How Ghana and Australia fought fall armyworm and what each learned from the other

Few invasive insects have moved across the planet as fast as the fall armyworm, Spodoptera frugiperda. Native to the Americas, the moth was first detected outside its home range in early 2016 in West Africa, reached Ghana the same year, and by 2019 had swept through sub-Saharan Africa, the Middle East, Southeast Asia and beyond. Its larvae feed on more than 350 plant species, but their taste for maize makes them uniquely threatening to Africa’s most widely cultivated staple crop. A new comparative analysis published in NeoBiota examines how Ghana and Australia prepared for, detected and responded to fall armyworm, and the findings carry a blunt message: both countries knew the pest was coming, both failed to keep it out, and what happened next depended far less on awareness than on how quickly each governance system converted that awareness into coordinated action.

The stakes are enormous. Crop insect pests alone are estimated to cause around US$14.4 billion in annual economic losses worldwide, and fall armyworm has become one of the most damaging invaders of cereal systems in Africa. Modelling studies show infestations can cut maize yields by up to 58% in affected regions, with combined impacts on major cereals across sub-Saharan Africa estimated at roughly US$13 billion per year. In Ghana, where maize is grown on about 1.3 million hectares with annual production near 3.5 million tonnes, fall armyworm infestations have reduced yields by 26.6 to 45%, equivalent to economic losses of US$177 to 284 million. Australia, which detected the pest in the Torres Strait Islands in early 2020, faces a predicted annual burden of A$14.2 to 39.3 million on producers within a decade of establishment, split between yield losses and increased production expenses.

The biology of the pest explains why containment is so difficult. Female moths lay egg masses of 100 to 200 eggs, with lifetime fecundity averaging around 1,500 and occasionally exceeding 2,000. Larvae feed for two to three weeks before pupating, burrowing into maize stems and cobs at multiple points, which complicates control. The species is highly migratory, capable of moving up to 2,000 kilometres annually, and thrives in warm climates. Molecular studies add a further twist: the Old World invasion involved multiple introduction events rather than a single spread, and population genomics supports an undocumented lag phase, implying the moth may have been present in some regions before the first official reports in 2016, overlooked or unreported. In Australia, genetic evidence points to more than one incursion, with Western Australian populations distinct from those in the east.

Australia’s response unfolded within a nationally coordinated biosecurity architecture. The Biosecurity Act 2015 provides national powers, state and territory laws supply enforcement for movement controls, and the Emergency Plant Pest Response Deed together with PLANTPLAN defines agreed procedures for incursions. Shortly after the first detection, in consultation with the Consultative Committee on Emergency Plant Pests, the National Management Group determined that eradication was not feasible, given the moth’s high reproductive capacity, long-distance dispersal, wide host range and the remoteness of infestations. That decision ended national eradication cost-sharing under the deed and shifted responsibility for ongoing control to state and territory governments, local councils and producers. The entire transition from detection to management occurred within weeks, a speed the analysis contrasts sharply with Ghana’s experience.

Surveillance technology is where Australia’s system shows its most advanced face. State-run and commercial smart-trap networks now integrate automated camera-enabled pheromone and light traps with machine learning to deliver near-real-time fall armyworm signals across production regions. Rapid in-field diagnostics using loop-mediated isothermal amplification confirm species identities within minutes, and wind-trajectory forecasting predicts moth movements, cueing earlier scouting and more targeted control. Quantitative monitoring data from the RapidAIM smart-trap network in Queensland show that, despite strong temporal fluctuations in pest pressure across key production regions, overall pest density declined after major peaks between 2024 and 2026, a trend the authors suggest may reflect the contribution of rapid post-border management. The Plant Biosecurity Research Initiative, linking seven plant research and development corporations with the federal department, has overseen more than AU$69 million in co-investment across over 20 collaborative projects since 2017.

Field management in Australia emphasises proactive monitoring and selective chemistry. When intervention is required, growers are advised to use selective insecticides such as spinosyns, emamectin benzoate and chlorantraniliprole, while pyrethroids are discouraged because of widespread resistance and harm to beneficial insects. Control targets small larvae before they establish in plant whorls, conserves natural enemies and adopts biological options including Bacillus thuringiensis and virus-based products. Resistance management relies on rotating insecticide classes, strategic spray decisions and protecting biological control agents. Genomic monitoring of Australian fall armyworm populations tracks the frequency of known resistance alleles, enabling earlier detection of emerging resistance phenotypes.

