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The project ‘Use of Stable Isotope Ratio Analysis (SIRA) for the identification of invasive species native in alien environments’ aimed to develop SIRA as an arthropod tree-pest decision tool to inform phytosanitary response. Modern analytical technologies, used in other fields can be applied to entomological research and pest control. Wood-boring larvae assimilate the isotope ratios of the wood they feed on, and isotope signatures can provide clues to the geographic origin of the emerged adults. The Asian longhorn beetle (ALB) Anoplophora glabripennis is among the most damaging invasive tree-pest insects in Europe and North America, and its detection can trigger an eradication response. Knowing if the source of detected specimens is local or foreign can influence the degree of response. A captured beetle with a local isotope signature probably developed from an egg laid locally one or two years earlier. The response to this would involve much effort and destruction of trees to locate further adults, larvae and exit holes made by adults in order to eradicate the pest. A captured beetle with a foreign (e.g. Chinese) isotope signature is more likely to be the only beetle present and an opportunity exists to trace the imported host wood to determine whether other adults may have emerged. In this case, only lower-cost localised monitoring for additional adult beetles would be required. A method based on the measurement of stable isotopes in adult ALBs to identify the origin of the wood from which they emerged was developed in the framework of the project activities. The method can detect that an ALB has emerged from European wood in at least 95% of cases. The method was calibrated with ALBs from 11 locations in China (n=55) and 6 locations in Europe (Italy, n=28). Additionally, samples of Monochamus galloprovincialis, Monochamus sutor, and Monochamus sartor – potential vectors of the pine wood nematode – from nine European countries (49 locations) were analysed. To examine whether SIRA of one pest can instruct about another pest with a similar feeding habit, six pest species (n = 5 adults each) and timber from which they emerged 20 to 1047 days after seizure at US ports (between 2012 and 2016) were analysed for hydrogen and carbon isotope ratios. We found a positive offset for carbon from timber to beetle on all but one species on Populus wood. Rearing beetles with lifecycles of 2 or more years in the laboratory is challenging. A most up to date guideline has been disseminated by USDA. However, to achieve higher survival rates from larvae to adult and create larger data sets, a more natural but controlled setting is recommended. While we demonstrated that SIRA can have a promising use in directing control efforts, more data may improve its power as an arthropod tree-pest decision tool.

A large proportion of the insects which have invaded new regions and countries are emerging species, being found for the first time outside their native range. Being able to detect such species upon arrival at ports of entry before they establish in non-native countries is an urgent challenge. The deployment of traps baited with broad-spectrum semiochemical lures at ports-of-entry and other high-risk sites could be one such early detection tool. Rapid progress in the identification of semiochemicals for cerambycid beetles during the last 15 years has revealed that aggregation-sex pheromones and sex pheromones are often conserved at global levels for genera, tribes or subfamilies of the Cerambycidae. This possibly allows the development of generic attractants which attract multiple species simultaneously, especially when such pheromones are combined into blends. Here, we present the results of a worldwide field trial programme conducted during 2018-2021, using traps baited with a standardised 8-pheromone blend, usually com-plemented with plant volatiles. A total of 1308 traps were deployed at 302 sites covering simultaneously or sequentially 13 European countries, 10 Chinese provinces and some regions of the USA, Canada, Australia, Russia (Siberia) and the Caribbean (Martinique). We intended to test the following hypotheses: 1) if a species is regularly trapped in significant numbers by the blend on a continent, it increases the prob-ability that it can be detected when it arrives in other countries/continents and 2) if the blend exerts an effective, generic attraction to multiple species, it is likely that previously unknown and unexpected spe-cies can be captured due to the high degree of conservation of pheromone structures within related taxa. A total of 78,321 longhorned beetles were trapped, representing 376 species from eight subfamilies, with 84 species captured in numbers greater than 50 individuals. Captures comprised 60 tribes, with 10 tribes including more than nine species trapped on different continents. Some invasive species were captured in both the native and invaded continents. This demonstrates the potential of multipheromone lures as ef-fective tools for the detection of 'unexpected' cerambycid invaders, accidentally translocated outside their native ranges. Adding new pheromones with analogous well-conserved motifs is discussed, as well as the limitations of using such blends, especially for some cerambycid taxa which may be more attracted by the trap colour or other characteristics rather than to the chemical blend.

