Application Of Imidacloprid Research Articles

Injeção de imidacloprido no controle do pulgão-preto-do-coqueiro

Trunk injection with Imidacloprid to control the palm aphid
 The injuries caused by the palm aphid, Cerataphis lataniae, on coconut plants may provoke economic losses. Thus, insecticide injection into the tree can provide protection and control against this pest. Our goal was to evaluate the efficiency of injection of imidacloprid on coconut trees to control the palm aphid. The experiment was carried out at the Lemos Maia experimental station, Ceplac, Una, Bahia, Brazil. The treatments applied were: 1) injection of 10 mL of the commercial product Provado® 200 SC (2 g i.a imidacloprid) in the stipe; 2) injection of 20 ml of Provado® 200 SC diluted in water (1 g i.a imidacloprid) and; 3) control (without insecticide application). The experiment was installed in a completely randomized design, with 15 replications, using leaf number 4 as samples. The parameters analyzed were number of aphids at 3 and 9 months after insecticide application and the number of leaflets/leaves with aphids at 26 months after application. The means were compared by the F and Tukey test at 5% probability level. All data were transformed into a log (x + 1). The aphid number and the number of leaflets per leaf infested with the aphid was higher in the control treatment. Thus, the application of imidacloprid via injection provided protection to coconut plants to the palm aphid, C. lataniae, until 26 months.

Relationship between imidacloprid residues and control effect on cotton aphids in arid region.

In this case, the dissipation and residues of imidacloprid as well as its control efficacy against aphids (Aphis gossypii Glover) in cotton cropping system were reported. After the final spray at the rates of 10.5-42.5g a.i. ha-1, the initial deposits were 0.59-2.25mgkg-1 with half-lives of 2.12-2.84days on leaves and 0.06-0.21mgkg-1 with half-lives of 1.51-4.20days in soil, respectively. The initial residues were significantly higher with longer persistence in the upper position of the leaf than in middle and lower positions. The different application dosages could induce a significant difference in the initial deposits, but not show consistent correlation with the dissipation rate. The repeated applications of imidacloprid could alter its residue levels and dissipation rates. The long-term residue concentrations of imidacloprid (60days after the final application) reached to the nondetectable level in soil. Combined with the control efficacy results, it was considered that the recommended dose of imidacloprid on cotton could be used effectively and safe in this arid area from the view of crop protection and environmental contamination.

Prenatal exposure to pesticide mixtures and adolescent externalizing behavior in the CHAMACOS study

Background: Previous studies have shown that prenatal pesticide exposure is associated with adverse child neurodevelopment, however it is unclear whether associations persist into adolescence and young adulthood. Moreover, previous research has focused primarily on exposure to single pesticides or pesticide classes at a time and has not accounted for co-exposure confounding by other pesticides. Methods: We implemented a two-stage Bayesian Hierarchical Model (BHM) to examine associations of prenatal exposure to mixtures of pesticides and maternal- and self-reported externalizing behaviors from the Behavior Assessment System for Children, 2nd edition (BASC-2) at age 16 years in the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS) birth cohort (n=567). We characterized agricultural applications of 11 pesticides from 5 different classes within 3 km of maternal residences during pregnancy using California’s Pesticide Use Reporting (PUR) data. Results: Associations for most pesticides were near null among all participants and in sex-stratified models, with some suggestive associations with self-reported behavior. Prenatal residential proximity to agricultural applications of imidacloprid, a neonicotinoid insecticide, was associated with more self-reported hyperactivity (β per 2-fold increase = 2.2; 95% Credible Interval (CrI): 0.2, 4.1), sensation seeking (β=2.2; 95% CI: 0.2, 4.2), and attention problems (β=2.15; 95% CI: 0.12, 4.13). We observed that associations of residential proximity to imidacloprid applications and self-reported hyperactivity were stronger in boys (β=3.7; 95% CI: 1.0, 6.4) than girls (β=1.2; 95% CI: -1.1, 3.4).Conclusion: We observed predominantly null associations of prenatal residential proximity to agricultural pesticide use and behavior among CHAMACOS participants at age 16, with some notable associations of proximity to imidacloprid applications and self-reported externalizing behaviors. Imidacloprid is now the most widely used insecticide in the world and additional studies are needed to evaluate its potential developmental neurotoxicity, particularly in the context of correlated exposure to multiple pesticides.

