Biosecurity's escalating its effort to eradicate yellow-legged hornets, following continued detections on Auckland's North Shore

More than 20 queens, and17 nests have been found and removed from Glenfield and Birkdale.

Property searches are underway within 200 metres of confirmed finds, with more than 2,100 residences being checked.

Biosecurity Commissioner Mike Inglis says they've placed more than 600 traps in those areas, and will keep adding more.