Hoverflies specialised to veteran trees in Europe
This Action Plan is dedicated to six hoverflies species that are specialised on veteran trees and wet, decaying wood. These saproxylic insects not only are important pollinators but also act as nutrient recyclers, pests’ predators, and indicators of ecosystem health. “Hoverflies specialised to veteran trees in Europe – Conservation Action Plan 2023–2030” sheds a light on the importance of appropriate forestry practices that keep into account the needs of pollinators species that rely on dead wood and ancient trees. The removal of veteran trees, the replacement of key tree species, and the implementation of hoverfly-unfriendly woodland management are all threats to these species.
Objective 1.1 Governance
1.1.1 Creation of a steering group
The IUCN SSC Hoverfly SG (HSG) reported that it was expected that the action Plan implementation would receive funding; however, no funds have been provided yet. Only activities that could proceed without financial support have been initiated
Status: in progress (25%)
Updated on: January 2026
To be completed: initial end date - 2023
Objective 1.2 Inclusion of pollinators in key legal documents
1.2.1 Conduct and support national Red List assessments for hoverflies in key European countries, including Greece, Bulgaria, Romania, Croatia, Slovenia, Austria, Italy, France, Slovakia, Czech Republic, Switzerland, Montenegro, and Ukraine.
The University of the Aegean has reported that in the "Action Plan for Pollinators in Greece" (Petanidou et al. 2025. A-phase, submitted to the Greek Ministry of the Environment, now under public consultation), the incorporated measure # 1.4.1.2 requires the "Completion of assessment of hoverflies until 2030".
Status: in progress (25%)
Updated on: April 2026
To be completed: 2028
1.2.2 Add key hoverfly species to national lists of protected species, including Sphiximorpha petronillae (Italy, Serbia, Montenegro, Greece), Chalcosyrphus pannonicus (Bosnia-Herzegovina, Bulgaria, Croatia, Greece, Poland, Romania, Serbia, Slovakia, Ukraine), Primocerioides regale (Greece, Serbia), and Brachypalpus chrysites (Austria, Czech Republic, France, Germany).
It was also reported that Serbia is the only country where these species (ref. As listed in Action 1.2.2 above) are officially protected with a National List of protected species. However, other listed countries have National Red Lists of hoverflies that include these species.
Status: in progress (25%)
Updated on: January 2026
To be completed: 2030
1.2.3 Explore existing policies and legal instruments for the protection of veteran trees
An exploration of existing policies and legal instruments for the protection of veteran trees will be part of the planned doctoral dissertation at the University of Novi Sad, Serbia
Status: in progress (25%)
Updated on: January 2026
To be completed: 2026
1.2.4 Instigating legal frameworks or policies for the protection of veteran trees in countries without any existing protection
Status: not started
Updated on: 11 July 2025
To be completed: 2028
Objective 1.3 Improving European protection
1.3.1 Consideration of veteran trees and wet decaying wood as well as the specialist hoverflies in the expansion of the European protected area network
Status: not started
Updated on: 11 July 2025
To be completed: 2025
1.3.2 Ensure protection of veteran trees in the context of the European Commission’s proposal for a Regulation on nature restoration
The European Commission (EC) reported that the Delegated Regulation for pollinator monitoring was published in September 2025 and is in force since mid-December 2025. This is a NRR related regulation that defines scientific method for monitoring pollinators, hoverflies included, and it has a rare and threatened species provision, which for some countries might include some of the species from the plan. https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=OJ:L_202502188
Status: in progress (25%)
Updated on: April 2026
To be completed: 2025
1.3.3 Convene a stakeholder platform with foresters and arboriculturists to provide recommendations on optimal management of veteran trees and moist decaying wood
Status: not started
Updated on: 11 July 2025
To be completed: 2026
Objective 1.4 Integration in existing plans
1.4.1 Ensure consideration of veteran trees, moist decaying wood and their specialised hoverflies in the EU habitat action plans
(Currently under public consultation) the proposed measure # 2.1.1.2 requires the creation of the list of requirements for feeding, nesting, etc., for syrphids among other taxa. In the same Action Plan, the proposed measure # 2.2.1.4 requires the identification and protection of old trees that host endangered species of saproxylic hoverflies and other pollinators. In the same Action Plan measure # 4.4.3. 1 requires that transport of burnt material and works in the burnt areas only if deemed absolutely necessary, with minimal disturbance and leaving enough trunks for saproxylic species, among them hoverflies.
