Parasite of Garry Oak- Cynipid Gall wasp : Disholcaspis spp.

Each year I find some branches of the younger Garry Oak trees that I have planted on the farm to have these small brown pillbox-like galls of an insect parasite . Usually the branch will die in the following year. I am attempting to get it identified. Also the branches of the trees these are found on often have deep scratches as if a bird was trying to get under the bark?? I think that leads to the weakening of the branch.  I have saved one top leader of a Garry Oak  tree like this by coating  the damaged section with grafting paste.

oakparasite2-1024x907
Galls produced by a cynipid gall wasp Disholcaspis spp

Margot Moser of Nanoose bay, suggested that these galls are  likely made by the Honey gall wasp  Disholcaspis eldoradensis. A light colored, cylindrical (8mm in diameter), flat-topped gall caused by a cynipid gall wasp.

I am not so sure and a look at the reference on California Oak Galls by Joyce Gross made me think it may even be Disholcaspis chrysolepidis

Phylum Arthropoda – Arthropods
Subphylum Hexapoda – Hexapods
Class Insecta – Insects
Order Hymenoptera – Ants, Bees, Wasps and Sawflies
Superfamily Cynipoidea
Family Cynipidae – Gall Wasps
Tribe Cynipini
Genus Disholcaspis
Species ?? Gall Wasp