Pest Risk Assessment Research Articles

Phyllocnistis citrella Stainton, 1856 Control Methods in the Lankaran-Astara Region

Research has been carried out on the biology and ecology of Phyllocnistis citrella Stainton. This is one of the main pests of lemon and tangerine gardens in Azerbaijan. To combat this pest, various agricultural methods and chemicals were used. The most effective combinations have been identified. A detailed description is given in the work. Guidelines for pest risk assessment have been developed, emphasizing measures to protect citrus orchards from heavy infestation by Phyllocnistis citrella.

Assessment of the potential area for the establishment of the Colorado potato beetle in Finland and Sweden

Summary The Colorado potato beetle (CPB, Leptinotarsa decemlineata) is a protected zone quarantine pest in the southern parts of Finland and Sweden. The units responsible for pest risk assessments in Finland and Sweden were requested to identify the geographical areas likely to be suitable for establishment of the CPB given a climate change scenario that covers the years 2023–2040. Based on previous studies, the northern limit of the potential range of the CPB appears to depend, above all, on where the summer temperatures enable the development of one complete generation. To identify such areas in Finland and Sweden, we first estimated the annual growing degree day (GDD) requirement (above 10 °C) of the CPB based on the two‐decade mean annual GDD in the northernmost locations where the CPB is present in Russia. The lowest mean annual GDD among these locations was 587 which was used as the GDD requirement of the CPB in this assessment. Next, we delineated the areas in Finland and Sweden where this GDD requirement was met in a recent time period (2003–2022) and in a future time period (2031–2050) assuming an intermediate greenhouse gas emission scenario, i.e., Representative Concentration Pathway (RCP) 4.5. The results show that the GDD requirement of 587 is met in large areas in southern Finland and Sweden, and by 2040, also in central Finland and the Baltic Sea coastline. We further assessed that there are enough hosts for the CPB to enable establishment in these areas. These areas were therefore assessed as likely to be suitable for the establishment of the CPB. Importantly, they include areas much further north than the current protected zones. This result was assessed to be rather robust since even a 20% higher GDD requirement (704) was met in a much larger area than the protected zones both in Sweden (in the recent and future climate) and in Finland (in the future climate). The greatest sources of uncertainty in the assessment are the uncertainty of the annual GDD that the CPB needs to complete its life cycle, the future climate projections, and the abundance of hosts necessary in a landscape to enable the CPB to establish.

Mechanistic microclimate models and plant pest risk modelling

AbstractClimatic conditions are key determining factors of whether plant pests flourish. Models of pest response to temperature are integral to pest risk assessment and management, helping to inform surveillance and control measures. The widespread use of meteorological data as predictors in these models compromises their reliability as these measurements are not thermally coupled to the conditions experienced by pest organisms or their body temperatures. Here, we present how mechanistic microclimate models can be used to estimate the conditions experienced by pest organisms to provide significant benefits to pest risk modelling. These well-established physical models capture how landscape, vegetation and climate interact to determine the conditions to which pests are exposed. Assessments of pest risk derived from microclimate conditions are likely to significantly diverge from those derived from weather station measurements. The magnitude of this divergence will vary across a landscape, over time and according to pest habitats and behaviour due to the complex mechanisms that determine microclimate conditions and their effect on pest biology. Whereas the application of microclimate models was once restricted to relatively homogeneous habitats, these models can now be applied readily to generate hourly time series across extensive and varied landscapes. We outline the benefits and challenges of more routine application of microclimate models to pest risk modelling. Mechanistic microclimate models provide a heuristic tool that helps discriminate between physical, mathematical and biological causes of model failure. Their use can also help understand how pest ecology, behaviour and physiology mediate the relationship between climate and pest response.

