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Diafenthiuron is the most common used pesticide in Pakistan that causes insect pest mortality by mitochondrial function inhibition. It has been reported in local news papers that this pesticide is entering in our fresh water bodies affecting aquatic life. The objective of this investigation was to report the LC50 value of diafenthiuron for grass carp, Ctenopharyngodon idella and to report the effect of various doses such as 0.0038 (T1), 0.05 (T2), 0.5 (T3), 1 (T4), 5 (T5) and 6.67 mg/L (T6) on complete blood count, serum biochemical profile and antioxidant parameters in kidney and liver of this fish following 96 h exposure. An untreated control group was maintained in parallel. Our results indicated that 96 h LC50 value of diafenthiuron for juvenile C. idella was 5.67 mg/L. Analysis of the hematological profile revealed that red blood cell (RBC) count, haematocrit, mean corpuscular hemoglobin concentration, hemoglobin, white blood cells, monocytes, granulocytes and lymphocytes significantly increased while RBC distribution width, mean corpuscular haemoglobin, mean corpuscular volume and platelet distribution width significantly decreased in diafenthiuron exposed treatments than control group. Significant increase in serum triglycerides level was observed in C. idella treatments exposed to diafenthiuron. Concentrations of catalase, superoxide dismutase and malondialdehyde also varied significantly in liver and kidney when compared between diafenthiuron treated and untreated C. idella. In conclusion, we are reporting that diafenthiuron can adversely affect the hematological, serum and antioxidant parameters of non-target organism like C. idella and its entry in water bodies must be prevented in order to conserve our fresh water ecosystems and food web. [ABSTRACT FROM AUTHOR]

The residue and dissipation studies of diafenthiuron, its metabolites and cyantraniliprole were carried out on okra under field conditions after two applications of Cyantraniliprole 7.3% w/w + Diafenthiuron 36.4% w/w SC @ 60 + 300 g a.i./ha. Okra fruit samples were collected at 0 (2 hr), 1, 3, 5, 7, 10 and 15 days after second spray. The samples were processed using QuEChERS methodology and analysed on LCMS/MS. The total initial residues of diafenthiuron (diafenthiuron + CGA 177960, CGA 227352, CGA 140408) in okra fruit were 0.28 and 0.55 mg kg−1 at single and double dose, respectively. The total residues of diafenthiuron dissipated below limit of quantification (LOQ) of 0.01 mg kg−1 at 10 days of application at both the doses. The initial residues of cyantraniliprole in okra were 0.23 and 0.42 mg kg−1 at single and double dose, respectively. The residues dissipated below

Diafenthiuron is a novel derivative of thiourea and is highly toxic to non-target organisms, necessitating its efficient removal from wastewater before discharge. This study compared diafenthiuron removal efficiencies at a target concentration of 1 µM using three methods: a 4 mg/L ozone (O3) treatment; an ultraviolet (UV) light treatment, applying UV254 radiation with a fluence of 60 mJ/cm2 for 10 min; and a combined O3/UV treatment utilizing ozone and ultraviolet light. An acute toxicity assessment was conducted using a modeled zebrafish embryo (Danio rerio). The diafenthiuron removal efficiencies were 49.59%, 54.51%, and 68.90% for the UV light, O3, and O3/UV treatments, respectively. The treatments showed additional benefits of exerting no negative impacts on the survival rate, heart rate, or body length of the zebrafish larvae posttreatment. The survival and heart rates at 120 hpf, as well as the body length at 96 and 120 hpf, showed significant differences between the advanced oxidation and 1 μM diafenthiuron treatment groups. However, these parameters remained consistent with those of the control group. The three treatments alleviated the spatiotemporal downregulation of the liver-specific marker fabp10a caused by diafenthiuron exposure. The UV light and O3/UV treatments were efficient at degrading diafenthiuron, causing decreased reactive oxygen species levels and increased pomc and prl expression levels. The O3-treated diafenthiuron and 1 μM diafenthiuron treatments increased the reactive oxygen species levels and decreased the pomc and prl expression levels. The combined O3/UV treatment showed the highest removal efficiency and the least toxicity, making it the most effective method for diafenthiuron degradation. This study provides valuable insights into the treatment of diafenthiuron-laden wastewater. [ABSTRACT FROM AUTHOR]

