Common Blue Damselfly
Enallagma cyathigerum
The Common Blue Damselfly is a widespread damselfly primarily found near standing water bodies. Males are bright blue with characteristic black markings, while females are often greenish or brownish in color. It is one of the most common damselfly species in Europe and inhabits a wide variety of habitats, ranging from small ponds to large lakes.
Details
Identification
Males with a cup-shaped black spot on the second abdominal segment; females with an ovipositor and often more inconspicuous coloring.
Social behavior
Solitary, but often forms large aggregations on riparian plants during the mating season.
Diet
Predatory; larvae feed on zooplankton and small insect larvae, adults hunt flying insects in flight.
Hunting strategy
Larvae are ambush predators using a labial mask; adults are active visual hunters in flight.
Spawning substrate
Insertion of eggs into living plant tissue of aquatic plants.
Overwintering
Overwintering occurs in the larval stage within the aquatic substrate.
Ecology
Ecological role
Important predator for small insects and a significant food source for birds, amphibians, and fish.
Natural predators
Birds, frogs, spiders, larger dragonflies, and fish (for larvae).
Competitor species
Other damselflies such as Coenagrion puella (Azure Damselfly).
Ecosystem service
Biological control of mosquito populations.
Threats
Destruction of riparian vegetation, eutrophication, and drying up of small water bodies.
Scientific profile
Profile
Distinguishing features
Males: Cup-shaped mark on S2, broad blue antehumeral stripes, only one black line on the side of the thorax. Females: Distinct vulvar spine on the underside of the 8th abdominal segment; the markings on segments S3-S7 are torpedo-shaped.
Role in food web
Important secondary consumer in aquatic and terrestrial ecosystems; links aquatic production with terrestrial predators.
Protection & threats
Main threats
Destruction of small water bodies, intensive fish farming (high predation pressure), eutrophication from agricultural runoff, and desiccation of habitats due to climate change.
Population trend
Stable; the species is widespread throughout Europe and is one of the most common dragonfly species (Source: IUCN, BfN).
Conservation measures
Protection and creation of vegetation-rich standing waters, reduction of nutrient input through buffer zones, avoidance of fish stocking in conservation ponds.