A Guide to Grapevine Abnormalities in South Africa - P.G. GOUSSARD

Quince stem-borer.

PHOTO 339. During the escape of adult quince stem-borer moths, parts of the pupae are pulled outside. Also note the fine wood shavings (10:00 position) which are worked to the outside in the course of the life cycle.

PHOTO 340. Characteristic, visually detectable damage associated with the feeding activities of stem- borers, are best exposed by a cross-section of affected wood sections. Note the incidence of wood shavings as well as the tunnel through which an adult quince stem-borer moth has probably already escaped to the outside. Not to be confused with eutypa dieback or other examples of the rugose wood complex.

218 • A Guide to Grapevine Abnormalities in South Africa