Diafenthiuron is a thiourea derivative propesticide widely used in agriculture and forestry, involved in inhibition of oxidative phosphorylation and interrupts the mitochondrial ATP synthesis of the pest. Because there is no research regarding the toxicological effects of this chemical on non-target species. Hence the present study aim to assess the acute toxicity of this insecticide on rabbits (Oryctolagus cuniculus). A total of 48 rabbits were categorized into four groups, with 12 rabbits in each group. The groups were named as TO (control), Tl (low dose), T2 (medium dose) and T3 (high dose). Rabbits in groups Tl, T2 andT3 received oral administration of diafenthiuron at doses of 500 mg/Kg, 1000 mg/Kg, and 1500 mg/Kg, respectively which is based on their body weight. This administration continued for a period of 45 days. The TO group served as the control group. Blood samples were collected at 15th, 30th and 45th day of experiment and analyzed for blood profile, hepatorenal performance and immunological analysis. Our results indicated that complete blood count was significantly (P=0.05) reduced, except for platelets level which were significantly higher in dosage dependent groups as compared to control group. Furthermore, antibody titer test for immunity against Rabbit Hemorrhagic Disease (RHD) virus was also reduced in dosage dependent groups. However, hepatorenal parameters (bilirubin, alanine aminotransferase, aspartate transaminase, alkaline phosphatase, urea and creatinine) were significantly elevated upon exposure to the higher dosage Of pesticide. Our study concluded that diafenthiuron has strong potential to cause toxicity even at sub lethal doses which in turn, affects the non-target organisms including human beings. Therefore, alternative ways must be used to avoid tire accumulation of this pesticide in the environment. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Applied Entomology is the property of Chinese Journal of Applied Entomology, Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Spodoptera frugiperda Smith (Lepidoptera: Noctuidae) is a polyphagous pest that has gained importance in soybean cultivation in recent years, due to the damage it causes to leaves and pods. The objective of this work was to evaluate the non-target effect of insecticides recommended and used to control Bemisia tabaci (Genn.) biotype B on S. frugiperda. The experimental design was entirely randomized with five treatments and fifty replications. The treatments were: 1. negative control (distilled water), 2. positive control (lufenuron), 3. buprofezin, 4. pyriproxyfen, and 5. diafenthiuron. In each replicate, one caterpillar was placed in a plastic cup, where sprayed soybean leaves with the maximum dosage of insecticides recommended for B. tabaci were placed.The treatments were evaluated daily during all stages: larval, pupal, and adult emergence and fecundity. The results obtained for larval mortality showed that diafenthiuron aimed 100% control, followed by pyriproxyfen with 28% and buprofezin with 12%. The duration of the larval period of the insects exposed to pyriproxyfen and buprofezin were longer compared to the control. While the biological parameters of pupae were found that pyriproxyfen caused lower pupal formation rate and higher pupal mortality, followed by buprofezin. In adult emergence, pyriproxyfen showed the lowest rate with 13.8% and the highest percentage of deformed adults with 60%. Thus, it was possible to conclude that the insecticides under study cause S. frugiperda mortality or effects on its biological patterns.