Status: in progress (50%)
Updated on: April 2026
To be completed: 2025
1.4.2 Ensure consideration of veteran tree specialised hoverflies in national action plans for insects and biodiversity strategies
The University of Novi Sad reported that there are relevant research questions planned for a PhD study specifically to assess to what extent saproxylic hoverflies and their habitats, particularly veteran trees, are integrated into EU biodiversity and forest policy frameworks. The detailed research steps will include analysis of key EU-level policy and legal documents (e.g. EU Biodiversity Strategy for 2030, EU Forest Strategy), comparative analysis across EU Member States and synthesis of EU guidance and implementation trends, including how SAP-aligned actions are supported or overlooked, and highlighting best practices as well as institutional or legal gaps.
Status: in progress (25%)
Updated on: April 2026
To be completed: (2025-2029)
Objective 1.5 Coverage in protected areas
1.5.1 Conducting a gap analysis to obtain an overview of the number of hoverfly populations specialised to veteran trees (Sphiximorpha petronillae, Chalcosyrphus pannonicus, Primocerioides regale, Brachypalpus chrysites, Chalcosyrphus jacobsoni and Chalcosyrphus nigripes) in- and outside protected areas
Status: not started
Updated on: 11 July 2025
To be completed: 2027
1.5.2 Instigate planning and designation of protected areas of currently unprotected key populations of Sphiximorpha petronillae, Chalcosyrphus pannonicus, Primocerioides regale, Brachypalpus chrysites, Chalcosyrphus jacobsoni and Chalcosyrphus nigripes
Status: not started
Updated on: 11 July 2025
To be completed: 2030
Objective 2.1 Distribution and ecology
2.1.1 .Conduct field surveys at localities of all historic records of veteran tree specialised hoverflies in the European Union and neighbouring countries as well as potential habitats
The University of the Aegean reported that the project "Presence, distribution, ecology, and conservation of the threatened Diptera Brachyopa minima and B. quadrimaculosa on the Island of Lesvos" has been selected for funding by WWF-Greece. Another project entitled "Filling the knowledge gaps for Merodon longisetus, a Critically Endangered hoverfly in Mediterranean ecosystems" has been submitted to IUCN for evaluation.
Status: in progress (25%)
Updated on: April 2026
To be completed: 2026-2029
2.1.2 Study genetic diversity of remaining populations of veteran tree specialised hoverfly species in Europe
University of Novi Sad reported that the collection of distributional data at European level, both published and unpublished from different sources (e.g. online platforms, private collections, museum data is being conducted, and specific attention is being paid to searching information on target species.
Status: not started
Updated on: April 2026
To be completed: 2029
2.1.3 Map the distribution of veteran trees across Europe and create a comprehensive European database, building on existing national and citizen science databases (e.g., Italy, Sweden, UK, Monumental Trees, VETCERT).