The oak lace bug (OLB) Corythucha arcuata (Say, 1832) is an invasive alien species (IAS) that potentially could have many negative impacts on European oak health. Certain measures can be applied to counteract these effects. However, these measures may not be acceptable for forest managers or other stakeholder groups, such as private forest owners, environmental NGOs or the general public. Thereby, we set out to study the perception and knowledge of foresters and other stakeholders on the health status of European oak forests affected by oak lace bug and to investigate what forest health management measures would be acceptable to these target groups. An online survey questionnaire was designed and distributed via social networks, as well as professional networks via e-mails. The survey questionnaire was completed by 2084 respondents from nine European countries: Austria, Croatia, Belgium, France, Hungary, Italy, Romania, Serbia and Slovenia. Even though only a little over 60% of respondents reported they had noticed the discolouration of oak leaves caused by OLB, almost all (93%) considered it to be a problem. As respondents come from a country where C. arcuata is widespread and established, people’s general knowledge and awareness of OLB began to increase. The survey revealed that foresters thought that the insect affected photosynthesis, acorn crop and the aesthetics of the trees, but cannot cause death of trees. However, they assume that the value of the wood would decrease (this fact is also supported by the respondents who are connected to an environmental NGO), but that OLB does not affect property value. However, forest owners claim that the value of the property can be affected and that people would avoid entering the forest. In terms of potential control methods, respondents preferred biological or mechanical measures over chemical ones. We consider this study to be a good basis for further research on the topic of perception, knowledge and attitudes related to OLB since we can expect that the IAS, such as OLB, will certainly spread to European countries that were not included in this survey.

Extensive literature review and interactions with researchers and managers dealing with Agrilus planipennis (emerald ash borer, EAB) and Agrilus anxius (bronze birch borer, BBB) has assessed the ‘state of the art’ as a basis for potential invasion of Europe by these pests. Although there is increasing information on the two pest species, further work especially from a European perspective is required to both anticipate and to react to incursions of the pests. The PREPSYS project addressed key questions and gaps in our knowledge on the pests’ biology, control (including firewood risks and treatments and biological control agents), dispersal and economic/environmental impacts. PREPSYS has pulled together the accumulated knowledge on EAB and BBB to prepare a European Toolbox for their detection and management and this has been published in a recent special edition of Forestry: An International Journal of Forest Research. This can form the basis for a coordinated approach to deal with the very real threats from EAB and BBB. It is known from North America and European Russia that there is usually a gap of several years between arrival and first detection of EAB. PREPSYS has assessed the range of options for survey and early detection of EAB or BBB and concluded that girdling of trees (stressing the trees) is the most effective for this purpose. However, there are logistic problems in using this technique and so use of traps with chemical lures is often more practical; a range is available with similar efficiencies in capturing adult beetles. Management of infestations is usually through felling of infested or dead trees and this is an expensive and time-consuming procedure. Extensive research in North America indicates that slowing progress of infestations using trunk injections of the insecticide Emamectin benzoate is an effective process to ‘buy time’ for selective felling and other measures. It is recommended that registration of the insecticide for use in Europe should be carried out urgently. In the longer term, introduction of parasitoids (natural enemies) from the native ranges of EAB is now becoming more effective after a slow initial period after releasing species from China and Russia. There is also detailed knowledge of the climatic requirements of these classical biological control agents and this has improved establishment and efficacy. Since there is a need for assessment of possible adverse impacts on non-target species, tests for potential use of these agents in Europe should be carried out urgently. Methods for mass production are, fortunately, already developed in the USA. Outreach and information provision are an important part of detection and management of EAB and information should be made increasingly available in Europe to prepare for the likely arrival of EAB from European Russia, Ukraine or any of the infested regions of the world., Report of the Euphresco project 2015-A-167 'Risk-based strategies to prepare for and manage invasive tree borers - Pest Risk Evaluation and Pest management SYStems (PREPSYS)'

