Common blue (Polyommatus icarus)

Deep Overview: Common Blue (Polyommatus icarus)

The Common Blue (Polyommatus icarus) is one of Europe’s most widespread and recognizable butterflies, known for its brilliant blue coloration (in males), small size, and adaptability to a variety of habitats. Despite its name, not all individuals are blue—females often display brownish wings with orange spots, making them more difficult to identify.

Taxonomy & Classification

• Kingdom: Animalia
• Phylum: Arthropoda
• Class: Insecta
• Order: Lepidoptera
• Family: Lycaenidae (Blues, Coppers, and Hairstreaks)
• Genus: Polyommatus
• Species: Polyommatus icarus
• Common Names:
  • Common Blue
  • Icarus Blue

Physical Description

• Wingspan: 28–36 mm (1.1–1.4 in)
• Coloration & Markings:
  • Males:
    • Bright iridescent blue upperwings with a thin black border and white fringe
  • Females:
    • Brown upperwings with variable blue scaling
    • Distinctive orange spots along wing edges
  • Underwings (both sexes):
    • Pale brown/gray with black spots, orange markings, and white halos
• Key Features:
  • Sexual dimorphism (males blue, females brownish)
  • Antennae are black-and-white banded with a clubbed tip

Distribution & Habitat

• Geographic Range:
  • Widespread across Europe, North Africa, and temperate Asia
  • Found as far as Iceland, the British Isles, and the Middle East
• Preferred Habitat:
  • Grasslands, meadows, coastal dunes, roadside verges, gardens, and woodland clearings
  • Prefers open areas with wildflowers, especially where clovers and bird’s-foot trefoil grow

Behavior & Adaptations

• Fast, Agile Flyers:
  • Males patrol territories searching for females
• Sun-Loving Species:
  • Active on warm, sunny days
• Camouflage & Protection:
  • Brownish underwings provide excellent camouflage when resting
• Multiple Generations per Year:
  • In warmer regions, there can be 2–3 broods per year

Diet & Feeding Habits

• Caterpillars (Larvae):
  • Feed on leguminous plants (bird’s-foot trefoil, clovers, medick)
• Adult Butterflies:
  • Nectar feeders preferring thistles, knapweed, clover, and dandelions
• Feeding Strategy:
  • Often seen nectaring with wings closed, revealing cryptic underwings

Reproduction & Life Cycle

• Breeding Season:
  • April to October (varies by region)
• Egg-Laying:
  • Females lay eggs on host plants, usually on leaf buds or stems
• Caterpillar Stage:
  • Pale green larvae with faint stripes
  • Have a mutualistic relationship with ants (ants “farm” them for secreted sugary substances)
• Pupation & Overwintering:
  • Overwinters as a chrysalis (pupa) among leaf litter or near plant roots
• Lifespan:
  • Adults live around 2–3 weeks

Predators & Threats

• Natural Predators:
  • Birds, spiders, predatory insects
• Human-Related Threats:
  • Habitat destruction due to intensive farming and urbanization
  • Overuse of pesticides and herbicides, reducing host plants and nectar sources
• Conservation Status:
  • Least Concern (LC) but experiencing localized declines in some areas

Ecological Importance

• Pollinator:
  • Contributes to pollination of wildflowers and crops
• Part of the Food Web:
  • Provides a food source for birds, reptiles, and predatory insects
• Ant Symbiosis:
  • Some caterpillars form mutualistic relationships with ants, which protect them from predators

Relationship with Humans

• Common in Gardens & Parks:
  • Frequently seen visiting nectar-rich flowers
• Indicator of Biodiversity:
  • The presence of Common Blues signals a healthy ecosystem
• No Agricultural Impact:
  • Larvae feed on wild plants, not crops

Fun Facts

• Males patrol constantly to find females, sometimes traveling great distances
• The “blue” color is structural, caused by microscopic wing scales reflecting light
• Can be confused with other blue butterfly species, like the Adonis Blue and Holly Blue
• One of the few butterflies that can have multiple generations per year in warm climates

Conclusion

The Polyommatus icarus is a widespread, adaptable butterfly that thrives in open, flower-rich habitats. Its brilliant blue coloration (in males), territorial behavior, and role as a pollinator make it an important and beautiful species. While still common, habitat destruction poses a growing threat to its populations.

