Biosecurity Efforts Research Articles

Four priority areas to advance invasion science in the face of rapid environmental change

Unprecedented rates of introduction and spread of non-native species pose burgeoning challenges to biodiversity, natural resource management, regional economies, and human health. Current biosecurity efforts are failing to keep pace with globalization, revealing critical gaps in our understanding and response to invasions. Here, we identify four priority areas to advance invasion science in the face of rapid global environmental change. First, invasion science should strive to develop a more comprehensive framework for predicting how the behavior, abundance, and interspecific interactions of non-native species vary in relation to conditions in receiving environments and how these factors govern the ecological impacts of invasion. A second priority is to understand the potential synergistic effects of multiple co-occurring stressors— particularly involving climate change—on the establishment and impact of non-native species. Climate adaptation and mitigation strategies will need to consider the possible consequences of promoting non-native species, and appropriate management responses to non-native species will need to be developed. The third priority is to address the taxonomic impediment. The ability to detect and evaluate invasion risks is compromised by a growing deficit in taxonomic expertise, which cannot be adequately compensated by new molecular technologies alone. Management of biosecurity risks will become increasingly challenging unless academia, industry, and governments train and employ new personnel in taxonomy and systematics. Fourth, we recommend that internationally cooperative biosecurity strategies consider the bridgehead effects of global dispersal networks, in which organisms tend to invade new regions from locations where they have already established. Cooperation among countries to eradicate or control species established in bridgehead regions should yield greater benefit than independent attempts by individual countries to exclude these species from arriving and establishing.

Inhibition of African swine fever virus in liquid and feed by medium-chain fatty acids and glycerol monolaurate

BackgroundThe ongoing African swine fever virus (ASFv) epidemic has had a major impact on pig production globally and biosecurity efforts to curb ASFv infectivity and transmission are a high priority. It has been recently identified that feed and feed ingredients, along with drinking water, can serve as transmission vehicles and might facilitate transboundary spread of ASFv. Thus, it is important to test the antiviral activity of regulatory compatible, antiviral feed additives that might inhibit ASFv infectivity in feed. One promising group of feed additive candidates includes medium-chain fatty acids (MCFA) and monoglyceride derivatives, which are known to disrupt the lipid membrane surrounding certain enveloped viruses and bacteria.ResultsThe antiviral activities of selected MCFA, namely caprylic, capric, and lauric acids, and a related monoglyceride, glycerol monolaurate (GML), to inhibit ASFv in liquid and feed conditions were investigated and suitable compounds and inclusion rates were identified that might be useful for mitigating ASFv in feed environments. Antiviral assays showed that all tested MCFA and GML inhibit ASFv. GML was more potent than MCFA because it worked at a lower concentration and inhibited ASFv due to direct virucidal activity along with one or more other antiviral mechanisms. Dose-dependent feed experiments further showed that sufficiently high GML doses can significantly reduce ASFv infectivity in feed in a linear manner in periods as short as 30 min, as determined by infectious viral titer measurements. Enzyme-linked immunosorbent assay (ELISA) experiments revealed that GML treatment also hinders antibody recognition of the membrane-associated ASFv p72 structural protein, which likely relates to protein conformational changes arising from viral membrane disruption.ConclusionTogether, the findings in this study indicate that MCFA and GML inhibit ASFv in liquid conditions and that GML is also able to reduce ASFv infectivity in feed, which may help to curb disease transmission.

306 Economic perspectives on biosecurity decision-making

Abstract African swine fever and many other livestock diseases present a host of challenges with a myriad of private and public good considerations. Chief among these challenges is identifying what drives livestock producer, self-protecting biosecurity efforts. Biosecurity adoption is an example of a private behavior that generates positive spillovers affecting the supply of a public good, that is, disease prevention. Encouraging producers to undertake specific biosecurity practices has proven useful in containing previous outbreaks of livestock disease in the United States, such as porcine epidemic diarrhea virus. Motivating producers to change production and management practices when a disease is not currently present in the United States can be much more difficult because of the (perceived or actual) lower probability of risk. National surveys of livestock producers were conducted to gain insight into decisions regarding ongoing and prospective biosecurity investment. Findings suggest producer and operation characteristics and diverse views on expected frequency of disease outbreaks, anticipated disease duration, and possible financial impact on operations underlie current and likely future biosecurity adoption. Furthermore, results point to both policy (e.g., indemnity provisions and cost sharing strategies) and market signals (e.g. market access and/or premiums paid or discounts incurred) from upstream livestock buyers have potential to incentivize biosecurity efforts.

