Insecticide Imidacloprid Research Articles

African cassava whitefly and viral disease management through timed application of imidacloprid

Cassava whitefly are a group of cryptic species within the Bemisia tabaci sensu lato complex that causes significant damage to cassava in Africa. B. tabaci Sub-Saharan Africa 1 (SSA1) is the major species in the study region which transmits plant-virus diseases to cassava and causes direct feeding damage. Benefits from management of cassava viral diseases through deployment of resistant varieties are being undermined by their susceptibility to B. tabaci SSA1 and the problem is exacerbated by high populations of B. tabaci in cassava fields. To develop a clean seed system that is disease-free, the judicious use of insecticides is required to manage this pest and vector. This study evaluated the effect of timing of insecticide application on controlling B. tabaci SSA1 population abundance and damage to cassava. Field trials were carried out between 2017 and 2018 in Kamuli and Wakiso districts of Uganda using the widely available insecticide Imidacloprid. Three cassava cultivars (NAROCASS1, SAUTI, KBH/2002/026) were planted in a randomized complete block trial design replicated three times. The insecticide was applied in split-plots designated as: (i) no protection (NP), no insecticide applied (control), (ii) early protection (EP), insecticide applied 2 times between 0 and 4 months after planting, (iii) long protection (LP), insecticide applied 3 times between 0 and 8 months after planting, and (iv) total protection (TP), insecticide applied 4 times between 0 and 12 months after planting. Except for control plots, stem cuttings were first dipped into a diluted solution of Imidacloprid prior to planting. Bi-monthly data were collected on the B. tabaci population, feeding damage, cassava mosaic disease and cassava brown streak disease. Stem cuttings and root yields were determined at harvest. The marginal rate of return for each treatment was calculated to determine cost effectiveness. Insecticide application effectively reduced B. tabaci populations, feeding damage and disease spread. Cassava yield differed significantly with insecticide treatment and amongst cultivars. Root and stem yield losses of >60% was recorded in unprotected control plots. The marginal rate of return of the early protection (0–4 MAP) program was 163%. We discuss these findings and the implication for judicious use of insecticides as part of a cassava clean seed system.

Pesticide risk to managed bees during blueberry pollination is primarily driven by off-farm exposures

When managed bee colonies are brought to farms for crop pollination, they can be exposed to pesticide residues. Quantifying the risk posed by these exposures can indicate which pesticides are of the greatest concern and helps focus efforts to reduce the most harmful exposures. To estimate the risk from pesticides to bees while they are pollinating blueberry fields, we sampled blueberry flowers, foraging bees, pollen collected by returning honey bee and bumble bee foragers at colonies, and wax from honey bee hives in blooming blueberry farms in southwest Michigan. We screened the samples for 261 active ingredients using a modified QuEChERS method. The most abundant pesticides were those applied by blueberry growers during blueberry bloom (e.g., fenbuconazole and methoxyfenozide). However, we also detected highly toxic pesticides not used in this crop during bloom (or other times of the season) including the insecticides chlorpyrifos, clothianidin, avermectin, thiamethoxam, and imidacloprid. Using LD50 values for contact and oral exposure to honey bees and bumble bees, we calculated the Risk Quotient (RQ) for each individual pesticide and the average sample RQ for each farm. RQ values were considered in relation to the U.S. Environmental Protection Agency acute contact level of concern (LOC, 0.4), the European Food Safety Authority (EFSA) acute contact LOC (0.2) and the EFSA chronic oral LOC (0.03). Pollen samples were most likely to exceed LOC values, with the percent of samples above EFSA’s chronic oral LOC being 0% for flowers, 3.4% for whole honey bees, 0% for whole bumble bees, 72.4% for honey bee pollen in 2018, 45.4% of honey bee pollen in 2019, 46.7% of bumble bee pollen in 2019, and 3.5% of honey bee wax samples. Average pollen sample RQ values were above the EFSA chronic LOC in 92.9% of farms in 2018 and 42.9% of farms in 2019 for honey bee collected pollen, and 46.7% of farms for bumble bee collected pollen in 2019. Landscape analyses indicated that sample RQ was positively correlated with the abundance of apple and cherry orchards located within the flight range of the bees, though this varied between bee species and landscape scale. There was no correlation with abundance of blueberry production. Our results highlight the need to mitigate pesticide risk to bees across agricultural landscapes, in addition to focusing on the impact of applications on the farms where they are applied.

Digging deep into a GAC filter – Temporal and spatial profiling of adsorbed organic micropollutants

A large pilot-scale granular activated carbon (GAC) filter was operated downstream in a full-scale wastewater treatment plant to remove organic micropollutants. To describe the spatial and temporal developments of micropollutant adsorption profiles in the GAC filter, micropollutants were extracted from GAC media taken at various filter depths and number of treated bed volumes. At a low number of treated bed volumes (2600 BVs), most micropollutants were adsorbed in the top layers of the filter. At increasing number of treated bed volumes (7300–15,500 BVs), the adsorption front for micropollutants progressed through the filter bed at varying rates, with sulfamethoxazole, fluconazole, and PFOS reaching the bottom layer before carbamazepine and other well-adsorbing micropollutants, such as propranolol and citalopram. Higher amounts of adsorbed micropollutants in the bottom layer of the filter bed resulted in decreased removal efficiencies in the treated wastewater. Mass estimations indicated biodegradation for certain micropollutants, such as naproxen, diclofenac, and sulfamethoxazole. A temporary increase in the concentration of the insecticide imidacloprid could be detected in the filter indicating that extraction of adsorbed micropollutants could provide an opportunity for backtracking of loading patterns.

CuMgFe-LDO as superior peroxymonosulfate activator for imidacloprid removal: Performance, mechanism and effect of pH

Recently, the pollution of neonicotinoid insecticides in aquatic environment has attracted attention. Due to its potential neurotoxicity, it is necessary to develop convenient and high-efficient methods to degrade neonicotinoid insecticides in water. In this study, a heterogeneous composite catalyst CuMgFe-LDO was prepared by precipitation-calcination method, and then used to activate peroxymonosulfate (PMS) to degrade a common neonicotinoid insecticide imidacloprid. The key parameters such as Cu:Mg:Fe ratio, catalyst dosage, PMS dosage and initial pH value were optimized. The results showed that CuMgFe-LDO/PMS system exhibited excellent catalytic performance, and imidacloprid could be completely degraded within 15 min under the optimum conditions ([CuMgFe-LDO] = 50 mg L−1, [PMS] = 0.2 mM and [imidacloprid]0 = 10 μM, initial pH = 4–9). Through quenching experiment, EPR test and characterization analysis, it was identified that the main active species in the system were Cu(III), SO4– and OH. In addition, pH had a great impact on the contribution of these active species. During the reaction, Cu and Fe may participated in valence circulation, and Mg was beneficial to the hydroxylation of catalyst surface and stabilization of copper ions. Finally, the main degradation pathways of imidacloprid were obtained by UPLC-MS/MS analysis, and the toxicity of the intermediate products was calculated with TEST program. In this paper, a high-efficient PMS activation strategy is proposed, which provided a reference for the further development of metal catalysts for advanced oxidation technology.

Susceptibility of a Mexican Field-Collected Wild Population of Diaphorina citri (Hemiptera: Liviidae) to Selected Insecticides

Abstract The Asian citrus psyllid, Diaphorina citri (Kuwayama) (Hemiptera: Liviidae), is a severe pest of citrus orchards worldwide. Its control is based mainly on the use of conventional insecticides, and resistance to many of those compounds is widespread. Phenotypic bioassays to detect resistance compare the response of a field-collected population with a laboratory-reared population that is susceptible to insecticides. This comparison usually does not involve a susceptible field-collected counterpart since its existence is currently rare. We found an isolated field population of D. citri living on a wild host, orange jasmine (Murraya paniculata [L.] Jack). Considering its lifetime fly capacity, gene flow with any insecticide-treated population was nonexistent or negligible. Thus, we determined the response in fourth-instar nymphs and unsexed 2- to 5-d-old adults in bioassays of commercial formulations of the commonly used insecticides chlorpyrifos, malathion, imidacloprid, and spinosad. In the bioassays, insects were placed on leaf discs previously immersed for 10 s in the respective insecticide concentrations. For adults, the lowest concentration–mortality response was with chlorpyrifos (lethal concentration 50 [LC50] of 0.72 mg L-1 and lethal concentration 95 [LC95] of 1.02 mg L-1). The highest toxicity response was with malathion (LC95 of 0.05 mg L-1). The highest toxicity response with fourth-instar nymphs was observed with spinosad (LC50 of 0.007, LC95 of 0.021 mg L-1). The estimated LC50 and LC95 values for chlorpyrifos, malathion, and spinosad were lower than those documented worldwide for these insecticides in susceptible populations of D. citri.

3D‐Architectured MoS2‐Microflower‐Modified Electrodes toward Electrochemical Determination of Imidacloprid

AbstractWe report the fabrication and analytical performance studies of electrochemical sensors based on hydrothermally grown 3D MoS2‐microflower‐modified Glassy Carbon (GCE) and Carbon Paste Electrodes (CPE) for the sensitive detection of the insecticide imidacloprid (IMI). As compared to MoS2/GCE, the fabricated MoS2/CPE demonstrates a faster electron transfer and better catalytic ability. MoS2/CPE sensor delivers its best performance towards the determination of IMI in PBS solution of pH 7.4, owing to its porous nature which can accommodate a higher number of active electrochemical reaction sites. The sensor exhibits a sensitivity value of 2.296 μA μM−1 cm−2 with lower detection and quantification limits of 12±0.24 nM and 40±0.8 nM respectively. The proposed sensor also exhibits linearity in the detection of IMI from 1 to 100 μM.

Green synthesis of novel magnetic porous organic polymer for magnetic solid phase extraction of neonicotinoids in lemon juice and honey samples

Natural rutin with abundant hydroxyl groups was used as a green monomer to synthesize hydroxyl-functional magnetic porous organic polymer (named Rut-MOP) through environmentally-benign diazo-coupling reaction for the first time. The Rut-MOP displayed high extraction capability for neonicotinoid insecticides (thiamethoxam, imidacloprid, acetamiprid and thiacloprid). Thus, a Rut-MOP based magnetic solid-phase extraction method combined with high performance liquid chromatography was established for sensitive determination of neonicotinoid insecticides in lemon juice and honey samples. Under optimized conditions, the linear response of neonicotinoids was 0.1–100.0 ng mL−1 for lemon juice and 8.0–1000.0 ng g−1 for honey. The limits of detection (S/N = 3) were 0.03–0.04 ng mL−1 and 2.5–3.0 ng g−1 for lemon juice and honey, respectively. The method recoveries were 82–118% with the relative standard deviations of 1.9–7.6%. The results demonstrate that the Rut-MOP based method can be served as a good alternative for the sensitive analysis of neonicotinoid insecticides in lemon juice and honey.

Ag nanoparticles-polypyrrole-carbon black/mesoporous TiO2 novel nanocomposite as ultrafast visible-light-driven photocatalyst

Effective design and fabrication of novel visible light-oriented photocatalysts is an existing challenging task that requires further dedicated efforts, and it has been always a main concern among the scientific community. This study deals with the design and fabrication of an extremely active and ultrafast ternary photocatalyst based on Ag nanoparticles, polypyrrole doped carbon black (PPy-C) and mesoporous TiO2 (m-TiO2). Sol-gel methodology along with sonication and photodeposition routes have been employed for the successful creation of the ternary framework. Ternary photocatalyst composed of uniform spherical titania nanoparticles (10–15 nm in size) perfectly intermingled with the polymeric linkage of PPy-C. Fruitful creation of unique trio photocatalyst between AgNPs, PPy-C and m-TiO2 was confirmed by XPS and XRD. FTIR analysis further supports the development of nanocomposite photocatalyst. TEM analysis showed uniform spherical m-TiO2 nanoparticles (10–15 nm in size) covered by PPy-C with compact nodes like appearance interlocked very well among each other. The newly developed Ag@PPy-C/m-TiO2 ternary photocatalyst exhibited band gap energy in desired visible range of spectra. The photocatalytic efficiency for all created photocatalysts has been evaluated taking Imidacloprid (insecticide derivative) and methylene blue (MB) dye as target pollutants. The novel Ag@PPy-C/m-TiO2 photocatalyst produced astonishing results with ultrafast removal of both Imidacloprid as well MB dye under visible light irradiation. The newly created ultrafast Ag@PPy-C/m-TiO2 photocatalyst has removed 96.0% of the insecticide Imidacloprid in only 25 min with almost ⁓ 2.65 times more efficient than bare m-TiO2 towards the removal of insecticide derivative. The present report offers a highly encouraging and vastly talented Ag@PPy-C/m-TiO2 ternary photocatalyst, enabling the ideal management of extremely lethal and notorious chemicals.