Status: not started
Updated on: 11 July 2025
To be completed: 2026
Objective 2.2 Improving knowledge of ecology and habitat requirements
2.2.1 Research on larval habitat preferences (tree species, microhabitat, decay stage) for the six prioritised veteran tree specialised hoverfly species
Status: not started
Updated on: 11 July 2025
To be completed: 2028
2.2.2 Research on necessary spatial requirements (and number of veteran trees or amount of decaying dead wood required) of the prioritised veteran tree specialised hoverflies
Status: not started
Updated on: 11 July 2025
To be completed: 2028
2.2.3 Study on the connectivity of populations, mobility of selected hoverfly species with focus on dispersal
Status: not started
Updated on: 11 July 2025
To be completed: 2028
2.2.4 Field survey to quantify availability of suitable and potential trees and appropriate microhabitats for the target hoverfly species
Status: not started
Updated on: 11 July 2025
To be completed: 2028
Objective 2.3 Improving knowledge to mitigate threats and improve management
2.3.1 Study methods to create breeding sites for veteran tree specialised hoverflies to promote their populations
Status: not started
Updated on: 11 July 2025
To be completed: 2028
2.3.2 Development of best practice guidance for habitat management and restoration of veteran trees, decaying moist wood and specialist hoverflies
University of Novi Sad reported that a brochure for the workshop on best practices has been prepared (Jan 2026). Furthermore, they are conducting systematic literature review, searching for papers mentioning different practices. Additionally, they will systematize these findings in a scientific publication, together with the results of a survey about best practices they plan to conduct among different practitioners.
Status: in progress (25%)
Updated on: April 2026
To be completed: 2025 (update 2030)
2.3.3 Study on how other habitats with trees (parks, gardens) can promote the species
Status: not started
Updated on: January 2026
To be completed: 2028
2.3.4 Study on effects of climate change on the availability of habitat
Status: not started
Updated on: 11 July 2025
To be completed: 2028
2.3.5 Study the effect of wildfires on veteran tree specialised hoverfly populations
In Greece, a research team in the Department of Geography (Laboratory of Biogeography & Ecology) has published field studies specifically on post-fire pollinator communities and plant-pollinator interaction networks including hoverflies (but not our target species) after major wildfires.
Status: not started
Updated on: April 2026
To be completed: 2029
Objective 2.4 Monitoring
2.4.1 Development of a standardised monitoring protocol for veteran tree specialised hoverflies
The IUCN HSG is in the process of preparing the protocol. They also reported that the monitoring protocol for rare and threatened species will be an integral part of the EUPOMS project.
Status: in progress (50%)
Updated on: January 2026
To be completed: 2026
2.4.2 Integration of monitoring scheme for veteran tree specialised hoverflies in European Pollinator Monitoring Scheme (EUPOMS)
The University of Novi Sad reported that the IUCN SSC Hoverfly Specialist Group suggested species from Species Action Plan found in Slovakia (Chalcosyrphus pannonicus and Brachypalpus chrysites) to be included in monitoring of rare and threatened species with each member state creating their own list.
Status: in progress (25%)
Updated on: April 2026
To be completed: 2026
2.4.3 Establishment of a monitoring scheme for effectiveness of conservation actions for threatened veteran tree specialised hoverflies
The monitoring scheme for effectiveness of conservation actions will be an integral part of the EUPOMS.
Status: in progress (25%)
Updated on: January 2026
To be completed: 2027
Objective 3.1 Veteran tree management
3.1.1 Ensure that existing management plans of relevant Natura 2000 sites and other protected areas consider veteran tree specialised hoverflies
The University of the Aegean reported that Measure # 7.3.4.1 in the Action Plan for Pollinators in Greece (currently under public consultation) requires the development of management plans for key pollinators, with priority given to hoverflies and wild bees.
Status: not started
Updated on: April 2026
To be completed: 2027
3.1.2 Adapt local forest management to protect and increase the number of veteran trees and amount of decaying moist wood in areas with occurrence of any of the target species
Status: not started
Updated on: 11 July 2025
To be completed: 2025
3.1.3 Explore options to reintroduce Sphiximorpha petronillae, Chalcosyrphus pannonicus and Primocerioides regale in areas or countries where they are regionally extinct
Status: not started
Updated on: 11 July 2025
To be completed: 2030
Objective 3.2 Improving population connectivity
3.2.1 Identify priority areas for future veteran tree habitats
Status: In progress (25%)
Updated on: January 2026
To be completed: 2029
3.2.2 Habitat preservation: Develop guidance for those providing training to foresters linked to Forest Certification Processes
Status: not started
Updated on: 11 July 2025
To be completed: 2026-2029
3.2.3 Creating larval habitat in areas with occurrence of highly threatened species How: Small cutting into living trees to produce saprun / breeding boxes (see 2.3.1)
Status: not started
Updated on: 11 July 2025
To be completed: 2025-2028
Objective 4.1 Reduce threats and enhance habitat availability in the wider landscape
4.1.1 Provide training material on how to recognise high value veteran trees
The IUCN HSG is in the process of preparing training material.
