Follow Us

Tel: 01926 883 385
Mob: 07790 553 110

Mon - Sat 9.00 - 18.00
Sunday Closed

Professional arborists

Oak Marble Gall

Scientific name: Andricus kollari Gall

Common name: Oak Marble Gall

Family: Cynipidae


This gall appears first as a pink-yellow round ball up to 2cm growing on oak. With age the gall becomes brown and woody. This is home to the Andricus kollari wasp. The larvae (present from June-September) grow inside the gall until they hatch into the adult wasps. The wasps then excavate a hole through the wall of the gall to escape. There can be several larvae in each gall. The exit holes that the wasps have made can be seen in Fig.1. The wasp lays its eggs at bud points of the plant. The tree responds to his by mutating its growth forming a gall. The wasp encourages this by injecting the bud with an irritant. Several galls are usually situated on the same stem. The kollari Wasp is thought to have no males in the species reproducing by females alone.

Effects of the pest:

The gall has little effect on the tree. They appear due to the mutation of bud growth as a response to the wasps egg laying. If the outbreak of wasps was so severe that a large percentage of buds were mutated, it would be likely to have a detrimental effect on the trees growth however such a large infestation has not been found yet.


Oak species.

Fig.1 – Andricus kollari gall close up showing exit holes.

Fig.2 - Andricus kollari galls on oak twig.

Free Advice and Quotations

Please give us a call for a price or to arrange a visit!

01926 883 385


Element Tree Care carries £5Million Public Liability Insurance and £10Million Employers Liability Insurance.


All management and senior workforce have a Foundation Degree qualification (FdSc) in Arboriculture and Horticulture.


Element Tree Care ensures all operators carry the relevant certificates of competency and have undergone NPTC training and assessments for each qualification.


Element Tree Care offers free advice to all customers. Written quotations are provided for all jobs and are also free of charge.

Professional Tree Surgeons

If you require the services of a qualified tree surgeon then simply give us a call

01926 883 385or

contact us