Toxicity of the Pesticides Imidacloprid, Difenoconazole and Glyphosate Alone and in Binary and Ternary Mixtures to Winter Honey Bees: Effects on Survival and Antioxidative Defenses.

To explain losses of bees that could occur after the winter season, we studied the effects of the insecticide imidacloprid, the herbicide glyphosate and the fungicide difenoconazole, alone and in binary and ternary mixtures, on winter honey bees orally exposed to food containing these pesticides at concentrations of 0, 0.01, 0.1, 1 and 10 µg/L. Attention was focused on bee survival, food consumption and oxidative stress. The effects on oxidative stress were assessed by determining the activity of enzymes involved in antioxidant defenses (superoxide dismutase, catalase, glutathione-S-transferase, glutathione reductase, glutathione peroxidase and glucose-6-phosphate dehydrogenase) in the head, abdomen and midgut; oxidative damage reflected by both lipid peroxidation and protein carbonylation was also evaluated. In general, no significant effect on food consumption was observed. Pesticide mixtures were more toxic than individual substances, and the highest mortalities were induced at intermediate doses of 0.1 and 1 µg/L. The toxicity was not always linked to the exposure level and the number of substances in the mixtures. Mixtures did not systematically induce synergistic effects, as antagonism, subadditivity and additivity were also observed. The tested pesticides, alone and in mixtures, triggered important, systemic oxidative stress that could largely explain pesticide toxicity to honey bees.

Pt nanoparticles decorated chitosan/ZnTiO3: Ternary visible-light photocatalyst for ultrafast treatment of insecticide imidacloprid and methylene blue

BackgroundDesign and fabrication of proficient visible light photocatalysts require dedicative effort and is an existing provoking research task. The present chaotic environmental scenario urgently demands to contemplate and work exhaustively on this critical issue. Therefore, the current research focused to design ultrafast visible light ternary photocatalysts of ZnTiO3 nanostructures coupling with chitosan (CTSN) and Pt nanoparticles (PtNPs). MethodsPt and CTSN associated ZnTiO3 ternary photocatalyst was successfully fabricated by modified sol-gel method followed by ultra-sonication and photo-reduction methodologies. Significant findingsThe research findings confirmed the formation of rhombohedral phase of ZnTiO3 involved in successful creation of ternary nanocomposite with PtNPs (4-15 nm) dispersed on ZnTiO3 (size ∼80-250 nm) and micron-sized sheets of CTSN. The newly fabricated Pt@CTSN/ZnTiO3 ternary photocatalyst was found to be highly ultrafast under visible light illumination, yielding 94.48 % degradation of target insecticide imidacloprid just in 25 min, representing ∼2.20 times greater proficiency than bare ZnTiO3 photocatalyst. Furthermore, the Pt@CTSN/ZnTiO3 was found to be highly destructive towards colored MB dye upon visible light exposure. The highly efficient and accelerated photocatalytic activity is attributed to the mesoporous structure, increased surface area, lowered bandgap with enhanced light absorption and a suppression in the recombination rate of the photogenerated charge carriers.

Efficacy of chemical and bio-pesticides on cowpea aphid, Aphis craccivora, and their residues on the productivity of fennel plants (Foeniculum vulgare)

The residual of pesticides after applications and their effects on plant parameters are very important to be estimated. Therefore, this study investigated the efficacy of six insecticides (acetamiprid, thiamethoxam, imidacloprid, azadirachtin, thiocyclam, and sulfoxaflor) against Aphis craccivora adults and their residue in fennel plants (Foeniculum vulgare) in two successive seasons. The physiological and phytochemical responses of fennel plants after exposure to these insecticides were studied. The tested insecticides were able to keep the reduction percentage of A. craccivora adults above 90% except of azadirachtin, which reached 52% only. Thiocyclam and sulfoxaflor were more effective in decreasing the number of A. craccivora adults than other treatments until 7th day after application. Significant effects were observed among different treatments compared to control for all the vegetative parameters of fennel plants. In the first season, the highest plant height (151.83 cm) and number of umbel/plant (77.63) were obtained in plants treated with thiocyclam with the values from fruit yield (2504 kg/fed) followed by azadirachtin (2281 kg/fed). The same trend for these parameters was obtained in the 2nd season. Azadirachtin demonstrated the best value of oil yield (2.99 and 3.77 ml/plant) for 2017 and 2018 seasons, respectively). The main chemical compound of fennel seed essential oils was estragole (methyl chavicol) and ranged from 68.10 (with Azadirachtin) to 79.90% (with control), the undesirable component, with increasing the amount of anethole (10.06%). It can be concluded that, thiocyclam, sulfoxaflor with neonicotinoid group could be included as a useful agent in a comprehensive aphid management programs in Egypt.

