Countries that are parties to international agreements such as the Convention on Biological Diversity (CBD) Kunming-Montreal Global Biodiversity Framework are required to manage biological invasions. Achieving these objectives, whether on a global or local scale, depends on a shared understanding among scientists, stakeholders, and authorities of the effectiveness of management practices. Despite extensive management interventions worldwide, there remains no consensus on what constitutes ‘success’ in biological invasions management. Building on our experience in the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) thematic assessment report on invasive alien species and their control, hereafter IPBES IAS assessment, this article reexamines what constitutes “successful management,” arguing that traditional ecology-centered approaches are insufficient. Rather, success must be defined through clear and measurable objectives that integrate ecological, social and economic dimensions. We emphasize the essential role of sustained long-term commitment, adequate funding, inclusive governance, and robust data systems in supporting effective and adaptive management. Particular attention is given to the need for monitoring, standardized data and indicators to link management actions to outcomes, while recognizing the importance of broad stakeholder engagement and knowledge exchange. By proposing an inclusive and adaptive approach, and encouraging transparency in communicating successes and failures, we provide a roadmap for strengthening management strategies. This perspective presents a transformative roadmap that redefines management success as an adaptive, evidence-based, and socially inclusive process aligned with global biodiversity and ‘Nature Positive’ goals.
Global food security and biosecurity are continually threatened by the prevalence and spread of plant pests with the ever-accelerating rate of global trade. The continuous advancement of artificial intelligence, such as large language models (LLMs) and machine learning, provides novel insights into plant pest risk management in the food trade, whereas their practical effectiveness remains insufficiently understood. Here, by integrating an LLM with the retrieval-augmented generation method, a machine learning-based network analysis and ecological niche modeling, we constructed a risk management framework and a decision support system to assess the multistage risk of pests in the citrus trade, thereby supporting priority risk management. The introduction risk of citrus pests tended to increase from 2003 to 2018, with 243 introduction risk pathways and 98 risk nodes, mainly including scale insects and fruit flies. Our findings highlight the high risk of co-introduction and co-establishment of multiple citrus pests at important citrus planting areas in southern China, as well as the risk of spread into high-latitude regions under climate change. The decision support platform demonstrated reliable citrus pest risk management performance. Additionally, our study provides novel insights into multistage risk management of plant pests with various trade pathways.
the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) released the most comprehensive global synthesis of the current knowledge on the biological invasion process and the impacts of invasive alien species, i.e., the Thematic Assessment Report on Invasive Alien Species and their Control (hereafter IPBES-IAS assessment, IPBES 2023a).This assessment includes data and knowledge from existing databases, peer-reviewed and gray literature, and knowledge from Indigenous Peoples and local communities to gain a global perspective on biological invasions across regions, ecosystems, and taxa (Figs.1,2).Here we place the IPBES-IAS assessment in the continuum of invasion science and policy history, describe the assessment process, and discuss the results.While Charles Darwin introduced a remarkable number of concepts relevant to invasion science
Although invasive alien species have long been recognized as a major threat to nature and people, until now there has been no comprehensive global review of the status, trends, drivers, impacts, management and governance challenges of biological invasions. The Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) Thematic Assessment Report on Invasive Alien Species and Their Control (hereafter 'IPBES invasive alien species assessment') drew on more than 13,000 scientific publications and reports in 15 languages as well as Indigenous and local knowledge on all taxa, ecosystems and regions across the globe. Therefore, it provides unequivocal evidence of the major and growing threat of invasive alien species alongside ambitious but realistic approaches to manage biological invasions. The extent of the threat and impacts has been recognized by the 143 member states of IPBES who approved the summary for policymakers of this assessment. Here, the authors of the IPBES assessment outline the main findings of the IPBES invasive alien species assessment and highlight the urgency to act now.
