Jul 2026· East African Journal of Agriculture and Biotechnology· Vol 9, pp. 296-315· 0 citations· 32 references
TL;DR
The inverse relationship between larval weight and development duration highlights the role of maize genotype in influencing FAW growth dynamics, with resistant varieties prolonging development and suppressing larval biomass accumulation.
Abstract
Maize (Zea mays L) has lost its natural defence mechanisms against herbivorous pests due to domestication and artificial selection that focused on productivity rather than pest resistance. The fall armyworm (FAW) has become an invasive pest of maize and other crops in Africa. The objective of this study was to determine the effect of maize genotypes, SC DUMA43, SC SUNGURA301, HARAKA WH101, Yellow landrace, Red landrace and FAWTH2003 on FAW feeding and development. The experiment was set in a laboratory in a no-choice bioassay in a Complete Randomised Design (CRD) replicated three times. Data was collected on the leaf weight after feeding, leaf damage score, larval mortality, average larvae weight, instar progression, larval period, pupation duration, average pupal weight, adult sex ratio and total lifecycle. Data was tested for normality and subjected to analysis of variance (ANOVA) using SAS v. 9.3.0. Genotype SC Sungura 301 and Haraka WH 101 were more preferred by FAW with leaf portion losses of 2.83g and 2.86g respectively, compared to FAWTH2003 with leaf portion loss of 2.02g. Maize genotypes had a significant (p ≤ 0.001) effect on larval weight, mortality and development time. FAWTH2003 had the highest mortality of the larvae at p ≤ 0.0001 significance. The larvae that fed on HARAKA WH101 had the heaviest larval weight (0.15 g) with the shortest larval duration (16.33 ± 0.88 days), suggesting superior nutritional quality and high susceptibility to infestation. In contrast, those larvae that fed on the FAWTH2003 genotype had the lightest larval weight (0.10g) and the longest duration (19.67±1.20 days), suggesting cases of antibiosis and possible antixenosis effects that reduced growth and delayed development. The inverse relationship between larval weight and development duration highlights the role of maize genotype in influencing FAW growth dynamics, with resistant varieties prolonging development and suppressing larval biomass accumulation. Integrating host plant resistance (HPR) in FAW management is necessary as an Integrated Pest Management (IPM) strategy.
The fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), is a devastating pest of maize, and host plant resistance offers a sustainable alternative to chemical control. This study evaluated the resistance of the maize germplasm CH1 against FAW through life table parameters, feeding and oviposition preferences and greenhouse experiment. Results showed that FAW larvae reared on CH1 exhibited significantly prolonged larval development (21.61 d vs. 12.49 d), reduced survival (65.00% vs. 94.00%), and lower fecundity (689.00 vs. 1369.93 eggs per female) compared to those on the susceptible control Huang C. Population parameters, including the intrinsic rate of increase (r) and net reproductive rate (R0), were significantly lower on CH1. Behavioral assays revealed strong feeding and oviposition preferences for Huang C over CH1. Greenhouse experiment confirmed that CH1 plants sustained only minor damage (Davis scale grade 2, resistant), whereas Huang C plants were severely damaged (grade 7, susceptible). These findings demonstrate that CH1 possesses multi-dimensional resistance against FAW, providing a promising genetic resource for breeding FAW-resistant maize varieties and supporting sustainable pest management strategies.
Spodoptera frugiperda is now widely distributed and has become a serious constraint to maize production in Asia and other regions. This pest has adverse effects on maize growth and yield, causing significant economic losses. Evaluating the responses and defense mechanisms of corn to S. frugiperda is essential. This study evaluated oviposition preference, leaf damage intensity, and trichome traits among 11 maize genotypes and one commercial hybrid used as a control. Oviposition preference was assessed under choice-test conditions by recording the number of egg clusters, total eggs, and egg-laying position on each genotype. Damage intensity was evaluated after artificial infestation with second-instar larvae, whereas trichome density and trichome length were measured microscopically. The fewest egg clusters were observed on the PG2 genotype (540 eggs), with most eggs positioned on the underside (abaxially) of the leaves. The lowest average damage intensity over four observations occurred in the PG7 genotype (32.27%), whereas the highest average trichome density was observed in the PG2 genotype (17.00/10mm²), and the longest average trichome length was observed in the PG7 genotype treatment (1.01 mm). Among all treatments, the PG7 genotype was the most resistant, showing lower damage intensity than the others. Identifying more resistant genotypes will help develop superior corn varieties that are resistant to S. frugiperda attacks and support sustainable agriculture.
Keywords: Spodoptera frugiperda, corn resistance, oviposition preference, trichome, damage intensity.