Bioclimatic Modelling Identifies Suitable Habitat for the Establishment of the Invasive European Paper Wasp (Hymenoptera: Vespidae) across the Southern Hemisphere.

Species distribution models (SDMs) are tools used by ecologists to help predict the spread of invasive species. Information provided by these models can help direct conservation and biosecurity efforts by highlighting areas likely to contain species of interest. In this study, two models were created to investigate the potential range expansion of Polistes dominula Christ (Hymenoptera: Vespidae) in the southern hemisphere. This palearctic species has spread to invade North and South America, South Africa, Australia, and more recently New Zealand. Using the BIOCLIM and MAXENT modelling methods, regions that were suitable for P. dominula were identified based on climate data across four regions in the southern hemisphere. In South America areas of central Chile, eastern Argentina, parts of Uruguay, and southern Brazil were identified as climatically suitable for the establishment of P. dominula. Similarly, southern parts of South Africa and Australia were identified by the model to be suitable as well as much of the North Island and east of the South Island of New Zealand. Based on outputs from both models, significant range expansion by P. dominula is possible across its more southern invaded ranges.

Pet or pest? Stable isotope methods for determining the provenance of an invasive alien species

The illegal pet trade facilitates the global dispersal of invasive alien species (IAS), providing opportunities for new pests to establish in novel recipient environments. Despite the increasing threat of IAS to the environment and economy, biosecurity efforts often lack suitable, scientifically-based methods to make effective management decisions, such as identifying an established IAS population from a single incursion event. We present a proof-of-concept for a new application of a stable isotope technique to identify wild and captive histories of an invasive pet species. Twelve red-eared slider turtles (Trachemys scripta elegans) from historic Australian incursions with putative wild, captive and unknown origins were analysed to: (1) present best-practice methods for stable isotope sampling of T. s. elegans incursions; (2) effectively discriminate between wild and captive groups using stable isotope ratios; and (3) present a framework to expand the methodology for use on other IAS species. A sampling method was developed to obtain carbon (δ13C) and nitrogen (δ15N) stable isotope ratios from the keratin layer of the carapace (shells), which are predominantly influenced by dietary material and trophic level respectively. Both δ13C and δ15N exhibited the potential to distinguish between the wild and captive origins of the samples. Power simulations demonstrated that isotope ratios were consistent across the carapace and a minimum of eight individuals were required to effectively discriminate wild and captive groups, reducing overall sampling costs. Statistical classification effectively separated captive and wild groups by δ15N (captive: δ15N‰ ≥ 9.7‰, minimum of 96% accuracy). This study outlines a practical and accessible method for detecting IAS incursions, to potentially provide biosecurity staff and decision-makers with the tools to quickly identify and manage future IAS incursions.

Will an incentive-compatible indemnity policy please stand up? Livestock producer willingness to self-protect.

This study evaluates the role of private market signals and conditional indemnity policies in livestock producer willingness to self-protect against disease and invest more in biosecurity. Our focus on Tier 1 swine diseases and U.S. hog producer decision-making is timely and informative for a multitude of current disease discussions. We find biosecurity effort adjusts to economic incentives in private, livestock markets and public, indemnity policies.

The force of Varroa: Anticipatory experiences in beekeeping biosecurity

Abstract In the last decade, in light of unexpected death and disappearance rates, pollinators (especially honey bees) have received increasing attention. This attention includes what Anderson (2010) refers to as anticipatory actions: efforts to predict, prepare for, and even preempt future threats. Research on anticipatory actions has tended to focus on regulatory and macro-political concerns; however, in this paper, how anticipatory actions are experienced by those involved provides orientation. Drawing on ethnographic and policy work on beekeeping biosecurity in Australia, the paper explores how beekeeping is being reconfigured in anticipation of the arrival of a particular agricultural pest: Varroa destructor. Australia is one of the few places that remains free of this parasite. Its impacts are expected to be catastrophic, and the anticipatory actions undertaken are extensive. Exploring how beekeepers are participating in and responding to Varroa's influence (even in its absence) adds depth to consideration of anticipatory action, as well as offering insights into how honey bee biosecurity efforts are not simply technical matters but world-making.

