Background

During surveys conducted in Mpumalanga in May 2025, aimed at investigating pine bark beetles, members of the TPCP team and Sappi detected an unknown bark beetle inhabiting galleries beneath the bark of harvested pine trees.
The morphology of this beetle did not match that of previously known pine-infesting bark beetles present in South Africa.

Identity

The beetle has been identified as Cyrtogenius luteus. Identification was confirmed using both morphological characteristics and DNA sequence data.
This species is a bark beetle (Curculionidae: Scolytinae), measuring approximately 2.2–2.4 mm in length. Adults vary in colour from golden brown to reddish-brown, depending on age.

Reported hosts

The species has been primarily recorded from a range of conifer hosts, particularly within the Pinaceae. Notable hosts include: Pinus densata, P. elliottii, P. insularis, P. khasia, P. massonia, P. pinaster, P. tabulaeformis, P. taeda, and P. yunnanensis.
In South Africa it was recovered from material of Pinus taeda.

Damage and symptoms

Damage and symptoms associated with C. luteus have not yet been formally documented in South Africa. Specimens were recovered from pine stumps several months after harvesting. The beetle may act as a secondary coloniser, targeting weakened or stressed trees.
However, as with other bark beetles, population build-up under favourable conditions may lead to spillover into adjacent, apparently healthy trees.

Origin and global distribution

Cyrtogenius luteus is native to Southeast Asia and has been recorded in Japan, Korea, the Philippines, China, and Myanmar.
The species has also been reported as invasive in Brazil, Uruguay, and Italy.

Distribution and prevalence in South Africa

The beetle has only been recorded in Mpumalanga

Biology and ecology

Cyrtogenius luteus is a small bark beetle that develops beneath the bark of conifers, particularly Pinus species, where it breeds within woody tissues.
The species has been captured in ethanol-baited traps, suggesting an attraction to stressed, damaged, or recently felled trees — a common ecological trait among bark beetles.
Although primarily associated with pines, it is not strictly host-specific, with very occasional records from non-conifer hosts such as Cornus controversa.

Should potential infestation of this pest be observed/suspected, please contact Sandisiwe Jali (Sandisiwe.jali@fabi.up.ac.za) to arrange a site visit or submit material to the TPCP Diagnostic Clinic.
Please distribute this pest alert to spread awareness.