Residue evaluation of imidacloprid, spirotetramat, and spirotetramat-enol in/on grapes (Vitis vinifera L.) and soil

Abstract

A combination of imidacloprid and spirotetramat effectively controls sucking pests on grapevines. Residues of these insecticides on grapes were evaluated after treatment with spirotetramat 12% + imidacloprid 12% (240 SC) three times at 90 and 180 g a.i. ha(-1). The samples were extracted and purified by QuEChERS method and analyzed by high-performance liquid chromatography with a photodiode array detector (imidacloprid) and gas chromatography mass spectrometry (spirotetramat and its metabolite spirotetramat-enol). Satisfactory results were obtained with ranges of 80.6-98.6% for the recovery, 3.1-10% for the relative standard deviation range, and 9.8-15.6% for the uncertainty. The limits of detection and quantification were 0.015 μg mL(-1) and 0.05 mg kg(-1), respectively. Initial residue concentrations of imidacloprid after the 90 and 180 g a.i. ha(-1) treatments were 0.912 (half-life 11 days) and 1.681 mg kg(-1) (half-life 12.4 days), respectively. For spirotetramat + spirotetramat-enol, the residue concentrations were 1.337 (half-life 5.6 days) and 2.0 mg kg(-1) (half-life 7.6 days) for the 90 and 180 g a.i. ha(-1) treatments, respectively. Spirotetramat degraded faster than spirotetramat-enol. After treatment at 90 g a.i. ha(-1), the initial residues of both insecticides were within European Union maximum residue limits and a 1-day pre-harvest interval (PHI) was adequate for safe consumption of grapes. After treatment at 180 g a.i. ha(-1), the required PHI was 7 day. Therefore, a PHI of 7 day should be used after treatment with imidacloprid and spirotetramat.

Approach to an integrated management of Oregmopyga peruviana (Granara de Willink & Diaz) (Hemiptera: Coccoidea: Eriococcidae) in Vitis vinifera L. ‘Negra Criolla’

“…A los 116 días después de la cosecha, la parcela destinada al MIP tiene una población de 7 y el testigo de 45 individuos por planta. Esto puede ser debido a que imidacloprid es efectivo contra plagas chupadoras por su alta persistencia (Mohapatra et al, 2015). Se observó un descenso en la población testigo debido a que para cada momento de evaluación se eligen nuevas plantas sin descortezar, teniendo poblaciones variables.…”

Determination, residue analysis and risk assessment of thiacloprid and spirotetramat in cowpeas under field conditions

“…The commonly used analytical methods for thiacloprid and spirotetramat are liquid chromatography (LC) 15 , 20 and LC-mass spectrometry (LC–MS/MS) 11 , 22 – 24 . In addition, we can see that the improved QuEChERS methods have been successfully used to recover thiacloprid or spirotetramat from many vegetables and fruits, such as cabbage 14 , apple 25 , tomato 26 , grape 21 , citrus 18 , cucumber 26 and green onion 27 . However, the method for simultaneously determining thiacloprid, spirotetramat and its four metabolites in vegetables was not established.…”

Adsorption and Desorption Behaviors of Spirotetramat in Various Soils and Its Interaction Mechanism

“…The transfer procedure of pesticide in soil is complex and has attracted more and more attention in recent years. − The degradation characteristics of pesticide and the sustainability of pesticide efficacy were related to the adsorption behavior in soil, and therefore, adsorption of pesticide in soil has a great influence on the ecotoxicological impact, environmental mobility, and rate of degradation. − Spirotetramat (Figure ) is a bidirectional systemicity insecticide in both xylem and phloem . As an inhibitor of acetyl-CoA carboxylase, spirotetramat can effectively prevent and control piercing–sucking mouthpart insects, such as Aphis citricola, coffee coccid, Bemisia tabaci, phylloxera, thrip, acarid, etc., via interfering with the fatty acid biosynthesis of insects. − At present, the research on spirotetramat mainly focuses on the prevention effect and synthetic process, ,− cross-resistance and acute toxicity of spirotetramat, , and analysis of residues and metabolites of spirotetramat in the environment. − Spirotetramat is generally considered to be innocuous and have low toxicity. − However, the United States Environmental Protection Agency (U.S. EPA) reported that spirotetramat is poisonous to bees and aquatic invertebrates, such as oysters, irritating to eyes, and has the potential to cause skin sensitization in animals and humans. , …”