AUTHOR=Biswas Shreosi , Kundu Aditi , Suby S. B. , Kushwah Abran Singh , Patanjali Neeraj , Shasany Ajit Kumar , Verma Rajesh , Saha Supradip , Mandal Abhishek , Banerjee Tirthankar , Kumar Anil , Singh Anupama 

TITLE=Lippia alba—a potential bioresource for the management of Spodoptera frugiperda (Lepidoptera: Noctuidae)

JOURNAL=Frontiers in Plant Science

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2024.1422578

DOI=10.3389/fpls.2024.1422578

ISSN=1664-462X

ABSTRACT=<p>Fall armyworm (FAW), <italic>Spodoptera frugiperda</italic> (J.E. Smith), a threat to maize production systems, is a polyphagous pest of global significance. There is no registered bioinsecticide of botanical origin to provide green remedy against this pest of concern. The present study reports for the first time the potency of the polar and non-polar bioinsecticidal leads sourced from <italic>Lippia alba</italic> (Mill.) N.E. Br. leaves. Shade-dried leaves of <italic>L</italic>. <italic>alba</italic> were extracted and evaluated; based on preliminary bioassay, the ethyl acetate leaf extract of <italic>L</italic>. <italic>alba</italic> (<italic>LEAE</italic>) was found to be the most potent against FAW in the <italic>in vitro</italic> and <italic>in vivo</italic> studies. Ultraperformance liquid chromatography–quadrupole time-of-flight–mass spectrometric (UPLC-QToF-MS) analysis of <italic>LEAE</italic> revealed the rich chemical profile of 28 compounds, dominated by flavones, namely, naringenin, trihydroxy-dimethoxy flavone, and dihydroxy-trimethoxy flavone. Among others, glycosides, such as clerodendrin, calceolarioside E, forsythoside B, geniposide, and martynoside, and glucuronides, such as luteolin-7-diglucuronide, tricin-7-O-glucuronide, and luteolin-7-O-glucuronide, were also identified. <italic>LEAE</italic> exhibited exceptionally high <italic>in vitro</italic> [LC<sub>50</sub> = 6,900 parts per million (ppm)] and <italic>in vivo</italic> (computed as damage score on a scale of 1–9) insecticidal activity against <italic>S</italic>. <italic>frugiperda</italic>, with no phytotoxicity at a dose as high as 20 times of LC<sub>50</sub>. <italic>LEAE</italic> also exhibited significant antifeedant, ovicidal, and growth regulatory activity at the 70–16,000 ppm (w/v) concentration range. <italic>In silico</italic> assessment revealed strong binding of martynoside, calceolarioside E, and forsythoside B with acetylcholinesterase-, sodium-, and chloride-dependent γ-aminobutyric acid (GABA) receptor and ryanodine receptor, respectively, facilitated by hydrogen bonds (conventional and C–H bonds) stabilized by hydrophobic pi–sigma, pi–pi stacked, pi–alkyl, and alkyl interactions. The present study established <italic>L. alba</italic> as a potential bioresource and secondary metabolite enriched <italic>LEAE</italic> as bioinsecticide for further product development.</p>