Drivers of global Scolytinae invasion patterns.

Biological invasions are affected by characteristics of invading species, strength of pathway connectivity among world regions and habitat characteristics of invaded regions. These factors may interact in complex ways to drive geographical variation in numbers of invasions among world regions. Understanding the role of these drivers provides information that is crucial to the development of effective biosecurity policies. Here we assemble for the first time a global database of historical invasions of Scolytinae species and explore factors explaining geographical variation in numbers of species invading different regions. This insect group includes several pest species with massive economic and ecological impacts and these beetles are known to be accidentally moved with wood packaging in global trade. Candidate explanatory characteristics included in this analysis are cumulative trade among world regions, size of source species pools, forest area, and climatic similarity of the invaded region with source regions. Species capable of sib-mating comprised the highest proportion on nonnative Scolytines, and these species colonized a higher number of regions than outbreeders. The size of source species pools offered little power in explaining variation in numbers of invasions among world regions nor did climate or forest area. In contrast, cumulative trade had a strong and consistent positive relationship with numbers of Scolytinae species moving from one region to another, and this effect was highest for bark beetles, followed by ambrosia beetles, and was low for seed and twig feeders. We conclude that global variation in Scolytine invasions is primarily driven by variation in trade levels among world regions. Results stress the importance of global trade as the primary driver of historical Scolytinae invasions and we anticipate other hitchhiking species would exhibit similar patterns. One implication of these results is that invasions between certain world regions may be historically low because of past low levels of trade but future economic shifts could result in large numbers of new invasions as a result of increased trade among previously isolated portions of the world. With changing global flow of goods among world regions, it is crucial that biosecurity efforts keep pace to minimize future invasions and their impacts.

Stakeholders’ perceptions towards non-native acacias and implications for their management in Portugal

Abstract Humans act as drivers for the introduction of non-native trees. Some non-native species may become invasive and cause undesirable impacts, thereby motivating targeted decision-making and management actions. Australian acacias (or wattles; genus Acacia subgenus Phyllodineae) have been introduced worldwide, offering both opportunities and risks for local communities. Understanding how stakeholders perceive invasive acacias is paramount to assist effective decision-making. We assessed stakeholders’ perceptions about these non-native acacias, their invasion process, social-ecological impacts and management. We conducted a questionnaire-based survey with experienced managers and decision-makers in Northern Portugal, where acacia invasions are widespread. We found that most stakeholders are not able to recognize non-native species, failing to identify the introduction period, drivers of dispersion and appropriate management methods of Australian acacias. We could also identify different stakeholder perceptions on the benefits and negative impacts provided by these species. We call for the implementation of technical training and information outreach strategies to address stakeholders’ lack of knowledge (and experience) on the recognition and identification of non-native trees, as well as on their introduction and invasion history, drivers of dispersion, costs and benefits, and effective management actions. Stakeholders’ engagement should be promoted in the design and implementation of biosecurity efforts to control (and/or adapt to) invasive acacias at relevant scales of invasion management.

Establishment and eradication of an alien plant species in Antarctica: Poa annua at Signy Island

Invasive alien species are among the most significant conservation threats for Antarctica, and the South Orkney Islands are highly exposed to this threat because of their location and intensity of human activity. The alien flowering plant species Poa annua is known to occur at several locations in the Antarctic Peninsula and the South Shetland Islands. Here we report the first occurrence record of P. annua observed in the natural environment on Signy Island, South Orkney Islands. This archipelago is distant from previous records of the species in Antarctica (> 1500 km), and at local scale also distant (c. 2 km) from the main concentration of human activity close to the research station on the island. During the austral summer 2017/2018 we recorded one clump of P. annua on the island, and eradicated all individuals as well as removing the associated soil. No reproductive structures were apparent on the plants, and the soil did not contain a seed bank. Molecular analyses using available sequence data in GenBank confirmed the taxonomic species identification and, at a global scale identified six different haplotypes, confirming that the Signy Island material belongs to a distinct lineage within the species. Given Signy’s northern and relatively mild location in the maritime Antarctic, likely closer to the natural climatic and environmental niche of P. annua, the island may be at high risk of invasion, meaning that monitoring and biosecurity efforts need to be enhanced and extended well beyond the immediate vicinity of the research station area.

