunan Provinces of China for 2 consecutive years to evaluate the final residue and dissipation dynamic of imidacloprid and buprofezin in citrus and soil. Both pesticides were extracted by the modified Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) method, while imidacloprid was determined by high-performance liquid chromatography (HPLC) and buprofezin was determined by gas chromatography (GC). The established method achieved a good linearity relationship (r = 0.9999) and high sensitivity, the LODs (limit of detection) of imidacloprid and buprofezin were 0.002–0.013 mg/kg, which can fully meet the need for pesticide residue detection. Average recoveries (AR) of imidacloprid and buprofezin in citrus and soil were 77.64–105.95% and 85.89–102.28%, with relative standard deviations (RSD) of 3.06–7.91% and 3.29–7.25%, respectively. Results of field trials showed that the half-lives of imidacloprid in citrus and soil were 1.90–3.97 and 2.52–16.98 days, and that of buprofezin were 1.69–9.14 and 1.21–8.56 days. On the 21st day after the last application, final residues of imidacloprid and buprofezin in all samples were below their maximum residue limits (MRL) stipulated by China, indicating that it is safe to apply 18% imidacloprid + buprofezin SC on citrus trees. In conclusion, 18% imidacloprid and buprofezin SC was recommended to be spared twice at the intervals of 7 days with dosages of 180 or 270 mg/L, and the citrus fruit can be harvested safely 21 days after the last application. These results help ensure the safe application of imidacloprid and buprofezin in citrus orchards.

The inappropriate application of imidacloprid destroys the ability of predatory natural enemies to control pests in the food chain: A case study of the feeding behavior of Orius similis on Frankliniella occidentalis

Insecticides are an indispensable and important tool for agricultural production. However, the inappropriate application of insecticides can cause damage to the food chain and ecosystem. Orius similis is an important predatory and natural enemy of Frankliniella occidentalis. Imidacloprid is widely used to control pests, but will inevitably exert adverse effects on O. similis. In order to determine the effect of different imidacloprid treatments on the ability of O. similis to prey on the 2nd-instar nymphs of F. occidentalis, we determined the toxicity and predation of imidacloprid on different stages of O. similis under contact and ingestion treatments. In addition, we used the Holling disc equation to evaluate the ability of O. similis to search and exhibit predatory activity following contact and ingestion treatments. Analysis showed that the highest LC10 and LC20 values for imidacloprid contact and ingestion toxicity treatment were 17.06 mg/L and 23.74 mg/L, respectively. Both imidacloprid treatments led toa reduction in the predatory of O. similis on prey. The functional responses of the 3rd to 5th instar nymphs, along with female and male O. similis adults to the 2nd-instar nymphs of F. occidentalis were consistent with the Holling type II response following contact and ingestion with imidacloprid. However, following imidacloprid treatment, the handing time (Th) of O. similis with single F. occidentalis was prolonged and the instantaneous attack rate (a) was reduced after imidacloprid treatment. The predatory capacity (a/Th) of female O. similis adults when treated with the LC10 concentration of imidacloprid by ingestion was 52.85; this was lower than that of the LC10 concentration of imidacloprid in the contact treatment (57.67). The extent of predation of O. similis on the 2nd-instar nymphs of F. occidentalis was positively correlated with prey density, although the search effect was negatively correlated with prey density. The most extensive search effect was exhibited by adult O. similis females. Simulations with the Hessell-Varley interference model showed that an increase in the number of O. similis would reduce search efficiency regardless of whether they were treated with imidacloprid or not. Thus, O. similis, especially female adults, exhibited strong potential for controlling the 2nd-instar nymphs of F. occidentalis. The toxicity of ingestion following treatment with the same concentration of imidacloprid in O. similis was greater than that of contact treatment. When using O. similis to control F. occidentalis in the field, we should increase the number of female adults released, and prolong the interval between imidacloprid treatment and O. similis exposure. This strategy will improve the control ability of O. similis, coordinate both chemical and biological control, reduce the impact of pesticides on the environment, and improve the efficiency of agricultural production.

