Small Red-eyed Damselfly
Erythromma viridulum
The Small Red-eyed Damselfly is a zygopteran species in the family Coenagrionidae, characterized by the bright red eyes of the males. It is closely associated with lentic water bodies containing abundant submerged and floating vegetation, such as hornwort or water milfoil. The species has been significantly expanding its range northwards in Europe as a result of climate change.
Details
Identification
Males with red eyes; abdominal segment 10 blue with black markings; sides of the thorax blue; females with pale eyes and continuous dark dorsal surface of the abdomen.
Social behavior
Males defend territories on the floating leaves of aquatic plants; often found in high population densities.
Diet
Larvae are predatory, feeding on small crustaceans and other insect larvae; adults consume small flying insects.
Hunting strategy
Larvae are ambush predators; adults hunt during flight or glean prey from vegetation.
Spawning substrate
Eggs are laid endophytically into the living tissue of aquatic plants such as Myriophyllum or Ceratophyllum.
Overwintering
Overwintering occurs during the larval stage within the water body.
Ecology
Ecological role
Important consumer in the food web of standing waters and prey for birds and larger dragonflies.
Natural predators
Birds, frogs, larger predatory dragonflies, spiders.
Competitor species
Red-eyed Damselfly (Erythromma najas), other coenagrionid damselflies.
Ecosystem service
Biological control of mosquito populations.
Threats
Destruction of aquatic vegetation, excessive eutrophication, and use of pesticides near shorelines.
Scientific profile
Profile
Distinguishing features
Smaller than Erythromma najas. Males are distinguished by the blue sides on S2 and S8 and the X-mark on S10. The pterostigma is light brown. Females lack a pale postocular stripe (distinction from Coenagrion species). Wing venation shows specific characteristics of the genus Erythromma.
Role in food web
Secondary consumer; regulates populations of small aquatic invertebrates and serves as an important food source for higher trophic levels.
Protection & threats
Main threats
Loss of vegetation-rich standing waters due to infilling or intensive use, excessive fish stocking (predation pressure and loss of macrophytes), and herbicide use near water bodies.
Population trend
Increasing; the species shows a clear expansion trend in Central Europe and is increasingly colonizing new habitats in more northern latitudes.
Conservation measures
Protection and creation of plant-rich standing waters, promotion of natural riparian vegetation, reduction of nutrient input to prevent algal mats that displace macrophytes.