Genetic evidence for plural introduction pathways of the invasive weed Paterson's curse (Echium plantagineum L.) to southern Australia.

Paterson’s curse (Echium plantagineum L. (Boraginaceae)), is an herbaceous annual native to Western Europe and northwest Africa. It has been recorded in Australia since the 1800’s and is now a major weed in pastures and rangelands, but its introduction history is poorly understood. An understanding of its invasion pathway and subsequent genetic structure is critical to the successful introduction of biological control agents and for provision of informed decisions for plant biosecurity efforts. We sampled E. plantagineum in its native (Iberian Peninsula), non-native (UK) and invaded ranges (Australia and South Africa) and analysed three chloroplast gene regions. Considerable genetic diversity was found among E. plantagineum in Australia, suggesting a complex introduction history. Fourteen haplotypes were identified globally, 10 of which were co-present in Australia and South Africa, indicating South Africa as an important source population, likely through contamination of traded goods or livestock. Haplotype 4 was most abundant in Australia (43%), and in historical and contemporary UK populations (80%), but scarce elsewhere (< 17%), suggesting that ornamental and/or other introductions from genetically impoverished UK sources were also important. Collectively, genetic evidence and historical records indicate E. plantagineum in southern Australia exists as an admixture that is likely derived from introduced source populations in both the UK and South Africa.

Many unreported crop pests and pathogens are probably already present

Invasive species threaten global biodiversity, food security and ecosystem function. Such incursions present challenges to agriculture where invasive species cause significant crop damage and require major economic investment to control production losses. Pest risk analysis (PRA) is key to prioritize agricultural biosecurity efforts, but is hampered by incomplete knowledge of current crop pest and pathogen distributions. Here, we develop predictive models of current pest distributions and test these models using new observations at subnational resolution. We apply generalized linear models (GLM) to estimate presence probabilities for 1,739 crop pests in the CABI pest distribution database. We test model predictions for 100 unobserved pest occurrences in the People's Republic of China (PRC), against observations of these pests abstracted from the Chinese literature. This resource has hitherto been omitted from databases on global pest distributions. Finally, we predict occurrences of all unobserved pests globally. Presence probability increases with host presence, presence in neighbouring regions, per capita GDP and global prevalence. Presence probability decreases with mean distance from coast and known host number per pest. The models are good predictors of pest presence in provinces of the PRC, with area under the ROC curve (AUC) values of 0.75-0.76. Large numbers of currently unobserved, but probably present pests (defined here as unreported pests with a predicted presence probability >0.75), are predicted in China, India, southern Brazil and some countries of the former USSR. We show that GLMs can predict presences of pseudoabsent pests at subnational resolution. The Chinese literature has been largely inaccessible to Western academia but contains important information that can support PRA. Prior studies have often assumed that unreported pests in a global distribution database represent a true absence. Our analysis provides a method for quantifying pseudoabsences to enable improved PRA and species distribution modelling.

Adoption of Secure Pork Supply Plan Biosecurity by U.S. Swine Producers.

There is mounting concern about the negative animal health and supply chain consequences of animal disease outbreaks in the United States. Recent disease outbreaks have drawn attention to the need for additional understanding of biosecurity efforts to reduce disease frequency, spread, and impact. Biosecurity is a key component of the Secure Pork Supply (SPS) Plan designed to provide business continuity in the event of a foreign animal disease outbreak as well as help protect operations from endemic diseases. Core biosecurity recommendations outlined in the SPS Plan are a written site-specific biosecurity plan and implementation of a perimeter buffer area and a line of separation. To-date, no benchmarking of SPS Plan biosecurity implementation has been done. Utilizing data from a 2017 survey of U.S. swine producers, this study shows that SPS Plan biosecurity adoption varies and is affected by how feasible producers believe implementation of each biosecurity practice is on their operation. Furthermore, binomial logit regression analyses indicate producer and operation demographics and producer risk attitudes and perceptions affect biosecurity adoption. Conditional probabilities reveal that adoption of biosecurity practices is overwhelmingly complementary, suggesting that one biosecurity practice likely increases marginal efficacy of another biosecurity practice. The insights this study provides regarding the complexities of biosecurity adoption are vitally important to both educators and policy makers.