Imidacloprid triggered changes in strawberry fruits on edible quality and phenolic profiles by applied at two growth stages

Increasing evidence showed that imidacloprid affects plants’ abiotic or biotic stress tolerance. However, the effects of imidacloprid on the quality of fruits remain elusive. This work aimed to study the effects of imidacloprid applied at different growth stages on the edible quality and phenolic profile of strawberry fruit in the field experiment. For the first time, lower fruit quality was observed in the mature strawberry fruits after imidacloprid treatment at the fruit-bearing completion stage (five days after pollination). Compared to the control group, the mature strawberry fruit wights and the SCC/TA ratio declined about 18.2–30.0 % and 10.3–16.8 %, respectively. However, those attributes did not occur in the mature strawberry fruits by imidacloprid treatment at the fruit maturation stage (30 days after pollination). Among the 30 phenolic compounds, nine presented significant up-regulation or down-regulation after imidacloprid application at two different growth stages, suggesting that the application period played an essential role in evaluating the effects of imidacloprid on the quality of fruits. A significant effect on fruit quality was presented at the strawberry early growth stage treated by imidacloprid. This study provided a new insight into how and when imidacloprid affects the quality of strawberry fruits, contributing to the future’s more scientific application of imidacloprid on strawberries.

The effects of pesticides on tomato pollinators depend on application practices and floral visitor assemblage

AbstractPesticide use affects biodiversity and ecosystem service provision. Yet, such effects may vary between pesticides, dosage, application timing and pollinator assemblage in the study area. Understanding such diversity of effects is essential to enable integrated pest management practices that minimize negative impacts on pollinators. Here, we use a controlled experiment to compare different strategies of pesticide application in tomato crops: no application, low‐intensity applications (every 7 days) and high‐intensity application (every 3–4 days) with the last being the usual practice used by farmers in the study region. We focus on imidacloprid that is a neonicotinoid insecticide commonly used in Brazil. We show the negative effects of imidacloprid on the pollinator visitation rate of tomato flowers varied between flower visitor species. While the bee Paratrigona lineata was negatively affected by the imidacloprid application, no effects were detected when analysing all other bees as a group, indicating a null net effect. Although some studies have shown this insecticide is extremely harmful to bees' health, others showed that some bees do not avoid it, which may explain our results. However, the visitation rate recovery for P. lineata was only detected in the less than the more intensive treatment after imidacloprid applications ceased. The fact that no differences in fruit production were detected between treatments (including control blocks) could result from a null net effect of the negative effects on pollinators and positive effects on pest control. Further studies would be needed to disentangle the two effects.

Co-exposure of dimethomorph and imidacloprid: effects on soil bacterial communities in vineyard soil.

In Taiwan, the pesticides dimethomorph and imidacloprid are recommended for pest control in vineyards. Therefore, tank-mixing of these two pesticides is usually a routine practice before application. This study analyzed the influence of vineyard soil microbial flora under the recommended and high dosages (100 times the recommended dosage) of dimethomorph and imidacloprid. Individual and combined applications of pesticides were also tested through batches of soil incubation experiments. Four treatments-control (C), dimethomorph (DT), imidacloprid (IM), and mixed application of dimethomorph and imidacloprid (ID)-were used in the experimental design. From the soil metabolism, no significant reaction was observed after 2 months in the recommended dosage group, regardless of whether the pesticides were being applied individually or combined. For the high dosage, imidacloprid showed a higher effect than the co-exposure treatments, showing a possible prolonged effect after its repetitive application. From PCoA analysis, pesticide treatments altered the soil ecology after 2 months, and the effect of imidacloprid can be explicitly observed at high dosages. At the phylum level, Acidobacteria can indicate pesticide application around the recommended dosage. It was inhibited by ID on day 7 and was augmented by all pesticides on day 63. The effect of the recommended dosage of pesticide mixtures after 2 months of incubation was revealed in the minor families Gemmataceae and Pirellulaceae, while the high dosage treatments affected both the core and the minor families. Our findings verified the changes in the composition of microbial communities upon pesticide application, which would affect carbon, nitrogen, sulfur, phosphorous cycles, and contaminant removal ability within the vineyard.

Impact of Variety and At-Planting Insecticides on Thrips (Thysanoptera: Thripidae) Management in Peanut

Tobacco thrips are one of the most prevalent early season insect pests in peanut production systems. Experiments were conducted in 2018 and 2019 in Stoneville Mississippi to evaluate integrated pest management approaches to mitigate negative effects of thrips. Experimental treatments included a normal and late planting date, varieties Georgia-06G and QR-14, and in-furrow insecticide treatments consisting of a non-treated control, phorate, and imidacloprid. Measurements included early and final plant stands, immature and adults thrips counts, and pod yield. In-furrow insecticide had a strong effect on number of thrips per plant with treatment thrips ranking of: phorate < imidacloprid < non-treated control. However, in-furrow insecticide had no interaction with variety or plating date. Although phorate provided greater thrips control than imidacloprid, pod yield for the two treatments was similar, and both in-furrow treatments had greater yield than the non-treated control. The variety QR-14 had greater pod yield than Georgia-06G when planted late. Overall, these results confirm that in-furrow insecticide applications of either imidacloprid or phorate are adequate in protecting against yield loss from thrips within a midsouthern peanut production environment.