Common blue (Polyommatus icarus)

Common tiger (Danaus genutia)

Orange Tip Butterfly (Anthocharis cardamines)

Comma butterfly (Polygonia c-album)

Old World Swallowtail (Papilio machaon)

Orange gull (Cepora judith)

Green hairstreak (Callophrys rubi)

Common copper (Lycaena phlaeas)

Mazarine Blue (Cyaniris semiargus)

Blue glassy tiger (Ideopsis similis)

Scarce Swallowtail (Iphiclides podalirius)

Download full size image The Small Tortoiseshell (Aglais urticae) is a charming butterfly species belonging to the family Nymphalidae, known for its striking appearance and widespread distribution across Europe and parts of Asia. Here's a detailed description: Physical Characteristics: The Small Tortoiseshell butterfly is of medium size, with a wingspan typically ranging from 45 to 55 millimeters. It displays a distinctive pattern of bright orange wings bordered by a black band with white spots. The forewings also feature a row of blue crescents near the outer edge, while the hindwings have a series of blue spots and a border of black and yellow. The undersides of the wings are mottled brown, providing effective camouflage when the butterfly is at rest. Habitat and Distribution: Small Tortoiseshell butterflies are commonly found in a variety of habitats, including meadows, grasslands, woodlands, gardens, and urban areas. They are distributed across much of Europe, including the British Isles, Scandinavia, and the Mediterranean region, as well as parts of Asia, such as Siberia, Central Asia, and the Middle East. They are particularly abundant in temperate regions with diverse plant species. Behavior and Life Cycle: Small Tortoiseshell butterflies are diurnal and active during the warmer months of the year, especially in spring and summer. They are strong and agile flyers, often seen fluttering among flowers in search of nectar and mates. The females lay eggs singly on the leaves of stinging nettles (Urtica spp.), which serve as the primary larval host plant. The caterpillars hatch from the eggs and feed on the leaves of the host plants before pupating and emerging as adult butterflies. Conservation Status: The Small Tortoiseshell is not considered globally threatened and is generally common and widespread throughout its range. However, like many butterfly species, it may face localized threats due to habitat loss, fragmentation, and degradation caused by agricultural intensification, urbanization, and climate change. Conservation efforts focused on preserving and restoring habitats, protecting larval host plants, and minimizing human disturbance are crucial for ensuring the long-term survival of this iconic butterfly species. Overall, the Small Tortoiseshell butterfly is a beautiful and ecologically important species, valued for its striking appearance, graceful flight, and role in pollination and ecosystem functioning. Its presence adds vibrancy and vitality to natural landscapes and serves as a symbol of the rich biodiversity of the regions where it is found.

Common blue (Polyommatus icarus)

Common blue (Polyommatus icarus)

False heath fritillary (Melitaea diamina)

Common blue (Polyommatus icarus)

Northern chequered skipper (Carterocephalus silvicola)

Mazarine Blue (Cyaniris semiargus)

Chestnut heath (Coenonympha glycerion)

Lesser marbled fritillary (Brenthis ino)

Common tiger (Danaus genutia)

European peacock (Inachis io)

Green hairstreak (Callophrys rubi)

Julia Heliconian (Dryas iulia)

Mazarine Blue (Cyaniris semiargus)

Common blue (Polyommatus icarus)

Common blue (Polyommatus icarus)

Scarce Swallowtail (Iphiclides podalirius)

Old World Swallowtail (Papilio machaon)

Common blue (Polyommatus icarus)

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