Towards a global DNA barcode reference library for quarantine identifications of lepidopteran stemborers, with an emphasis on sugarcane pests

Lepidopteran stemborers are among the most damaging agricultural pests worldwide, able to reduce crop yields by up to 40%. Sugarcane is the world’s most prolific crop, and several stemborer species from the families Noctuidae, Tortricidae, Crambidae and Pyralidae attack sugarcane. Australia is currently free of the most damaging stemborers, but biosecurity efforts are hampered by the difficulty in morphologically distinguishing stemborer species. Here we assess the utility of DNA barcoding in identifying stemborer pest species. We review the current state of the COI barcode sequence library for sugarcane stemborers, assembling a dataset of 1297 sequences from 64 species. Sequences were from specimens collected and identified in this study, downloaded from BOLD or requested from other authors. We performed species delimitation analyses to assess species diversity and the effectiveness of barcoding in this group. Seven species exhibited <0.03 K2P interspecific diversity, indicating that diagnostic barcoding will work well in most of the studied taxa. We identified 24 instances of identification errors in the online database, which has hampered unambiguous stemborer identification using barcodes. Instances of very high within-species diversity indicate that nuclear markers (e.g. 18S, 28S) and additional morphological data (genitalia dissection of all lineages) are needed to confirm species boundaries.

Public–Private Partnerships for Biosecurity: An Opportunity for Risk Sharing

AbstractPrivate efforts to prevent and control biological pests and infectious diseases can be a public good, and so incentivising private biosecurity management actions is both desirable and problematic. Compensation contracts can encourage biosecurity efforts, provide support against the collapse of economic sectors, and create an insurance network. We conceptualise a novel biosecurity instrument relying on formal compensation private–public partnerships using contract theory. Our framework explains how the public sector can harness increased private biosecurity measures by making payments to agents which depend both on their performance and that of the other stakeholders. Doing so allows the government to spread the risk across signatory agents. The framework also improves our understanding of government involvement due to public effects of biosecurity, influenced by the private agents’ capacity to derive private benefit from their own efforts on monitoring and control. Lastly, these theoretical results provide a foundation for further study of contractual responsibility sharing for pest management.

Multiplexed lateral flow immunoassay to discriminate Solenopsis invicta, Solenopsis richteri, and Solenopsis invicta × richteri hybrids

Solenopsis invicta and Solenopsis richteri are aggressive, highly invasive ant species from South America that were introduced into North America in the early part of the twentieth century. Biosecurity efforts in the US included the establishment of a quarantine to minimize the human-assisted spread of these ants. A limitation of the quarantine is rapid identification/discrimination of these ants when found entering non-quarantined areas. Using monoclonal antibodies designed toward S. invicta and S. richteri venom protein 2, we developed a multiplexed lateral flow immunoassay that provides a rapid and portable method for the identification of S. invicta, S. richteri, and the S. invicta × richteri hybrid. The multiplexed lateral flow immunoassay was validated against 39 unique ant species, and only S. invicta, S. richteri, and the S. invicta × richteri hybrid were detected. The assay did not detect proteins from the congener S. geminata known to produce a S. invicta venom protein 2 ortholog. The invasive fire ant multiplexed lateral flow immunoassay provides a new tool for regulatory agencies in the US to enforce quarantine protocols and limit the spread of these invasive ants.

Import volumes and biosecurity interventions shape the arrival rate of fungal pathogens.

Global trade and the movement of people accelerate biological invasions by spreading species worldwide. Biosecurity measures seek to allow trade and passenger movements while preventing incursions that could lead to the establishment of unwanted pests, pathogens, and weeds. However, few data exist to evaluate whether changes in trade volumes, passenger arrivals, and biosecurity measures have altered rates of establishment of nonnative species over time. This is particularly true for pathogens, which pose significant risks to animal and plant health and are consequently a major focus of biosecurity efforts but are difficult to detect. Here, we use a database of all known plant pathogen associations recorded in New Zealand to estimate the rate at which new fungal pathogens arrived and established on 131 economically important plant species over the last 133 years. We show that the annual arrival rate of new fungal pathogens increased from 1880 to about 1980 in parallel with increasing import trade volume but subsequently stabilised despite continued rapid growth in import trade and recent rapid increases in international passenger arrivals. Nevertheless, while pathogen arrival rates for crop and pasture species have declined in recent decades, arrival rates have increased for forestry and fruit tree species. These contrasting trends between production sectors reflect differences in biosecurity effort and suggest that targeted biosecurity can slow pathogen arrival and establishment despite increasing trade and international movement of people.