Invasive non-native xylophagous longhorn, bark and jewel beetles are a serious threat to the biosecurity of urban, rural and forest trees, causing long-term damage and tree mortality. This has major impacts on pest and tree management as well as ecosystem services provide by trees. These beetles arrive in various forms of timber including logs, lumber, wood packaging, pallets and live trees for planting. Hence, early detection at or close to points of entry is therefore of paramount importance for the implementation and success of eradicating an invasive species. This project aimed to advance previous studies (Rassati et al., 2014; 2015) that demonstrated multi-funnel traps baited with multi-lures could be used to monitor for invasive beetles at points of entry of imported wood, but focusing primarily on longhorn beetles (Cerambycidae). The traps and lures currently available for surveillance of invasive xylophagous beetles were reviewed (Down and Audsley, 2017) and were used together with work conducted by INRA (Roques et al., 2017) to select lures for testing at 21 ports of entry and 22 forest sites. This study determined that, using black cross-vane or multi-funnel traps in a parallel set-up across the partner countries, the optimal detection strategy is to use pheromone blends in combination with the host plant volatiles, ethanol and α-pinene. This maximises the taxonomic diversity of beetles captured, particularly Cerambycidae and minimises the number of traps and lures required. Over 80 species of Cerambycidae were captured in both years (2017 and 2018) of study. Such traps and lures are not suitable for Buprestidae. A standard protocol was produced that should be followed so that surveillance can be standardised and consistent and could contribute towards compliance with community regulations on national surveys for European quarantine pests. Although the cost-effectiveness of individual trapping programmes will always have to be evaluated on a case by case basis, there are potential benefits from replacing single-lure trapping programmes with combined multi-lure programmes for early detection. Including multi-lures in a single trap reduces the number of traps required, effort of deployment and servicing, and increases the number of different target species captured, thereby increasing trapping efficacy and reducing costs compared to multiple traps baited with single lures. Trap density is also an important success parameter for early detection, which in turn increases the probability of successful eradication thereby reducing costly pest damages., Report of the Euphresco project 2015-F-175 'Multi-lure and multi-trap surveillance for invasive tree pests (Multitrap)'

International audience

There is a high threat of harmful impact arising from material infested by Anoplophora chinensis (Citrus longhorned beetle; CLB) and Anoplophora glabripennis (Asian longhorned beetle; ALB) within EU territory. While interceptions of CLB with plants for plantings have been reduced in the last years due to recommended measures according to the implementing decision 2012/138/EU of the EU Commission, ALB is intercepted in wood packaging material in continuously high numbers. Measures against these species require import inspections as well as eradication or containment measures demanding high personnel and financial resources. More readily available and validated detection methods are important. This project followed up promising methods for detection and identification that were developed in the previous project ANOPLORISK. In order to connect proper usage of available methods with measures required according to EU legislation, contingency plans for both, ALB and CLB were developed for Germany that could serve as models for other European countries. The EUphresco project will focus on: - Detection methods for wood boring stages - Detection of adult ALB with pheromone baited traps - Molecular tools for diagnosis - Development of contingency plans, Scientific report of the Euphresco funded project 'Further Development of Risk Management for the EC listed Anoplophora species, A. chinensis and A. glabripennis' (ANOPLORISK-II)

Success story of the Euphresco project 'Further development of risk management for the EC listed Anoplophora species, A. chinensis and A. glabripennis'

Slide of the Euphresco project 'Further development of risk management for the EC listed Anoplophora species, A. chinensis and A. glabripennis' (Anoplorisk II), Project funded through the Euphresco network