Neonicotinoid Residues in Sugar Beet Plants and Soil under Different Agro-Climatic Conditions

European sugar beet was mostly grown from seeds treated by neonicotinoids which provided efficient control of some important sugar beet pests (aphids and flea beetles). The EU commission regulation from 2018 to ultimately restrict the outdoor application of imidacloprid, thiamethoxam, and clothianidin could significantly affect European sugar beet production. Although alternative insecticides (spinosad, chlorantraniliprole, neem) are shown to have certain effects on particular pests when applied as seed treatment, it is not likely that in near future any insecticide will be identified as a good candidate for neonicotinoids’ substitution. The aim of this research is to evaluate residue levels (LC-MS/MS method) of imidacloprid and thiamethoxam applied as seed dressing in sugar beet plants during two growing seasons in fields located in different agro-climatic regions and in greenhouse trials. In 2015, 25 to 27 days post planting (PP) maximum of 0.028% of imidacloprid and 0.077% of thiamethoxam were recovered from the emerged plants, respectively. In 2016, the recovery rate from the emerged plants 40 days PP was 0.003% for imidacloprid and 50 days PP was up to 0.022% for thiamethoxam. There were no neonicotinoid residues above the maximum residue level in roots at the time of harvesting, except in case of samples from thiamethoxam variant collected from greenhouse trials in 2016 (0.053 mg/kg). The results of this research lead to the conclusion that the seed treatment of sugar beet leaves minimal trace in plants because of the complete degradation while different behavior has been observed in the two fields and a glasshouse trial regarding the residues in soil. Dry conditions, leaching incapacity, or irregular flushing can result in higher concentrations in soil which can present potential risk for the succeeding crops. The results of our study could provide additional arguments about possible risk assessment for seed treatment in sugar beet.

Measurement of biorational effect of imidacloprid on some aphids spp. as well as on wheat (Triticum aestivum L.) using biochemical parameters and ISSR-PCR.

Aphid species are the most common insect pest infesting wheat plants. The LC values of imidacloprid against aphid spp., ISSR-PCR molecular markers and biochemical parameters in wheat plant in the present study were carried out. The LC50 of imidacloprid on Rhopalosiphum maidis, Rhopalosiphum padi, Sitobion avenae, and Schzaphis graminum were 71.626, 85.853, 91.05, and 115.806, respectively. While, the biochemical parameters in treated wheat plants including; total protein, RNA, and DNA contents increased in all experimental groups. Moreover, total carbohydrates and soluble sugar also increased in treated wheat seedlings. Also, the genetic diversity studies revealed that among six ISSR primers produced 36 amplified DNA fragments in a molecular weight range of (480-1545bp). About 28 fragments were monomorphic, and 8 fragments were polymorphic. It can be concluded that the effectiveness of imidacloprid against sucking insects in treated wheat plants may due to few genetic variations and some metabolic changes in the Triticum. aestivum. PRACTICAL APPLICATIONS: The current study indicated that the potent efficacy of imidacloprid against different aphid spp. which were the most insect pest in wheat plants. As well as the application of imidacloprid as seed dressing insecticide, significantly increase carbohydrate, protein, amino acids, and RNA content in T. aestivum plants. While there was no significant increase in DNA in treated one. The recorded increase in these biochemical parameters may due to the increase in the gene expressions as a result of the application of such pesticides. These results explain the extra mechanism of the effect of imidacloprid against sucking insects. Also, the conducted results explain the effect of imidacloprid as a seed dressing insecticide in wheat crop protection from sucking insects and increasing seed germination, increasing seed wheat and number of seeds/spike.

