Oak Processionary Research Articles

Exploring oak processionary caterpillar induced lepidopterism (Part 1): unveiling molecular insights through transcriptomics and proteomics

Lepidopterism, a skin inflammation condition caused by direct or airborne exposure to irritating hairs (setae) from processionary caterpillars, is becoming a significant public health concern. Recent outbreaks of the oak processionary caterpillar (Thaumetopoea processionea) have caused noteworthy health and economic consequences, with a rising frequency expected in the future, exacerbated by global warming promoting the survival of the caterpillar. Current medical treatments focus on symptom relief due to the lack of an effective therapy. While the source is known, understanding the precise causes of symptoms remain incomplete understood. In this study, we employed an advanced method to extract venom from the setae and identify the venom components through high-quality de novo transcriptomics, venom proteomics, and bioinformatic analysis. A total of 171 venom components were identified, including allergens, odorant binding proteins, small peptides, enzymes, enzyme inhibitors, and chitin biosynthesis products, potentially responsible for inflammatory and allergic reactions. This work presents the first comprehensive proteotranscriptomic database of T. processionea, contributing to understanding the complexity of lepidopterism. Furthermore, these findings hold promise for advancing therapeutic approaches to mitigate the global health impact of T. processionea and related caterpillars.

Stakeholder exposure to and knowledge of tree pests and diseases and their management in urban areas

Urban trees and forests provide many benefits to the urban environment and are important for climate change adaptation. Yet, they are increasingly threatened by insect pests and diseases, hereafter tree pests/diseases. There is little evidence of the risk awareness and knowledge of different urban stakeholders of this growing threat, how they are affected by tree pests/diseases, and how they might respond to it. To fill this gap, we undertook an online survey of different key stakeholder groups associated with urban trees and forests in Germany. A majority of 75.8 % of the 186 respondents consider urban tree pests/diseases a severe problem and 51.1 % reported high knowledge of tree pests/diseases. There was a lack of knowledge of certain reportable quarantine pests/diseases (e.g., canker stain of plane, emerald ash borer, Xylella) and pest/disease management options (e.g., manual treatment methods and tree diversification). Respondents were most affected by the horse chestnut leafminer (61.3 %), ash dieback (58.1 %) and oak processionary moth (50.0 %). The most widely used pest remedial measures were improvements of tree living conditions (60.8 %) and purchases of plants from certified or trusted local sources (59.7 %). Multiple correspondence analysis showed a significant association between levels of knowledge of tree pests/diseases and pest management responses (11.7 %). Our results suggest that future efforts to improve urban tree health should be enhanced and tailored to the different requirements of various stakeholder groups. The findings of this first comprehensive study with a purely urban focus will inform the development of future activities that prevent or reduce the spread of tree pests/diseases in urban areas. Data AvailabilityThe survey respondents did not give permission for the full data to be accessed or used by third parties.

Exploring oak processionary caterpillar induced lepidopterism (part 2): ex vivo bio-assays unmask the role of TRPV1

As human skin comes into contact with the tiny hairs or setae of the oak processionary caterpillar, Thaumetopoea processionea, a silent yet intense chemical confrontation occurs. The result is a mix of issues: skin rashes and an intense itching that typically lasts days and weeks after the contact. This discomfort poses a significant health threat not only to humans but also to animals. In Western Europe, the alarming increase in outbreaks extends beyond areas near infested trees due to the dispersion of the setae. Predictions indicate a sustained rise in outbreaks, fueled by global changes favoring the caterpillar’s survival and distribution. Currently, the absence of an efficient treatment persists due to significant gaps in our comprehension of the pathophysiology associated with this envenomation. Here, we explored the interaction between the venom extract derived from the setae of T. processionea and voltage- and ligand-gated ion channels and receptors. By conducting electrophysiological analyses, we discovered ex vivo evidence highlighting the significant role of TPTX1-Tp1, a peptide toxin from T. processionea, in modulating TRPV1. TPTX1-Tp1 is a secapin-like peptide and demonstrates a unique ability to modulate TRPV1 channels in the presence of capsaicin, leading to cell depolarization, itch and inflammatory responses. This discovery opens new avenues for developing a topical medication, suggesting the incorporation of a TRPV1 blocker as a potential solution for the local effects caused by T. processionea.

