Jurnal Hama dan Penyakit Tumbuhan Tropika

Pheromone-based monitoring and population dynamics of Spodoptera frungiperda: implications for maize IPM in Lampung Province, Indonesia

2026-01-19T03:56:39+00:00

Spodoptera frugiperda is a major pest of maize, capable of causing damage throughout all crop growth stages. This study evaluated the use of sex pheromone traps to monitor adult male populations of S. frugiperda, characterize population dynamics during maize growth, and determine optimal trap density under field conditions. A trap density experiment was conducted using four pheromone trap densities (10, 20, 30, and 40 trap/ha⁻¹), each replicated five times. Adult moth captures were recorded at 7-day intervals from trap installation until harvest. In a separate assessment, the intensity of leaf and ear damage was compared between maize plots equipped with pheromone traps and conventional plots without pheromone deployment. Adult capture data revealed clear population fluctuations, with peak abundance occurring during the early vegetative stage of maize, followed by a gradual decline toward harvest. Increasing trap density significantly increased the number of male moths captured, indicating a density-dependent response to pheromone deployment. Maize plots with pheromone traps consistently exhibited lower leaf and ear damage than conventional plots, demonstrating a strong association between reduced adult populations and decreased crop injury. These results indicate that pheromone traps are effective tools for monitoring S. frugiperda populations and for identifying critical intervention periods within an integrated pest management (IPM) framework. While primarily serving as monitoring devices, higher trap densities also showed potential to reduce mating success when deployed over sufficiently large areas. The species-specific nature of pheromone traps further supports environmentally sustainable pest management by minimizing non-target effects.

Molecular detection and characterization of potato virus Y-NTN and cucumber mosaic virus-S in microtubers and G0 tubers of red and Granola potato

2025-11-25T03:10:29+00:00

This study aimed to detect and molecularly characterize viruses infecting microtubers and G0 tubers of red and Granola potato varieties produced by PT. G10 Agrotechnology, Medan, Indonesia. A total of 50 microtubers and 50 G0 tubers from each variety were collected and tested using serological methods, including enzyme-linked immunosorbent assay (ELISA) and dot immunobinding assay (DIBA), followed by reverse transcription polymerase chain reaction (RT-PCR) and nucleotide sequence analysis. Serological and molecular assays showed that all microtuber samples were free from potato virus Y (PVY), potato virus X (PVX), potato virus S (PVS), and cucumber mosaic virus (CMV). In contrast, G0 tubers were infected by PVY and CMV, whereas PVX and PVS were not detected. The incidence of PVY and CMV reached 80.0% and 82.0%, respectively, in red potato G0 tubers and 28.0% for both viruses in Granola G0 tubers. RT-PCR successfully amplified the coat protein (CP) genes of PVY and CMV, producing fragments of approximately 801 bp and 657 bp, respectively. Sequence and phylogenetic analyses identified the PVY isolates as belonging to the PVY-NTN strain and the CMV isolates as closely related to the CMV soybean stunt strain (CMV-S). These findings indicate that microtubers produced through tissue culture were virus-free, whereas viral infection occurred during the screen-house multiplication stage. The results provide important baseline information for virus monitoring and management strategies to support the production of high-quality potato seed in Indonesia.

Overview of infestation status and management of the rice leaffolder, Cnaphalocrocis medinalis (Guenée) (Lepidoptera: Pyralidae), in Malaysian paddy areas

2025-10-31T03:29:58+00:00

The rice leaffolder, Cnaphalocrocis medinalis (Guenée) (Lepidoptera: Pyralidae), is a major foliar pest of rice (Oryza sativa L.) across Asia, including Malaysia, where recent outbreaks have re-established it as a significant constraint to rice productivity. This review synthesizes current knowledge on its biology, life cycle, feeding behavior, and ecological interactions within Malaysian rice agroecosystems. Available evidence indicates that pest outbreaks are closely associated with environmental factors, particularly high humidity and dense crop canopies, while natural enemies—including parasitoids and predators—play a critical role in regulating field populations. Habitat management practices, such as the introduction of flowering plants along rice bunds, may enhance natural enemy activity and contribute to the suppression of rice leaffolder populations. In addition, augmentative biological control using Trichogramma spp. represents a promising strategy for early-stage suppression of the pest. Integrating these ecological and biological approaches within an Integrated Pest Management (IPM) framework offers a viable pathway to reduce reliance on chemical inputs while improving system resilience. This review also identifies key research gaps and provides directions for developing locally adapted, sustainable management strategies for C. medinalis in Malaysia.

