On my oak trees, there are round growths about the size of a fingernail or larger that have a small hole in each to allow bug access. Inside the round hole grows a bug that when the round growth busts open, the bug exits. I have not seen the bug when it exits the growth. There are approximately 50 such growths ranging from .5 |
What you describe are called oak tree galls and are made by a wasp. Generally, insecticidal control is not satisfactory because the wasps are physically protected within the galls. As a rule, the galls are unsightly but will not harm your tree. Where practical, pruning of infested twigs may help to reduce the problem on lightly-infested trees. However, pruning is impractical if large trees are heavily infested. A commercial arborist may be able to provide assistance with valuable plantings. |