Commission Delegated Regulation (EU) 2025/2188 of 19 September 2025 supplementing Regulation (EU) 2024/1991 of the European Parliament and of the Council by establishing a science-based method for monitoring pollinator diversity and pollinator populations

THE EUROPEAN COMMISSION,

Having regard to the Treaty on the Functioning of the European Union,

Having regard to Regulation (EU) 2024/1991 of the European Parliament and of the Council of 24 June 2024 on nature restoration and amending Regulation (EU) 2022/869 (1), and in particular Article 10(2),

Whereas:

(1) Regulation (EU) 2024/1991 requires Member States to improve pollinator diversity and reverse the decline of pollinator populations at the latest by 2030 and thereafter to achieve an increasing trend of pollinator populations, measured at least every six years from 2030, until satisfactory levels are achieved.

(2) The Commission is to establish a science-based method for monitoring pollinator diversity and pollinator populations (the ‘monitoring method’) that provides a standardised approach for collecting annual data on the abundance and diversity of pollinator species across ecosystems, and for assessing pollinator population trends and the effectiveness of restoration measures.

(3) Regulation (EU) 2024/1991 requires Member States to monitor annually the abundance and diversity of pollinator species using the monitoring method and to report the results of the monitoring to the Commission.

(4) To ensure the collection of high-quality data and thereby a scientifically sound assessment of progress towards the target for restoration of pollinator populations, the monitoring method should be based on established scientific principles and methods. Despite being standardised across Member States, the monitoring method should allow sufficient flexibility to address local environmental conditions.

(5) The scope of the monitoring method should target the taxonomic groups of pollinators for which there is sufficient technical capacity for monitoring or where such capacity can be built cost-effectively in the short term. The scope should be reviewed and broadened to additional taxonomic groups of pollinators when the technical capacity increases in the future.

(6) To ensure the cost-effectiveness of the monitoring method, a variety of approaches should be used for monitoring of common pollinator species and rare pollinator species. Common species should be monitored on sites selected by applying a stratified random sampling approach. Rare pollinator species should be monitored by targeted field visits as population trends for these species cannot be discerned by stratified random sampling at a limited number of monitoring sites.

(7) Considering the limited capacity for monitoring of rare pollinator species by targeted field visits, efforts should be focused on the most threatened species at Union or national level, and Member States should be allowed to limit the monitoring to 15 rare pollinator species. The number of rare pollinator species to be monitored should be reviewed and enlarged when capacity for targeted monitoring increases in the future.

(8) Regulation (EU) 2024/1991 requires Member States to ensure that the monitoring data comes from an adequate number of monitoring sites to ensure representativeness across their territories. For this, and to ensure that the trend in pollinator abundance and diversity can be confidently determined, it is necessary to set a minimum for the number of monitoring sites at which data is to be collected in each Member State. Setting this minimum number will allow Member States to monitor a larger number of monitoring sites so they can better detect changes in pollinator abundance and diversity.

(9) The activity of pollinators is affected by various environmental conditions, which depend on local circumstances. Therefore, the monitoring should be limited to periods in which pollinators are active at the adult stage of their life cycle. Suitable environmental conditions for monitoring should be defined at national, regional, or local level, as appropriate.

(10) The diversity of common pollinator species should be described using the Shannon-Wiener Diversity Index (2), a widely accepted metric for quantifying biological diversity. The abundance of common pollinator species should be quantified by combining the abundances of individual pollinator species for which monitoring data are sufficient.

(11) It is appropriate to combine abundance and diversity of all common species monitored into a single common pollinator indicator, which provides one value per Member State per year.

(12) Alien species, as defined in Regulation (EU) No 1143/2014 of the European Parliament and of the Council (3), should not be taken into account when assessing the abundance and diversity of pollinator species, since the presence of such species cannot be considered as a contribution to native pollinator communities but rather constitutes a threat to biodiversity.

(13) Since the Shannon-Wiener Diversity Index is not a suitable metric for the diversity of rare species, in order to represent the overall diversity of pollinator species, both common and rare, it is appropriate to integrate rare pollinator species into the assessment of pollinator diversity through a pollinator species richness indicator, i.e. an indicator that combines the number of rare and common pollinator species recorded in a Member State. The monitoring of rare species should exclude moths, because the monitoring burden cannot be estimated due to the current lack of red list assessments for moths.

