Effects of fast and slow wilting soybean genotypes on fall armyworm (Spodoptera frugiperda) growth and development

Authors: AYALA, JESSICA - University Of Arkansas; VASQUEZ, ALEJANDRO - University Of Arkansas; BALAKRISHNAN, DEVI - University Of Arkansas; MADRIGAL, EVELYN - University Of Texas Rio Grande Valley; George, Justin; KARIYAT, RUPESH - University Of Arkansas

Submitted to: Communicative and Integrative Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/3/2024
Publication Date: 5/19/2024
Citation: Ayala, J., Vasquez, A., Balakrishnan, D., Madrigal, E., George, J., Kariyat, R. 2024. Effects of fast and slow wilting soybean genotypes on fall armyworm (Spodoptera frugiperda) growth and development. Communicative and Integrative Biology. 17. https://doi.org/10.1080/19420889.2024.2354421.
DOI: https://doi.org/10.1080/19420889.2024.2354421

Interpretive Summary: The fall armyworm (FAW, Spodoptera frugiperda), is considered as a major pest of soybean (Glycine max) worldwide. This study examined the impact of FAW feeding on 17 soybean accessions that vary in their water use efficiency (WUE) traits, by examining FAW growth and development traits along with plant growth response. Soybean accessions that vary in wilting speed were exposed to FAW damage for 48 hours at three different soybean growth stages (V3, R3, R6) and the growth and development of the FAW and soybeans were monitored. Development markers such as mass gain, pupal mass, and adult mass were observed for FAW, along with soybean height, number of leaves, trichome density, and yield. The potential influence of these soybean accession traits were also measured in a feeding initiation time study. Results showed that faster wilting soybean accessions grow taller and have more leaves than slower wilting accessions, but FAW survivorship and mass gain were lower on slower wilting accessions. Additionally, the yield was higher in the slower wilting soybean accessions compared to faster wilting soybeans. Soybean accessions with increased WUE are not forced to trade insect resistance or yield for WUE and instead we see an increased response by the plant to deter herbivory. Research findings from this study will have practical applications in selecting soybean lines with increased WUE and insect resistance to complement chemical applications by growers.

Technical Abstract: Soybean (Glycine max) is the most important plant protein source in the world for both humans and animals, and fall armyworm (FAW, Spodoptera frugiperda), is considered as a major pest of this row crop worldwide. The aim of this study was to examine the impact of FAW feeding on soybean accessions that vary in their water use efficiency (WUE) traits, by examining FAW growth and development traits along with plant growth response. Soybean accessions that vary in wilting speed were exposed to FAW damage for 48 hours at three different soybean growth stages (V3, R3, R6) and the growth and development of the FAW and soybeans were monitored. FAW development markers such as mass gain, pupal mass, and adult mass were observed, along with soybean height, number of leaves, trichome density, and yield. The potential influence of these traits were also measured in a feeding initiation time study. Results showed that faster wilting soybean accessions grow taller and have more leaves than slower wilting accessions, but FAW survivorship and mass gain were lower on slower wilting accessions. Additionally, the yield was higher in the slower wilting soybean accessions compared to faster wilting soybeans. Soybean accessions with increased WUE are not forced to trade insect resistance or yield for WUE and instead we see an increased response by the plant to deter herbivory. Research findings from this study can be used to generate soybean lines which display increased WUE and insect resistance to complement chemical applications by growers.