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ARS Home » Southeast Area » Stoneville, Mississippi » Southern Insect Management Research » Research » Publications at this Location » Publication #405485
Research Project: Insect Control and Resistance Management in Corn, Cotton, Sorghum, Soybean, and Sweet Potato, and Alternative Approaches to Tarnished Plant Bug Control in the Southern United States

Location: Southern Insect Management Research

Title: Estimation of the Level of Economic Injury of Fall Armyworm (Spodoptera frugiperda) on Maize

Author
item THEJASWINI, SANGA - University Of Agricultural Sciences
item DESHMUKH, SHARANABASAPPA - University Of Agricultural Sciences
item HANUMANTHASWAMY, BAGIVALU - University Of Agricultural Sciences
item SOUMYA, THOGALERI - University Of Agricultural Sciences
item MALLIKARJUNA, HOSAMANE - University Of Agricultural Sciences
item Reddy, Gadi

Submitted to: Southwestern Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/12/2025
Publication Date: 7/11/2025
Citation: Thejaswini, S., Deshmukh, S.S., Hanumanthaswamy, B.C., Soumya, T.M., Mallikarjuna, H.B., Reddy, G.V. 2025. Estimation of the Level of Economic Injury of Fall Armyworm (Spodoptera frugiperda) on Maize. Southwestern Entomologist. 50(3):1-17. https://doi.org/10.3958/059.050.0308.
DOI: https://doi.org/10.3958/059.050.0308

Interpretive Summary: Maize (Corn) is an important crop worldwide, ranking third after rice and wheat among cereals worldwide. One of the most destructive pests of maize is the fall armyworm (FAW), a lepidopteran polyphagous pest indigenous to tropical and subtropical America. Pest management through IPM methods often includes developing and using economic threshold levels. We investigated the relationship between the larval density of FAW and yield loss in maize to determine the lowest pest population causing sufficient economic damage to justify control expenditures economically. Chemical pesticides can adversely impact the environment, and their rising costs have calculated EIL for important pests imperative. The studies indicated that Economic threshold levels for FAW on maize in India indicate were calculated as 0.75 of the Economic Injury Level (EIL) values, suggesting that Economic Threshold Level (ETL) values were 0.19, 0.22, and 0.46 larvae per plant, with an overall ETL value of 0.29 larvae per plant.

Technical Abstract: Studies on the economic injury level of fall armyworm (FAW), Spodoptera frugiperda (J. E. Smith), were carried out at Zonal Agricultural and Horticultural Research Station, in Shivamogga, India, during October 2020 and July 2021sown crop. Yield loss (%) increased with increasing larval density and declined with older crop stages. The highest yield loss of 49.1% and 43.5% occurred when three 2nd instar larvae were released per plant 15 or 25 days after sowing, versus 6.5% loss if one 2nd instar larva was released per plant 35 days after sowing on October 2021 and on July 2022 sown crop. In contrast, on July 2022 sown crop recorded the highest losses (50.1 and 41.1%) occurred when three 2nd instar larvae were released per plant 15 or 25 days after sowing, compared to 11.2% loss when one 2nd instar larva was released per plant released 35 days after sowing. the economic injury level for FAW on maize in the study region was calculated as 2.7, 3.0, and 6.8 larvae per 10 plants if present at 15, 25, and 35 days after sowing with an overall EIL of 4.0 larvae per 10 plants up to 35 DAS on the October 2021 sown crop. During July 2022, EIL values were 1.9, 2.2, and 4.1 larvae per 10 plants, with an overall EIL of 2.9 larvae per 10 plants for this period.