A SURVEY BASED ON THE USE OF IMIDACLOPRID ON GREEN LEAFY VEGETABLES IN REMOTELY LOCATED SAGAR, INDIA

The low literacy level of the vegetable growers in the selected region of India is responsible for the use of highly toxic organophosphate pesticides on green leafy vegetables. Although in the Indian market imidacloprid (less toxic) is available but due to its high price and less effectiveness compared to that of organophosphates is not preferred to control pests on green leafy vegetables. The present research is a survey-based study designed to know the insecticide management practice among insecticide dealers, vegetable growers and comparison of obtained information with chromatographic results. The combination of survey and instrumental method (micellar liquid chromatographic technique) was utilized to determine whether the information collected from vegetable growers and insecticide dealers were similar and signicantly correlated with analytical data or not. Among the selected 48 samples of green leafy vegetables, imidacloprid was detected only in 6 samples. The survey of the insecticide dealers and vegetable growers conrmed that the vegetable growers used toxic organophosphates pesticides instead of less toxic imidacloprid. Survey data collected from vegetable growers and pesticide dealers were also tested by chromatographic method and a signicant correlation was found between them, which clearly demonstrates the minimum use of safe insecticide (imidacloprid). Imidacloprid insecticide was detected on green leafy vegetables after a preliminary survey of vegetable growers and pesticide dealers. Survey results revealed the use of potentially harmful pesticides other than imidacloprid which are banned from using in vegetables. Analytical results showed signicantly less use of imidacloprid on green leafy vegetables.

Temporal variation of imidacloprid concentration and risk in waterways discharging to the Great Barrier Reef and potential causes

The widely used neonicotinoid insecticide imidacloprid has emerged as a significant risk to surface waters and the diverse aquatic and terrestrial fauna these ecosystems support. While herbicides have been the focus of research on pesticides in Australia's Great Barrier Reef catchment area, imidacloprid has been monitored in catchments across the region since 2009. This study assessed the spatial and temporal dynamics of imidacloprid in 14 waterways in Queensland, Australia over seven years in relation to land use and concentration trends. Imidacloprid could be quantified (i.e., concentrations were greater than the limit of reporting) in approximately 54% of all samples, but within individual waterways imidacloprid was quantified in 0 to 99.7% of samples. The percent of each catchment used to grow bananas, sugar cane and urban explained approximately 45% of the variation in imidacloprid concentrations and waterway discharge accounted for another 18%. In six waterways there were significant increases in imidacloprid concentrations and the frequency and magnitude of exceedances of aquatic ecosystem protection guidelines over time. Overall, the risk posed by imidacloprid was low with 74% of samples protecting at least 99% of species but it was estimated that upto 42% of aquatic species would experience harmful chronic effects. Potential explanations of the changes in imidacloprid were examined. Not surprisingly, the only plausible explanation of the increases was increased use of imidacloprid. While field-based measurement of the effects of imidacloprid are limited in the Great Barrier Reef Catchment Area (GBRCA) the risk assessment indicates that biological harm to aquatic organisms is highly likely. Action to reduce imidacloprid concentrations in the GBRCA waterways is urgently required to reverse the current trends and mitigate environmental impacts.

Insecticide seed treatment against corn leafhopper: helping protect grain yield in critical plant growth stages.