Assessing the effectiveness of imidacloprid and thiamethoxam via root irrigation against Megalurothrips usitatus (Thysanoptera: Thripidae) and its residual effects on cowpea.

Systemic neonicotinoid insecticides (NEOs) applied by seed-treatment or root application have emerged as a prevalent strategy for early-season insect pest management. This research investigated the effectiveness of imidacloprid and thiamethoxam, administered through root irrigation, in managing thrips in cowpea [Vigna unguiculata (Linn.) Walp.], and the residual properties of both insecticides in cowpea and soil. The results show that thrips density depends on the application rate of insecticides. At the maximum application rate (1,500 µg/ml, active ingredient), imidacloprid and thiamethoxam controlled thrips densities below the economic injury level (EIL, the EIL of thrips on cowpea was 7/flower) for 20 days and 25 days with the density of 6.90 and 6.93/flower at the end of the periods, respectively. Imidacloprid and thiamethoxam residues decreased gradually over time and decreased sharply after 15 days after treatment (DAT), the 2 insecticides were not detected (<0.001 mg/kg) at 45 DAT. According to our findings, the application of imidacloprid and thiamethoxam via root irrigation proved residual control lasting up to 20-25 days for controlling thrips damage at experimental rates, with a strong association to their residual presence in cowpea (0.6223 < R2 < 0.9545). Considering the persistence of the imidacloprid and thiamethoxam, the maximum tested application rate (1,500 µg/ml) was recommended. As the residues of imidacloprid and thiamethoxam were undetectable in cowpea pods at all tested rates, it may be suggested that the use of each insecticide is safe for consumers and effective against thrips, and could be considered for integrated thrips management in the cowpea ecosystem.

Effects of mixed application of avermectin, imidacloprid and carbendazim on soil degradation and toxicity toward earthworms

The application of pesticides in mixtures often exerts multiple pressures on agricultural soils in the short term. Therefore, it is necessary to assess the effects of mixed application on the environmental behavior and ecotoxicity of pesticides in soil. In this study, we assessed the effects of three common pesticides through mixed application on soil degradation and toxicity toward the earthworm Eisenia fetida. Compared with the degradation half-lives (DT50) the single pesticide, the DT50 values of avermectin, imidacloprid and carbendazim in the binary mixtures were similar. However, their DT50 values in the ternary mixtures were approximately 1.5 times longer than those in the individual applications, enhancing their stable in soil after two or three applications. The ternary mixtures of the pesticides showed significantly synergistic toxicity toward E. fetida, while their binary mixtures exhibited a changing interaction throughout the entire effect level range. The ternary mixtures activated higher SOD and CAT activities in E. fetida than the individual treatments, confirming their synergistic effects. By conducting avoidance tests with E. fetida, ternary toxic interactions were effectively assessed within a relatively short testing period. In summary, the three pesticides in ternary mixtures exhibited longer degradation half-lives and synergistic toxicity toward earthworms compared to individual or binary mixtures.

Synergistic interactions between three insecticides and Beauveria bassiana (Bals.-Criv.) Vuill. (Ascomycota: Hypocreales) in lesser mealworm, Alphitobius diaperinus Panzer (Coleoptera: Tenebrionidae), larvae

Topical applications of insecticides β-cyfluthrin, imidacloprid, and spinosad in combination with Beauveria bassiana (topical and contact filter paper application) induced synergistic interactions in lesser mealworm larvae, increasing mortality and in some cases numbers of larval cadavers exhibiting conidiogenesis. Reduced concentrations (LC10, LC20, LC30) of the insecticides induced sublethal effects in lesser mealworm larvae, inhibiting development (mass, head-capsule width, moulting) after eight days’ exposure and movement behaviour (area explored and distance travelled) after 3 h’ exposure. The most potent synergist was ß-cyfluthrin, it strongly inhibited larval development and movement while significantly increasing mortality and conidiogenesis in B. bassiana-infected larvae. Imidacloprid also strongly inhibited larval development and movement, but only produced weak short-lived synergistic increases in mortality, with no increase in conidiogenesis. Spinosad induced no effect on development and limited effect on movement, but still induced moderate short-lived synergistic increases in mortality and conidiogenesis. Intoxicated larvae exposed to B. bassiana on filter paper for 3 h showed no synergistic interactions, except when intoxicated by spinosad.