Preparing Colombian coffee production for climate change: Integrated spatial modelling to identify potential robusta coffee (Coffea canephora P.) growing areas

Meeting future demand for coffee under climate change is a challenge. Approaches that can inform where coffee may grow best under current and future climate scenarios are needed. Robusta coffee (Coffea canephora P.) is planted in many tropical areas and makes up around 40% of the world’s coffee supply. However, as the climate shifts, current robusta areas may become less productive, while in other areas new growing regions for robusta may emerge. Colombia is one of the world’s most important Arabica coffee producer, famous for its high-quality coffee. Although robusta coffee is not yet a commercial crop in Colombia, it could be one of the future bastions for robusta coffee in South America contributing to meeting the increasing demand, but this remains unexplored. We aimed to identify areas with highest biophysical and socio-economic potential to grow robusta coffee in Colombia. An integrated modelling approach was used, combining climate suitability and crop-yield modelling for current and future climate scenarios, soil constraints, pest risk assessment and socio-economic constraints to identify the regions with the highest potential productivity and the lowest pest and climate change risks with good market access and low security risks which don’t further expand the agricultural frontier. Our results showed that parts of the foothills along the eastern Andean Mountain ranges, the high plains of the Orinoquía region and the wet parts of the Caribbean region are the best candidates for the potential development of robusta coffee plantations in Colombia. The crop-yield model indicated highest yields of green coffee on the foothills of the eastern Andean Mountain range with an estimated average yield of 2.6 t ha−1 (under rain-fed conditions) which is projected to occur at elevations below 600 m avoiding interference with the traditional and established Arabica coffee regions in Colombia. Under a 2 °C global warming scenario climate change is projected to have the largest impacts on the Caribbean region. Therefore, larger scale irrigated production system could be an appropriate option in the Caribbean region, while diversified smallholder robusta coffee agroforestry systems are considered more favourable in the Orinoquía region.

Including climate change in pest risk assessment: Current practices and perspectives for future implementation

AbstractThe evaluation of the potential for newly arrived species to survive and the determination whether a founder population can become established and subsequently spread and cause negative impacts are crucial considerations when performing a pest risk assessment in plant health. Climate change has clear consequences concerning the potential range of pests, and their potential for spread and impacts. Despite its importance, no guidance exists to support the evaluation of whether and how climate change should be incorporated into pest risk assessment. This paper reviews how climate change has been considered so far, not only in the area of pest risk assessment but also in other domains and provides guidance on how its incorporation could affect the overall assessment. Furthermore, from this analysis, some possible solutions for incorporating climate change into pest risk assessment are provided, taking into account that its outcomes have profound political, economic, social and environmental implications.

Climate change in pest risk assessment: Interpretation and communication of uncertainties

AbstractThe prevailing climatic conditions found in a region are the primary determinant of the suitability of that area to support pests and diseases. Pest risk assessment is the primary biosecurity tool used to assess that suitability, but the changing climatic conditions owing to greenhouse gas emissions are rarely considered. Future changes in temperature and rainfall patterns may make the environmental suitability of a region more or less favourable for existing populations and cause populations to move to other regions where those pests and diseases may not be established. Future projections of climate change are uncertain, which makes it challenging to incorporate climate change into pest risk analysis, but aspects of human psychology can help us think about how to communicate the risks within the constraints of those uncertainties more effectively. Here we review the broad trends, magnitude and uncertainties of climate change, and the interpretation of climate change scenarios, and make recommendations for appropriate framing and communication of the future risks posed by climate change within pest risk assessments.

Modelling tools for including climate change in pest risk assessments

AbstractThis paper provides a comprehensive overview of the modelling tools available for integrating climate change impacts into pest risk assessments (PRA), elucidating the existing methodologies and models employed to understand the potential distributions of pests based on historical data and under future climate change scenarios. We highlight the strengths and weaknesses of these models and provide commentary on their ability to identify emerging threats due to climate change accurately and adequately, considering pest establishment likelihood, host crop exposure and the distribution of impacts. The simplest methods are based on climate‐matching models, degree‐day development models and Köppen–Geiger climate classification. Correlative species distribution models derive species–environment relationships and have been applied to PRA with mixed success. When fitted models are applied to different continents they are usually challenged to extrapolate climate suitability patterns outside the climate space used to train them. Global climate change is creating novel climates, exacerbating this ‘transferability’ problem. Some tools have been developed to reveal when these models are extrapolating. Process‐oriented models, which focus on mechanisms and processes rather than distribution patterns, are inherently more reliable for extrapolation to novel climates such as new continents and future climate scenarios. These models, however, require more skill and generally more knowledge of the species to craft robust models.

