Andricus lignicola
Videos
Cola-nut galls develop as a chemically induced distortion of leaf axillary or terminal buds on pedunculate oak or sessile oak trees, caused by the agamic gall wasp Andricus lignicola which lays single
Andricus lignicola Cola nut Gall
Cola-nut gall cut open to show the unilocular cavity
Oak marble galls showing two stunted and two normal-sized examples
Cola-nut gall showing exit hole
Gall
Videos
Galls or cecidia are a kind of swelling growth on the external tissues of plants. Plant galls are abnormal outgrowths of plant tissues, similar to benign tumors or warts in animals. They can be caused
Andricus lignicola
…may help to reduce an infestation. While fairly large, and sometimes present in quite large numbers on scrub specimens, they cause no measurable harm. Gall Gall wasp…
Oak artichoke gall caused by Andricus foecundatrix
Artichoke gall cut open to reveal wasp larva
Knopper gall caused by Andricus quercuscalicis