Brilliant Emerald
Somatochlora metallica
The Brilliant Emerald is a medium-sized dragonfly characterized by its striking overall metallic green coloration and brilliant green eyes in adults. It primarily inhabits standing or slow-flowing waters that are often shaded by trees or located near forests. Males are known for their persistent patrolling flights along the shoreline, rarely taking breaks for feeding or resting. The larval development occurs in the aquatic sediment and typically lasts between two and three years.
Details
Identification
Body metallic green, forehead with yellow lateral spots, eyes brilliant green, male abdominal appendages characteristically shaped.
Social behavior
Solitary; males exhibit strong territorial behavior and defend sections of the shoreline against rivals.
Diet
Adults hunt flying insects (mosquitoes, flies); larvae are predatory, feeding on aquatic insects, tadpoles, and small crustaceans.
Hunting strategy
Adults are active aerial predators; larvae are ambush predators in the sediment.
Spawning substrate
Eggs are deposited during flight into loose shore substrate, mud, or among aquatic plants.
Overwintering
Overwintering occurs as larvae in the sediment at the bottom of the water body.
Ecology
Ecological role
Important predator for regulating insect populations in both aquatic and terrestrial habitats.
Natural predators
Birds (e.g., Hobby), larger dragonflies; larvae are preyed upon by fish and aquatic beetles.
Competitor species
Downy Emerald (Cordulia aenea), other emerald dragonflies.
Ecosystem service
Biological pest control through the consumption of mosquitoes.
Threats
Loss of near-natural riparian zones, water pollution, and climate change (drying up of habitats).
Scientific profile
Profile
Distinguishing features
Yellow spots on the frons (distinction from Cordulia aenea); the male abdomen is strongly constricted at the 3rd segment and club-shaped from the 5th segment onwards. Females possess a prominent, perpendicularly protruding ovipositor (vulvar scale).
Role in food web
Wichtiger Prädator im aquatischen und terrestrischen Ökosystem; reguliert Insektenpopulationen; dient selbst als Beute für größere Prädatoren.
Protection & threats
Main threats
Eutrophication of water bodies, loss of riparian vegetation due to construction, drying out of small water bodies as a result of climate change, intensive forestry use near forest waters.
Population trend
Widespread and mostly stable in Germany, locally declining in some southern regions or due to progressive drying of habitats.
Conservation measures
Protection and restoration of shore zones, preservation of forest ponds and near-natural flowing waters, reduction of nutrient inputs from agriculture.