Nanoparticle-delivered RNAi-based pesticide target screening for the rice pest white-backed planthopper and risk assessment for a natural predator

Vacuolar-type (H+)-ATPase (vATPase) is a conserved multi-subunit eukaryotic enzyme composed of 14 subunits that form a functional complex consisting of an ATP-hydrolytic domain (V1) and a proton-translocation domain (V0). ATP hydrolysis and subsequent H+ translocation rely heavily on a fully assembled V1/V0 complex. Since vATPase is crucial for insect survival, it is a viable molecular target for pest control. However, detailed functional analyses of the 14 subunits and their suitability for pest control have not been fully explored in a single insect species. In this study, we identified 22 vATPase subunit transcripts that correspond to 13 subunits (A1, A2, B, C, D, E, F, G, H, a1, a2, c and d) in the white-backed planthopper (WBPH), Sogatella furcifera, a major hemipteran pest of rice. RNAi screens using microinjection and spray-based methods revealed that the SfVHA-F, SfVHA-a2 and SfVHA-c2 subunits are critical. Furthermore, star polymer (SPc) nanoparticles were utilized to conduct spray-induced and nanoparticle-delivered gene silencing (SI-NDGS) to evaluate the pest control efficacy of RNAi targeting the SfVHA-F, SfVHA-a2 and SfVHA-c2 transcripts. Target mRNA levels and vATPase enzymatic activity were both reduced. Honeydew excreta was likewise reduced in WBPH treated with dsRNAs targeting SfVHA-F, SfVHA-a2 and SfVHA-c2. To assess the environmental safety of the nanoparticle-wrapped dsRNAs, Cyrtorhinus lividipennis Reuter, a major natural enemy of planthoppers, was also sprayed with dsRNAs targeting SfVHA-F, SfVHA-a2 and SfVHA-c2. Post-spray effects of dsSfVHA-a2 and dsSfVHA-c2 on C. lividipennis were innocuous. This study identifies SfVHA-a2 and SfVHA-c2 as promising targets for biorational control of WBPH and lays the foundation for developing environment-friendly RNAi biopesticides.

The first host plant dataset of Curculionidae Scolytinae of the world: miscellaneous Tribes

Tribes Coriacephilini, Corthylini, Cryphalini, Ernoporini, Trypophloeini, Xyloctonini, and Xyloterini (Coleoptera: Curculionidae; Scolytinae) include spermophagous, phloeophagous, and xylomycetophagous species. Besides direct damage caused by burrowing into host plant tissues, some species are vectors of aggressive pathogens causing plant dieback and death, with consequent economic and ecological relevance. The international trade in plants and wood products is one of the main pathways for the introduction of non-native species worldwide. In this context, data availability on host plants and their economic uses is essential in pest risk assessment and for planning effective detection and monitoring strategies against invasive species. This paper provides a complete and updated list of host plants, with economic categorization, for 2139 scolytine species.

Bioclimatic similarity between species locations and their environment revealed by dimensionality reduction analysis

Species distribution modeling is an active research topic with applications in conservation management, pest risk assessment, and population ecology. Several machine-learning methods have been applied to estimate species distribution. Non-linear dimensionality reduction techniques aim to preserve the similarity among objects at a reduced dimension for visualization, clustering, and feature selection. We propose a framework that uses Uniform Manifold Approximation and Projection (UMAP) to analyze bioclimatic variables associated with environmental (background) and species samples. Our objective was to identify geographic areas similar to those inhabited by the species. We hypothesize that the similarity between species locations and their environment in the reduced dimension will reflect similarity in the multivariate bioclimatic space. We estimated the probability of background points near a species point utilizing the latent nearest neighbor distance distribution. We tested this procedure with ten insect pest species of global importance and found that UMAP was able to generate a gradient of similarity between geographic areas and species occurrence. We also found that background-species latent distance tends to have a convergent non-linear relationship with the mean value of bioclimatic variables, thus supporting our key assumption. The performance of UMAP as a binary classifier and comparison with MaxEnt supports its use in modeling of species distribution. Potential applications are discussed for multi-species and multi-scenario analysis, as well as projection to new regions.