Prioritizing potential invasive alien species, introduction pathways, and likely places susceptible to biological invasions is collectively critical for developing the targeting of management strategies at pre-border, border, and post-border. A framework for prioritizing the invasion management that considered all these elements in combination is lacking, particularly in the context of potential coinvasion scenarios of multispecies. Here, for the first time, we have constructed a coupling framework of biological invasions to evaluate and prioritize multiple invasion risks of 35 invasive alien mealybugs (IAMs) that posed a significant threat to the agri-horticultural crops in China. We found that the imported tropical fruits from free trade areas of the Association of Southeast Asian Nations to entry ports of southern China were the primary introduction pathway for IAMs, vectored on various fruit commodities. There was also a high probability for cointroductions of potential multi-IAMs with a single imported tropical fruit. The potential distribution of such IAMs with dissimilar net relatedness were mainly located in southern China. These distributions, however, are likely to expand to the higher latitudes of northern China under future climate and land use/land cover changes. Temperature and anthropogenic factors were both independently and collectively determining factors for the diversity and distribution patterns of imported IAMs under near-current climate conditions. Our findings highlight that these multiple components of global change have and will continue to facilitate the introduction and establishment risks of IAMs in southern China, as well as the spread risk into northern China. Additionally, our findings, for the first time, demonstrated management prioritization across the continuous invasion stages of 35 IAMs in China, and provide additional insights into the development of targeting of their biosecurity and management decisions.
Inclusivity is fundamental to progress in understanding and addressing the global phenomena of biological invasions because inclusivity fosters a breadth of perspectives, knowledge, and solutions. Here, we report on how the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) assessment on invasive alien species (IAS) prioritized inclusivity, the benefits of this approach, and the remaining challenges.
In Zimbabwe, the structure and integrity of various ecosystems is rapidly deteriorating, in part due to invasive alien plants. While there is recognition of the challenges posed by invasive alien plants and the complexity surrounding their successful management, very little has been done, documented or evaluated in the country recently, including classical weed biological control activities. We review the current status of invasive alien plants and classical weed biological control in Zimbabwe especially their management and legislation governing this management. We record the presence and distribution of weed biological control agents currently in Zimbabwe. The Biological Control Target Selection (BCTS) system was used to identify invasive plant species in Zimbabwe that could benefit from on-going or new classical biological control programmes. While biological control has been implemented in the country since the 1960s, and significant control has been achieved on floating aquatic macrophytes, no biological agent has been released on a terrestrial weed since 1961. However, 10 agents released in neighbouring South Africa have spread naturally into the country on contiguous plant populations and some are providing gratuitous control of some of the weeds. We identified 19 invasive alien plants that could be successfully managed through classical weed biological control, and for 12 of these, this could be achieved at minimal cost, as agents are available within the region. Zimbabwe, perhaps with the help of international aid organisations investing in the region, could: a) conduct extensive surveys of established biological control agents already present in the country; b) redistribute these agents into areas of the country where they are not already present and foster those spreading north in South Africa and likely to arrive eventually through natural spread, and; c) initiate new weed biological control programmes against new targets by importing new agents available from South Africa or Australia.
The third objective of the Convention on Biological Diversity, the fair and equitable sharing of benefits arising out of the use of genetic resources was further developed when the Nagoya Protocol on Access and Benefit Sharing came into effect in 2014. Interpretation of how this agreement is being implemented is wide-ranging and there are implications for biological control. A survey of biological control workers indicated that while some countries have facilitated access to biological control genetic resources, requirements in other countries have impeded biological control implementation. There was consensus that benefits to provider countries should be in the form of supporting local research communities. There was also agreement that the free use and exchange of biological control genetic resources has provided benefits to the global community, including to both providers and recipients of the agents. It is recommended that consideration of the free use and exchange principal should be a key element of Access and Benefit Sharing measures for the future.
Invasive alien plant species (IAPs) are causing significant negative impacts on agricultural production, threatened native species and ecosystems, the services they provide and public health thereby affecting European biodiversity and its economy. IAPs invade all types of natural and managed habitat and their impacts, through increased numbers and area invaded, are growing exponentially. Current control options in Europe are largely limited to manual and chemical control, which is high cost, short-term in effectiveness and with regards to chemical control declining in public acceptability. Globally, classical biological control (CBC) is widely and successfully used to manage many IAPs. CBC aims to redress the ecological imbalance caused by the IAPs, generally being released without their natural enemies. The steps are to select, risk assess potential specific natural enemy biocontrol agents of the IAP (from the IAP's native range) and follow regulatory approval prior to releasing them to ecologically suppress their abundance. CBC is not widely used in Europe. Only five active programmes exist. In this paper, we apply an existing framework to develop a ranked list of environmental IAPs named in the EU Regulation on Invasive Species for biocontrol. We used a scoring system based on existing knowledge on the IAPs impacts, the amount of effort needed to deliver a CBC programme targeting them and the feasibility and likelihood of success of such programmes. We identify 16 IAPs in Europe for which CBC has relatively high potential and discuss existing knowledge that can underpin any future investments in such activities against each of these IAPs. The top three species being Pontederia crassipes, Pistia startiotes and Acacia saligna. This research should support decision-making on the instigation of future CBC programmes against environmental IAPs in Europe. We set this analysis in the context of other operational and regulatory constraints on developing CBC programmes against environmental IAPs in Europe.
