Cerambyx cerdo (Linnaeus) - Great Capricorn beetle

Coleoptera: Cerambycidae

IDENTIFICATION

Adult beetles are 24 to 53 mm long, with a blackish body and legs.²⁵ Male antennae are twice as long as the body, while those of the female extend to the elytral apex.²⁵ The pronotum is roughly textured and greater in width than in length. The tapered elytra are reddish-brown towards the apex.²⁵ The elytral apex has well developed sutural spines.¹²⁸

HOST TREES

Quercus (main host), Carpinus, Castanea, Ceratonia, Fagus, Fraxinus, Juglans, Pyrus, Robinia, Salix and Ulmus.^{25, 85, 128}

LOCATION OF INFESTATION WITHIN THE TREE

Larvae feed on the inner bark, sapwood and heartwood along the stem.^{25, 128}

HOST CONDITION

Mature, weakened (e.g. diseased, pruned) trees, especially those growing in open and sunny locations.^{25, 85, 117, 128} Occasionally young or healthy trees are attacked.⁸⁵

DISTRIBUTION

Europe, Asia, Caucasus, Asia Minor and northern Africa.^{25, 121, 128}

SIGNS AND SYMPTOMS

Females lay eggs in the bark.¹¹⁷ Larvae develop in the inner bark before penetrating into the sapwood, and then into the heartwood.^{25, 117, 128} Larval galleries are long, irregular and widen as the larvae increase in size.^{25, 117, 128} Larval development may take up to 2 to 5 years.^{25, 117}

Pupation occurs in the sapwood (approximately 80 mm deep) in a large, elongate, oval pupal cell that is partitioned from the larval gallery by a calcareous operculum secreted by the larvae.¹²⁸ Adults overwinter in the pupal cell and emerge at the end of spring, during the summer, or at the beginning of fall.^{25, 117} Exit holes are more or less oval and up to 2 cm in diameter. Brown frass also accumulates at the base of infested trees.

Dark resin seeps from holes at attack sites.¹¹⁷ Several generations may develop in the trunk. Re-infestation may continue year after year, highly degrading the wood and in some cases causing death of the infested tree.^{117, 128}

A - Male C. cerdo (24-53 mm long). Antennae are twice the body length.

B - Female C. cerdo (24-53 mm long).Antennae extend to the elytral apex.

C - Elongate and oval C. cerdo pupal chamber.

D - Adult C. cerdo. Elytra are reddish-brown towards the apex.

E - C. cerdo larval galleries within the sapwood.

F - Long, irregular-shaped C. cerdo larval galleries in the inner bark. Galleries widen as the larvae increase in size.

Photo credits

• A Zoological Institute, Russian Academy of Sciences
• B Zoological Institute, Russian Academy of Sciences
• C Gyorgy Csoka, Hungary Forest Research Institute, Image 1231104, forestryimages.org, Feb. 4, 2003
• D Gyorgy Csoka, Hungary Forest Research Institute, Image 1231106, forestryimages.org, Feb. 4, 2003
• E Karl-Heinz Apel, Landesforstanstalt Eberswalde, Abteilung Waldschutz
• F Gyorgy Csoka, Hungary Forest Research Institute, Image 1231105, forestryimages.org, Feb. 4, 2003