Two spotted spider mite Tetranychus urticae Koch is an economically serious pest posing threat to major vegetable crops. Roving survey in and around Coimbatore region revealed that farmers do not target mites with acaricides instead they use higher dose of insecticides at frequent intervals which results in development of resistance. The bioassay results revealed that fenpropathrin (2.07 to 6.86-folds) and fenazaquin (2.74 to 7.13-folds) exhibit higher susceptibility, whereas diafenthiuron (5.35 to 12.25-folds) revealed a low to moderate level of resistance. The propargite (43.80 to 60.63-folds) and chlorfenapyr (61.01 to 75.10-folds) exhibited high resistance, followed by spiromesifen (222.28 to 300.26-folds) and buprofezin (382.60 to 417.87-folds), with extremely high level of resistance. The higher specific activity of GST (4.54-folds), MFO (10.06-folds) and CarE (15.06-folds) in Puthupalayam population suggested the role of biochemical resistance. A significant positive correlation was observed between diafenthiuron and CarE activity (r = 0.981*), fenpropathrin and MFO activity (r = 0.964*). [ABSTRACT FROM AUTHOR]

Cotton is an important cash crop of Pakistan and export commodity. Yield of cotton crop is affected by many factors but insect pests especially whitefly Bemisia tabaci (Homoptera: Aleyrodidae) is destroying cotton crop yield and quality in recent times. Many control measures are adopted against this pest including chemical control methods. Due to certain environmental issues and insecticide resistance problems, adoption of alternate methods of insect control is imperative. In this experiment we used some insecticides alone and in combination with Salicylic acid against B. tabaci. Flonicamid 50% DF at the rate of 80 g/ac and Diafenthiuran 50% SC at the rate of 200 mL/ac were used against Whitefly. Salicylic acid (SA) by Sigma-Aldrich 500 G was used 01 mL/L of water along with the tested insecticides under field conditions. Highest reduction 90.63% was observed in Flonicamid+SA treatment followed by 82.89% in Diafenthiuran +SA, Flonicamid 77.76%, Diafenthiuron 76.28% and lowest 29.36% reduction was observed in SA treatment with respect to control after 72 hrs. of treatment application. After 7 days maximum reduction 83.43% was observed in Flonicamid+SA followed by 69.02 % in Diafenthiuron+SA, 77.76% in Flonicamid, 66.37% in Diafenthiuron and lowest 21.97% recorded in SA treatment. In SA treatments population of rove beetle, green lace wing and spiders was significantly higher as compared to other treatments. It is evident from the results that SA has enhanced plant resistance against whitefly and thus reduced the damage of pest. SA can be used as alternative combination for the management of cotton whitefly and the amount of insecticide can be reduced for the control of whitefly. [ABSTRACT FROM AUTHOR]

Understanding how endogenous and exogenous factors such as annual seasonal rhythm and photoperiodism affect pesticide toxicity is important to designing integrated pest management strategies. The two-spotted spider mite Tetranychus urticae Koch (Acari: Tetranychidae), a worldwide phytophagous pest species distributed across different zones with contrasting environmental conditions, is a good model for exploring how photoperiodism and seasonality affect their responses against pesticides. In this study, we conducted a laboratory experiment from March 2017 to November 2018 in which T. urticae populations were reared under three photoperiod regimes (10L:14D, 12L:12D, and 18L:6D) in environmentally controlled incubators, and assessed the toxicity of the two pesticides, diafenthiruon and propargite, on T. urticae every month. To determine potential mechanisms underlying the changes in pesticide toxicity, we measured body size and total GSTs activity of T. urticae along with the toxicity measurements in 2018. Our results showed that the photoperiod regime did not significantly affect the toxicity of each of the two pesticides to T. urticae. However, unlike photoperiodism, the toxicity of both pesticides was found to be season-dependent, being higher during spring and summer and lower during the winter. This suggests that seasonality could induce in those T. urticae populations, an endogenous mechanism that influenced their susceptibility to the tested pesticides. Pearson's correlation analyses showed that only the body size had a weak negative correlation with pesticide toxicity, thereby suggesting that pesticides could have higher toxicity on smaller T. urticae. Taken together, our study showed that seasonality can affect pesticide toxicity, thereby providing practical insights into the management strategies against T. urticae. [ABSTRACT FROM AUTHOR]

