Identify and prevent oak pinhole borer infestations
The wood boring beetle Platypus cylindrus infests and breeds in cut, windblown, standing dead and dying trees. Although it used to be rare in Britain, populations rapidly grew in the south and southeast when the severe gales of 1987 produced an abundance of breeding materials. Beetle numbers never returned to pre-hurricane levels and today the beetles have a continuing supply of breeding materials in the form of weakened oaks suffering from oak dieback and decline.
P. cylindrus now has the status of a timber pest in Britain but it is not directly responsible for killing trees.
This page will help you to identify P. cylindrus and to prevent timber infestation.
- Infests oak and other important timber species
- Damage at felling sites and timber yards
- Bores into the inner tree trunk (heartwood)
- Reduces timber value
- Tunnels do not significantly reduce timber strength
- Spoils appearance of timber products
Once P. cylindrus has tunnelled into logs it can no longer be controlled with insecticide – but careful management can minimise the damage and protect against infestation.
- Manage the harvest operation with the biology of the beetle in mind
- Inspect all logs regularly
- Logs and timber salvaged from dying trees should always be regarded as a potential source of beetles
- Spray high value logs with an insecticide approved for use on cut logs in May and July
The lifecycle of P. cylindrus usually takes two years from egg to adult, but can occasionally take one year.
- Adults most active between mid-July and mid-September
- Males bore into logs and stumps
- Females lay eggs inside tunnels
- Larvae pass through 4-5 growth stages
- Larvae transform into adults then feed on fungi inside gallery tunnels
P. cylindrus was once a rare insect in Britain – today it is a pest. This may be because many oaks are weak and suffering from oak dieback and decline, which makes them attractive to the beetles.
Forest Research is involved in projects to study oak decline: