Abstract
The Fall armyworm (Spodoptera frugiperda), a formidable pest now widespread in Nepal, poses a major threat to maize production, underscoring the need for detailed biological insights to inform effective management strategies. Therefore, this study was conducted under laboratory conditions to assess the morphometric and biological parameters of FAW on Zea mays. Morphometric traits such as head capsule width and length, body length and width, adult body length, and wingspan were examined. Biological parameters, including the duration of larval instars, pre-pupal, pupal, and adult stages, were also analyzed. In larvae, the smallest measurements were recorded in the first instar (head capsule length 0.20±0.02 mm; width 0.31±0.02 mm; body length 1.48±0.08 mm; body width 0.30±0.03 mm), while the largest were observed in the sixth instar (2.85±0.09 mm, 2.86±0.06 mm, 33.23±0.43 mm, and 5.15±0.14 mm, respectively). Pupae measured 14.45±0.78 mm in length and 4.40±0.04 mm in width. The adult forewing span (30.5±1.6 mm) was larger than the hindwing span (22.6±1.0 mm), with a body length of 13.8±0.9 mm. Egg hatching took 2 days, and the larval stage lasted between 9 and 14.3 days. The pre-pupal and pupal stages lasted 2.20±0.47 and 9.08±0.90 days, respectively, followed by an adult lifespan of 5.50±1.50 days. The results shed light on the lifecycle, essential for understanding its population dynamics and guiding ecologically based management.
Keywords
References
- Atreya, K., Gartaula, H. N., & Kattel, K. (2025). Household seed security: A case of maize and wheat seed systems in the mountains of Nepal. Agricultural Systems, 229, 104419. https://doi.org/10.1016/j.agsy.2025.104419 [Google Scholar]
- Bankar, D. R., Bhamare, V. K., Mahajan, R. S., Najare, P. B., & More, A. S. (2025). Biology and life tables of invasive fall armyworm Spodoptera frugiperda on sunflower, Helianthus annuus. Journal of Environmental Biology, 46(2), 212-221. DOI: http://doi.org/10.22438/jeb/46/2/MRN-5373 [Google Scholar]
- Bhatti, Z., Ahmed, A. M., Khatri, I., Rattar, Q., Rajput, S., Tofique, M., & Younas, H. (2021). First report of morphometric identification of Spodoptera frugiperda JE Smith (Lepidoptera: Noctuidae) an invasive pest of maize in Southern Sindh, Pakistan. Asian Journal of Agriculture and Biology, 2021(01), 1-10. https://doi.org/10.35495/ajab.2020.03.169 [Google Scholar]
- Bista, S., Thapa, M. K., & Khanal, S. (2020). Fall armyworm: Menace to Nepalese farming and the integrated management approaches. International Journal of Environment, Agriculture and Biotechnology, 5(4), 1001–1018. https://doi.org/10.22161/ijeab.54.21 [Google Scholar]
- Bogati, S., Kunwar, S. R., & Amgain, L. P. (2021). Assessment of nutrient expert ®-hybrid maize model on productivity and profitability of winter maize in Terai region of eastern Nepal. Heliyon, 7(10), e08096. https://doi.org/10.1016/j.heliyon.2021.e08096 [Google Scholar]
- Chaudhary, S., Patel, C. J., & Ghetiya, L. V. (2023). Biology and Morphometrics of Fall Armyworm Spodoptera frugiperda (J. E. Smith) on Maize. International Journal of Current Microbiology and Applied Sciences, 12(5), 184–198. https://doi.org/10.20546/ijcmas.2023.1205.025 [Google Scholar]
- Chen, G. M., Alam, A., Ge, C., Khan, K. A., Ghramh, H. A., Ali, J., Tonğa, A., Li, Q., & Chen, R. (2025). Steinernema carpocapsae as a promising biological control agent against Spodoptera frugiperda pupae. Crop Protection, 197, 107369. https://doi.org/10.1016/j.cropro.2025.107369 [Google Scholar]
- Chisonga, C., Chipabika, G., Sohati, P. H., & Harrison, R. D. (2023). Understanding the impact of fall armyworm (Spodoptera frugiperda J. E. Smith) leaf damage on maize yields. PLOS ONE, 18(6), e0279138. https://doi.org/10.1371/journal.pone.0279138 [Google Scholar]
- Choudhari, V. N., Bhamare, V. K., More, D. G., Magar, S. J., & Hinge, V. R. (2024). Biology and biometrics of fall armyworm, Spodoptera frugiperda (J.E. Smith) on fodder maize. International Journal of Advanced Biochemistry Research, 8(12), 767–773. https://doi.org/10.33545/26174693.2024.v8.i12j.3278 [Google Scholar]