(14) To assess the effectiveness of restoration measures implemented in a Member State, trends in the abundance and diversity of pollinator species should be estimated in agricultural ecosystems, forest ecosystems, and other ecosystems, respectively, given that the restoration measures are substantially different in each of those ecosystem types,

HAS ADOPTED THIS REGULATION:

Article 1

Definitions

For the purpose of this Regulation, the following definitions shall apply:

(1) ‘bees’ means species of Anthophila (Apoidea), excluding the honeybee (Apis mellifera);

(2) ‘hoverflies’ means species of Syrphidae;

(3) ‘butterflies’ means species of Papilionoidea;

(4) ‘moths’ means species of the following families of Heterocera: Brachodidae, Castniidae, Cimeliidae, Drepanidae, Erebidae (including Lymantriinae), Euteliidae, Geometridae, Heterogynidae, Limacodidae, Noctuidae, Nolidae, Notodontidae, Sesiidae, Sphingidae, Uraniidae, and Zygaenidae, provided they have a wingspan of 20 mm or more assessed on the basis of literature;

(5) ‘day-active moths’ means species of moths that are active in the daytime at the adult stage of their lifecycle;

(6) ‘night-active moths’ means species of moths that are active at night at the adult stage of their lifecycle;

(7) ‘LUCAS master grid’ means a variation of the INSPIRE Lambert Azimuthal Equal Area 1 km Grid (Grid_ETRS89-LAEA_1km), based on the ETRS89 Lambert Azimuthal Equal Area Coordinate Reference System (ETRS89-LAEA), with a fixed projection centre at 52° N, 10° E (4);

(8) ‘stratified random sampling of monitoring sites’ means a standardised statistical sampling, where monitoring sites have an equal probability of being selected from a population that is partitioned in sub-populations (strata);

(9) ‘biogeographical regions’ means biogeographical regions listed in Article 1, point (c)(iii), of Council Directive 92/43/EEC (5);

(10) ‘other ecosystems’ means ecosystems other than agricultural ecosystems and forest ecosystems that are aggregated in one stratum;

(11) ‘transect walk’ means a data collection method in which a surveyor walks a predetermined route (transect) in order to gather field data on pollinator species;

(12) ‘observation period’ means the period of the year which corresponds to the flying season of the large majority of the pollinator species;

(13) ‘light trap’ means a device which attracts pollinator species during the night-time by using light and captures them in a container;

(14) ‘assessment period’ means the time period over which progress to the target referred to in Article 10(1) of Regulation (EU) 2024/1991 is assessed;

(15) ‘alien species’ means alien species as defined in Article 3(1) of Regulation (EU) No 1143/2014.

Article 2

Target species

Member States shall collect data on the abundance and diversity of pollinator species in the following taxonomic groups:

(a) bees;

(b) hoverflies;

(c) butterflies;

(d) moths.

Article 3

Monitoring sites

(a) agricultural ecosystems;

(b) forest ecosystems;

(c) other ecosystems.

In addition to the stratification referred to in the first subparagraph, Member States may apply stratification by NUTS regions, classes of altitude, protection status or more refined categories of land use or land cover.

The number of sites in each stratum shall be proportional to the geographical share of that stratum in the terrestrial territory of a given Member State.

The distances between the monitoring sites shall be at least:

(a) 10 km for Member States with a terrestrial territory above 75 000 km2;

(b) 5 km for Member States with a terrestrial territory between 20 000 km2 and 75 000 km2;

(c) 1 km for Member States with a terrestrial territory between 1 000 km2 and 20 000 km2.

There shall be no minimum distance between the monitoring sites for Member States with a terrestrial territory below 1 000 km2.

(a) more than 30 % of the monitoring site is without terrestrial vegetation;

(b) the monitoring site is partially or fully located in urban centres, urban clusters or peri-urban areas;

(c) at least 30 % of the monitoring site is inaccessible due to the presence of public infrastructure or because the monitoring site is located in a public area with restricted access, such as a military zone, border zone or hunting zone;

(d) at least 30 % of the monitoring site is inaccessible because the monitoring site is located in a private area which is a border zone or hunting zone;

(e) the monitoring site is situated at a latitude above 65° N;

(g) the monitoring site cannot be attributed to one of the strata referred to in paragraph 4

The list of monitoring sites shall not be changed in the course of an assessment period.

Article 4

Observation period

Member States shall define, for each site, the observation period during which the data collection in accordance with Articles 5 and 6 shall take place every year. The observation period shall not be changed in the course of an assessment period.

Article 5

Data collection protocol for bees, hoverflies, butterflies and day-active moths

(a) bees;

(b) hoverflies;

(c) butterflies and day-active moths.

(a) temperature (in °C);

(b) cloud cover (in oktas);

(c) wind speed (in m/s);

(d) fog (presence/absence);

(e) precipitation (presence/absence);

(f) start time (hh:mm);

(g) any other relevant parameters that may affect the data collection.

(a) for bees and hoverflies: 1,5 m to each side of the surveyor, 1,5 m ahead of the surveyor, and 1,5 m above the surveyor;

(b) for butterflies and day-active moths: 2,5 m to each side of the surveyor, 5 m ahead of the surveyor, and 5 m above the surveyor.

Article 6

Data collection protocol for night-active moths

(a) temperature (in °C);

(b) cloud cover (in oktas);

(c) wind speed (in m/s);