BACKGROUND: Recently, chlorfenapyr and diafenthiuron have been widely used to prevent and control diseases and pests in tea production. However, rare studies have investigated the dissipation patterns of chlorfenapyr, diafenthiuron and their metabolites simultaneously in tea matrices. Here, we established an analytical method to investigate the degradation patterns of five target compounds in tea shoots and made tea samples. Moreover, the dietary intake risk assessment of chlorfenapyr–diafenthiuron mixture among Chinese populations was evaluated based on the supervised field experiment. RESULTS: The mean recoveries of the primary analytes at five spiking levels were between 95.6% and 112.6% in tea shoots and made tea, respectively, and the values of RSD (relative standard deviation) were lower than 9.7% for all the target analytes. The field trial results showed that the half‐lives of chlorfenapyr and diafenthiuron based on the residue definition were 10.0–12.4 days and 4.3–5.9 days, respectively, in tea shoots. For the dietary intake risk assessment, the risk quotient (RQ) values in made tea ranged from 30.4% to 73.9% at the pre‐harvest interval of 14 days, which were significantly less than 100%. CONCLUSION: The accuracy and precision of the developed method were satisfied by the measurement requirements according to the validation results. The dynamic dissipation experiments suggested that diafenthiuron was much easier to dissipate than chlorfenapyr. Moreover, the existence of tralopyril made the half‐life of chlorfenapyr significantly increase, indicating that practical application of chlorfenapyr should take careful consideration of its metabolite. Finally, the potential chronic dietary risks of the chlorfenapyr–diafenthiuron mixture to human communities were within the acceptable range. © 2022 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Molecular identification/ characterization of Bemisia tabaci (Genn.) collected across five agroecological zones of West Bengal, India revealed that it resembles genetic group Q. Seed treatment with thiamethoxam 70WS 3 g/ kg seed incorporated with seedling treatment with acetamiprid 20SP @ 1g/ l, seedling rising under insect proof net and border netting with insect proof net showed efficacy with reducing the occurrence and dispersal of thrips Scirtothrips dorsalis Hood, mite Polyphagotersonemus latus and whiteflies B. tabaci; while their least incidence was observed with IPM module (integration of seed treatment, seedling treatment, seedling raising under insect proof net, border netting technology, installation of yellow sticky trap and need based spot application of spiromesifen and diafenthiuron), with 92.97, 82.68 and 72.97% reduction, respectively; and 98.56% reduction of chilli leaf curl virus (CLCV) incidence could be obtained through IPM with maximum yield of green chili (1.66 t/ ha). Panchagavya, dasaparni and bhramvastra appeared as potent biopesticides in reducing the CLCV causative agents. [ABSTRACT FROM AUTHOR]

Copyright of Forensic Science & Technology is the property of Institute of Forensic Science, Ministry of Public Security and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Bio-efficacy of synthetics, entomopathogenic fungi and natural products were evaluated against chilli thrips, Scirtothrips dorsalis (Hood) during rabi season at College of Agriculture, Hassan (Oct. 2019 to Jan. 2020). The insecticides were applied on 30-60 days old crop at the peak infestation of thrips. One week after application, most of the insecticides showed significant reduction in thrips population and were superior to untreated control. Of these, diafenthiuron accounted for maximum reduction in thrips population (87%) at 7th day after spray followed by acephate (77%), spinosad (69%) and imidacloprid (60%). Further, diafenthiuron treatment continued to record significant decline in thrips population up to 10th day. Further, diafenthiuron application was found significantly more effective upto 14 days after application and resulted in higher fruit yield of 42.20 quintals/ha. So, use of diafenthiuron and conventional insecticide, acephate alternatively is ideal as the avoidable loss was similar (52.83%). This practice would also reduce the cost of plant protection as well as the insecticide pressure on this key pest of chilli crop. [ABSTRACT FROM AUTHOR]