Pathogens of the oak processionary moth Thaumetopoea processionea: Developing a user-friendly bioassay system and metagenome analyses for microorganisms

The oak processionary moth (OPM) Thaumetopoea processionea is a pest of oak trees and poses health risks to humans due to the urticating setae of later instar larvae. For this reason, it is difficult to rear OPM under laboratory conditions, carry out bioassays or examine larvae for pathogens. Biological control targets the early larval instars and is based primarily on commercial preparations of Bacillus thuringiensis ssp. kurstaki (Btk). To test the entomopathogenic potential of other spore-forming bacteria, a user-friendly bioassay system was developed that (i) applies bacterial spore suspensions by oak bud dipping, (ii) targets first instar larvae through feeding exposure and (iii) takes into account their group-feeding behavior. A negligible mortality in the untreated control proved the functionality of the newly established bioassay system. Whereas the commercial Btk HD-1 strain was used as a bioassay standard and confirmed as being highly efficient, a Bacillus wiedmannii strain was ineffective in killing OPM larvae. Larvae, which died during the infection experiment, were further subjected to Nanopore sequencing for a metagenomic approach for entomopathogen detection. It further corroborated that B.wiedmannii was not able to infect and establish in OPM, but identified potential insect pathogenic species from the genera Serratia and Pseudomonas.

Commodity risk assessment of Corylus avellana plants from the UK.

The European Commission requested the EFSA Panel on Plant Health to prepare and deliver risk assessments for commodities listed in Commission Implementing Regulation (EU) 2018/2019 as 'High risk plants, plant products and other objects'. This Scientific Opinion covers plant health risks posed by plants of Corylus avellana imported from the United Kingdom (UK) as: (a) bundles of 1- to 2-year old whips or transplants, (b) bundles of 1- to 2-year old cell grown plants, (c) 1- to 7-year old bare root single plants and (d) up to 15-year old single plants in pots, taking into account the available scientific information, including the technical information provided by the UK. All pests associated with the commodity were evaluated against specific criteria for their relevance for this opinion. Two EU quarantine pests, Phytophthora ramorum (non-EU isolates) and Thaumetopoea processionea fulfilled all relevant criteria and were selected for further evaluation. For the selected pests, the risk mitigation measures implemented in the technical dossier from the UK were evaluated taking into account the possible limiting factors. For these pests an expert judgement is given on the likelihood of pest freedom taking into consideration the risk mitigation measures acting on the pest, including uncertainties associated with the assessment. In the assessment of risk, the age of the plants was considered, reasoning that older trees are more likely to be infested mainly due to longer exposure time and larger size. The degree of pest freedom varies among the pests evaluated, with P. ramorum being the pest most frequently expected on the imported plants. The expert knowledge elicitation indicated with 95% certainty that between 9939 and 10,000 of the single plants in pots up to 15-year old will be free from P. ramorum (non-EU isolates).

PHENTHAUproc – An early warning and decision support system for hazard assessment and control of oak processionary moth (Thaumetopoea processionea)

The incidence of oak processionary moth (OPM), Thaumetopoea processionea L. (Lep., Notodontidae), in Central Europe has increased since the 1990s. Given potential climatic and land-use changes, increased abundance and range expansion of OPM may occur in the future. These changes could lead to more severe defoliation of oaks and higher threats to humans and animals, caused by the urticating hairs (setae) released by OPM larvae. These negative impacts on oak trees, people and animals urgently require effective hazard mitigation strategies.For OPM hazard assessment and decision support on OPM monitoring and control, the online early warning system “PHENTHAUproc – phenology modelling of Thaumetopoeaprocessionea” was created and validated. PHENTHAUproc implements daily updated temperature-based procedures to calculate the phenological development of OPM and to model the host trees’ phenology, i.e. bud swelling and leaf unfolding of Quercus robur L.The hatching date of the first instar larvae (L1) is calculated using three different already existing models. To determine the onset of L1 feeding, a bud swelling model for Q. robur was generated for the first time. The phenological development of OPM larvae and pupae is predicted by a model which was first created based on laboratory rearing data for the distinct development stages.Moreover, an existing leaf unfolding model for Q. robur was included into PHENTHAUproc. The predicted date of leaf unfolding can be complemented by in situ observations of leaf unfolding by the German Meteorological Service (DWD). The predicted dates of leaf unfolding and OPM forth instar development are used to define the optimal timespan for control measures such as the prophylactic spraying of biological insecticides. In addition, modelling of larval and pupal development can be used to estimate the seasonally increasing hazard resulting from setae dissemination, as well as to calculate the onset of monitoring of flying moths with pheromone traps.PHENTHAUproc provides phenological forecasts on a local and regional level, i.e. for weather station locations and raster maps countrywide. The models can be used anywhere in Europe as soon as air temperature data and information on potential adaptations of OPM to local climate and host tree phenology are available. This enables phenological forecasts for timely and effective protection of oak tree vitality as well as human and animal health against OPM-related hazards.

