Rode Lijst van de lieveheersbeestjes in Vlaanderen: kansen voor een betere bescherming en een aangepast natuurbeheer

Red Lists assess the extinction risk of species and are an important
tool to prioritise species conservation and management measures.
Worldwide, quantitative IUCN criteria are used to estimate the threat
status of species at the regional level. In Flanders (north Belgium),
about 70.000 distribution records of ladybirds were collected in 36%
of all the grid cells (1 x 1 km²) since 1990 during a large-scale citizen-
science project. Applying the IUCN criteria to the 36 resident
‘conspicuous’ ladybirds in Flanders resulted in two Regionally extinct
species, three Endangered species and six Vulnerable species. A further
seven species were considered Near threatened and the remaining
15 species (39%) were assessed as Least concern. Three species were
classified as Data deficient. Using the Red List status, we delineated
ladybird hotspots which turn out to be located mainly in grid cells
with large areas of Natura2000 sites. The ladybird dataset from Flanders
provides evidence that IUCN Red List criteria can be applied to
this charismatic, but relatively under-surveyed insect group. For calculating
a distribution trend, we advocate the use of a high grid cell
resolution (e.g., 1 x 1 km² or 5 x 5 km²). For estimating the geographic
range, the use of extent of occurrence (EOO) instead of area of
occupancy (AOO) is advisable when the survey coverage is relatively
low. We discuss the opportunities of the availability of a ladybird Red
List for regional conservation measures.