The application of demographic characteristics of Ectropis grisescens (Lepidoptera: Geometridae) in pest risk assessment of IPM.

Ectropis grisescens Warren is one of the most important pests of tea plants. In this study, data on the development, survival, and fecundity of E. grisescens were collected at 15, 22, and 32 °C and analyzed by using the age-stage, two-sex life table. At 15 °C, the duration of the preadult period of E. grisescens was significantly prolonged (81.06 days), with high mortality (69.0%), and the proportion of emerged female adults was extremely low (7.0%). At 32 °C, the preadult period was significantly shortened (29.12 days), with high preadult mortality (74.0%), and a low proportion of emerged female adults (15.0%). At 22 °C, with low preadult mortality (24.0%), and a high proportion of emerged female adults (26.0%). The overall effects of the shorter preadult duration, higher preadult survival rate, higher proportion of emerged female adults, higher fecundity (F = 350.88 eggs/♀), and higher net reproductive rate (R0 = 91.23 offspring/individual) at 22 °C resulted in the highest values of the intrinsic rate of increase (r = 0.1054 days-1) and finite rate of increase (λ = 1.1112 days-1). Computer simulation showed that E. grisescens populations can increase much faster at 22 °C than at 15 and 32 °C. The weighted population size and cumulative weighted insect-days provided the dynamics necessary for estimating the damage potential of E. grisescens in devising economical pest management programs. Our results demonstrate that populations of E. grisescens were able to develop at a broad range of temperatures and adapt to the high temperatures. These finding can be utilized to improve the management of E. grisescens.

Assessment of the probability of introduction of Thaumatotibia leucotreta into the European Union with import of cut roses.

Following a request from the European Commission, the EFSA Panel on Plant Health performed a quantitative pest risk assessment to assess whether the import of cut roses provides a pathway for the introduction of Thaumatotibia leucotreta (Lepidoptera: Tortricidae) into the EU. The assessment was limited to the entry and establishment steps. A pathway model was used to assess how many T.leucotreta individuals would survive and emerge as adults from commercial or household wastes in an EU NUTS2 region climatically suitable in a specific season. This pathway model for entry consisted of three components: a cut roses distribution model, a T. leucotreta developmental model and a waste model. Four scenarios of timing from initial disposal of the cut roses until waste treatment (3, 7, 14 and 28 days) were considered. The estimated median number of adults escaping per year from imported cut roses in all the climatically suitable NUTS2 regions of the EU varied from 49,867 (90% uncertainty between 5,298 and 234,393) up to 143,689 (90% uncertainty between 21,126 and 401,458) for the 3- and 28-day scenarios. Assuming that, on average, a successful mating will happen for every 435 escaping moths, the estimated median number of T. leucotreta mated females per year from imported cut roses in all the climatically suitable NUTS2 regions of the EU would vary from 115 (90% uncertainty between 12 and 538) up to 330 (90% uncertainty between 49 and 923) for the 3- and 28-day scenarios. Due to the extreme polyphagia of T. leucotreta, host availability will not be a limiting factor for establishment. Climatic suitability assessment, using a physiologically based demographic modelling approach, identified the coastline extending from the northwest of the Iberian Peninsula through the Mediterranean as area suitable for establishment of T. leucotreta. This assessment indicates that cut roses provide a pathway for the introduction of T. leucotreta into the EU.

Jewels on the go: exotic buprestids around the world (Coleoptera, Buprestidae)

Buprestidae (Coleoptera: Buprestoidea) is one of the three wood-borer beetle groups of major phytosanitary interest worldwide, together with Cerambycidae and Scolytinae (Curculionidae). As in other beetle families, some buprestid species have been unintentionally or intentionally introduced around the world, in some cases causing significant environmental and economic damage in the invaded territories. Despite the phytosanitary relevance of the Buprestidae, information regarding the identity of exotic buprestids, their biogeographic areas of origin, introduction pathways, and larval host plants, have remained scattered in the literature. Our objective was to summarize much of the existing knowledge on these topics in the present paper. Our analysis resulted in a list of 115 exotic buprestids worldwide, representing introductions both within and between biogeographic realms and corresponding to less than 1% of the known buprestid species worldwide. Invasiveness does not seem to be linked to their larval host plant preferences, as introduced species utilize 158 plant genera in 70 plant families and are equally represented in all feeding guilds (monophagous, oligophagous, and polyphagous). As trade of plants or plant parts can serve as a pathway for future introductions, the information reported in this review can help in pest risk assessment.