The development of the field of biological control of weeds in Australia is described, from the first attempts in 1903 to the present day. The interest sparked by the obvious success of prickly pear program, apparent from 1930 to 1935, resulted in several programs during the next 20 years, followed by a decline in activity until the 1970s when activity increased enormously following the success of the skeleton weed program and the effective use of a plant pathogen for the first time. This momentum was maintained until the beginning of the present century with several successes and was marked by several important advances in genetic profiling, host-specificity testing, economic evaluation, conflict of interest resolution and the ecology of insect/plant interactions, including evaluation of the effectiveness of individual introductions. Biological control has proved to be a valuable and effective approach to weed management in Australia with 39% of all programs considered to produce complete or near-complete control, 30.5% partial control and an average benefit-cost ratio of 23:1. Funding for research has been variable with a decline from the late 1990s but with a significant increase again since 2020.
Recent advances in gene‐editing technologies have opened new avenues for genetic pest control strategies, in particular around the use of gene drives to suppress or modify pest populations. Significant uncertainty, however, surrounds the applicability of these strategies to novel target species, their efficacy in natural populations and their eventual safety and acceptability as control methods. In this article, we identify issues associated with the potential use of gene drives in agricultural systems, to control pests and diseases that impose a significant cost to agriculture around the world. We first review the need for innovative approaches and provide an overview of the most relevant biological and ecological traits of agricultural pests that could impact the outcome of gene drive approaches. We then describe the specific challenges associated with using gene drives in agricultural systems, as well as the opportunities that these environments may offer, focusing in particular on the advantages of high‐threshold gene drives. Overall, we aim to provide a comprehensive view of the potential opportunities and the remaining uncertainties around the use of gene drives in agricultural systems.
The legacy of deliberate and accidental introductions of invasive alien species to Australia has had a hefty economic toll, yet quantifying the magnitude of the costs associated with direct loss and damage, as well as for management interventions, remains elusive. This is because the reliability of cost estimates and under-sampling have not been determined. We provide the first detailed analysis of the reported costs associated with invasive species to the Australian economy since the 1960s, based on the recently published InvaCost database and supplementary information, for a total of 2078 unique cost entries. Since the 1960s, Australia has spent or incurred losses totalling at least US$298.58 billion (2017 value) or AU$389.59 billion (2017 average exchange rate) from invasive species. However, this is an underestimate given that costs rise as the number of estimates increases following a power law. There was an average 1.8–6.3-fold increase in the total costs per decade since the 1970s to the present, producing estimated costs of US$6.09–57.91 billion year-1 (all costs combined) or US$225.31 million–6.84 billion year-1 (observed, highly reliable costs only). Costs arising from plant species were the highest among kingdoms (US$151.68 billion), although most of the costs were not attributable to single species. Of the identified weedy species, the costliest were annual ryegrass (Lolium rigidum), parthenium (Parthenium hysterophorus) and ragwort (Senecio jacobaea). The four costliest classes were mammals (US$48.63 billion), insects (US$11.95 billion), eudicots (US$4.10 billion) and monocots (US$1.92 billion). The three costliest species were all animals – cats (Felis catus), rabbits (Oryctolagus cuniculus) and red imported fire ants (Solenopsis invicta). Each State/Territory had a different suite of major costs by species, but with most (3–62%) costs derived from one to three species per political unit. Most (61%) of the reported costs applied to multiple environments and 73% of the total pertained to direct damage or loss compared to management costs only, with both of these findings reflecting the availability of data. Rising incursions of invasive species will continue to have substantial costs for the Australian economy, but with better investment, standardised assessments and reporting and coordinated interventions (including eradications), some of these costs could be substantially reduced.