Efficacy of different insecticides against brown planthopper, Nilaparvata lugens (Stål) in rice

The on farm trials were conducted to determine the efficacy of conventional and novel insecticides against brown planthopper (BPH), Nilaparvata lugens (Stål), in rice during kharif 2017 and 2018. All the treatments were effective for BPH management than control. The results of the first year study revealed that the application of Imidacloprid 17.8 SL @ 100 ml ha-1 was found superior by registering lower population of BPH (4.70/ hill) followed by Flonicamid 50 WG @ 150 g ha-1 with 5.67 BPH/hill after 7 days after spray. However, during the second year trial conducted on different insecticides revealed that BPH population was recorded lowest i.e., 3.60 per hill with the application of Buprofezin 25 SC @ 1000 ml ha-1 after 10 days after spray. The effect of this insecticide application was also resulted in the highest grain yield (74.51 q/ha) and maximum benefit cost ratio (6.09).

Pollinator exposure to systemic insecticides and fungicides applied in the previous fall and pre-bloom period in apple orchards

Pollinators provide a crucial ecosystem service by pollinating commercially cultivated crops, but they are frequently exposed to various agricultural chemicals used for pest management. In this study, we assessed the potential exposure of pollinators to various systemic insecticides and a fungicide used in apple orchards. Residue levels were determined for the whole flower as well as pollen and nectar separately for pre-bloom applications of acetamiprid, imidacloprid, sulfoxaflor, thiacloprid, thiamethoxam, and myclobutanil. Very low pesticide residue levels (2–70 parts per billion, ppb) were found in the whole flower, pollen and nectar samples compared with pesticide concentrations of 60–200 parts per million (ppm) in applied foliarly only 5 days earlier. Insecticide residues from nectar and pollen samples were below the USA EPA classification of No Observable Effect Limit (NOEL) for acute toxicity to honey bees, suggesting that a single foraging visit to flowers may not cause toxicity to bees. However, cumulative acute exposure from multiple flower visits could potentially be harmful to bees, and needs to be studied further. We also examined apple flowers for residues of several systemic insecticides that were applied for brown marmorated stink bug control late in the fall of the previous season. None of the fall sprays that contained premixed insecticide active ingredients (viz., thiamethoxam + lambda-cyhalothrin, and imidacloprid + beta-cyfluthrin), including multiple applications of individual active ingredients (viz., dinotefuran, clothianidin, and sulfoxaflor), persisted until the following spring. Based on these findings, fall applications of insecticides used for controlling invasive pests such as the brown marmorated stink bug (Halyomorpha halys) and the spotted lanternfly (Lycorma delicatula) could be considered safe to pollinator species foraging in apple orchards during the spring bloom the following season.

Insecticide resistance management against thrips (Thysanoptera: Thripidae) on onion in the central Rift Valley of Ethiopia

Two field experiments were conducted in the Central Rift Valley of Ethiopia in the hot and cool dry seasons of 2016/2017 with the objective to develop an insecticide resistance management program on thrips infesting onion. The first experiment dealt with the evaluation of four different insecticides namely profenofos, λ–cyhalothrin, imidacloprid, and spinetoram in different sequences on thrips population and their effect on yield. The second experiment examined the effect of admixing the surfactant organosilicone with imidacloprid, spinetoram and dimethoate. A Randomized Complete Block Design with three replications was used for both experiments. Data on number of thrips, bulb yield and economic returns were collected. The insecticide imidacloprid and spinetoram resulted in fewer numbers of thrips and higher yields than profenofos and λ –cyhalothrin. Application of the more effective insecticides when the thrips population was high followed by less effective insecticides resulted in better control and higher economic return. Surfactant added insecticides gave a fewer numbers of thrips and higher yields than the corresponding insecticides applied without surfactant. The sequential application of spinetoram and imidacloprid with less effective λ-cyhalothrin and profenofos by mixing with adjuvant are recommended for thrips control as an integral component of thrips management in the Central Rift Valley of Ethiopia.

