Ceanothus stem gall moth

A sporatic but potentially damaging pest, the ceanothus stem gall moth, Periploca ceanothiella (Cosens), is present throughout the west coast in concert with the distribution of Ceanothus species. The moth lays eggs on the buds and flowers of Ceanothus. The young larvae bore into the stem and feed within causing tissue to gall. The larvae overwinter inside these galls which are very noticeable in the early spring. They then pupate and emerge as adult moths in summer.

Research by Munro in 1963 showed a wide range of susceptibility of Ceanothus species. Pruning out and disposing of galled materials may reduce overall damage as the moth only has one generation a year.


Munro, J.A. 1963. Biology ofthe Ceanothus stem-gall moth, Periploca ceanothiella (Cosens). J. Res. Lepid. 1:183-190.

Johnson, W.T. and H.H. Lyon. 1991. Insects that feed on trees and shrubs. 2nd ed. Cornell University Press, New York. pp.438-439.


Galls of ceanothus stem gall moth
Photo: Rosetta
Closeup of galls
Photo: Rosetta
Gall near flower buds
Photo: Rosetta