The historical record of releases of 288 species of weed biological control agents in Australia was analysed to examine if considering the damage/host type relationship of agents can offer insights into why some agents and not others have proved to be effective in producing partial or complete control of the target weed. Specifically, the effectiveness of agents released in Australia was examined in relation to their feeding guild and the functional group (growth form) of the target weed. Biotrophic pathogens (rusts/smuts), sap feeders and root/crown feeders were effective in producing control more often than other guilds. Effectiveness of biological control across weed functional groups was somewhat similar, although herbaceous biennials/perennials tended to be more effectively controlled than other functional groups. Significant biological control was recorded for at least one case in each of the 31 of the 37 feeding-guild/weed functional group combinations for which there were data. Possible explanations for the greater success of some guilds are explored, as are caveats with using such inductive approaches to predict effectiveness in classical weed biological control.
French broom (Genista monspessulana) (Fabaceae) is a perennial species native to the Mediterranean basin. Introduced in the 19th century as an ornamental plant, it is currently invasive in California and Australia. The current research is focused on biocontrol with the use of the phytophagous weevil Lepidapion argentatum (Brentidae). Its capacity to develop both in the stem galls and pods of French broom makes it a promising candidate. The impact on the reproduction of French broom was studied in Southern France and revealed that it could effectively reduce the number of viable seeds by 18.8%, but also increased the number of aborted seeds by 10% within the attacked pods. To evaluate the specificity of L. argentatum, choice and no-choice tests were performed in 2012 and 2015 on a total of 36 non-target closely related species. Results revealed the presence of galls and larvae in the stems of seven species, including two endemic Californian lupines; i.e., Lupinus arboreus blue and Lupinus chamissonis. In the future, new tests will be conducted to determine if L. argentatum is able to complete its entire development lifecycle on the non-target species where galls have previously been observed.
With the advent of new genetic technologies such as gene silencing and gene drive, efforts to develop additional management tools for weed management is gaining significant momentum. These technologies promise novel ways to develop sustainable weed control options because gene silencing can switch-off genes mediating adaptation (e.g. growth, herbicide resistance), and gene drive can be used to spread modified traits and to engineer wild populations with reduced fitness. However, applying gene silencing and/or gene drive is expected to be inherently complex as their application is constrained by several methodological and technological difficulties. In this review we explore the challenges of these technologies, and discuss strategies and resources accessible to accelerate the development of gene-tech based tools for weed management. We also highlight how gene technologies can be integrated into existing management tactics such as classical biological control, and their possible interactions.
The conical snail,Cochlicella acuta, is an introduced pest of grain crops in Australia. Biological control ofC. acutahas been attempted using the parasitoid fly,Sarcophaga villeneuveana, sourced from southern France, but has failed. Molecular genetics of the snails and climatic matching have suggested greater success might be realised using flies from southern Iberia (Spain and Portugal) or Morocco. We measured levels of parasitism ofC. acutabyS. villeneuveanaat several sites within southern Iberia, and near the previous fly release site in Australia. Emergence of flies was slightly higher in Iberia, compared with Australia, but 31% of theS. villeneuveanathat reached pupal stage withinC. acutain Iberia were hyperparasitised (up to 63% at individual sites). No hyperparasites emerged from Australian collections ofC. acuta. These data encourage further searches in southern Iberia for more effective populations ofS. villeneuveanafor use as biological control agents.
Invasive alien plants reduce ecosystem service delivery, resulting in environmental, economic and social costs. Here we review the returns on investment from biological control of alien plants that invade natural ecosystems. Quantifying the economic benefits of biological control requires estimates of the reductions in ecosystem goods and services arising from invasion. It also requires post-release monitoring to assess whether biological control can restore them, and conversion of these estimates to monetary values, which has seldom been done. Past studies, mainly from Australia and South Africa, indicate that biological control delivers positive and substantial returns on investment, with benefit:cost ratios ranging from 8:1 to over 3000:1. Recent studies are rare, but they confirm that successful biological control delivers attractive returns on investment, which increase over time as the value of avoided impacts accumulates.