Ghana’s response took a different path. Fall armyworm was first reported in April 2016 in the Yilo Krobo District of the Eastern Region, and emergency control programmes initially focused on distributing subsidised synthetic insecticides. The government allocated US$4 million for emergency insecticide procurement and education in 2017. Between 2017 and 2023, the Ministry of Food and Agriculture procured and distributed 556,968 litres and 98,688 kilograms of insecticides to smallholder farmers, covering an estimated 2.49 million hectares. Studies show that 68 to 88% of maize farmers primarily relied on insecticides, with smaller proportions adopting improved maize varieties, soaps and detergents, or traditional practices like ash and sand applications. This overwhelming dependence has accelerated resistance, elevated costs and created environmental and health risks, particularly where run-off contaminates rural water sources.

The formal coordination machinery in Ghana arrived late. A 15-member National Taskforce was inaugurated on 10 May 2017, almost a year after the first official detection, drawing members from the National Disaster Management Organisation, the Environmental Protection Agency, the Council for Scientific and Industrial Research, development partners including USAID, DFID, CABI and GIZ, agribusinesses and farmer representatives. The taskforce organised itself into three subcommittees covering planning and coordination, management and surveillance, and awareness creation, and the Plant Protection and Regulatory Services Directorate compiled infestation statistics across all 261 districts. International collaborations with FAO and CABI promoted integrated pest management strategies, including crop rotation, intercropping, tolerant maize varieties and biological control. CABI’s Pest Risk Information Service, which integrates satellite data, pest life-cycle models and real-time field observations to deliver alerts by text message and Community Information Centres, improved the timing of control measures by over 30% and increased adoption of IPM practices by 9% in East African evidence. As a longer-term strategy, Ghanaian researchers with partners are advancing biological control by identifying promising egg parasitoids such as Telenomus remus, strengthening rearing capacity and coordinating pilot mass-rearing and release trials, while research programmes have developed maize varieties with improved resistance.

The comparison clarifies which practices are transferable and which are not. The most transferable are those that improve coordination and responsiveness without requiring heavy capital investment: simple escalation triggers, clearer allocation of institutional responsibilities, stronger farmer and extension reporting pathways, structured feedback loops from national agencies to local actors, and practical surveillance systems combining formal monitoring with community-based reporting. Australia’s smart-trap networks with automated image analysis and strict border quarantine, by contrast, demand major financial, institutional and intellectual investment before adoption elsewhere. Structural constraints also matter. Australia benefits from island geography, no land borders and relatively low population density, which reduce introduction pressure and make surveillance more manageable. Ghana operates with porous regional movement pathways, fewer public resources and greater reliance on externally supported programmes, differences that directly affect the cost, speed and sustainability of implementation.

The deeper lesson of the analysis is that biosecurity success should not be understood simply as eradication versus failure. A global review of 672 eradication programmes for plant pests found that about half achieved their objective, with success strongly linked to pest biology, speed of detection and resources committed, and eradication is rarely feasible for highly mobile, polyphagous pests once established. Australia’s experience with other invaders, such as myrtle rust and Varroa destructor, shows that strong governance can still lead to a transition from eradication to long-term management, while examples like fruit fly pest-free area systems demonstrate that governance, surveillance and movement control can support continued pest freedom under suitable conditions. For countries with constrained resources, the analysis argues, selective investment becomes especially important, emphasising systems that improve detection, reporting and coordination rather than expensive high-technology platforms. Once fall armyworm is established, effective long-term management depends on timely coordination, practical surveillance, insecticide resistance management, IPM development and sustained local capacity for safer, locally adapted control options, including greater investment in identifying, conserving and augmenting locally adapted natural enemies as a more durable regional approach than reliance on imported insecticides.

Subject of Research: Biosecurity

Article Title: Biosecurity responses to fall armyworm ( Spodoptera frugiperda ) in Ghana and Australia: Comparative analysis and practical implications

Article References: Hamza, P. F., Abbas, A., Ketting, P., & Etebari, K. (2026). Biosecurity responses to fall armyworm (Spodoptera frugiperda) in Ghana and Australia: Comparative analysis and practical implications. NeoBiota, 107, 155-174. https://doi.org/10.3897/neobiota.107.186265

Image Credits: AI Generated

DOI: 10.3897/neobiota.107.186265

Keywords: biosecurity, fall armyworm, Spodoptera frugiperda, invasive species, integrated pest management, food security, responses, fall, armyworm, Spodoptera, frugiperda, Ghana