Excretion of non-metabolized insecticides in honeydew of striped pine scale

Honeydew production is a characteristic of soft scales and other hemipteran insects. Honeydew has the capacity to alter the ecology of predators and parasitoids because it is used as a food resource and can contain insecticidal proteins from hemipteran host plants. We examined honeydew excreted by the striped pine scale (Hemiptera: Coccidae), Toumeyella pini (King), after feeding on pine trees treated with systemic insecticides to determine whether they could eliminate insecticidal compounds in honeydew. Imidacloprid and spirotetramat were applied at labeled rates to soil or foliage. Water sensitive paper was used to measure honeydew production and liquid chromatography coupled to mass spectrometry (LC-MS) to analyze excreted insecticide concentrations. Foliar and soil applications of imidacloprid caused a 25-fold reduction honeydew produced by scales six days after treatment (DAT). In contrast, spirotetramat treatments did not affect honeydew production. Parent compounds of both insecticides were detected in honeydew. However, on imidacloprid treated plants, these compounds were detected at similar concentrations in honeydew collected at 4 DAT from soil and foliar treatments. Imidacloprid was only detected from soil treatments at 8 DAT. Similarly, the spirotetramat parent compound was found 4 DAT after soil and foliar treatments, but only at 8 DAT in foliar treatments. At this time the concentration of spirotetramat in honeydew was six-fold higher than at 4 DAT. We conclude that striped pine scales excrete insecticides in honeydew even when the toxicant greatly reduces honeydew production. Honeydew excretion is thus a mechanism of bioaccumulation and has the potential to harm honeydew-feeding organisms.

Oligotrophic bacterium Hymenobacter latericoloratus CGMCC 16346 degrades the neonicotinoid imidacloprid in surface water

The intensive and extensive application of imidacloprid in agriculture has resulted in water pollution and risks to aquatic invertebrates. However, pure bacteria remediation of imidacloprid in surface water environments has not been studied. Here, we isolated an imidacloprid-degrading bacterium from a water environment, examined its imidacloprid degradation in pure culture and surface water, sequenced its genome, and compared its Clusters of Orthologous Groups (COG) protein categorization with that for another imidacloprid-degrading bacterium. The isolate was an obligate oligotrophic bacterium, Hymenobacter latericoloratus CGMCC 16346, which degraded imidacloprid via hydroxylation by co-metabolism in pure culture. Resting cells degraded 64.4% of 100 mg/L imidacloprid in 6 days in the presence of co-substrate maltose, and growing culture degraded 40.8% of imidacloprid in 10 days. H. latericoloratus CGMCC 16346 degraded imidacloprid in surface water without co-substrate supplementation and retained imidacloprid-degrading activity after 30 days. The half-life of imidacloprid in surface water was decreased from 173.3 days in the control to 57.8 days by CGMCC 16346 inoculation. Genome sequencing and COG analysis indicated that carbohydrate metabolism and transport, cell wall/membrane biogenesis, and defense mechanisms are enriched in H. latericoloratus CGMCC 16346 compared with the copiotrophic imidacloprid-degrading Pseudoxanthomonas indica CGMCC 6648, indicating that H. latericoloratus CGMCC 16346 is adapted to live in oligotrophic water environments and biofilms. H. latericoloratus CGMCC 16346 is a promising bioremediation agent for elimination of imidacloprid contamination from surface water.

Imidacloprid Poisoning of Songbirds Following a Drench Application of Trees in a Residential Neighborhood in California, USA.

In March 2017, 26 American goldfinches (Spinus tristis) were found dead following a drench application of imidacloprid in California (USA). Identical seed fragments were present in the digestive tracts. Imidacloprid was detected in 4 separate pooled samples from 18 birds, in crop/gizzard contents (4.8 ± 1.3 ppm; range 2.2–8.5 ppm) and liver tissues (3.9 ± 0.6 ppm; range 2.1–4.8 ppm). We suspect that fallen elm (Ulmus sp.) seeds were contaminated with imidacloprid during the drench application and subsequently ingested, resulting in acute toxicity and death. Environ Toxicol Chem 2019;38:1724–1727. © 2019 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC.