The corn leafhopper, Dalbulus maidis (Hemiptera: Cicadellidae), spreads maize stunt pathogens and requires timely and effective crop protection. We determined the interaction between maize phenology and the vector feeding/infection period by stunt pathogens with the residual efficacy of neonicotinoid insecticidal seed treatments. Greenhouse- and field-grown maize plants, seed-treated with clothianidin or imidacloprid insecticides, were infested during seven growth stages with corn leafhoppers reared under controlled conditions on maize plants displaying infection symptoms by both spiroplasma (corn stunt spiroplasma, Spiroplasma kunkelii) and phytoplasma (maize bushy phytoplasma) pathogens. In the greenhouse and field settings, seed treatment reduced the stunt disease symptoms and corn yield loss during the VE-V4 maize growth stages and caused no phytotoxicity. The neonicotinoid seed treatment reduced 20-60% of the yield losses from the corn stunt disease until the V4 growth stage. Infestation by infective corn leafhoppers in the V12 maize growth stage caused a 25-30% yield loss irrespective of seed treatment, yet no stunt disease symptom was evident. Nonetheless, corn yield losses and visual stunt symptoms as rated by a nine-category ordinal scale were strongly correlated (r=0.79, P < 0.01). These results reinforce that maize plants are more susceptible to leafhopper stunt disease during the VE-V4 growth stages (emergence to the fourth-leaf stage). Seed treatment helps reduce the damage in the early growth stages (VE-V2), although supplemental control measures depending on leafhopper population density may be needed from VE-V12 to protect yield losses from the maize stunt condition. © 2021 Society of Chemical Industry.

Prewetting Induced Hydrophilicity to Augment Photocatalytic Activity of Nanocalcite @ Polyester Fabric.

To eliminate imidacloprid insecticide from wastewater, nanocalcite was grafted onto the surface of pretreated polyester fabric. The process of seeding was followed by the low temperature hydrothermal method for the growth of nanocalcite for the functionalization of fabric. The goal of this study was to improve the hydrophilicity of the nanocalcite photocatalyst that had been grafted onto the surface of polyester fabric (PF) using acidic and basic prewetting techniques. The morphological characteristics, crystalline nature, surface charge density, functional groups of surface-modified nanocalcite @ PF were determined via SEM, XRD, FTIR, and Zeta potential (ZP), respectively. Characterization results critically disclosed surface roughness due to excessive induction of hydroxyl groups, rhombohedral crystal structure, and high charge density (0.721 mS/cm). Moreover, contact angle of nanocalcite @ PF was calculated to be 137.54° while after acidic and basic prewetting, it was reduced to 87.17° and 48.19°. Similarly, bandgap of the as fabricated nanocalcite was found to be 3.5 eV, while basic prewetted PF showed a reduction in band gap (2.9 eV). The solar photocatalytic mineralization of imidacloprid as a probe pollutant was used to assess the improvement in photocatalytic activity of nanocalcite @ PF after prewetting. Response surface methodology was used to statistically optimize the solar exposure time, concentration of the oxidant, and initial pH of the reaction mixture. Maximum solar photocatalytic degradation of the imidacloprid was achieved by basic prewetted nanocalcite @ PF (up to 91.49%), which was superior to acidic prewetted fabric and as-fabricated nanocalcite @ PF. Furthermore, HPLC and FTIR findings further indicated that imidacloprid was decomposed vastly to harmless species by basic prewetted nanocalcite @ PF.

Protective effects of antioxidant vitamins (C plus E) against oxidative damage induced by the insecticide imidacloprid in male rats

IntroductionImidacloprid (IMC) is a synthetic neonicotinoid insecticide that is used in agriculture against harmful insects.AimThis study aimed to investigate the adverse effects of the IMC formulation on biochemical, hematological parameters, oxidative stress markers, pro-inflammatory cytokines, alpha-fetoprotein (AFP), and testosterone levels in male rats, and to determine the potential protective activity of vitamin C and E against IMC insecticides in rats.Material and methodsThe rats were divided into four groups. The first group was used as a control. The second, third, and fourth groups received vitamin C (200 mg/kg) plus vitamin E (200 mg/kg), IMC (45 mg/kg), and IMC plus vitamin C and E, respectively, for 28 days. At the end of treatment, blood and tissue samples were collected. Biochemical, hematological parameters, oxidative stress markers, pro-inflammatory cytokines, AFP, and testosterone were evaluated.ResultsThe results elucidated that the IMC significantly caused elevation in the serum liver and kidney functions, lipid profile, AFP, and pro-inflammatory marker levels, as well as liver and kidney oxidative stress markers. While the serum testosterone level and complete blood count were disturbed, besides that, the liver and kidney antioxidant enzymes activities were decreased.ConclusionsThe protective effect of vitamins C plus E against IMC toxicity in the rat have a beneficial role in combating the adverse effects of IMC.