Accelerating Bayesian inference for stochastic epidemic models using incidence data

We consider the case of performing Bayesian inference for stochastic epidemic compartment models, using incomplete time course data consisting of incidence counts that are either the number of new infections or removals in time intervals of fixed length. We eschew the most natural Markov jump process representation for reasons of computational efficiency, and focus on a stochastic differential equation representation. This is further approximated to give a tractable Gaussian process, that is, the linear noise approximation (LNA). Unless the observation model linking the LNA to data is both linear and Gaussian, the observed data likelihood remains intractable. It is in this setting that we consider two approaches for marginalising over the latent process: a correlated pseudo-marginal method and analytic marginalisation via a Gaussian approximation of the observation model. We compare and contrast these approaches using synthetic data before applying the best performing method to real data consisting of removal incidence of oak processionary moth nests in Richmond Park, London. Our approach further allows comparison between various competing compartment models.

Commodity risk assessment of Quercus robur plants from the UK.

The European Commission requested the EFSA Panel on Plant Health to prepare and deliver risk assessments for commodities listed in Commission Implementing Regulation (EU) 2018/2019 as 'High-risk plants, plant products and other objects'. This Scientific Opinion covers plant health risks posed by plants of Quercus robur imported from the UK as: (a) bundles of 1- to 2-year-old whips and seedlings, (b) 1- to 7-year-old bare root plants for planting and (c) less than 1- to 15-year-old plants in pots, taking into account the available scientific information, including the technical information provided by the UK. All pests associated with the commodity were evaluated against specific criteria for their relevance for this opinion. Two EU quarantine pests, Cronartium quercuum and Phytophthora ramorum (non-EU isolates), two protected zone quarantine pests, Cryphonectria parasitica and Thaumetopoea processionea and four pests not regulated in the EU, Coniella castaneicola, Meloidogyne mali, Phytophthora kernoviae and Trinophylum cribratum, fulfilled all relevant criteria and were selected for further evaluation. For the selected pests, the risk mitigation measures included in the technical dossier from the UK were evaluated taking into account the possible limiting factors. For these pests an expert judgement is given on the likelihood of pest freedom taking into consideration the risk mitigation measures acting on the pest, including uncertainties associated with the assessment. In the assessment of risk, the age of the plants was considered, reasoning that older trees are more likely to be infested mainly due to longer exposure time and larger size. The degree of pest freedom varies among the pests evaluated, with C. castaneicola being the pest most frequently expected on the imported plants. The expert knowledge elicitation indicated with 95% certainty that between 9,711 and 10,000 per 10,000 less than 1- to 15-year-old plants in pots will be free from C. castaneicola.

Strategies for public health adaptation to climate change in practice: social learning in the processionary Moth Knowledge Platform.

Social learning theory can support understanding of how a group of diverse actors addresses complex challenges related to public health adaptation. This study focuses on one specific issue of public health adaptation: oak processionary moth (OPM) adaptation. With a social learning framework, we examined how public health adaption strategies gradually develop and are adjusted on the basis of new knowledge and experiences. For this qualitative case study, data were collected through 27 meetings of the Processionary Moth Knowledge Platform in the Netherlands and six additional interviews. Results indicate that relations between stakeholders, including experts played a major role in the learning process, facilitating the development and implementation of OPM adaptation and connecting local challenges to national adaptation strategies. Uncertainties regarding knowledge and organization were recurrent topics of discussion, highlighting the iterative and adaptive nature of public health adaptation. The study emphasizes the importance of building relationships among stakeholders and small steps in the learning process that can lead to the creation of new strategies and, if successful, the prevention of negative health impacts.

Commodity risk assessment of Fagus sylvatica plants from the UK.