Residual behaviour of imidacloprid in the country bean growing soil

The assessment of residual behavior of imidacloprid (Admire 20SL) in the soil of country bean agroecosystem and its risk assessment for consumption was studied. QuEChERS method was used for the extraction and clean-up of samples and the residues of imidacloprid was estimated using Gas Chromatography. The dissipation studies in the soil system were carried out by application of imidacloprid at five different dosages i.e. 100, 200, 300, 400, and 500 g a.i. ha-1. Average initial deposits of imidacloprid were found to be 0.99, 1.33, 1.62, 1.83 and 2.20 mg.kg-1. The residues reached below determination limit (BDL) of 0.01 mg kg-1 in 9 days for recommended dose and 12 days for remaining higher dosages. Half-life (T1/2)) of imidacloprid in the soil was observed to be 1.88, 1.74, 1.73, 1.56 and 1.52 days for 100, 200, 300, 400, and 500 g a.i. ha-1, respectively. The chemodynamics study of imidacloprid spray indicated that only 27.20 -28.40% sprays were deposited to the target site (plant canopy) and 71.60-72.80% were lost to non-target site such as soil and air. The drift of imidacloprid to soil (39.47-40.20%) was higher than the air (32.13-32.60%). Based on degradation pattern and maximum, the recommended preharvest interval (PHI) might be eight 9 days and a waiting period of two days might be suggested for reapplication of the imidacloprid in country bean agroecosystem.
 Bangladesh J. Agril. Res. 44(1): 89-101, March 2019

Imidacloprid is compatible with control provided by the predator Jalysus wickhami Van Duzee (Hemiptera: Berytidae) in flue-cured tobacco (Nicotiana tabacum L.)

Jalysus wickhami Van Duzee is the most abundant predator in North Carolina flue-cured tobacco production but information on the effect of contemporary pest management practices and interactions with other arthropods is lacking. We measured the effect of systemic imidacloprid on J. wickhami in field experiments during 2015 and 2016 by surveying its abundance, the abundance of its prey; the pests Heliothis virescens (Fabricus), Manduca sexta L., and Manduca quinquemaculata (Haworth, 1803); and other predatory arthropods in the agro-ecosystem. Systemic imidacloprid applications did not reduce J. wickhami abundance nor increase the abundance of H. virescens, M. sexta, and M. quinquemaculata, indicating natural control was not affected. J. wickhami abundance was positively correlated with the abundance of prey and predators from another feeding guild, suggesting species interactions have significant implications for the predators.

Management of White grub (Leucopholis burmesterie) infesting Arecanut through Entomopathogenic Nematodes under field conditions

The present investigation was carried out to find out the response of combined application of native strains of EPN and imidacloprid insecticide on suppression of root grub Leucopholis burmesterie and other symptomatic parameters in root grub affected arecanut palms and yield. The result indicated that significant reduction in grub population as well as increase yield and emergence of healthy roots in treated palms compare to farmer practice. The combined application of EPN, Steinernema carpocapsae @ 1.0 × 107 P−1 + imidacloprid @ 0.004% (1 ml/5 litre water/palm) has resulted in an average 53.1% reduction of grub population within two years of treatment then exclusive application of EPN and imidacloprid (P<0.05) in root grub infested arecanut gardens at Karnataka. Resulted, native strains S. carpocapsae combination with imidacloprid may be used as an effective curative measure for root grub infestation in arecanut. The infectivity of the tested EPNs against root grub is opens up a new hope of utilizing them in insect pest management in arecanut.

Management of Yellow Mosaic Disease of Mungbean Against Mungbean Yellow Mosaic Virus (MYMV) in Bangladesh

The prime aim of the study was to manage of Yellow mosaic disease of mungbean against Mungbean yellow mosaic virus (MYMV) by using one newly release botanical nutrient and through three selected insecticides. BARI (Bangladesh Agricultural Research Institute) released variety BARI mung-5, three insecticides (Imidacloprid, Acmix and Sobicron) and one botanical nutrient PPN (Peak performance nutrients) were used in the experiment. The plants were grown for pulse production and natural inoculums were relied upon for the infection of MYMV. Growth parameters, yield attributes and physiological features were significantly influenced by the application of selected insecticides and PPN combinations. Disease incidence and disease severity of MYMV were significantly varied among the treatments. Application of Imidacloprid with PPN combination gave the lowest disease incidence (3.13, 5.24 and 6.24% per plot and 14.33, 15.49 and 21.87% per plant) at 30, 40 and 50 DAS, respectively while the highest disease incidence (7.77, 13.70 and 19.24% per plot and 39.33, 48.20 and 56.63% per plant) were found in control at 30, 40 and 50 DAS, respectively. Application of Imidacloprid with PPN also gave the lowest disease severity (5.00, 6.00 and 13.33% at 30, 40 and 50 DAS, respectively while the highest disease severity (27.33, 35.00 and 45.00%) at 30, 40 and 50 DAS, respectively were measured in control treatment when no insecticides and PPN was used. If the disease is established once in the field then it is difficult to manage. As the disease is transmitted by vector (whitefly), the growers are suggested to control the vector populations before reaching economic damage and severe disease infection.