Salim Salim, Sulaeha Sulaeha· Journal of Global Innovation...· 0 citations
The laboratory efficacy of three plant-based oil extracts (Ricinus communis, cashew nut shell liquid (CNSL), and Thevetia neriifolia), together with two positive controls (Topbio and the entomopathogenic fungus BotaniGard 22WP), was evaluated in this study for the management of S. frugiperda. Second and third instar larvae were exposed to increasing doses of each treatment, and larval mortality, feeding rate, weight gain, and mean observation time were recorded over a 14 day period. The experiment was arranged in a completely randomized block design with three replicates per treatment. A beta regression model was applied to analyze larval mortality in relation to treatment type and dose. Significant differences (p < 0.05) were observed among the tested biopesticides. Cashew nut shell liquid extracts resulted in the highest larval mortality from concentrations ≥2%, followed by Topbio and the entomopathogenic fungus BotaniGard 22WP, which also significantly reduced larval feeding and development. Extracts of R. communis and T. neriifolia exhibited moderate efficacy. Furthermore, Topbio and cold-extracted CNSL showed the lowest LD₅₀ values (0.0067984 and 0.0069042, respectively), indicating high toxicity against S. frugiperda larvae. Overall, the findings demonstrate the potential of biopesticides as effective alternatives to chemical insecticides and emphasize the need for optimization of their formulations and application strategies to enhance field-level performance.
Keywords: fall armyworm; maize; biological control; biopesticides.
Fernand Amoussou Sotondji, K. Karlsson Green, S. Azonkpin et al.· African Journal of Tropical...· 0 citations
Infestation by the invasive fall armyworm-FAW (Spodoptera frugiperda) pest has recently emerged as an important constraint for maize (Zea mays L) production, which is frequently managed using chemical pesticides. However, the inappropriate use of chemical pesticides can cause deleterious effects on the environment and humans, and enhance pest resistance. This study evaluated the potential of locally produced microbial inoculants and plant bioactive extracts, and push-pull strategy of cowpea (Vigna unguiculata) intercropping as control measures for FAW infestation on maize plants, while serving as nutrient replenishing source via biological nitrogen fixation. This field study was setup as split plot in two alternate cropping seasons (September 2021 and April 2022) and cropping systems (mono- and inter-cropping) as main plots, and seven treatments as sub-plots (Control, chemical–NPK+Lamida gold, Tithonia diversifolia–Ti+Piper guineense–Pi, Plant growth-promoting bacteria–PGPB+Endophytic fungi–EF, EF+Pi and PGPB+EF+Ti+Pi). Results highlight statistical identical performance of microbial inoculants or plant bioactive extracts and chemical pesticides in reducing FAW infestation by 13-73.9 %. Bio-amendments significantly (P<0.05) increased maize height, 1000 maize grain weight, cob length and degree of filling compared to the untreated control. Maize-cowpea intercrop significantly increased FAW infestation in some treatments when compared to maize monocrop. In September 2021, FAW infestation correlated (P<0.05) negatively with 1000 maize grain weight (r = -0.7), cob length (r = -0.7), number of grains on the longest line (r = -0.8) and degree of filling (r = -0.7) in the monocrop plot. These findings highlight the ability of locally produced microbial inoculants and plant bioactive extracts as sustainable alternatives to mitigate FAW infestation on maize. Thereby, opening up possibilities for further investigation on mechanisms of action that can be explored for biological pest control.
Schneideur Ndongho Tanting, Marie Noela Olougou Enyoe, A. Tening et al.· Asian Journal of Advances in...· 0 citations
Data suggest that combining silicon-induced resistance with T. pretiosum biological control offers an effective and durable approach to controlling fall armyworm while improving maize performance.
K. Haider, Muhammad Sufian, Dilawar Abbas et al.· Journal of plant diseases an...· 0 citations
Background: Fall armyworm (Spodoptera frugiperda J. E. Smith) is an invasive insect pest of maize that can cause substantial foliar damage and adversely affect crop production. Host-plant resistance offers a sustainable and environmentally compatible approach for managing this pest; however, information on resistance in diverse maize germplasm remains limited. Therefore, identifying resistant genotypes is important for supporting the development of fall armyworm-resistant maize.
Aims: The present study screened 25 maize genotypes for resistance to the invasive insect pest fall armyworm under artificial infestation conditions.
Study Design: A randomised block design (RBD) with three replications was used.
Place and Duration of Study: The study was conducted during Kharif 2025 at the Winter Nursery Centre, ICAR-Indian Institute of Maize Research, Rajendranagar, Hyderabad.
Methodology: Fall armyworm larvae were reared on a chickpea-casein-based artificial diet, and first instar neonates were released onto plants at the V5 phenological stage. Leaf damage rating (LDR) was scored on a 1-9 scale at 7, 14, and 21 days after infestation (DAI); genotypes were categorised as resistant (1-3), moderately resistant (3-6), and susceptible (6-9).
Results: The LDR at 14 days after infestation varied from 2.58 to 7.34 across genotypes. Three genotypes, CML 71 (2.81), DMRE-63 (2.58), and CML 67 (2.92), were classified as resistant; 19 genotypes were moderately resistant; and three genotypes, MIL 9-1662 (6.2), CM 202 (6.44), and Sarhad HSRB (7.34), were susceptible.
Conclusion: The resistant genotypes identified in this study may serve as valuable sources of resistance for incorporation into maize breeding programmes aimed at developing FAW-resistant genotypes.
Unknown authors· Journal of Advances in Biolo...· 0 citations