Results of field experiments conducted at Kalyani, Nadia, West Bengal during Rabi seasons of 2016-2017 and 2017-18 with some newer insecticides against cotton aphid and jassid are reported. Imidacloprid 17 per cent SL @ 150 mL ha-1 and diafenthiuron + acetamiprid @ 600 g ha-1 were significantly superior in controlling cotton aphid and recorded 95.00 and 93.97 per cent mortality respectively at 3 d after spraying. Diafenthiuron+ acetamiprid @ 500 and 600 g ha-1 was significantly superior in controlling cotton jassid, recording 91.46 and 92.73 per cent mortality respectively at 3 d after spraying. [ABSTRACT FROM AUTHOR]

Whitefly, Bemisia tabaci (Gennadius), in North Cotton Growing Zone of India adversely affect cotton yield. Both the nymphal and adult stages of whitefly cause damage by sucking the sap from leaf tissue and honey dew secretion. In this study, the efficacy of new generation insecticides, viz. pyriproxyfen 10EC@1250 ml/ha, spiromesifen 22.9SC @500 ml/ha, flonicamid 50WG @200g/ha, and diafenthiuron 50WP @ 500g/ha were evaluated against different stages of whitefly under confined as well as field conditions in Bt cotton.The experiment conducted in screen house revealed significantly higher per cent reduction of whitefly nymphs in spiromesifen 22.9SC (49.36, 75.17) followed by pyriproxyfen 10EC (33.26, 75.07) in comparison to all other treatments after 5 and 7 days of spray, respectively. Under field conditions, pooled analysis of six experiments showed that flonicamid 50WP was more effective, being at par with pyriproxyfen 10EC, diafenthiuron 50WP, spiromesifen 22.9SC after 10 days of spray as compared to standard check, ethion 50EC and control against whitefly adults. It is concluded that pyriproxyfen10EC and spiromesifen 22.9SC have good nymphicidal action while flonicamid 50WP and diafenthiuron 50WP have adulticidal action.Therefore, for its effective management, these novel insecticides can be rotated alternatively depending upon the stage of pest dominating in the cotton field.

The whitefly Bemisia tabaci Middle East‐Asia Minor 1 (MEAM1), previously known as B biotype, is a major agricultural pest with a reputation for developing resistance to insecticides. DNA‐based identification revealed that B. tabaci MEAM1 is the dominant species within Australian cotton cropping. Discriminating doses of 10 mg/L for pyriproxyfen and 300 mg/L for both diafenthiuron and bifenthrin were determined from bioassay data collected in 2010–2015. Resistance to these insecticides was tested in whitefly populations collected in 2017 from cotton crops in Queensland and New South Wales. This study reports on the presence of pyriproxyfen resistance in B. tabaci MEAM1 at seven locations in Queensland and New South Wales. One population from Goondiwindi was resistant to bifenthrin, whereas no populations tested had resistance to diafenthiuron. To determine the presence of resistance alleles to organophosphates and pyrethroids, reference populations of susceptible and resistant whiteflies (pyriproxyfen, bifenthrin and neonicotinoid) were tested. The resistance mutation L925I was found in a pyrethroid‐resistant population and in some individuals from the pyriproxyfen‐resistant population. The mutation F331W that confers organophosphate and carbamate resistance was found in all individuals tested including the susceptible reference population, indicative of a widespread distribution in Australian B. tabaci MEAM1. The cotton industry has revised the insecticide resistance management strategy for B. tabaci, to restrict the usage of pyriproxyfen to a single application within a 30‐day window. Our results argue against the use of organophosphate and carbamate insecticides in Australian cotton, because B. tabaci MEAM1 populations show significant resistance levels. Furthermore, both pesticide groups are highly disruptive to a diverse range of natural enemy populations, and as such, widespread use likely contributes to pest outbreaks. [ABSTRACT FROM AUTHOR]

