Disinfestation of DRYOCOSMUS KURIPHILUS (chestnut gall wasp) in Castanea scion wood

Dryocosmus kuriphilus is a species of gall wasp known by the common names chestnut (Castanea) gall wasp, Oriental chestnut gall wasp, and Asian chestnut gall wasp.

chestnut gall wasp
chestnut gall wasp

It is native to China and it is known in many other parts of the world, particularly the Northern Hemisphere, as an introduced species and an invasive horticultural pest. It attacks many species of chestnut (genus Castanea), including most cultivated varieties. It is considered the world’s worst pest of chestnuts,

The following is an extract from https://www.actahort.org/books/1019/1019_37.htm

Studies were conducted to determine if high temperature treatment was a viable method of disinfesting Dryocosmus kuriphilus larvae in Chinese chestnut buds (Castanea). Preliminary experiments indicated that the warmest lethal temperature for ‘Qing’ Chinese chestnut buds was influenced by the time of collection, diameter of the scion wood, and the duration of the heat treatment. Forced-air heating with a programmable Tenney chamber and radio frequency heating in a custom built unit were problematic and more expensive methods of treating chestnut scion wood than hot water immersion in a recirculating bath. ‘Qing’ scion buds from wood immersed in a water bath at 52 or 53°C for 10 min and grafted onto AU-Cropper seedling rootstock had 75 and 25% graft union success, respectively and produced scion growth without galls. Untreated ‘Qing’ buds had 80% graft union success, but galls formed on 42% of the successfully-grafted trees. These results indicate that hot water immersion is an effective method for inducing D. kuriphilus larvae mortality in chestnut buds before growth begins in the spring. Gall wasp larvae also were killed after hot water immersion of small galls attached to chestnut stems at ≥49°C for 5 min.