Bidessus minutissimus
(Germar, 1824)
Minutest Diving Beetle
Aquatic Coleoptera
Conservation Trust
OVERVIEW
Bidessus minutissimus is a tiny diving beetle belonging to the family Dytiscidae, living up to its name as one of Britain's smallest aquatic beetles. This specialist species is adapted to acidic, nutrient-poor waters in heathland and moorland environments, where it plays a crucial role in maintaining the ecological balance of these unique aquatic communities.
CLASSIFICATION
DISTRIBUTION
Current Range: Scattered distribution across northern England, Wales, and Scotland, primarily in upland heathland and moorland areas with suitable acidic water bodies.
Habitat Distribution: Found in acidic bog pools, flushes, seepage areas, and shallow acidic ponds in heathland and moorland environments, particularly those with Sphagnum moss and low nutrient levels.
ECOLOGY & HABITAT
Acidic Pools
Shallow bog pools and flushes with low pH and nutrients
Heathland
Open heathland with scattered pools and seepage areas
Sphagnum Moss
Moss-dominated margins providing shelter and microhabitats
Life Cycle: Complete metamorphosis with both larvae and adults aquatic, adapted to acidic conditions
Diet: Predatory - feeds on small invertebrates, mites, and organic particles in the water column
Acid Adaptation: Specialised physiology allows survival in low pH environments that exclude many competitors
CONSERVATION STATUS
Key Threats:
- Heathland habitat loss and fragmentation
- Drainage and water table changes
- Nutrient enrichment and eutrophication
- Climate change affecting upland water levels
- Acidification changes due to atmospheric pollution
Population Trend:
CONSERVATION ACTIONS
Heathland Protection
Protect and restore heathland and moorland habitats
Hydrology Management
Maintain natural water levels and prevent drainage
Water Quality
Prevent nutrient enrichment and maintain acidic conditions
Survey & Monitoring
Regular monitoring of populations and habitat condition