Dissemination of Imidacloprid Through Dairy Cattle Manure and Its Effect on the Biological Control Agent, Spalangia endius (Hymenoptera: Pteromalidae), and a Filth Fly Host, Musca domestica (Diptera: Muscidae).

Filth flies, including house flies, Musca domestica L., develop in animal manure. Adult house flies often are controlled with pesticides such as imidacloprid. How imidacloprid disseminates and persists after it contaminates manure was measured at a dairy farm. A week after application of imidacloprid via fly bait to cattle manure, a mean of approximately 4 ppm of imidacloprid, and as high as 15 ppm, was quantifiable up to 12 cm from the application site, but not farther. Laboratory experiments addressed the impact of 15 ppm of imidacloprid in manure on egg-to-adult development of house flies and on the biological control ability of a house fly pupal parasitoid, Spalangia endius Walker. In uncontaminated manure, 93% of eggs developed to adults, versus 7% in contaminated manure. In the parasitoid experiment, fly pupae were placed in contaminated or uncontaminated manure with or without S. endius. In the absence of S. endius, nearly 100% of flies emerged, with or without imidacloprid. In the presence of S. endius, only 11% of flies emerged from uncontaminated manure, versus 36% from contaminated manure; and parasitoids emerged from 82% of hosts in uncontaminated manure versus 53% in contaminated manure. These results suggest that realistic concentrations of imidacloprid in filth fly breeding habitat may interfere with house flies developing to the pupal stage, but also with parasitoids locating and utilizing house flies. However, after 1 wk, the effects on parasitoids will be low 12 cm beyond where bait was applied.

Imidacloprid Soil Drenches Affect Weight and Functional Response of Spined Soldier Bug (Hemiptera: Pentatomidae).

There are ongoing concerns of potential direct and indirect lethal and sublethal effects of insecticides on nontarget arthropod populations. The risk to natural enemies from systemic insecticides is mainly through exposure to the active ingredient by ingestion, and such risk may be elevated for omnivores that feed on treated plants, as well as herbivores that also feed on those same treated plants. Podisus maculiventris (Say), an important natural enemy in many agricultural systems, can be potentially exposed to the neonicotinoid imidacloprid when ingesting contaminated prey and feeding on plants subjected to soil-drench applications of this compound. In the current study, we examined the potential impact of imidacloprid soil drenches on some functional and morphological endpoints. Cabbage plants were treated with soil drenches of imidacloprid that corresponded to half and full recommended labels rates against whiteflies and aphids. Fourth instar diamondback moth, Plutella xylostella (Linnaeus) (Lepidoptera: Plutellidae), larvae on plants were used as prey in our experiments; P. xylostella is not a target of imidacloprid applications but may co-occur with other pests in systems where the insecticide is applied. We found that exposure to imidacloprid-treated plants did not cause significant mortality neither to P. maculiventris nor to P. xylostella, but both treatment concentrations impaired the predation, with consequences for predator weight gain during the assessment period. Our results corroborate those from other studies and demonstrate that effects from systemic insecticides can transcend trophic levels to affect natural enemies indirectly, such as through exposure from feeding on pests not targeted by the insecticide.

Lethal and Sublethal Effects of Selected Systemic and Contact Insecticides on Nephaspis oculata (Coleoptera: Coccinellidae), in a Tri-Trophic System.