- Dessie, B., Ferede, B., Taye, W., & Shimelash, D. (2024). Field infestation of the invasive fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae) on maize in Southern Ethiopia. Crop Protection, 178, 106587. https://doi.org/10.1016/j.cropro.2024.106587 [Google Scholar]
- EL-Lebody, K. A., Allam, R. D. A., & Rashad, A. M. (2024). Morphology, damage symptoms and biology of Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) strains in Egypt. Egyptian Academic Journal of Biological Sciences. A, Entomology, 17(4), 17–26. https://doi.org/10.21608/eajbsa.2024.389023 [Google Scholar]
- Fan, Z., Song, Y., Zhao, S., & Wu, K. (2024). Invasion of fall armyworm led to the succession of maize pests in Southwest China. Journal of Integrative Agriculture, 23(4), 1300–1314. https://doi.org/10.1016/j.jia.2023.09.016 [Google Scholar]
- Firake, D. M., & Behere, G. T. (2020). Bioecological attributes and physiological indices of invasive fall armyworm, Spodoptera frugiperda (J. E. Smith) infesting ginger (Zingiber officinale Roscoe) plants in India. Crop Protection, 137, 105233. https://doi.org/10.1016/j.cropro.2020.105233 [Google Scholar]
- G. C., S., Bhusal, A., & Khatri, L. (2020). An introduction of fall armyworm (Spodoptera frugiperda) with management strategies: a review paper. Nippon Journal of Environmental Science, 1(4), 1010. https://doi.org/10.46266/njes.1010 [Google Scholar]
- Hailu, T., Getu, E., Wagari, M., Muluken, G., & Tesfaye, T. (2024). Biology and host preference studies of Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae) in Ethiopia. SINET: Ethiopian Journal of Science, 46(3), 326–339. https://doi.org/10.4314/sinet.v46i3.9 [Google Scholar]
- Hong, S., Titayavan, M., Intanon, S., & Thepkusol, P. (2022). Biology and life table parameters of fall armyworm, Spodoptera frugiperda on three maize cultivars grown in Thailand. Chiang Mai University Journal of Natural Sciences, 21(1), e2022001. https://doi.org/10.12982/CMUJNS.2022.001 [Google Scholar]
- Huang, L. L., Xue, F. S., Chen, C., Guo, X., Tang, J. J., Zhong, L., & He, H. M. (2021). Effects of temperature on life‐history traits of the newly invasive fall armyworm, Spodoptera frugiperda in Southeast China. Ecology and Evolution, 11(10), 5255-5264. [Google Scholar]
- Kalyan, D., Mahla, M. K., Babu, S. R., Kalyan, R. K., & Swathi, P. (2020). Biological parameters of Spodoptera frugiperda (J. E. Smith) under laboratory conditions. International Journal of Current Microbiology and Applied Sciences, 9(5), 2972–2979. https://doi.org/10.20546/ijcmas.2020.905.340 [Google Scholar]
- Kasige, R. H., Dangalle, C. D., Pallewatta, N., & Perera, M. T. M. D. R. (2022). Egg cluster characteristics of fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae) in Sri Lanka under laboratory conditions. Journal of Agricultural Sciences–Sri Lanka, 17(1). [Google Scholar]
- Khatun, M. M., Ali, M. R., Hossain, M. S., Hoque, M. M., & Latif, M. A. (2022). Biology and Morphometrics of Fall Armyworm, Spodoptera frugiperda on Maize Plant. Bangladesh Journal of Agricultural Research, 47(2), 225-239. [Google Scholar]
- Kusi, F., Nboyine, J. A., Adjebeng-Danquah, J., Agrengsore, P., Seidu, A., Quandahor, P., Sugri, I., Adazebra, G. A., Agyare, R. Y., Asamani, E., Kwabena, J. Y., Otchere-Darko, E., & Etwire, P. M. (2024). Effect of insecticides and intercropping systems on fall armyworm (Spodoptera frugiperda (J.E. Smith)) infestations and damage in maize in northern Ghana. Crop Protection, 186, 106909. [Google Scholar]
- Lekha, M. K., Swami, H., Vyas, A. K., & Ahir, K. C. (2020). Biology of fall armyworm, Spodoptera frugiperda (JE Smith) on different artificial diets. Journal of Entomology and Zoology Studies, 8, 584-586. [Google Scholar]
- Madali, H., Behera, U. K., Ranasingh, N., Rout, M. K., Behera, P., Das, S., Satapathy, C. R., & Padhi, J. (2025). Developmental biology and morphometric of Spodoptera frugiperda (J.E. Smith, 1797) in laboratory conditions. International Journal of Advanced Biochemistry Research, SP-9(4), 195–200. https://www.doi.org/10.33545/26174693.2025.v9.i4Sc.4092 [Google Scholar]
- Maharani, Y., Puspitaningrum, D., Istifadah, N., Hidayat, S., & Ismail, A. (2021). Biology and life table of fall armyworm, Spodoptera frugiperda (JE Smith) (Lepidoptera: Noctuidae) on maize and rice. Serangga, 26(4), 161-174. [Google Scholar]
