European house borer: what to look for

Page last updated: Thursday, 12 October 2017 - 9:31am

Please note: This content may be out of date and is currently under review.

Signs of infestation

The most obvious signs of infestations are:

Exit holes: Adult beetles emerge through oval-shaped exit holes, 5-10mm in length and run in line with the grain. Frass, a mixture of fine powdery particles of wood dust and pellets of excrement, can sometimes be found below the timber where beetles have emerged.

EHB exit holes run with the wood grain
An oval-shaped EHB exit hole. The hole is 5-10mm in length and in-line with the grain

Structural damage: Galleries within the wood are formed by the boring larvae, which can affect the structural integrity of wood. Galleries rarely break through the timber surface and are therefore seldom detected.

Frass: Boring larvae leave the tunnels packed with a mixture of wood dust and droppings, known as frass. The frass can sometimes be found close to where beetles have emerged.

Blisters: Where boring larvae has eaten through tunnels and packed them with frass, long blister-like swellings under the surface may be evident.

Sound: Soft scraping sounds may be heard as the borer eats through the timber.

Galleries: Galleries are tunnels created by the boring larvae, and are frequently packed with frass. These galleries may be evident in timber that has been planed, sawn, or split.

Tracks: EHB beetles may make tracks in the frass seen beside exit holes.

Spider webs: EHB beetles may sometimes be trapped in nearby spider webs following exit.

Contact information

Pest and Disease Information Service (PaDIS)
+61 (0)8 9368 3080

European house borer: what to look for