Eurasian Bluets (Coenagrion)

Here’s an overview of the Eurasian Bluets, referring typically to several closely related damselfly species in the genus Coenagrion, often just called bluets. These small, slender damselflies are common across much of Europe and northern Asia.

🧬 Eurasian Bluets – General Overview

• Scientific group: Coenagrion spp.
• Family: Coenagrionidae
• Common names: Eurasian Bluets, Damselflies
• Size: 30–35 mm in body length
• Flight season: Late spring to late summer (May–September in temperate regions)

🔍 Key Eurasian Bluet Species

1. Common Blue Damselfly (Enallagma cyathigerum)
   • Widespread across Europe and Asia
   • Males: Bright blue with black markings
   • Females: Variable, from blue to brown forms
   • Found in a wide variety of freshwater habitats, including lakes, ponds, canals, and slow rivers
2. Azure Damselfly (Coenagrion puella)
   • Common in western and central Europe
   • Males: Light blue with a characteristic U-shaped mark on the second abdominal segment
   • Females: Blue or green with black pattern
   • Prefers weedy ponds and ditches
3. Variable Damselfly (Coenagrion pulchellum)
   • Similar to C. puella, but with more variable thoracic markings
   • Males: Blue with distinctive “wine glass” pattern on abdomen
   • Females: Also variable, often darker
   • More habitat-specific – prefers rich, still waters with plenty of vegetation
4. Northern Damselfly (Coenagrion hastulatum)
   • Restricted to northern Europe and mountain peatlands
   • Males: Blue with narrow black “dagger” shape on segment 2
   • A cold-climate specialist

🧠 Identification Tips (Male)

• Bright blue and black pattern on body
• Wings clear with narrow stalks, held closed over the back
• Markings on abdominal segment 2 are key to species-level ID (e.g., U, wine glass, dagger shapes)

🌿 Habitat

• Prefer still or slow-moving freshwater:
  • Lakes, ponds, marshes, canals, ditches
• Some tolerate disturbed or urban habitats, others are restricted to clean, unpolluted wetlands

🐛 Life Cycle

• Eggs laid in aquatic vegetation
• Larvae (naiads) live underwater for 1–2 years, feeding on small aquatic invertebrates
• Adults emerge in spring/summer
• Mating involves characteristic “wheel” position
• Short adult life (~a few weeks), focused on mating and dispersal

⚠ Conservation Status

• Most bluet species are listed as Least Concern, but:
  • Some (C. mercuriale, C. ornatum) are threatened or declining due to:
    • Wetland drainage
    • Pollution
    • Climate change
• Conservation efforts include:
  • Protecting wetland habitats
  • Monitoring species distribution through citizen science and survey schemes

🔎 Interesting Facts

• Bluets are weak fliers compared to dragonflies, staying close to vegetation
• Males often patrol territories aggressively
• Excellent indicators of freshwater ecosystem health

If you’re looking for:

• 🗺️ Distribution maps
• 📷 Photos of each species
• 🔬 ID guide with comparison tables
• 📋 Conservation case studies (e.g. UK Biodiversity Action Plan species)

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