Since the late 1990s, the oak processionary moth, Thaumetopoea processionea (L.), has been occurring at high population densities in eastern Austria. Particularly, infestations in areas of human settlement have created increasing interest in this insect due to health problems caused by the urticating hairs of the larvae. New methods for biological control are desirable. Like essentially all forest Lepidoptera, T. processionea is host for entomopathogenic microsporidia. These obligatory parasitic protists have been evaluated as biocontrol agents against an other oak pest, Lymantria dispar (Weiser & Novotny, 1987; Jeffords & al., 1988). Life history traits of T. processionea make this insect an even more promising target for the use of microsporidia. The larvae are highly gregarious and stay together in nests made of larval silk for resting periods and molting. Microsporidia utilize several pathways for horizontal transmission that would be aided by these features: spores can be released after host death from cadavers as well as from living larvae via silk or feces. Additionally, many microsporidia are vertically transmitted (summarized in Maddox & al., 1998). In this project, T. processionea larvae from various regions in eastern Austria were screened for the natural occurrence of microsporidia. One isolate, Endoreticulatus sp., was further studied and mass produced in a laboratory host, L. dispar, that is easy to rear and does not pose a health hazard for people working with the insects. An inoculative release was attempted on isolated trees infested with T. processionea. In einem zweijährigen Screening untersuchten wir das Auftreten von Mikrosporidien bei Thaumetopoea processionea an verschiedenen Standorten in Ostösterreich. In neun von 18 Populationen wurden Mikrosporidiosen nachgewiesen, die Prävalenzen lagen zwischen 1,9 % und 15,4 %. Basierend auf lichtmikroskopischen Befunden waren die gefundenen Pathogene den Gattungen Endoreticulatus, Nosema, Cystosporogenes und Vairimorpha zuzuordnen. Endoreticulatus sp. vermochte im Labor Raupen von Lymantria dispar zu infizieren. Das erlaubte die einfache Produktion von Inokulum sowie Untersuchungen mit einem ungefährlichen Wirtsinsekt. Laborversuche mit L. dispar zeigten einen langsamen Krankheitsverlauf, der aber in signifikant erhöhter Mortalität resultierte (nur 26 % der oral inokulierten Tiere entwickelten sich zu Imagines), sowie eine effiziente horizontale Übertragung. Eine inokulative Freilassung wurde versucht: dazu wurden Endoreticulatus-Sporen in wässriger Suspension auf Blätter isoliert stehender, von T. processionea befallenen Eichen ausgebracht. Die Inokulation war erfolgreich, allerdings auf niedrigem Niveau – die maximale Infektionsrate lag bei 9,5 %.

We have been surveying a gypsy moth, Lymantria dispar (Lep., Lymantriidae), population in the oak forest of Klingenbach near Eisenstadt, Austria, since 1992. During the last gradation from 1993 to 1996, we studied the natural enemy complex at this site in comparison with other locations where no outbreak occurred (HOCH et al. 2001). During the latency years, an experimental study on the impact of predators on L. dispar pupal populations was performed (GSCHWANTNER et al. 2002). The population density was recorded regularly; in the winter 2001/02, the egg mass surveys indicated a rising population after seven years of latency. We used this opportunity to study the parasitoid complex in the progradation phase. This phase of gypsy moth population dynamics was not studied in our previous work. Moreover, it allowed us to repeat the investigation during the outbreak after 11 years. Seit 1992 führen wir in einem Eichenmischwald bei Klingenbach, nahe Eisenstadt, Österreich, Abundanzerhebungen des Schwammspinners, Lymantria dispar (Lep., Lymantriidae) mittels Eigelegezählungen durch. Im Jahre 2002 zeichnete sich nach sieben Jahren der Latenz ein Anstieg der Populationsdischte ab. Die Zahl von 1,2 Gelegen/Baum im Winter 2002/03 deutete auf eine beginnende Massenvermehrung. Die Dichte an Eigelegen war im folgenden Winterhalbjahr mit 9,7 pro Baum extrem hoch. Durch stadienspezifische Aufsammlungen von L. dispar Raupen oder Puppen und deren Zucht im Labor ermittelten wir die durch Parasitoide verursachte Mortalität sowohl im Progradationsjahr 2003 als auch im Jahr der Kulmination 2004. Generell war die Mortalität der Raupen und Puppen sehr gering. Im Jahr der Progradation vermochte einzig Parasetigena silvestris (Dipt., Tachinidae) nennenswerte Mortalität von 23,7% bei Altraupen zu verursachen. Die sehr warme, trockene Witterung im Mai-Juni 2003 bedingte eine ausgesprochen schnelle Raupenentwicklung. Im Frühjahr 2004 zeigten die Raupenaufsammlungen noch geringere Parasitierungsraten. Es dominierten P. silvestris und Blepharipa sp. (Dipt., Tachinidae) mit 8,5% bzw. 8,0% bei den Altraupen. Aufsammlungen von Puppen im Jahr 2004 zeigten anhand der ypischen Fraßbilder eine Mortalität durch Calosoma spp. (Col., Carabidae) von 13% an den Zweigen des Baumbestandes bis 38% in der Strauchschicht. Die Ergebnisse unserer Untersuchung zum Antagonistenkomplex in der Phase der Progradation und Kulmination werden im Vergleich mit entsprechenden Daten aus der letzten Gradation 1993 diskutiert.