Effects of Elevated CO2 Concentration on Host Adaptability and Chlorantraniliprole Susceptibility in Spodoptera frugiperda

Abstract

Elevated atmospheric carbon dioxide concentrations (eCO2) can affect both herbivorous insects and their host plants. The fall armyworm (FAW), Spodoptera frugiperda, is a highly polyphagous agricultural pest that may attack more than 350 host plant species and has developed resistance to both conventional and novel-action insecticides. However, the effects of eCO2 on host adaptability and insecticide resistance of FAW are unclear. We hypothesized that eCO2 might affect insecticide resistance of FAW by affecting its host plants. To test this hypothesis, we investigated the effect of eCO2 on (1) FAW’s susceptibility to chlorantraniliprole after feeding on wheat, (2) FAW’s population performance traits (including the growth and reproduction), and (3) changes in gene expression in the FAW by transcriptome sequencing. The toxicity of chlorantraniliprole against the FAW under eCO2 (800 µL/L) stress showed that the LC50 values were 2.40, 2.06, and 1.46 times the values at the ambient CO2 concentration (400 µL/L, aCO2) for the three generations, respectively. Under eCO2, the life span of pupae and adults and the total number of generations were significantly shorter than the FAW under aCO2. Compared to the aCO2 treatment, the weights of the 3rd and 4th instar larvae and pupae of FAW under eCO2 were significantly heavier. Transcriptome sequencing results showed that more than 79 detoxification enzyme genes in FAW were upregulated under eCO2 treatment, including 40 P450, 5 CarE, 17 ABC, and 7 UGT genes. Our results showed that eCO2 increased the population performance of FAW on wheat and reduced its susceptibility to chlorantraniliprole by inducing the expression of detoxification enzyme genes. This study has important implications for assessing the damage of FAW in the future under the environment of increasing atmospheric CO2 concentration.

Unraveling the multifaceted effects of climatic factors on mountain pine beetle and its interaction with fungal symbionts

“…The ramifications of this adaptation extend beyond mere developmental changes to influencing insect life history traits and population dynamics. This is consistent with observations in several lepidopteran species, where eCO 2 exposure reduced larval duration and doubled the population growth rate (Akbar et al., 2016; Lu et al., 2022; Qi et al., 2017; Qian et al., 2017). Thus, eCO 2 concentration may significantly impact MPB biology, ultimately affecting the related ecological and evolutionary processes with their host plants and microbial symbionts (Zavala et al., 2013).…”

Genome-Wide Scanning Loci and Differentially Expressed Gene Analysis Unveils the Molecular Mechanism of Chlorantraniliprole Resistance in Spodoptera frugiperda

“…The excess of 1000 third-instar S. frugiperda larvae were tested at the LC 50 concentration of chlorantraniliprole via the leaf impregnation method adapted from a previous study . After 48 h postexposure, surviving larvae were grouped for further selection with chlorantraniliprole.…”

“…The excess of 1000 thirdinstar S. frugiperda larvae were tested at the LC 50 concentration of chlorantraniliprole via the leaf impregnation method adapted from a previous study. 28 After 48 h postexposure, surviving larvae were grouped for further selection with chlorantraniliprole. Through ten successive selections, chlorantraniliprole-resistant (Ch-R) and chlorantraniliprole-susceptible (Ch-Sus) strains were developed to use as controls.…”

Insecticide Susceptibility and Detoxification Enzyme Activity of Frankliniella occidentalis under Three Habitat Conditions

“…Li et al [40] showed that CarE, GST, and CYP450 activity in F. occidentalis increase significantly after treatment with an LC 25 dose of spinetoram, while the activity of AChE decreases. Detoxification enzymes play essential roles in the survival of insects exposed to adverse environments [41][42][43][44]. Therefore, higher detoxifying enzyme activity indicates the involvement of those enzymes in insecticide stress, thereby changing the insecticide susceptibility in insects.…”