Thiamethoxam, Clothianidin, and Imidacloprid Seed Treatments Effectively Control Thrips on Corn Under Field Conditions

Abstract

With the widespread adoption of no-tillage technology, outbreaks of thrips have caused serious damage to summer corn fields in China. Therefore, effective control of pest populations is often essential for cost-effective crop production. In this study, experiments were conducted in 2014 and 2015 to determine the control efficacy of seven neonicotinoid insecticide seed treatments against corn thrips and the effects of these treatments on natural enemy population densities and emergence rates, seedling characteristics, and yield of corn. The results showed that among the tested neonicotinoid seed treatments, thiamethoxam (1.0 and 2.0 g active ingredient (AI)/kg of seeds), clothianidin (1.0 and 2.0 g AI/kg of seeds), and imidacloprid (2.0 g AI/kg of seeds) showed the highest control efficacy against corn thrips throughout the corn growing season. Seed treatments with acetamiprid, nitenpyram, dinotefuran, and thiacloprid at rates of 1.0 and 2.0 g AI/kg of seeds were difficult to effectively control thrips on summer corn. Neonicotinoid seed treatments showed no adverse effects on the numbers of spiders and lady beetles. Furthermore, treatments did not negatively influence the seedling growth or development of corn but did prevent yield losses. Therefore, treating corn seeds with thiamethoxam, clothianidin, and imidacloprid can provide effective protection against early-season thrips and reduce yield losses under field conditions.

Early season growth of corn as influenced by seed treatment

“…These results are similar to those reported by Ding et al. (2018) where seed treatment with 1.0 or 2.0 mg a.i. kernel −1 clothianidin increased the height, growth index, and root length of seedlings in a field study in China.…”

“…The increase in growth stage, height, and root surface area in the current study suggests treatment with clothianidin + B. firmus increased early season growth in corn. These results are similar to those reported by Ding et al (2018) where seed treatment with 1.0 or 2.0 mg a.i. kernel −1 clothianidin increased the height, growth index, and root length of seedlings in a field study in China.…”

Seed Treatment with Diamide and Neonicotinoid Mixtures for Controlling Fall Armyworm on Corn: Toxicity Evaluation, Effects on Plant Growth and Residuality

“…These two insecticides were recently labeled as a seed treatment for controlling FAW and exhibited a high level of control efficacy against this species ( Zhang P. et al, 2016 ; Pes et al, 2020 ). Neonicotinoid insecticides such as CLO and THI have been widely used as seed treatments in multiple crops and exhibit good activity against a broad range of pests including aphids ( Zhang P. et al, 2016 ; Zhang Z. et al, 2016 ), whiteflies ( Zhang et al, 2011 ), and thrips ( Reisig et al, 2012 ; Ding et al, 2018 ). To the best of our knowledge, there are no prior studies assessing the efficacy of diamides in combination with neonicotinoids for FAW larval control as seed treatments.…”

“…Our results were different from those reported by Abdu-Allah and Hashem (2017) and Huang et al (2015) but consistent with studies showing that neonicotinoid seed treatments could promote seed germination and increase primary root length, weight, and height of corn seedlings ( Horii et al, 2007 ; Duan et al, 2012 ; Zhang et al, 2015 ). The stimulation of growth parameters may be the result of improved activity of antioxidants and stress-related enzymes such as guaiacol peroxidase and glucose-6-phosphate dehydrogenase ( Ding et al, 2018 ). Previous studies have shown that insecticides, especially neonicotinoids, cause a decline in natural enemies and pollinators ( Moser and Obrycki, 2009 ; Bredeson and Lundgren, 2018 ).…”

Fatores ambientais e tempo de degradação foliar de neonicotinóides no controle químico de insetos sugadores em soja

“…Isto pode ter ocorrido devido à hidroxilação da ponte de etileno no anel de imidazolinidina, redução do grupo nítrico ou oxidação do imidaclopride em álcool 6-cloropicolítico (SUR;STORK, 2003). Por outro lado, o tiametoxam pode se decompor em clotianidina, o que pode contribuir para sua atividade contínua na planta e maior efetividade no controle de insetos (DING et al, 2018).…”