Status: in progress (50%)
Updated on: January 2026
To be completed: 2025
4.1.2 Promote veteran tree survival in forests in the general wider landscape
Status: not started
Updated on: 11 July 2025
To be completed: 2025-2030
4.1.3 Promote veteran tree survival in public spaces (roadsides, parks, gardens, etc.)
Status: not started
Updated on: 11 July 2025
To be completed: 2025
4.1.4 Promote veteran tree survival in agricultural areas
Italy promotes the survival of veteran trees in agricultural areas; however, there currently is no information about similar initiatives in other countries.
Status: In progress
Updated on: 11 July 2025
To be completed: 2025
4.1.5 Promote integrated pest management and reinforce recommendation to ban or reduce pesticides and herbicides in forests and parks
Status: not started
Updated on: 11 July 2025
To be completed: 2028
Objective 5.1 Public awareness of veteran tree specialised hoverflies
5.1.1 Prepare general outreach material
IUCN published a piece by IUCN Save Our Species highlighting the growing conservation concern for Europe’s veteran tree hoverflies. Its purpose is to raise awareness of the species’ dependence on ancient trees, and outline the threats they face https://iucnsos.org/protecting-europes-veteran-tree-hoverflies/.
The University of Novi Sad reported that a brochure on best practices was created, which serves for the promotion of veteran trees in general. A workshop on best practices was planned for January 27th, 2026.
Status: In progress (25%)
Updated on: April 2026
To be completed: initial end date - 2024 (update based upon
completed actions 2028)
5.1.2 Create information signs in areas with occurrence of threatened veteran tree specialised hoverflies to inform about the values, habitats and threats
There is a negotiation process underway to include information signs in Kamenicki Park, Novi Sad (Serbia), which features veteran oak trees.
Status: in progress (25%)
Updated on: January 2026
To be completed: 2026 (update 2029)
5.1.3 Provide information about the veteran tree specialised hoverflies action plan and implementation on the EU Pollinator Information Hive
Some information has been provided to the EU Pollinator Information Hive on the implementation of this action plan.
Status: in progress (25%)
Updated on: January 2026
To be completed: initial end date - 2023
5.1.4 Provide case studies on successful veteran tree conservation approaches
It was also noted that Kamenicki Park, Novi Sad (Serbia) serves as a case study for monitoring and conservation efforts focused on veteran trees.
Status: in progress (25%)
Updated on: January 2026
To be completed: 2029
5.1.5 Awareness raising with foresters
The University of Novi Sad proposed three speakers who will deliver presentations at the best-practices workshop targeted at land managers and foresters, where case studies showcasing successful veteran tree management will be presented. The invitation to attend the workshop was shared through multiple channels, including forestry associations and relevant professional networks.
Status: not started
Updated on: April 2026
To be completed: 2026
Objective 5.2 Citizen engagement
5.2.1 Facilitate the development of a label ‘Veteran Tree Biodiver-City’ to distinguish municipalities which maintain veteran trees in parks
Status: not started
Updated on: 11 July 2025
To be completed: 2026
5.2.2 Engage citizens in veteran tree specialised hoverfly surveys
Status: not started
Updated on: 11 July 2025
To be completed: 2027
5.2.3 Engage citizens in creating larval habitats for veteran tree specialised hoverflies
Status: not started
Updated on: 11 July 2025
To be completed: 2025