The Oak Pin-hole Borer, Platypus cylindrus, is a wood borer – not a wood feeder. It is one of a species of small beetles (usually only about 5mm long) where an adult male, attracted to the smell of fermenting sap, bores into the wood of stressed and dead oak trees. After it has tunneled a few centimetres into the wood, the passage is inspected by a female beetle which, on emerging, mates with the incumbent male. The pair then re-enter the borehole and while the female continues tunneling, the male clears away the frass.
These beetles have a symbiotic, or mutually beneficial, relationship with certain fungi. Fungal spores are collected and carried into the tunnel where they develop and provide food for adult and larval beetles. This fungal group, known as ‘ambrosia fungi’, depend on the beetles for dispersal to new trees. The oak pinhole beetle is thus also known as an ambrosia beetle.