The Efficacy of Selected Insecticides Against Wheat Aphids on Irrigated Wheat in North Western Amhara, Ethiopia

Aphid infestations cause significant losses in wheat production. The experiment was conducted at the Koga irrigation site during 2021 to evaluate the efficacy of commercial insecticides for the management of wheat aphids. Seven types of insecticides with unsprayed control were laid in a completely randomized block design with three replications. The result showed a reduced aphid infestation with maximum grain yield were from dimethoate, imidacloprid, lambda-cyhalotrin, profenfos + lambda-cyhalothrin, imidacloprid + lambda-cyhalothrin, and profenofos-sprayed plots. However, the greater net benefit and marginal rate of return were provided by the applications of imidacloprid and dimethoate insecticides. The economically feasible insecticide application can be considered as an effective aphid management practice in wheat production.

Comparative Analysis of the Effect of Different Insecticide Treatments on Nagpur Mandarin in Biomass Accumulation

The Comparative Analysis of the Effect of Different Insecticide Treatments in Nagpur Mandarin on Biomass Accumulation was conducted during the Ambia bahar of 2009-10. The experiment was carried out on an eight-year-old Nagpur mandarin orchard with a spacing of 6.0 m x 6.0 m at Futala farm, College of Agriculture, Nagpur. The study aimed to assess the impact of different insecticide treatments on Citrus psylla management. A trial comprising of eleven treatments was set in the Randomized Block Design (RBD), replicated thrice, with each treatment plot having four plants. Four branches were selected from each plant at random and tagged. The population of citrus psylla (both nymph and adult) was counted on the twigs of 5 cm fresh growth of the shoot from all the four sides of the plant during Ambia bahar of 2009-2010. The study found that imidacloprid 0.25 ml/l, acetamiprid 0.1 g/l, and quinalphos 1 ml/l + karanj oil (pongamia oil) 10 ml/l were the most effective treatments based on biomass accumulation (wet weight basis). Meanwhile, treatments with lower efficacy were Verticillium lecani 4 g/l + mineral oil 5 ml/l, azadirachtin 2 ml/l, mineral oil 5 ml/l, and Verticillium lecani 4 g/l. Furthermore, the application of imidacloprid 0.25 ml/l, acetamiprid 0.1 g/l, thiomethoxam 0.1 g/l, and quinalphos 1 ml/l + karanj oil (pongamia oil) 10 ml/l were found to be the most effective treatments based on biomass accumulation on a dry weight basis. The results indicated that treatments with imidacloprid, acetamiprid, thiomethoxam, and quinalphos with karanj oil were the most effective in promoting higher growth of new flush, bearing (buds, flowers and fruit), and biomass accumulation on both wet weight and dry weight basis. Among them, the treatment with imidacloprid at 0.25 ml/l was found to be the most effective.

Determination of the Absorption, Translocation, and Distribution of Imidacloprid in Wheat

Neonicotinoids, a class of insecticides, are widely used because of their novel modes of action, high insecticidal activity, and strong root uptake. Imidacloprid, the most widely used insecticide worldwide, is a representative first-generation neonicotinoid and is used in pest control for crops, vegetables, and fruit trees. With such a broad application of imidacloprid, its residue in crops has attracted increasing scrutiny. In the present study, 15 wheat seedlings were placed in a culture medium containing 0.5 mg/L or 5 mg/L imidacloprid for hydroculture. The content of imidacloprid in the wheat roots and leaves was determined after 1 day, 2 days, and 3 days of hydroculture to explore the migration and distribution of imidacloprid in wheat. The results showed that imidacloprid was detected both in the roots and leaves of the wheat plant, and the content of imidacloprid in the roots was higher than that in the leaves. Furthermore, the imidacloprid concentration in the wheat increased with increasing exposure time. After 3 days of exposure, the roots and leaves of the wheat in the 0.5 mg/L treatment group contained 4.55 mg/kg ± 1.45 mg/kg and 1.30 mg/kg ± 0.08 mg/kg imidacloprid, respectively, while the roots and leaves of the 5 mg/L treatment group contained 42.5 mg/kg ± 0.62 mg/kg and 8.71 mg/kg ± 0.14 mg/kg imidacloprid, respectively. The results from the present study allow for a better understanding of pesticide residues in crops and provide a data reference for the environmental risk assessment of pesticides.

