Beyond the Mortality Effect: Spodoptera frugiperda Multiple Nucleopolyhedrovirus Promotes Changes in Feeding and Inhibits Larval Growth and Weight Gain in Fall Armyworm
Infection by <i>Spodoptera frugiperda</i> multiple nucleopolyhedrovirus (SfMNPV) profoundly alters the physiology of <i>S. frugiperda</i> (Lepidoptera: Noctuidae), promoting molecular responses that activate genes related to cellular defense. These responses demand substantial energy and lead to feeding dysfunction. Knowledge about the effects of SfMNPV on weight gain and leaf consumption rate is still incipient; in this context, we evaluated the survival rate, weight gain, leaf consumption rate, and body size of <i>S. frugiperda</i> exposed to different concentrations of SfMNPV. A completely randomized design was used in the laboratory. Treatments consisted of SfMNPV from the commercial product Cartugen<sup>®</sup>, diluted at different concentrations and applied on a Petri dish: 9.00 × 10<sup>3</sup>, 1.80 × 10<sup>4</sup>, 3.75 × 10<sup>4</sup>, 7.50 × 10<sup>4</sup>, 1.35 × 10<sup>5</sup>, 2.25 × 10<sup>5</sup>, and 3.75 × 10<sup>5</sup> occlusion bodies (OBs)/mL. Fifty first-instar larvae were used per treatment. The median lethal concentration was estimated at 1.32 × 10<sup>5</sup> OBs/mL (95% confidence interval = 1.22 × 10<sup>5</sup>-1.43 × 10<sup>5</sup> OBs/mL). Nonlinear regression analysis of sublethal effects showed that the expected weight of the control (W<sub>0</sub>), the angular parameter (B), and the effective concentration capable of reducing larval weight by 50% (EC<sub>50</sub>) were 47.40 mg, 1.42, and 1.16 × 10<sup>4</sup> OBs/mL, respectively. Leaf consumption was inhibited at lower concentrations and increased at higher concentrations among surviving larvae, and larval growth (measured by head diameter, body length, and body width) was lower when larvae were exposed to SfMNPV than in the control. Our data suggest that SfMNPV at low concentrations causes dysfunctions that prevent normal development in surviving individuals, resulting in reduced consumption rate, body growth, and weight gain. Overall, our analysis indicates that the impact of SfMNPV extends beyond mortality; low concentrations can affect larval growth and feeding consumption rate in <i>S. frugiperda</i>.
Authors
- José Bruno Malaquias (ORCID: https://orcid.org/0000-0003-3937-9575)
- Bruna Araújo Candido
- Silvio Lisboa de Souza (ORCID: https://orcid.org/0000-0001-8036-7483)
- Rosilda Mara Mussury (ORCID: https://orcid.org/0000-0002-8961-9146)
- Francisco de Sousa Ramalho (ORCID: https://orcid.org/0000-0001-8363-9237)
- Fábio Mielezrski (ORCID: https://orcid.org/0000-0003-3409-2479)
- Carlos Henrique de Brito (ORCID: https://orcid.org/0000-0002-0195-0986)
- Isabel Lopes de Medeiros
- Janayne Maria Rezende (ORCID: https://orcid.org/0000-0001-5287-3207)
- Luiz Fernando de Santana Santos (ORCID: https://orcid.org/0000-0002-8979-7030)
- Anderson Delfino Mauricio Nunes (ORCID: https://orcid.org/0009-0009-2844-2373)
- Bianca Marina Costa Nascimento (ORCID: https://orcid.org/0000-0003-0354-6132)
- Wanderlan Gonçalves Praxedes Júnior
Institutions
- Universidade de Ribeirão Preto (BR)
- Universidade Federal da Paraíba (BR)
- Universidade Federal da Grande Dourados (BR)
- Brazilian Agricultural Research Corporation (BR)
- University of Évora (PT)
- Fundação de Apoio a Pesquisa do Estado de Goiás (BR)
Publication Details
- Journal
- Microorganisms
- Published
- 2025-12-19
- DOI
- https://doi.org/10.3390/microorganisms14010001
- Primary Topic
- Viral Infectious Diseases and Gene Expression in Insects
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
- Conselho Nacional de Desenvolvimento Científico e Tecnológico
- Universidade Federal da Paraíba
- Pró-Reitoria de Pesquisa, Universidade Federal do Rio Grande do Sul