Establishment patterns of non-native insects in New Zealand

Insects comprise the majority of non-native animal species established around the world. However, geographic biases in knowledge hamper an overall understanding of biological invasions globally. A dataset of accidentally introduced non-native insect species established in New Zealand was compiled from databases, entomological literature, and examination of specimens in the New Zealand Arthropod Collection. For each non-native species, the first recorded location and first recorded date of detection was obtained. Excluding intentionally introduced species, there are 1477 non-native insect species successfully established in New Zealand across 16 orders, 234 families and 1017 genera. Four orders (Coleoptera, Hemiptera, Hymenoptera and Diptera) contributed 77.5% of all established insect species. Herbivores represented the largest feeding guild (47.7%), comprised of polyphagous (48.3%) or oligophagous (39.7%) species. The majority of these species originated in the Australasian (36.7%) and Palearctic regions (24.8%). Regression trees, using a binary recursive partitioning approach, found the number of international tourist arrivals, exotic vegetation cover, and regional gross domestic product were the main factors explaining spatial patterns of recently established species. Gross domestic product best explained temporal patterns of establishment over the last century. Our findings demonstrate that broad-scale analyses of non-native species have important applications for border biosecurity by providing insight into the extent of invasions. In New Zealand, the current trajectory indicates fewer non-native species are establishing annually, suggesting biosecurity efforts are being effective at reducing rates of establishment.

Biosecurity Implications for the Synthesis of Horsepox, an Orthopoxvirus.

This article examines the biosecurity and biodefense implications resulting from the recent creation of horsepox virus, a noncirculating (extinct) species of orthopoxvirus. Here we examine the technical aspects of the horsepox virus synthesis and conclude that orthopox synthesis experiments currently remain technically challenging-and will continue to be so, even once this work is published in the scientific literature. This limits potential misuse by some types of nefarious actors. We also examine the implications of one stated purpose for the recreation of horsepox virus: the development of a smallpox vaccine. If the development is successful, it could take advantage of US government incentives for the priority FDA review of medical countermeasures (MCMs) against biosecurity threats. However, if this case leads to the determination that this incentive is counterproductive for security, the newly created priority review voucher program should be more clearly defined or limited based on need. Limiting the program could have costs that require further consideration, however, as general incentives for biodefense medical countermeasure development are required for MCMs to be available. Finally, while the recreation of horsepox virus was not technically trivial, nor was it cell-free, this experiment was a de facto demonstration of already-assumed scientific capabilities. The ability to recreate horsepox, or smallpox, will remain no matter what policy controls are put into place. It will be impossible to close off all avenues for nefarious misuse of gene synthesis, or misuse of biological materials more broadly. As a result, we advocate for the implementation of policy, regulations, and guidance that will make illicit recreation harder, more burdensome, more detectable, and, thus, more preventable without having sweeping negative consequences for the research enterprise. As part of our biosecurity efforts, we must also encourage and enable scientists to participate actively and to do all they can to safeguard their technical fields from irresponsible or illicit actions.

PhytophthoraContamination in a Nursery and Its Potential Dispersal into the Natural Environment

A detailed site investigation of a eucalypt nursery suffering disease losses revealed the causal agent to be Phytophthora boodjera. The pathogen was detected in vegetation surrounding the nursery production area, including the lawn, under the production benches during the growing season, and, most importantly, from plant debris in used trays. However, it was not found in the container substrate, water supplies, or production equipment or on the workers themselves. The sterilization methods used by the nursery were shown to be ineffective, indicating that a more rigorous method was required. Boiling trays for 15 min or steaming at 65°C for 60 min eradicated P. boodjera. This pathogen was more pathogenic to the eucalypts tested in their early seedling stage than P. cinnamomi. Tracing of out-planting to revegetation sites showed that P. boodjera was able to spread into the environment. Dispersal via out-planting to native vegetation may affect seedling recruitment and drive long-term shifts in native plant species. Inadequate nursery hygiene increases the risk of an outbreak and can limit the success of biosecurity efforts as well as damage conservation efforts.