Preface

The emerging pest and disease incursions in coconut growing countries result in great economic yield losses and negative impact to the industry, biodiversity loss, and disrupted native and agricultural system.Repeated use of the same active ingredient of pesticide to control pests and diseases could lead to pest and disease resistance. The inevitable effect of climate change, other environmental factors, and the destruction of natural enemies could trigger the incursion and migration of devastating pests and diseases. The massive planting and replanting could create homogeneity in coconut farms, predisposing these to disease infection and pest infestation. The concurrent reported outbreaks of Brontispa in Southeast Asia, Coconut Rhinoceros Beetle, Guam type (CRB-G) in Guam, and Asia-Pacic countries, Coconut Scale Insect in the Philippines, Lethal Yellowing in Jamaica, and Mexico, Bogia Coconut Syndrome in Papua New Guinea, Sexava, Rhyncophorus in Indonesia, and the recognition of the need to develop international biosecurity protocols for safe germplasm exchange have prompted the International Coconut Community (ICC) to hold the 1st IPM symposium.We know that pests and diseases reduced the ability of the industry to fully benefit from the market opportunities. In the face of this situation ICC Sessions and Ministerial meetings as the highest authority and the ICC recommended the ICC Secretariat to convene an IPM symposium to help countries overcome low coconut production due to pests and diseases.The general objective of the symposium is to establish an international IPM network system and synergy to protect the coconut producers & industries and conserve the coconut genetic resources and diversity from the adverse impact of pests and diseases through expertise and experience sharing.The specific objectives of the symposium are:1. To bring together key members of the scientific community for an interactive discussion on emerging issues and advances related to IPM, that will help enhance and develop IPM extension and research on invasive coconut pests and diseases2. To craft ecologically sound, science-based, and sustainable pest and disease management approaches based on IPM practices across countries.3. To create an international platform/network among coconut growing countries to strengthen the development of IPM strategies, pest and disease risk assessment, and inter-country collaborations that will address the research gaps and challenges of managing invasive pests/diseases losses and negative impact on the industry, biodiversity loss, and disrupted native and agricultural system.List of Editor-in-Chief, Managing Editor, Associate Editor, Scientific Committee of IPM Symposium Proceedings are available in this Pdf.

Monitoring ten insect pests in selected orchards in three Azorean Islands: The project CUARENTAGRI.

The data we present are part of the CUARENTAGRI project, which involves all archipelagos of the Macaronesia (Azores, Madeira, Canary Islands and Cabo Verde). The project aims to: i) identify and evaluate the risks associated with the introduction of new arthropod pests; ii) study the population dynamics of selected arthropod pest species currently responsible for the damage of key target crops and iii) develop monitoring systems, based on prediction and/or population dynamics of the crop pests, creating warnings and a phytosanitary prevention system. In this contribution, we compile data for three Azorean Islands (Terceira, São Jorge and São Miguel Islands), where pheromone-baited traps were placed in pastures, potato fields and several orchards' types (apples, banana, chestnuts, olives, orange and strawberry), during three consecutive years (2020, 2021 and 2022). A total of 114,827 specimens of insects (Arthropoda, Insecta) were collected, belonging to four orders, six families and ten recorded pest species. A total of eight species are considered introduced (Cosmopolitessordidus (Germar, 1824), Drosophilasuzukii (Matsumura, 1931), Bactroceraoleae (Rossi, 1790), Ceratitiscapitata (Wiedemann, 1824), Phthorimaeaoperculella (Zeller, 1873), Cydiapomonella (Linnaeus, 1758), Cydiasplendana (Hübner, 1799) and Grapholitamolesta (Busck, 1916); n = 84,986 specimens) and two native non-endemic (Mythimnaunipuncta (Haworth, 1809) and Spodopteralittoralis (Boisduval, 1833); n = 17,465 specimens). This study intended to contribute to a better knowledge of the arthropods pests that can affect the Azorean crops and will serve as a baseline for future monitoring actions, pest risk assessments and prevention systems.