Cardamom is an important spice crops used all over the world as a flavoring agent of food materials. The productivity is limited by insect pests and thus effective insecticide which does not leave residues in the produce is the need of the hour. Diafenthiuron 50 WP @ 300 g a.i ha−1 was found effective in managing both the cardamom shoot and capsule borer, Conogethes punctiferalis Guenee and thrips, Sciothrips cardamomi Ramk and thus can be recommended for pest management. Cardamom capsules were collected from the plants that were sprayed with diafenthiuron at the recommended dose of 200 g a.i ha−1 and double the dose (400 g a.i ha−1), which were then analyzed under HPLC with a normal phase column. The diafenthiuron residue was below the detectable levels of 0.05 µg g−1 in the harvested produce (both fresh and cured) after twelve and fourteen days of spray. So, capsules can be harvested safely without any risk of insecticide residues 12 days after spraying of diafenthiuron and thus can be recommended for usage in cardamom plantations. [ABSTRACT FROM AUTHOR]

A method was developed for the quantitative determination of spirotetramat, diafenthiuron and their metabolite residues (spirotetramat-enol, spirotetramat-enol-glucoside, spirotetramat-monohydroxy, spriotetramat-keto-hydroxy, diafenthiuron-urea, diafenthiuron-amide) by QuEChERS-ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The samples were homogenized, extracted with V (acetonitrile) : V(formic acid)=10 : 1, and cleaned-up by custom QuEChERS tubes. The separation was performed on a Shimadu Shim-pack XR-ODS column(75 mm × 2.0 mm, 1.6 μm). The compounds were identified by MS/MS in positive electrospray ionization (ESI+) and multiple reaction monitoring (MRM) mode, and quantified by external standard method. The linearities of diafenthiuron-urea and diafenthiuron-amide ranged from 0.001 to 0.1 mg/L. And that of the other six compounds ranged from 0.005 to 0.5 mg/L, with the correlation coeffecients higher than 0.999 3. At the fortified level from 0.001 mg/kg to 0.5 mg/kg in pear, grape, watermelon, kale, celery and leek, the average recoveries of all the eight compounds ranged from 68% to 94% with the relative standard deviations varied from 5.4% to 15%. The limits of quantification (LOQ) of the analytes were 0.001-0.005 mg/kg. The method is simple, rapid, accurate and suitable for the confirmation and quantification of those eight compounds in fruits and vegetables. [ABSTRACT FROM AUTHOR]

Diafenthiuron, an insecticide widely used in the management of pests of cardamom and cotton, was assessed for its toxicity-effect on beneficials commonly found in these ecosystems. Diafenthiuron was found to be toxic to honey bees, the prime pollinators of crop plants. Diafenthiuron at the highest tested dose caused 40% mortality to the coccinelid grubs at 48 h after treatment so, diafenthiuron was found to be slightly harmful. Monocrotophos, on the other hand has been found to be a highly toxic pesticide. Diafenthiuron is moderately harmful to the adults of Chelonus blackburni L. The testing was done using the insecticide diafenthiuron. An insecticidecoated vial (scintillation) bioassay was performed. It was found that there was 86.67% mortality in 48 h, at the recommended dose. Diafenthiuron is highly toxic to the silkworm, killing more than 80% of the caterpillars in 24 h, at all the doses tested. Diafenthiuron, even in the highest dose tested, is non-toxic to the earthworm, Perionyx excavatus, which was found to have a 3.33% mortality. As far as fish are concerned, the common carp, Cyprinus carpio L., is found to be highly susceptible to diafenthiuron and even doses 10 times lower than the field dose can kill the fish within 6 h.

