Endophytic fungi confirmed as entomopathogens of the new invasive pest, the fall armyworm, Spodoptera frugiperda (JE Smith) (Lepidoptera: Noctuidae), infesting maize in South Sumatra, Indonesia

Siti Herlinda,Radix Suharjo,Jelly Milinia Puspita Sari,Mimma Gustianingtyas,Suwandi Suwandi,Ragil Putri Lestari

doi:10.1186/s41938-021-00470-x

Abstract

BackgroundThe fall armyworm, Spodoptera frugiperda (JE Smith) (Lepidoptera: Noctuidae), is a new invasive pest in Indonesia causing financial losses. S. frugiperda larvae hide in the leaf midrib all day. To overcome the hidden larvae, pathogenic endophytic fungi are needed. The objective of this research was to molecularly identify the endophytic fungal species from South Sumatra and determine the most pathogenic species against S. frugiperda larvae. Endophytic fungal identification was based on morphological and molecular characteristics. The molecular identification was based on gene sequential analysis of Intergenic Transcribed Spacer (ITS) 1 and ITS 4. Bioassay of the endophytic fungal species was treated against the 2nd larval instar of S. frugiperda.ResultThe results of molecular identification revealed endophytic fungal species consisted of Chaetomium sp. (GaTpeOi, JgTjPr, PiCrPga, and CaCjPga isolates), Aspergillus niger (L.) Van Tieghem (PsgTjPr, JgByU, and JaBuBys), Beauveria bassiana (Balsamo) Vuillemin (JgSPK, JaGiP, JaSpkPGA(2), JgCrJr, and JaTpOi (1) isolates), Curvularia lunata (Wakker) Boed. (JaGiPRB, CMTJP, JaMsBys, JaSpkPga(3), and JgTgSr isolates), Aspergillus flavus Link. (JgPWSR isolate), Penicillium citrinum Thom F 1539 (JaTpOi(2) isolate), and Metarhizium anisopliae (Metschn.) Sorokin (CaTpPGA isolate). All fungal isolates were deposited in the GenBank. The endophytic fungal species of B. bassiana (JgSPK isolate) caused up to (22.67%) mortality, C. lunata (JaSpkPga(3) isolate) caused (17.33%) mortality, and M. anisopliae (CaTpPga isolate) caused (8%) mortality of the pest’s larvae. First report of B. bassiana and C. lunata isolated from maize (Zea mays L.), while M. anisopliae was isolated from red chili (Capsicum annuum L.) as entomopathogenic endophytic fungi against S. frugiperda larvae in Indonesia.ConclusionThe endophytic fungi species of B. bassiana, C. lunata, and M. anisopliae had potentials as entomopathogens of S. frugiperda.

Highlights

The fall armyworm, Spodoptera frugiperda (JE Smith) (Lepidoptera: Noctuidae), is a new invasive pest in Indonesia causing financial losses
The endophytic fungal species were identified based on the molecular analysis carried out at a laboratory accredited according to the ISO 17025 standard
Based on the similarity value, it is stated that if the similarity value is 100%, it means that the isolates are the same strain, whereas if the similarity value of 99% indicates that the isolates are the same species, and if the similarity value of the isolates is 89–99%, that means they are the same genus (Henry et al 2000)

Summary

Introduction

The fall armyworm, Spodoptera frugiperda (JE Smith) (Lepidoptera: Noctuidae), is a new invasive pest in Indonesia causing financial losses. Herlinda et al Egypt J Biol Pest Control (2021) 31:124 it has spread throughout the world and its first record in Indonesia was in March 2019 in West Sumatra (Sartiami et al 2020) and in July 2019 in South Sumatra (Hutasoit et al 2020). Larvae are found on the surface of leaves or maize stalks in the morning and hide in the leaves’ midribs (Gustianingtyas et al 2021). Such behavior makes it difficult to be controlled

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