Nephaspis oculata (Blatchley, 1917) is a whitefly predator which has been reported feeding on several whitefly species. In South Florida, it attacks rugose spiraling whitefly, an invasive pest of urban trees which was first reported in the United States in 2009. The management of rugose spiraling whitefly relies heavily on the use of insecticides which may negatively impact biological control agents. We studied the effect of bifenthrin (spray) and imidacloprid (drench) application on survival, fecundity, and behavior of N. oculata in the laboratory. Adult beetles survived significantly longer in control and systemic imidacloprid compared to bifenthrin treatment, but there was no significant difference between control and systemic imidacloprid applications. However, the fecundity of beetles in the imidacloprid treatment was significantly lower than the control. There was no significant difference between the survival of beetles in bifenthrin and control treatments 3 mo post application. Beetles avoided bifenthrin-treated leaves but did not avoid systemic imidacloprid-treated in a no-choice test. Also, beetles' feeding rate on bifenthrin-treated rugose spiraling whitefly nymphs was significantly lower in a no-choice test. In the choice test, there was a significant difference in feeding rates on whiteflies between choices of bifenthrin/control but no significant difference in the control/control or in imidacloprid/control treatments. The results from this study shows that while systemic imidacloprid has sublethal effects on N. oculata, it does not significantly affect mortality of adult beetles in the tri-trophic system tested. Therefore, using systemic imidacloprid and N. oculata for controlling rugose spiraling whitefly might be compatible or at least not significantly incompatible.

Jasmonic Acid Seed Treatment Stimulates Insecticide Detoxification in Brassica juncea L.

The present study focused on assessing the effects of jasmonic acid (JA) seed treatment on the physiology of Brassica juncea seedlings grown under imidacloprid (IMI) toxicity. It has been observed that IMI application declined the chlorophyll content and growth of seedlings. However, JA seed treatment resulted in the significant recovery of chlorophyll content and seedling growth. Contents of oxidative stress markers like superoxide anion, hydrogen peroxide, and malondialdehyde were enhanced with IMI application, but JA seed treatment significantly reduced their contents. Antioxidative defense system was activated with IMI application which was further triggered after JA seed treatment. Activities of antioxidative enzymes and contents of non-enzymatic antioxidants were enhanced with the application of IMI as well as JA seed treatment. JA seed treatment also regulated the gene expression of various enzymes under IMI stress. These enzymes included respiratory burst oxidase (RBO), Ribulose-1,5-bisphosphate carboxylase/oxygenase (RUBISCO), NADH-ubiquinone oxidoreductase (NADH), carboxylesterase (CXE), chlorophyllase (CHLASE), cytochrome P450 monooxygenase (P450). JA seed treatment up-regulated the expressions of RUBISCO, NADH, CXE, and P450 under IMI toxicity. However, expressions of RBO and CHLASE were down-regulated in seedlings germinated from JA seed treatment and grown in presence of IMI. Seed soaking with JA also resulted in a significant reduction of IMI residues in B. juncea seedlings. The present study concluded that seed soaking with JA could efficiently reduce the IMI toxicity by triggering the IMI detoxification system in intact plants.

Effects of imidacloprid and a neonicotinoid mixture on aquatic invertebrate communities under Mediterranean conditions

Neonicotinoid insecticides are considered contaminants of concern due to their high toxicity potential to non-target terrestrial and aquatic organisms. In this study we evaluated the sensitivity of aquatic invertebrates to a single application of imidacloprid and an equimolar mixture of five neonicotinoids (imidacloprid, acetamiprid, thiacloprid, thiamethoxam, clothianidin) using mesocosms under Mediterranean conditions. Cyclopoida, Cloeon dipterum and Chironomini showed the highest sensitivity to neonicotinoids, with calculated NOECs below 0.2 μg/L. The sensitivity of these taxa was found to be higher than that reported in previous studies performed under less warm conditions, proving the high influence of temperature on neonicotinoid toxicity. The short-term responses of the zooplankton and the macroinvertebrate communities to similar imidacloprid and neonicotinoid mixture concentrations were very similar, suggesting that the concentration addition model can be used as a plausible hyphotesis to assess neonicotinoid mixture effects in aquatic ecosystems. Long-term mixture toxicity assessments, however, should consider the fate of the evaluated substances in the environment of concern. As part of this study, we also demonstrated that Species Sensitivity Distributions constructed with chronic laboratory toxicity data and calculated (multi-substance) Potentially Affected Fractions provide an accurate estimation to asssess the ecotoxicologial risks of imidacloprid and neonicotinoid mixtures to aquatic invertebrate species assemblages.