A menu of measures to manage trade-related plant pest risks, and a review of methods for demonstrating measure efficacy

Ever-increasing global trade is one of the most important introduction pathways for plant pests. A diverse range of risk-reducing measures can be applied depending on the pest, the commodity and the import requirements. We used a review of over 1,800 risk reduction measures to extend a risk framework and menu of measures, previously developed for horticulture, to be applied to any commodity. We also reviewed how the efficacy of risk reduction measures is demonstrated, and assessed the maturity of the supporting science. We identified 39 unique risk reduction measures that were classified according to how they reduce risk. These were grouped under ten measure categories and four risk reduction objectives (minimising exposure to pest, minimising vulnerability of the commodity, reducing infestation rate and reducing establishment risk). These could then be applied against one or more consignment stages (production, post-production and post-border). Measures covered both commercial activities that reduce risk and may contribute to pest risk assessment, and regulated measures mandated to address unrestricted risk. Almost 90% of citations included measures that minimised exposure to pests or reduced infestation. Some measures were rarely reported, and some commodity classes had few measures associated with them, suggesting that available measures are being underutilised. Clear guidance was apparent for demonstrating efficacy of some measures (e.g., kill treatments), but lacking for many others. Compiling a ‘menu of risk reduction measures’ according to how they reduce risk, accompanied by clear guidelines for demonstrating efficacy, provides a robust basis for agreement between jurisdictions, and the further development, refinement and communication of efforts to both assess and manage the risk of global, trade-related pest movement. Agreement on how efficacy can be demonstrated for less utilised measures identified in this study will contribute to the further development of risk-based trade.

Competition: A Missing Component of Fruit Fly (Diptera: Tephritidae) Risk Assessment and Planning.

Tephritid fruit flies are internationally significant pests of horticulture. Because they are also highly invasive and of major quarantine concern, significant effort is placed in developing full or partial pest risk assessments (PRAs) for fruit flies, while large investments can be made for their control. Competition between fruit fly species, driven by the need to access and utilise fruit for larval development, has long been recognised by researchers as a fundamental component of fruit fly biology, but is entirely absent from the fruit fly PRA literature and appears not be considered in major initiative planning. First presenting a summary of the research data which documents fruit fly competition, this paper then identifies four major effects of fruit fly competition that could impact a PRA or large-scale initiative: (i) numerical reduction of an existing fruit fly pest species following competitive displacement by an invasive fruit fly; (ii) displacement of a less competitive fruit fly pest species in space, time or host; (iii) ecological resistance to fruit fly invasion in regions already with competitively dominant fruit fly species; and (iv) lesser-pest fruit fly resurgence following control of a competitively superior species. From these four major topics, six more detailed issues are identified, with each of these illustrated by hypothetical, but realistic biosecurity scenarios from Australia/New Zealand and Europe. The scenarios identify that the effects of fruit fly competition might both positively or negatively affect the predicted impacts of an invasive fruit fly or targeted fruit fly control initiative. Competition as a modifier of fruit fly risk needs to be recognised by policy makers and incorporated into fruit fly PRAs and major investment initiatives.

Pest risk assessment of Amyelois transitella for the European Union.