The European Commission requested the EFSA Panel on Plant Health to prepare and deliver risk assessments for commodities listed in Commission Implementing Regulation (EU) 2018/2019 as 'High risk plants, plant products and other objects'. This Scientific Opinion covers plant health risks posed by plants of Fagus sylvatica imported from the United Kingdom (UK) as: (a) 1- to 7-year-old bare root plants for planting, (b) < 1- to 15-year-old plants in pots and (c) bundles of 1- to 2-year-old whips and seedlings, taking into account the available scientific information, including the technical information provided by the UK. All pests associated with the commodity were evaluated against specific criteria for their relevance for this opinion. Two EU quarantine pests, Phytophthora ramorum (non-EU isolates) and Thaumetopoea processionea, and two pests not regulated in the EU, Meloidogyne mali and Phytophthora kernoviae, fulfilled all relevant criteria and were selected for further evaluation. For the selected pests, the risk mitigation measures implemented in the technical dossier from the UK were evaluated taking into account the possible limiting factors. For these pests an expert judgement is given on the likelihood of pest freedom taking into consideration the risk mitigation measures acting on the pest, including uncertainties associated with the assessment. In the assessment of risk, the age of the plants was considered, reasoning that older trees are more likely to be infested mainly due to longer exposure time and larger size. The degree of pest freedom varies among the pests evaluated, with M. mali being the pest most frequently expected on the imported plants. The expert knowledge elicitation (EKE) indicated with 95% certainty that between 9,793 and 10,000 plants in pots up to 15 years old per 10,000 will be free from M. mali.

Possibilities to reduce drift by 75 percent in biocidal applications of insecticides with cannon sprayers

BackgroundInsecticides are applied on a large scale in the environment to control the oak processionary moth (Thaumetopoea processionea) for the protection of human health. Drift of the insecticides to non-target areas is a risk for the surrounding biodiversity. Since the habitats of the caterpillars are usually restricted to the treetops, the sprayers used to apply biocidal products must be able to transport the droplets over longer distances. Therefore, cannon sprayers are often used. In this study, spray drift in an oak avenue from a cannon sprayer with hydraulic atomisation was measured with two different nozzles. The aim of this study is to compare spray drift when using a cannon sprayer with different drift-reducing nozzles with cannon sprayers with pneumatic atomisation to find options to reduce drift to non-target areas.ResultsThe results show that compared to the basic drift values for biocidal products using a cannon sprayer with pneumatic atomisation, a cannon sprayer with ID-120-05 POM nozzles achieves a drift reduction of 75% and a classification in this reduction class. No drift reduction could be determined with a cannon sprayer with AirMix 110-05 nozzles.ConclusionsBetter knowledge of drift of biocidal products is of utmost urgency in order to be able to compare and classify the currently used technologies. When using a cannon sprayer, this study shows that specific drift values are recommended based on the type of atomisation, as droplet size is an important factor in reducing drift. By choosing the technology with the highest drift reduction, the drift of biocidal products into the environment can be minimised by 75%, thus ensuring a much better protection of the environment.

Quantifying Invasive Pest Dynamics through Inference of a Two-Node Epidemic Network Model

Invasive woodland pests have substantial ecological, economic, and social impacts, harming biodiversity and ecosystem services. Mathematical modelling informed by Bayesian inference can deepen our understanding of the fundamental behaviours of invasive pests and provide predictive tools for forecasting future spread. A key invasive pest of concern in the UK is the oak processionary moth (OPM). OPM was established in the UK in 2006; it is harmful to both oak trees and humans, and its infestation area is continually expanding. Here, we use a computational inference scheme to estimate the parameters for a two-node network epidemic model to describe the temporal dynamics of OPM in two geographically neighbouring parks (Bushy Park and Richmond Park, London). We show the applicability of such a network model to describing invasive pest dynamics and our results suggest that the infestation within Richmond Park has largely driven the infestation within Bushy Park.

Effects of an entomopathogenic nematode applied against Thaumetopoea processionea on non-target arthropods under field conditions

Entomopathogenic nematodes are increasingly used in biological pest control, and are considered to be environmentally friendly. However, due to their potentially wide range of insect hosts, they may detrimentally affect biodiversity. We here investigate effects of nematode applications against the oak processionary moth, Thaumetopoea processionea, on non-target organisms using beat sheet sampling and light trapping. While such effects have been repeatedly explored for soil and xylobiontic arthropods, effects on herbivorous insects are largely unexplored. We found no statistically significant short- or longer-term effects on either Lepidoptera or other insect orders. While we cannot completely rule out some weak short-term reductions in individual numbers (−12 %), considerable long-term effects on non-target insects can be largely ruled out. Provided a targeted localized application, applying the nematode Steinernema feltiae seems to be an environmentally friendly method for controlling populations of T. processionea at locations with increased risks for human health.