IMPACT OF DECONTAMINATION PROCESSES ON THE REDUCTION OF PESTICIDE RESIDUES IN GREEN CHILLI

This study has been designed to determine the extent of pesticide residue removal from chilli fruits through common household practices. One time foliar application of quinalphos, profenophos, ethion, cyhalothrin, imidacloprid, and acetamiprid was done as a tank mix at recommended doses at 50% fruit formation stage. Samples were collected after 48 hr of spray, subjected to various decontamination treatments, and analysed using the validated QuEChERS method employing GC-ECD (Gas Chromatograph Electron capture detector), and Liquid Chromatograph Tandem Mass Spectrometer (LC-MS/MS). Compared to all the treatments, soaking in 5% acetic acid for one min was found to be most effective in the removal of quinalphos (23.68%), profenophos (19.47%), ethion (23.33%), and cyhalothrin (25.00%). The next best treatment was found to be soaking for one min in lukewarm water, which removed 20-30% of quinalphos, ethion, cyhalothrin, and acetamiprid residues.

Evaluating Efficacy and Chemical Concentrations of Commonly Used Insecticides Targeting Tarnished Plant Bug in Mid-South Cotton

Studies were conducted from 2017 to 2021 at nine locations across Arkansas, Louisiana, Mississippi, and Tennessee to evaluate efficacy, residual control, and effective chemical concentrations of commonly used insecticides targeting tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), nymphs in Mid-South cotton. Foliar applications of imidacloprid, flonicamid, thiamethoxam, oxamyl, dicrotophos, acephate, novaluron, and sulfoxaflor were applied at locally recommended rates. Plots were sampled for nymphs at 4, 7, and 10 d after treatments (DAT), and leaves were analyzed for concentration of active ingredients from plots located in one site in 2021 at 4, 7, 10, and 14 DAT. Across all sampling dates, insecticide treatments reduced nymph infestations compared to untreated control, except for imidacloprid at 10 DAT. All insecticide treatments resulted in higher lint yields compared to untreated control. Overall, sulfoxaflor, novaluron, and acephate offered the best control of nymphs and provided the greatest yield protection among treatments. Moderate control was achieved with thiamethoxam, oxamyl, and dicrotophos. Imidacloprid and flonicamid resulted in less control. Concentrations of flonicamid, thiamethoxam, dicrotophos, acephate, and novaluron persisted up to 14 DAT in leaves. Imidacloprid and oxamyl were not detected at 7, 10, or 14 DAT, and sulfoxaflor was not detected at 14 DAT in leaves. In these studies, control of tarnished plant bug nymphs never exceeded 75% regardless of insecticide or sampling date. The moderate efficacy and short residual control shown in these studies explain why multiple insecticide applications within short intervals are needed to manage heavy tarnished plant bug populations

Yield protection afforded by imidacloprid during Hessian fly infestation in six genotypes

AbstractThe Hessian fly (Mayetiola destructor Say) is a gall midge that infests and feeds upon wheat (Triticum aestivum L.). Recently, a new form of tolerance (QHft.nc‐7D) was identified in the breeding line LA03136E71 (PI 700336). Partial resistance allows immature Hessian fly to thrive in small numbers and does not function like antibiosis. Little is known about the potential yield drag of using partial resistance. In this study, we evaluated six genotypes: one containing QHft.nc‐7D (LA03136E71), one containing H13, and four potentially susceptible genotypes. All genotypes were evaluated with two different seed treatment regiments of imidacloprid: no treatment and a two times rate of imidacloprid. All tested genotypes were planted in six‐to‐eight replications of a full factorial design in four environments. Subsamples of yield trial plots were taken to measure percent infested tillers and a number of larvae/pupae per tiller. Plots were harvested and grain yield was recorded. There was a significant (p[&gt;F] &lt; 0.05) reduction of percent infested tillers and a number of larvae/pupae per tiller related to the imidacloprid treatment. Imidacloprid treatment significantly (p[&gt;T] &lt; 0.05) reduced the number of larvae/pupae per tiller for LA03136E71. There was no significant (p[&gt;T] &gt; 0.05) grain yield increase associated with treatment for LA03136E71. This indicates that a two times application of imidacloprid on LA03136E71 (QHft.nc‐7D) did not improve yield yet reduced infestation. Therefore, QHft.nc‐7D, while allowing Hessian fly to thrive on the plant, does not significantly compromise yield.