Diafenthiuron is a thiourea compound that has a novel mode of action as it inhibits mitochondrial functioning in insect pests. It has been reported in local newspapers that this pesticide is entering in our fresh water bodies on regular basis and it is a potential threat for aquatic life. The present study was designed to determine effect of Diafenthiuron, a commonly used pesticide in Pakistan, on the hematology, serum biochemical profile and elemental composition of a non-target organism, Labeo rohita ( L. rohita ). A sub-lethal dose (0.0075 mg L -1 ) of Diafenthiuron was applied under short (2, 4 and 8 days) and long term (16, 32 and 64 days) experimental conditions. Our results indicated that the pesticide exposed fish had significantly higher white blood count, lymphocyte, red blood cell count, hemoglobin, hematocrit, mean corpuscular volume, red cell distribution width than the control group. However, platelets count, plateletcrit and platelet distribution width were significantly reduced in Diafenthiuron treatments than their respective control groups. Concentration of total serum proteins, albumin, globulin, cholesterol, triglycerides and AST were disturbed in pesticide exposed treatments compared to control groups. Comparison of elemental concentrations revealed that calcium, potassium and cadmium concentration varied significantly when compared between Diafenthiuron treated and untreated L. rohita . In conclusion, we are reporting that Diafenthiuron can adversely affect the hematological, serum and elemental concentrations of a non-target organism like L. rohita and may therefore pose a threat to the food web. [ABSTRACT FROM AUTHOR]

A farmers survey was conducted to perceive their knowledge of pest control and its impact on resistance to insecticides in whitefly. Most farmers had some school education and were able to identify the major pests of cotton, but they used descriptive rather than specific names when defining a pest. They exclusively relied on chemical pest control and sprayed 4-5 active ingredients in almost 7-8 applications. The majority of them applied insecticide mixtures at doses higher than recommended and followed a calendar spraying schedule. Laboratory bioassays indicated a low level of resistance of B. tabaci to imidacloprid, acetamiprid, nitenpyram, buprofezina, pyriproxyfen, diafenthiuron, spirotetramat, and flonicamid with resistance ratios of 5.13-, 3.0-, 4.90-, 4.14-, 3.42-,4.73-, 3.08- and 1.93- fold, respectively compared with a susceptible population. However, the bioassays showed a medium level of resistance (16.4- fold) to bifenthrin. In conclusion, B. tabaci showed a low level of resistance to the insecticides used and for the attainment of satisfactory pest control, farmers should be educated on the correct use of insecticides and also about alternatives to chemical control. [ABSTRACT FROM AUTHOR]

Tetranychus urticae Koch is one of the most important phytophagous mite species worldwide, and Neoseiulus californicus (McGregor) is the main predatory mite species marketed for control of this pest in Brazil. The present study aimed to evaluate the toxicity of acaricides on both prey and predator mites and to assess mechanisms of resistance to acaricides in the predator. Concentration-response curves for the mite populations were established using the acaricides abamectin, chlorfenapyr, diafenthiuron, spiromesifen and fenpyroximate. Acaricide field dose effect on predator survival was also assessed. Additionally, synergism of PBO, TPP and DEM to fenpyroximate and chlorfenapyr was performed on the predator to preliminarily assess the involvement of detoxification enzymes on their toxicities. Ovicidal effects of acaricides were also evaluated on N. californicus eggs. Abamectin was the most toxic acaricide for both T. urticae (LC 50 varying from 0.02 to 0.24 mg/L) and N. californicus (LC 50 varying from 3.92 to 4.94 mg/L). Chlorfenapyr, diafenthiuron, fenpyroximate and spiromesifen are promising acaricides for the integrated management of T. urticae in combination with N. californicus . However, spiromesifen efficacy is stage dependent. Resistance of N. californicus to chlorfenapyr (RR 50  = 14.69-times) and fenpyroximate (RR 50  = 113.96-times) was observed for Bonito and Brejão populations, respectively. Synergism of chlorfenapyr toxicity in both N. californicus populations suggested an involvement of CYP450-dependent monooxygenases in the resistance, while these and esterases seem to be involved in the resistance to fenpyroximate. Survival of N. californicus was reduced to zero in a maximum of 12 h, to abamectin only. Excepting abamectin, the other acaricides must have their use encouraged regarding chemical-biological control association. [ABSTRACT FROM AUTHOR]