Effects of Oak Processionary Moth (Thaumetopoea processionea L.) Outbreaks on the Leaf Performance and Health of Urban and Forest Oak Trees (Quercus robur L.) in Brandenburg, Germany

Forest insects are among the most important factors of disturbance in European forests. The increase in and duration of drought stress events due to climate change not only increase the vulnerability of rural and urban forests but also predispose weakened stands to insect pest calamities. In this context, many German and European forest research institutes and environmental institutions report an increase in the densities and calamity developments of the oak processionary moth (Thaumetopoea processionea L.) not only in oak and mixed-oak forests but also in smaller areas where oak trees regularly occur, e.g., parklands, urban areas, copses, avenues, recreational forests, etc. It is expected that the oak processionary moth (OPM) will benefit from the overall weakened vitality of both individual oaks and oak stands in the future and that mass outbreaks will occur at an increased frequency. This paper reports on the effects that the OPM can have on tree performance for rural forest and urban oak trees by applying the chlorophyll fluorescence non-destructive diagnostic method for the identification and quantification of damage to oak leaves. The aim of the study was to investigate the effects of OPM frass activity on tree leaf health using chlorophyll fluorescence measurements, comparing infested host oaks with non-infested oaks in urban and forest environs. The study assessed: 1. the quantum efficiency of photosystem II (PS II), which counts as an indicator for leaf conditions, 2. the performance index, which indicates the efficiency of the photosynthetic light reaction, 3. the energy loss of the photosynthetic reaction, which is an indicator for cell damage, and 4. the degree of open reaction centers in PS II, which indicates how well light energy can be absorbed for photosynthesis. Infested urban and rural oaks showed a significantly reduced quantum yield of PS II by up to 10% compared to non-infested oak leaves. The leaf performance was significantly reduced by up to 35% for infested urban oaks and by up to 60% for infested forest oaks, respectively. The energy losses were two times higher for infested urban and forest oaks. However, OPM infestation led to a higher reduction in the photosynthetic performance in the leaves of forest oaks compared to that of urban oaks. In order to avoid permanent damage, suitable countermeasures must be taken quickly, as, immediately after pest infestation, the performance decreases significantly. A lower performance means a significant loss in biomass production as well as in tree vitality.

Corneal epithelial ingrowth after perforating corneal injury: a case report

BackgroundEpithelial ingrowth is a rare complication after ocular perforation and can become manifest many years after the primary trauma.Case presentationA 49-year-old patient presented with a positive Seidel test of unclear origin at her left eye, as well as a sharply defined anterior-stromal corneal scar at both eyes. Prior operations included a bilateral laser-assisted blepharoplasty 3 months earlier. The patient indicated to have been on holiday to France 5 months earlier, during an ongoing oak processionary moth caterpillars infestation.The examination using confocal microscopy confirmed a corneal perforation at the left eye and revealed corneal epithelial ingrowth capped with scarred stroma in both eyes. We performed a penetrating keratoplasty at the left eye. The scarred and perforated host cornea was divided into 4 pieces for further investigation: microbiology (negative), virology (negative), histology and transmission electron microscopy (TEM). Histology revealed differently structured epithelium, centrally inverted into the stroma through defects in Bowman’s layer. TEM revealed full thickness corneal perforation with an epithelial plug extending to the lower third of the cornea, but without evidence of epithelial cell migration into the anterior chamber.Our differential diagnosis of the unclear positive Seidel test with epithelial ingrowth was as follows: (1) corneal perforation by hairs of the oak processionary moth caterpillar, although no hairs could be found histologically; (2) corneal perforation during laser-assisted blepharoplasty, which may be supported by the presence of pigmented cells on the posterior surface of Descemet´s membrane, pointing to a possible iris injury.ConclusionConsequently, we highlighted that contact lenses can be useful, safe and inexpensive protective devices in upper eyelid procedures to protect the cornea against mechanical iatrogenic trauma.

Inference for epidemic models with time-varying infection rates: Tracking the dynamics of oak processionary moth in the UK.

Invasive pests pose a great threat to forest, woodland, and urban tree ecosystems. The oak processionary moth (OPM) is a destructive pest of oak trees, first reported in the UK in 2006. Despite great efforts to contain the outbreak within the original infested area of South‐East England, OPM continues to spread.Here, we analyze data consisting of the numbers of OPM nests removed each year from two parks in London between 2013 and 2020. Using a state‐of‐the‐art Bayesian inference scheme, we estimate the parameters for a stochastic compartmental SIR (susceptible, infested, and removed) model with a time‐varying infestation rate to describe the spread of OPM.We find that the infestation rate and subsequent basic reproduction number have remained constant since 2013 (with R0 between one and two). This shows further controls must be taken to reduce R0 below one and stop the advance of OPM into other areas of England. Synthesis. Our findings demonstrate the applicability of the SIR model to describing OPM spread and show that further controls are needed to reduce the infestation rate. The proposed statistical methodology is a powerful tool to explore the nature of a time‐varying infestation rate, applicable to other partially observed time series epidemic data.