Exposure to Temperature and Insecticides Modulates the Expression of Small Noncoding RNA-Associated Transcripts in the Colorado Potato Beetle, Leptinotarsa decemlineata (Coleoptera: Chrysomelidae).

The Colorado potato beetle (Leptinotarsa decemlineata (Say)) is an insect that can adapt to various challenges, including temperature fluctuations or select insecticide treatments. This pest is also an ongoing threat to the potato industry. Small noncoding RNAs such as miRNAs, which can control posttranscriptionally the expression of various genes, and piRNAs, which can notably impact mRNA turnover, are modulated in insects under different conditions. Unfortunately, information regarding the expression status of key players involved in their synthesis and function is for the most part lacking. The current study thus aims at assessing the levels of such targets in L. decemlineata exposed to hot and cold temperatures as well as treated to the insecticides chlorantraniliprole, clothianidin, imidacloprid, and spinosad. Transcript expression levels of Ago1, Ago2, Ago3, Dcr2a, Dcr2b, Expo-5, Siwi-1, and Siwi-2, components of pathways associated with small noncoding RNA production or function, were measured by qRT-PCR and revealed modulation of select transcripts in response to temperature challenges and to select insecticides. RNAi-mediated reduction of Ago2 transcript levels in L. decemlineata injected with Ago2-targeting dsRNA and exposed to cold and warm temperatures was also conducted. Changes in survival rates were observed for the latter condition in dsRNA- versus saline-injected insects. These results showcase the differential expression of select targets involved in small noncoding RNA homeostasis and provide leads for the subsequent assessment of their involvement during stress response in L. decemlineata using RNAi-based approaches.

Two novel bioassays useful for the quick assessment of chemical effects on the behavior of mosquito larvae (Culicidae) and adult earthworms (Lumbricidae)

The behavior, i.e., observable response of an organism can serve as a useful indicator of environmental quality. In the absence of death and other sublethal effects, behavioral changes can represent early warning signs of toxic effects. In the present contribution, we present two novel bioassays useful for the quick assessment of chemical effects on the behavior of mosquito larvae (Culicidae) and adult earthworms (Lumbricidae). These bioassays could have applications in ecological risk assessment and laboratory based ecotoxicological testing. The novel assays are:•A bioassay for the assessment of chemical toxicity on the swimming, breathing and resting behavior of Culicidae larvae.•A bioassay for the assessment of chemical toxicity on the escape behavior of Lumbricidae in water.•These bioassays were carried out using the systemic insecticide imidacloprid and documented the relatively rapid onset of the neurotoxic effects of imidacloprid to experimental organisms.

Detection and detoxification of imidacloprid in food samples through ionic liquid-stabilized CuNi alloy nanoparticle-decorated multiwall carbon nanotubes

Ionic liquid-stabilized CuNi alloy nanoparticle-decorated multiwall carbon nanotubes have been developed, which demonstrate the electrochemical detection as well as catalytical degradation of imidacloprid insecticide in food samples.

Occurrence and insecticide susceptibility of the grain aphid Sitobion avenae in northern Mongolia

A survey was carried out to determine the prevalence of Sitobion avenae (S. avenae) in the central agriculture zone of northern Mongolia (including Darkhan-Uul, Selenge, Tuv, and Erdenet aimags). Bioassays were used to assess the pest's susceptibility to three regularly used insecticides (deltamethrin, fenvalerate, and imidacloprid). DNA sequencing was used to look into the genotypes of codons 918 and 1014 of the Voltage-gated sodium channel (VGSC) gene in S. avenae. The findings revealed that in 2019, the population density of S. avenae was low in 159 fields and medium in 31, and the infestation rate was low in 73 fields, medium in 117 fields. Even at a concentration of 0.005%, high mortality rates (&gt;84 per cent) of S. avenae nymphs were detected after 72 hours of exposure to the three insecticides, indicating that this pest was susceptible to all three insecticides tested. In our grain aphid samples, the pyrethroid resistance-causing mutations (M918L and L1014F) in the voltage-gated sodium channel were not detected.