Four-banded Longhorn Beetle (Leptura quadrifasciata)

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Four-banded Longhorn Beetle (Leptura quadrifasciata)

Family: Cerambycidae (Longhorn beetles)
Common names: Four-banded Longhorn, Four-banded Flower Longhorn

🪲 Identification

Size: 10–20 mm in length
Body: Slender, elongated, slightly flattened
Coloration:
- Black body with four irregular yellow bands across the elytra (hardened wing covers)
- Bands can vary in shape and size but typically form a distinctive pattern
Antennae: Long and threadlike, often longer than the body in males
Legs: Black with possible yellowish tinge on the femora

This species mimics wasps in appearance (Batesian mimicry), deterring potential predators.

🌸 Habitat

Woodlands, forest edges, hedgerows, and flower-rich meadows
Found on flowers, particularly in the Apiaceae (carrot family), where adults feed on nectar and pollen

🌱 Diet

Larvae:
- Develop in dead or decaying wood of broadleaved trees like birch, willow, and alder
- Especially found in moist or wet wood (e.g., logs near water)
Adults:
- Feed on pollen and nectar
- Seen on umbellifers and other flowering plants during warm summer months

🔁 Life Cycle

Eggs: Laid in cracks of decaying hardwood
Larvae: Bore into the wood and feed for 2–3 years
Pupation: Occurs within the wood
Adults: Emerge from June to August, with peak activity in mid-summer

Adults are diurnal and often seen basking in the sun or visiting flowers.

🌍 Distribution

Widespread across Europe, including:
- Northern and Central Europe
- Parts of the British Isles
Also found in Western Asia
Prefers moist deciduous woodlands near streams or wetlands

⚠️ Similar Species

Other flower longhorns (Leptura spp.) may appear similar, but L. quadrifasciata is the only one with a distinct four-banded pattern.
May be confused with wasps at a glance due to yellow-black warning colors

🧬 Ecological Role

Pollinator: Adults help pollinate wildflowers
Decomposer: Larvae contribute to the breakdown of deadwood, supporting forest ecosystems

🛡️ Conservation Status

Not currently threatened
Populations benefit from the preservation of old-growth forests, deadwood, and wildflower diversity

The Four-banded Longhorn Beetle (Leptura quadrifasciata) is a beautiful, ecologically valuable insect — a bridge between forest and meadow life. Its presence is a good indicator of healthy woodland environments and biodiversity-rich habitats.