Effects of imidacloprid and thiamethoxam on the development and reproduction of the soybean aphid Aphis glycines

Abstract

The soybean aphid Aphis glycines Matsumura (Hemiptera: Aphididae) is a primary pest of soybeans and poses a serious threat to soybean production. Our studies were conducted to understand the effects of different concentrations of insecticides (imidacloprid and thiamethoxam) on A. glycines and provided critical information for its effective management. Here, we found that the mean generation time and adult and total pre-nymphiposition periods of the LC50 imidacloprid- and thiamethoxam-treatment groups were significantly longer than those of the control group, although the adult pre-nymphiposition period in LC30 imidacloprid and thiamethoxam treatment groups was significantly shorter than that of the control group. Additionally, the mean fecundity per female adult, net reproductive rate, intrinsic rate of increase, and finite rate of increase of the LC30 imidacloprid-treatment group were significantly lower than those of the control group and higher than those of the LC50 imidacloprid-treatment group (P < 0.05). Moreover, both insecticides exerted stress effects on A. glycines, and specimens treated with the two insecticides at the LC50 showed a significant decrease in their growth rates relative to those treated with the insecticides at LC30. These results provide a reference for exploring the effects of imidacloprid and thiamethoxam on A. glycines population dynamics in the field and offer insight to agricultural producers on the potential of low-lethal concentrations of insecticides to stimulate insect reproduction during insecticide application.

Effects of multigenerational imidacloprid and thiamethoxam stress on metabolism and physiology of Aphis glycines Matsumura (Hemiptera: Aphididae)

“…Ding et al [13] showed that thiamethoxam had a better control impact on corn thrips Frankliniella williamsi Hood (Thysanoptera: Thripidae) than imidacloprid under the same dosing conditions [12,13]. Our previous study also confirmed that imidacloprid had a stronger impact on the growth and reproduction of the soybean aphid population than thiamethoxam at the same concentration [14]. Although they are both neonicotinoids, their heterocyclic structures might lead them to have different pest control effects [11].…”

“…The body no longer needs to synthesize a large amount of antioxidant enzymes and consume a large amount of energy substances to resist the damage of insecticides. Hence, the enzyme activity gradually decreased generation by generation [14,16,30,31]. Furthermore, we found that changes in peroxidase or pyruvate kinase did not accompany changes in trehalase activity.…”

Evaluation of insecticidal efficacy against maize leaf aphid [Rhopalosiphum maidis (Fitch)] under inner terai condition of Nepal

“…Thiamethoxam [(EZ)-3-(2-chloro-1,3-thiazol-5yl-methyl)-5-methyl-1,3,5-oxadiazinan-4-ylidene(nitro)amine] is classified according to the pharmacophore as Nnitroguanidineneonicotinoid (Cui et al, 2018). Thiamethoxam is presently one of the most effective chemicals for the control of sucking pests such as aphids (Zhang et al, 2021), whiteflies (Kumar et al, 2019), thrips, some microlepidoptera, and a number of coleopteran species. The result is in line with the findings of Aston et al (2022) who reported that sublethal concentrations of flonicamid and thiamethoxam increase fecundity and phloem-feeding behavior on Myzus persicae.…”

The Synergistic Effect of Thiamethoxam and Synapsin dsRNA Targets Neurotransmission to Induce Mortality in Aphis gossypii

“…On the other hand, sublethal doses of insecticides can cause reduced reproduction, decreased longevity, delayed development, and compromised locomotion or learning in pest insects, beneficial insects, as well as non-target organisms [ 8 , 9 , 10 ]. For examples, sublethal doses of neonicotinoids cause reduced reproduction, body weight, honeydew excretion, and longevity in aphids [ 11 , 12 ]. In beneficial insects, such as honeybees and bumblebees, defects in foraging [ 13 , 14 ], circadian rhythms and sleep [ 15 , 16 , 17 ], learning and memory [ 18 , 19 ], and abnormal neural development [ 19 ] have been detected.…”