- Manjula, K., Saheb, Y. P., Sudheer, M. J., & Rao, A. R. (2019). Studies on biology, feeding habits and natural enemies of fall armyworm, Spodoptera frugiperda, a new invasive pest in India. Journal of Entomology and Zoology Studies, 7(6), 1245-1250. [Google Scholar]
- Marri, D., Mensah, S. A., Kotey, D. A., Abraham, J., Billah, M. K., & Osae, M. (2023). Basic developmental characteristics of the fall armyworm, Spodoptera frugiperda (JE Smith) (Lepidoptera: Noctuidae), reared under laboratory conditions. Psyche: A Journal of Entomology, 2023(1), 6917316. https://doi.org/10.1155/2023/6917316 [Google Scholar]
- Mohamed, H. O., Dahi, H. F., Awad, A. A., Gamil, W. E., & Fahmy, B. F. (2023). Damage symptoms, development, and reproductive performance of the fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) on fodder maize and cob. Academia Biology, 1(1), 1-10. https://doi.org/10.20935/AcadBiol6073 [Google Scholar]
- Navasero, M. M., & Navasero, M. V. (2020). Life cycle, morphometry and natural enemies of fall armyworm, Spodoptera frugiperda (JE Smith) (Lepidoptera: Noctuidae) on Zea mays L. in the Philippines. Journal of the International Society for Southeast Asian Agricultural Sciences, 26(2), 17-29. [Google Scholar]
- Neupane, S., Pokhrel, S., Tiwari, S., Bhandari, G., Adhikari, P., & Poudel, S. (2023). Biology and Morphometrics of Fall armyworm (Spodoptera frugiperda) in Chitwan, Nepal. International Journal of Applied Biology, 7(2). https://doi.org/10.20956/ijab.v7i2.32027 [Google Scholar]
- Ojumoola, O. A., & Omoloye, A. A. (2022). Biology and morphometrics of the fall armyworm, Spodoptera frugiperda J. E. Smith (Lepidoptera: Noctuidae) in Ibadan, southwest Nigeria. FUDMA Journal of Agriculture and Agricultural Technology, 8(1), 351-363. [Google Scholar]
- Rajisha, P. S., Muthukrishnan, N., Nelson, S. J., Jerlin, R., Marimuthu, P., & Karthikeyan, R. (2022). Biology and nutritional indices of the fall army worm Spodoptera frugiperda (JE Smith) on maize. Indian Journal of Entomology, 84(1). [Google Scholar]
- Reddy, N. A., Saindane, Y. S., Chaudhari, C. S., & Landage, S. A. (2021). Biology of fall armyworm Spodoptera frugiperda (J.E. Smith) on maize under laboratory conditions. The Pharma Innovation Journal, 10(9), 1997–2001. [Google Scholar]
- Sairam, M., Maitra, S., Sagar, L., Biswas, T., Bárek, V., Brestic, M., & Hossain, A. (2025). Application of precision nutrient tools for the optimization of fertilizer requirements and assessment of the growth and productivity of maize (Zea mays L.) in the northeastern Ghat of India. Journal of Agriculture and Food Research, 21, 101958. https://doi.org/10.1016/j.jafr.2025.101958 [Google Scholar]
- Sharma, S., Tiwari, S., Thapa, R. B., Neupane, S., Reddy, G. V., Pokhrel, S., & Muniappan, R. (2022). Life cycle and morphometrics of fall armyworm (Spodoptera frugiperda) (Lepidoptera: Noctuidae) on maize crop: Life cycle and morphometrics of fall armyworm. SAARC Journal of Agriculture, 20(1), 77-86. https://doi.org/10.3329/sja.v20i1.60532 [Google Scholar]
- Siddhapara, M. R., Patel, K. M., & Patel, A. G. (2021). Biology and morphometrics of fall army worm Spodoptera frugiperda (JE Smith) on Maize. Indian Journal of Entomology. https://doi.org/10.5958/0974-8172.2020.00257.6 [Google Scholar]
- Wang, M., Huang, W., Dong, Y., Huang, Y., Zhang, B., Sun, G., Elkahky, M., & Huang, C. (2025). Temporal analyses of global suitability distribution for fall armyworm based on multiple factors. Ecological Indicators, 171, 113181. [Google Scholar]
- Woo Heo, J., Bin Kim, S., & Kim, D.-S. (2022). Effects of intergenerational host plant alterations on developmental parameters of Spodoptera frugiperda (Lepidoptera: Noctuidae). Journal of Asia-Pacific Entomology, 25(3), 101945. [Google Scholar]
- Youssef, M. A. M., Bakry, M. M. S., & Abdel-Baky, N. F. (2024). Effect of maize hybrids on the biological characteristics of the fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), under laboratory conditions. Brazilian Journal of Biology, 84, 1-10. https://doi.org/10.1590/1519-6984.283850 [Google Scholar]