Following a request from the European Commission, the EFSA Panelon Plant Health performed a pest risk assessment of Amyelois transitella (Lepidoptera: Pyralidae), the navel orangeworm, for the EU. The quantitative assessment considered two scenarios: (i) current practices and (ii) a requirement for chilled transport. The assessment focused on pathways of introduction, climatic conditions and cultivation of hosts allowing establishment, spread and impact. A. transitella is a common pest of almonds, pistachios and walnuts in California, which is the main source for these nuts imported into the EU. Based on size of the trade and infestation at origin, importation of walnuts and almonds from the USA was identified as the most important pathways for entry of A. transitella. Using expert knowledge elicitation (EKE) and pathway modelling, a median estimate of 2,630 infested nuts is expected to enter the EU each year over the next 5 years (90% certainty range (CR) from 338 to 26,000 infested nuts per year). However, due to estimated small likelihoods of transfer to a host, mating upon transfer and survival of founder populations, the number of populations that establish was estimated to be 0.000698 year-1 (median, 90% CR: 0.0000126-0.0364 year-1). Accordingly, the expected period between founding events is 1,430 years (median, 90% CR: 27.5-79,400 year). The likelihood of entry resulting in establishment is therefore considered very small. However, this estimate has high uncertainty, mainly concerning the processes of transfer of the insect to hosts and the establishment of founder populations by those that successfully transfer. Climate matching and CLIMEX modelling indicate that conditions are most suitable for establishment in the southern EU, especially around the Mediterranean basin. The median rate of natural spread was estimated to be 5.6 km/year (median, 90% CR 0.8-19.3 km/year), after an initial lag period of 3.1 year (mean, 90% CR 1.7-6.2 year) following the establishment of a founder population. If A. transitella did establish, estimated median yield losses in nuts were estimated to be in the order of 1-2% depending on the nut species and production system. A scenario requiring imports of nuts to be transported under chilled conditions was shown to provide potential to further reduce the likelihood of entry.

Habitat heterogeneity and topographic variation as the drivers of insect pest distributions in alpine landscapes

Insect pests pose a large threat to alpine landscapes, especially under global environmental change conditions. It is necessary to explore the effects of environmental factors on the distribution of pests and provide implications for pest management in alpine landscapes. The main objective of this study was to explore whether habitat heterogeneity and topographic variation could drive insect pest distributions in alpine landscapes. We used species distribution modelling to project the distributions of 58 insect pest species in alpine landscapes based on occurrence records from 5513 field sites and different sets of environmental variables (i.e., climate, climate + habitat heterogeneity, climate + topographic variation, and climate + habitat heterogeneity + topographic variation). Then, we applied the jackknife method to determine the contribution of environmental variables to insect pest distributions. We found that habitat heterogeneity and topographic variation could significantly affect the distribution probability for all insect pest species in Qinghai, China. The response curves of the probability of pest distribution to habitat heterogeneity and topographic variation vary depending on the species present in alpine landscapes. There were four types of response curves of habitat heterogeneity and topographic variation to insect pest distribution probability, namely, 1) increasing, 2) decreasing, 3) increasing and then decreasing, and 4) decreasing and then increasing. Habitat heterogeneity and topographic variation should be integrated into modelling the distributions of insect pest species in alpine landscapes for pest risk assessment.

Southern Range Expansion of the Emerald Ash Borer, Agrilus planipennis, in Russia Threatens Ash and Olive Trees in the Middle East and Southern Europe

Agrilus planipennis (Coleoptera: Buprestidae) is the most serious invasive pest of ash trees (Fraxinus spp., Oleaceae) in the world. It has not yet reached the range of olive tree plantations, however it has been shown to complete its life cycle in this host tree. This pest native to East Asia was first found in Europe in Moscow in 2003 and has been spreading ever since. The aims of this study were to determine if the southern border of the range has already reached the Caucasus and to assess the potential range in this region based on host availability and heat availability. In 2021, we surveyed ash trees south to the known range in Russia. We did not find the pest in six cities in the North Caucasus region but found it in the city of Azov close to the Caucasus. Analysis of information about 550 localities of ash trees in the Caucasus showed that Fraxinus spp. is common throughout the region. The calculation of annual growing degree days base 10 °C indicated that the places where Fraxinus spp. grow above 1500 m are too cold for A. planipennis and therefore could potentially become a refuge for ash trees. The spread of A. planipennis to the Caucasus is of concern. First, the forest ecosystems of this region are endangered, since European ash Fraxinus excelsior is much more common there than in the currently infested regions in Russia. Second, the Russian Caucasus can become the gateway to Georgia, Armenia, Azerbaijan, Turkey and other countries of the Middle East and Southern Europe. We propose using Fraxinus angustifolia, F. ornus and Olea europaea growing in the Caucasus and adjacent regions as sentinel trees for the monitoring and pest risk assessment of these tree species.