Fall armyworm (FAW), Spodoptera frugiperda (Lepidoptera: Noctuidae), is a highly invasive polyphagous pest that causes great economic losses to agricultural production. Emamectin benzoate (EMB) is one of the most popular biopesticides with high antipest, anti-parasitic and anti-nematode activities and low toxicity. The present study was conducted to determine the lethality of EMB to FAW for 24 h. Sublethal effects of EMB on FAW parental and offspring generations were also assessed. LC10, LC20 and LC50 EMB for 24 h on FAW third instar larvae were 0.0127 mg/L, 0.0589 mg/L, and 0.1062 mg/L, respectively. A low dose of sublethal concentrations of EMB could significantly influence the life cycle of FAW parental and offspring generations. Sublethal concentration (LC20) of EMB significantly prolonged the pupal period of male and increased the pupal weight of male but not of female, and significantly delayed the oviposition period and longevity of adult FAW. In the FAW offspring generation, sublethal concentrations significantly increased the mortality of offspring pupae and pre-adults, and reduced the development time of offspring larvae and pre-adult male and female. Sublethal concentrations (LC10 and LC20) of EMB significantly decreased the FAW oviposition period. However, only LC10 significantly reduced FAW F1 female fecundity. No significant difference was found in the intrinsic rates of natural increase (rm), finite rate of population increase (λ), and net reproductive rate (R0) of FAW offspring exposed to sublethal concentrations. This is the first study to determine the sublethal concentrations of EMB on the life table parameters of two FAW generations. These findings can provide important implications for the rational utilization of FAW insecticides.
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Agriculture
2022,
12(7), 959; https://doi.org/10.3390/agriculture12070959
10, LC
20and LC
50EMB for 24 h on FAW third instar larvae were 0.0127 mg/L, 0.0589 mg/L, and 0.1062 mg/L, respectively. A low dose of sublethal concentrations of EMB could significantly influence the life cycle of FAW parental and offspring generations. Sublethal concentration (LC
20) of EMB significantly prolonged the pupal period of male and increased the pupal weight of male but not of female, and significantly delayed the oviposition period and longevity of adult FAW. In the FAW offspring generation, sublethal concentrations significantly increased the mortality of offspring pupae and pre-adults, and reduced the development time of offspring larvae and pre-adult male and female. Sublethal concentrations (LC
10and LC
20) of EMB significantly decreased the FAW oviposition period. However, only LC
10significantly reduced FAW F
1female fecundity. No significant difference was found in the intrinsic rates of natural increase (r
m), finite rate of population increase (λ), and net reproductive rate (R
0) of FAW offspring exposed to sublethal concentrations. This is the first study to determine the sublethal concentrations of EMB on the life table parameters of two FAW generations. These findings can provide important implications for the rational utilization of FAW insecticides. View Full-Text
Keywords:lethality determination; life table; generation; longevity; fecundity
Figure 1
MDPI and ACS Style
Liu, Z.-K.; Li, X.-L.; Tan, X.-F.; Yang, M.-F.; Idrees, A.; Liu, J.-F.; Song, S.-J.; Shen, J. Sublethal Effects of Emamectin Benzoate on Fall Armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae). Agriculture 2022, 12, 959. https://doi.org/10.3390/agriculture12070959
AMA Style
Liu Z-K, Li X-L, Tan X-F, Yang M-F, Idrees A, Liu J-F, Song S-J, Shen J. Sublethal Effects of Emamectin Benzoate on Fall Armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae). Agriculture. 2022; 12(7):959. https://doi.org/10.3390/agriculture12070959
Chicago/Turabian Style
Liu, Zhuo-Kun, Xue-Lin Li, Xiao-Feng Tan, Mao-Fa Yang, Atif Idrees, Jian-Feng Liu, Sai-Jie Song, and Jian Shen. 2022. "Sublethal Effects of Emamectin Benzoate on Fall Armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae)" Agriculture 12, no. 7: 959. https://doi.org/10.3390/agriculture12070959
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