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A QuEChERS (quick, easy, cheap, effective, rugged, and safe) technique using ultrahigh‐performance liquid chromatography with tandem mass spectrometry for the analysis of spinosad (spinosyn A + spinosyn D), thiocyclam, and nereistoxin in cucumber was developed with mean recoveries of 93−104%, relative standard deviations of ≤9%, and limits of quantification of 0.01 mg/kg. Field trials of spinosad and thiocyclam were performed in 12 representative cultivating areas in China. Field trial results indicate that spinosyn A and spinosyn D easily dissipated in cucumber with half‐lives of 2.48–6.24 and <3 days, respectively. Nereistoxin was produced after thiocyclam application and was more persistent than its parent. The terminal residues of spinosad were all below the maximum residue limits (0.2 mg/kg) in China, whereas the terminal concentration of nereistoxin (calculated as the stoichiometric equivalent of thiocyclam), which was much higher than that of thiocyclam, was far beyond the maximum residue limits of thiocyclam in cucumber (0.01 mg/kg) established by the European Union. The predicted no‐effect concentrations of spinosyn A, spinosyn D, thiocyclam, and nereistoxin leaching into groundwater were estimated using China‐PEARL (Pesticide Emission Assessment at Regional and Local scales) models after application. However, the dietary (food and water) exposure risk quotient for different populations was below 1 with a preharvest interval set at 5 days after the last application, indicating that the application of spinosad and thiocyclam in cucumber was unlikely to pose unacceptable risk for human health. This study provides data for the safe use of spinosad and thiocyclam in cucumber ecosystem. [ABSTRACT FROM AUTHOR]

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.

Tuta absoluta (Meyrick) is a devastating pest of tomato. This pest is becoming resistant to many of the pesticides that used in the tomato fields. In this research, the efficacy of four bio-insecticides namely, thiocyclam, spinosad, Bacillus thuringiensis (B.t) and azadirachtin (Azadirachta indica) were studied on the tomato leaf miner in the laboratory and field conditions. Laboratory experiments were performed in a randomized complete plot design with three replications against 1st, 2ndand 3rd larvae. Field experiment was carried out on three larval stages based on recommended doses of pesticides in the form of a completely randomized block. The results showed that in laboratory conditions, LC50 values and lower and upper bond with 95% confidence limits of thiocyclam, spinosad, B.t and azadirachtin on third instar larvae after 72 h, were 902.01(680.3-1442.54), 1793.41 (1326.08-2924.97), 2239.30 (2074.19-2442.10) and 2572.09 (2423.62-2736.74), respectively. In field experiments, thiocyclam and spiosad had the highest efficiency on mortality of the larvae with an average loss of 95.35% and 80.59%. B.t and azadirachtin with an average mortality of 67.29% and 66.40% had the lowest effect, respectively. The results showed that the third instar larvae were less sensitive than the first and second instar larvae for all pesticides. The results of two experiments show that spinosad, B.t and azadirachtin had less insecticidal efficacy compared with thiocyclam on tomato leaf miner. Recent study recommended using thiocyclam in integrated management of this pest. [ABSTRACT FROM AUTHOR]

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Abstract: In this study, a nereistoxin analogue insecticide, thiocyclam, was administered to adult male albino rats by gavage dose of 135, 270 and 540mg/kg b.w. repeated for 5days at 24h intervals. Control animals received only water. Thiocyclam was tested for its potential to cause genotoxic effects in rat bone marrow cells using an in vivo micronucleus assay. After 24h of the last treatment, rats from all dose levels were sacrificed. Bone marrow cells were collected and assayed for the presence of micronuclei. Thiocyclam did not cause any increase in the incidence of micronucleated polychromatic erythrocytes in rats bone marrow at any of the dose levels. The polychromatic erythrocytes/normochromatic erythrocytes (PCE:NCE) ratio was found to be in the range from 0.50±0.11 to 0.55±0.02. The results of this study demonstrate that the effect of thiocyclam is not significant in the rat in vivo micronucleus assay. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

• A method for detection of four nereistoxin-related pesticides was developed. • The established method was applied to 20 plant foods. • The pre-processing steps of extraction and derivatization were optimized. • Repeatability and reproducibility of the method in 5 laboratories were verified. A method was developed for the simultaneous determination of four nereistoxin-related pesticides, viz. cartap, thiocyclam, thiosultap-monosodium, and thiosultap-disodium, in 20 plant foods. The samples were extracted using a hydrochloric acid solution containing cysteine hydrochloride, derivatized to nereistoxin under alkaline conditions, and analyzed by gas chromatography with electron capture detector. The average recoveries of the method were 72–108%, with relative standard deviations (RSDs) of 0.3–14.7% (n = 1200, p < 0.05). The intermediate precision and reproducibility experiments using established methods were also carried out. All the results passed the Cochrane and Grubbs tests (n = 2400, p < 0.05). The RSDs of intermediate precision and RSDs of reproducibility among laboratories were in the ranges 1.7–10.9% and 2.4–15.3% (n = 2400, p < 0.05), respectively, indicating that the accuracy and precision of the method are satisfactory. This method can be used to detect nereistoxin-related pesticides in plant foods. [ABSTRACT FROM AUTHOR]

• Dissipation kinetics of thiocyclam were evaluated in tomato using LC-HRMS. • Nereistoxin, a thiocyclam metabolite, was more persistent (>60 days) • Four nereistoxin metabolites were also detected in samples. • Nereistoxin should be monitored in routine laboratories rather than thiocyclam. • More nereistoxin toxicity data are necessary to perform proper risk assessment. Reduced pesticides use, alongside increased organic farming, has created a need for new biological products, such as thiocyclam, to control pests. Thiocyclam has scarcely been studied, making the study of its degradation in fruits and vegetables, such as tomatoes, an urgent requirement. To monitor thiocyclam metabolites in tomato, dissipation studies were carried out using a liquid chromatography-Orbitrap mass spectrometry (UHPLC-Orbitrap MS) method for 60-days after foliar application. Thiocyclam was not persistent (DT 50 < 15 days), but nereistoxin - its primary metabolite - remained present in the tomatoes for >60 days. Four nereistoxin metabolites, detected at low concentrations (<100 µg/kg), were also monitored. This is the first time a study has provided dissipation patterns for thiocyclam and nereistoxin. The results obtained suggest revising the legislation concerning these compounds is required. Toxicological studies must also be carried out because there is no toxicity data currently for thiocyclam or nereistoxin. [ABSTRACT FROM AUTHOR]