Agricultural officials in Napa and Sonoma are scouring vine imports from southern California after several discoveries of glassy-winged sharpshooter egg clusters.

Inspectors have discovered around five instances of sharpshooter eggs in vines coming into Napa and Sonoma nurseries.

In Sonoma, the alarm was first raised on 17 February, followed by another discovery on 8 March. Both clusters were found at vineyard nurseries in Petaluma. Sharpshooter eggs were also discovered on plants entering the Napa Valley.

None of the egg clusters so far discovered had fully developed although officials declared that the egg clusters were ‘viable’ and would have hatched.

State authorities have upped the level of vigilance, due also to the increasing shipments of vines from southern California at this time in the growing season.

Glassy-winged sharpshooters pose a huge threat to vines as they carry Pierce’s disease – a condition which prevents vines from taking nutrients and water from the soil properly.

Written by Oliver Styles, and agencies