Bean dip bioassay was performed with six insecticides on the mortality response in tomato thrips- Thrips palmi Karny and Scirtothrips dorsalis Hood. The LC50 values ranged from 1.591 to 17.018 ppm, and spinosad with the least LC50 value of 1.591 ppm at 95% confidence limit was the most toxic. It was followed by cyantraniliprole (2.425 ppm), diafenthiuron (2.396 ppm), imidacloprid (5.110 ppm), fipronil (13.560 ppm) and dimethoate (17.018 ppm). Thus, spinosad, diafenthiuron and cyantraniliprole were observed to be more toxic. [ABSTRACT FROM AUTHOR]

In this study, we firstly employed response surface methodology to optimize the extraction conditions for separating diafenthiuron from fresh tea leaves via subcritical fluid extraction. Besides, the surface structure was characterized before and after the extraction. The results revealed that the experimental value was fitted to a second-order polynomial equation and the separation efficiency was estimated to be 92.89%, which is highly enough when applied in the industrial manufacture. Therefore, we performed subcritical fluid extraction experiments in the modified optimal conditions (i.e., 33 °C extraction temperature, 22 min extraction time, and 6.6:1 liquid-to-solid ratio) and measured a related value of 91.65%, consistent with the calculated result. Moreover, the surface structure of the tea leaves was intact after the extraction. [ABSTRACT FROM AUTHOR]

In this work, we have fabricated gold nanoparticles (Au NPs) with multifunctional groups of 4-hydroxy-6-methyl-3-nitro-2-pyridone-dithiocarbamate derivative and used as plasmonic sensor for simple and competitive detection of diafenthiuron in water and food samples. The multifunctional groups ( OH, NO 2 and CO) of HMNP-DTC-Au NPs showed strong ability to interact with diafenthiuron, yielding to form stable HMNP-DTC-Au NPs-diafenthiuron supramolecular network, which results a red-shift in the SPR peak and a color change from red to blue. The plasmonic sensor exhibits good linearity between the absorbance ratio at A 618 /A 522 and the concentration of diafenthiuron in the range of 0.05–10 μM with a correlation coefficient ( R 2 ) of 0.997. The designed plasmonic sensor showed high selectivity toward diafenthiuron with a detection limit of 7.1 nM, which is lower than the permissible limit of diafenthiuron. The developed plasmonic sensor was successfully applied to detect diafenthiuron in water and food samples with good recoveries, avoiding multiple steps for complicated surface modifications on Au NPs and tedious sample preparations. [ABSTRACT FROM AUTHOR]

The evolution of resistance to carbodiimide (a toxic metabolite of diafenthiuron) and four neonicotinoids imidacloprid, acetamiprid, thiamethoxam, and thiacloprid in the Pakistani populations of sweetpotato whitefly (Bemisia tabaci Gennadius) was monitored from 1996 to 2015 using a leaf-dip bioassay. Diafenthiuron, imidacloprid, and acetamiprid were introduced into Pakistani agriculture in mid-1990s and heavily used since then, because B. tabaci resistance and consequently control failures to conventional insecticides such as organophosphates, carbamates, and pyrethroids were widespread during the 1990s. According to the current studies, resistance to carbodiimide, imidacloprid, and acetamiprid during 1996-2010 and to thiamethoxam during 1999-2007 remained very low, but then it rose sharply, and by the year 2015, the B. tabaci resistance increased to very high levels. Among neonicotinoids, thiacloprid was the latest introduction in Pakistan in 2002. There was no thiacloprid resistance in 2002 and 2003, a low tomoderate resistance during 2004-2006, and a very high resistance during 2007-2010 that even exceeded resistance to previous neonicotinoids. We may conclude that diafenthiuron and neonicotinoids remained effective against B. tabaci for 15 yr following their intensive use under field conditions, before a significant resistance, leading to their field failures, occurred in Pakistan. [ABSTRACT FROM AUTHOR]