The great capricorn beetle (Cerambyx cerdo) belongs to the family Cerambycidae. It is an astonishing beetle of slender body about 5 cm length with extremely long antennae made up of thick and knotty flagellomeres. The antennae of the males – photo 1- are twice the length of the body, while that of females -photos 2nd, 3rd, 4th and 5th- are as long as the body. The body is shiny and elegant black, except for the end of the elytra, which turns towards a mahogany shade. The surface of the pronotum is rough and displays a tooth on each side, while the surface of the elytra shows fine stippling.
There are similar to the great capricorn species of Cerambycidae, among them Ergates faber with a more oval body, Cerambyx welensii without the tooth on each side of the pronotum and with a larger area of mahogany on the elytra, and Cerambyx scopolii of smaller size.
The larvae feed on the wood of oaks and holm oaks. These are white, soft caterpillars reaching 10 cm that spend years drilling galleries in trunks, mainly in old oaks. It is common for a great capricorn infestation to persist in one oak until having the trunk fully drilled.
[photos Oriol Oms (1st), Jordi Badia (2nd) and Florenci Vallès (3rd, 4th and 5th)]