Donacia bicolora
(Zschach, 1788)
Two-tone Reed Beetle
Aquatic Coleoptera
Conservation Trust
OVERVIEW
Donacia bicolora is a distinctive reed beetle named for its characteristic two-tone metallic coloration. This semi-aquatic species is associated with branched bur-reed and club-rush communities, representing a specialist component of high-quality wetland ecosystems. Its scattered distribution and specific habitat requirements make it a valuable indicator of pristine aquatic plant communities.
CLASSIFICATION
DISTRIBUTION
Current Range: Scattered populations in southern England and Northern Ireland, with most records from areas with well-developed wetland systems and high water quality.
Habitat Distribution: Associated with beds of branched bur-reed (Sparganium erectum) and club-rush (Schoenoplectus) in stream-fed ponds, lake margins, and river backwaters requiring minimal pollution and disturbance.
ECOLOGY & HABITAT
Stream-Fed Ponds
Ponds with continuous flow and high water quality
Bur-Reed Beds
Branched bur-reed and club-rush communities
Pristine Waters
Exceptional water quality essential for survival
Life Cycle: Complete metamorphosis with larvae developing on submerged roots and rhizomes
Diet: Adults feed on aerial parts of host plants; larvae feed on submerged root systems
Water Quality Dependence: Requires very high water quality and is highly sensitive to pollution and disturbance
CONSERVATION STATUS
Key Threats:
- Wetland habitat degradation
- Water pollution and nutrient enrichment
- Loss of native aquatic plant communities
- Water level management changes
- Climate change impacts on wetland systems
Population Trend:
CONSERVATION ACTIONS
Water Quality Protection
Maintain exceptional water quality standards in wetland systems
Habitat Management
Protect and restore stream-fed pond and lake margin habitats
Plant Community Management
Maintain diverse native aquatic plant communities
Population Surveys
Regular monitoring and search for new populations