Great Capricorn Beetle

cerambyx cerdo

The Great Capricorn Beetle is one of Europe's largest and most impressive insect species, renowned for its striking size and magnificent antennae. As a key member of the longhorn beetle family, this insect plays an important ecological role in forest ecosystems by colonizing older, weakened deciduous trees, particularly ancient oaks. Its presence is often a vital indicator of high-biodiversity old-growth woodland habitats, which are increasingly rare across its native European range. Although adults have a relatively short lifespan of just a few weeks, the species spends the majority of its life cycle as a hidden wood-boring larva deep within the trunks of majestic oaks. For nature enthusiasts, catching a glimpse of this nocturnal giant crawling along rugged oak bark on a warm summer evening is a thrilling and unforgettable wildlife encounter.

Habitat: Found in old-growth deciduous forests, wood-pastures, and historic parklands containing ancient, sun-exposed oak trees.

Appearance

This large beetle features an elongated, robust body measuring between 3 to 6 centimeters, with a coloration that transitions from deep black on the head and thorax to a rich, reddish-brown near the tips of its wing covers (elytra). Its most defining feature is its exceptionally long, segmented antennae; in males, these can extend up to twice the total length of the body, while the female's antennae are slightly shorter, matching her body length. The thorax is heavily wrinkled or rugose, and its powerful legs terminate in grippy claws designed for climbing rough tree bark.

KingdomAnimaliaPhylumArthropodaClassInsectaOrderColeopteraFamilyCerambycidaeGenusCerambyx

Great Capricorn Beetle

Interesting facts

Despite their formidable appearance and powerful jaws, adult Great Capricorn Beetles are entirely harmless to humans.

The beetle gets its name from the long, curved antennae of the male, which resemble the horns of a wild ibex or capricorn.

The larval stage of this beetle lasts between three and five years, while the adult beetle lives for only a few weeks to a couple of months.

Special abilities

When threatened, the beetle can rub its prothorax against its mesothorax to produce a loud squeaking sound intended to startle predators.

The larvae harbor specialized gut microbes that allow them to digest tough cellulose and lignin from old oak wood over several years.

Their massive antennae are packed with sensitive receptors, helping males detect female pheromones and fermenting oak sap from great distances.

Measurements & details

Length: 3-6 cm
Wingspan: 8-12 cm
Weight: 0.002-0.006 kg
Lifespan: 3-5 years
Top Speed: 5 km/h
Clutch Size: 100-300
Incubation: 10-20 days

Diet & Feeding

Larvae feed exclusively on the inner wood of oak trees, while adult beetles consume sugary tree sap, nectar, and sweet ripe fruits.

Age differences: Larvae are strictly xylophagous, boring into and consuming solid oak wood, whereas adult beetles feed on liquid sap and soft plant matter.