First report of Fusarium incarnatum causing fruit rot of chili pepper in Indonesia

2025-10-23T07:16:13+00:00

Chili pepper (Capsicum annuum L.) is a widely cultivated horticultural crop with significant potential as an export commodity. Fruit rot of chili pepper was recorded in Lubuk Cuik village, North Sumatra Province, Indonesia. One hundred and fifty symptomatic fruits were randomly collected from four locations using purposive random sampling. Fungal colonies were isolated from infected fruits until pure cultures were obtained. Pure colonies observed for macroscopic examination exhibited abundant, dense white aerial mycelia with a brown–yellowish base. Microscopic observations revealed numerous long and slender macroconidia, 3–5 septate, with a curved shape and tapering ends. Microconidia were rare, pyriform to obovate in shape, and mostly 0–1 septate. Chlamydospores were thick-walled, intercalary, globose, and produced singly or in chains. Molecular identification was performed using the internal transcribed spacer (ITS) and translation elongation factor (TEF-1α) regions. The pathogenicity of the eight Fusarium incarnatum isolates was tested twice. The morphological characteristics, phylogenetic analysis, and pathogenicity assay confirmed that all isolates were consistent with Fusarium incarnatum. This study represents the first confirmed report of F. incarnatum causing fruit rot of chili pepper in Indonesia.

Fumigant activity of three aromatic essential oils against fruit fly Bactrocera carambolae

2025-10-21T05:56:17+00:00

Essential oils have attracted considerable attention as environmentally friendly alternatives to synthetic insecticides because of their selective neurotoxicity, high volatility, and rapid biodegradability. This study investigated the chemical composition and fumigant toxicity of the essential oils of Melaleuca cajuputi, Amomum cardamomum, and Myristica fragrans against the fruit fly Bactrocera carambolae. The chemical constituents of each oil were characterized by gas chromatography–mass spectrometry (GC–MS), and their fumigant toxicity was evaluated by determining the median lethal concentration (LC50) and 90% lethal concentration (LC90). GC–MS analysis identified 27 compounds in M. cajuputi oil, with 1,8-cineole (34.88%), α-terpineol (10.52%), β-caryophyllene (10.44%), α-humulene (5.74%), and limonene (5.15%) as the major constituents. A. cardamomum oil contained 32 compounds and was dominated by 1,8-cineole (60.48%), followed by β-pinene (8.24%) and α-terpineol (5.35%). In contrast, M. fragrans oil contained 12 compounds, with sabinene (21.51%), α-pinene (17.34%), terpinen-4-ol (15.92%), β-pinene (15.10%), β-phellandrene (8.72%), and α-terpinene (5.95%) as the principal constituents. Among the three oils, M. fragrans exhibited the highest fumigant toxicity against B. carambolae, with LC50 and LC90 values of 0.05 and 0.48 μL/L, respectively, followed by M. cajuputi (LC50 = 0.82 μL/L; LC90 = 1.48 μL/L) and A. cardamomum (LC50 = 2.58 μL/L; LC90 = 3.43 μL/L). The superior fumigant toxicity of M. fragrans was associated with its characteristic mixture of monoterpene hydrocarbons and oxygenated monoterpenes, whereas the high proportion of 1,8-cineole in A. cardamomum alone did not result in greater toxicity. These findings demonstrate that M. fragrans essential oil is a promising botanical fumigant for the management of B. carambolae and highlight the importance of overall chemical composition rather than the abundance of a single constituent in determining fumigant efficacy.