The effectiveness of ground‐based applications of Bacillus thuringiensis var. kurstaki for controlling oak processionary moth Thaumetopoea processionea (Lepidoptera: Thaumetopoeidae)

AbstractThe effectiveness of ground‐based applications of Bacillus thuringiensis var. kurstaki (Btk) for controlling oak processionary moth (OPM) was evaluated by comparing the numbers of larval nests on treated and untreated oak trees in Richmond Park, in west London, UK. A total of 760 oak trees (Quercus robur) were monitored over a period of 4 years from 2014 to 2017, and the effects of current treatment and previous treatment history on nest numbers were analysed using general linear mixed models. Two applications of Btk applied 7–10 days apart in the spring, just after egg hatch, reduced the numbers of larval nests by 86–94%. In 2015, the effectiveness of treatment decreased as tree height increased, whereas in 2016 and 2017 nest numbers were reduced by a similar percentage across all tree height classes. The effects of treatment were relatively short‐lived, because at the scale at which the insecticide applications were carried out, trees were re‐colonised rapidly by adult OPM flying in from the surrounding area. Consequently, nest numbers generally returned to pre‐treatment densities within 1–2 years.

Effects of an Entomopathogenic Nematode Applied Against Thaumetopoea Processionea on Non-Target Arthropods Under Field Conditions

Effects of an Entomopathogenic Nematode Applied Against Thaumetopoea Processionea on Non-Target Arthropods Under Field Conditions

Understanding climate health adaptation in practice: adaptation to the oak processionary moth in The Netherlands

Abstract Background Understanding of climate health adaptation and its organisation and implementation is limited. This presentation focuses on the adaptation to the oak processionary moth (OPM). The OPM spreads out northwards through Europe, and human contact leads to reactions in skin mucous membranes, conjunctivitis, pharyngitis and respiratory distress. Literature has focused largely on the ecology and epidemiology of the OPM. However, there is limited understanding of the organisation and implementation of climate health adaptation knowledge and coordinating an effective response. Methods In an explorative case study we examined the current OPM adaptation strategies in practice. Semi-structured interviews with 26 actors in The Netherlands were held to unravel the problem and the complexities involved in OPM adaptation. Results The results indicate that the context of OPM adaptation is multidimensional, given the involvement of many interdependent actors. At regional and local level early networks emerge aiming to improve the effectiveness of OPM adaptation. At the national level the Knowledge Platform OPM was set up, in which actors collaborate to collect and share knowledge and experience. Nevertheless, OPM strategies are based on ad hoc approaches with ambiguous tasks and expertise. In addition, actors have different perceptions and values concerning health, sustainability, risks and responsibilities influencing decision-making processes, collaboration and a coordinated approach. Conclusions The generation of knowledge and its translation into practical strategies calls for interdisciplinary cooperation in knowledge development. Climate health adaptation involves more than technical and organisational solutions alone. It also entails the development of a shared problem perception and solution space in which citizens are also engaged. Therefore, implementation of vertical and horizontal coordination climate health adaptation strategies are required.

Estimating expansion of the range of oak processionary moth (Thaumetopoea processionea) in theUKfrom 2006 to 2019

AbstractThe expansion of oak processionary moth (OPM) in South‐East England continues despite ongoing efforts to control the pest since its introduction in 2006.Using locations of OPM larval nests, supplied by the Forestry Commission and recorded as part of ongoing surveillance and control measures from 2006 onwards, we show that the expansion of the range of OPM in South‐East England up to 2019 was biphasic with a higher rate of expansion from 2015 onwards.The maximum rate of OPM range expansion in the United Kingdom from 2006 to 2014 was estimated as 1.66 km/year (95% CI = [1.22, 2.09]), whereas the 2015–2019 expansion rate was estimated as 6.17 km/year (95% CI = [5.49, 6.84]). This corresponds to an estimated species range distribution area of 7077 km2in 2019.To explain the faster expansion of OPM range from 2015 onwards, we discuss potential reasons that include: natural capability of species of both short‐ and long‐distance dispersal; external factors such as environmental heterogeneity; a reduction of active control.