following criteria for the occurrence of leafminers in Britain are
taken from the Review published in January 2012, by Tony Davis:
A.M. (2012). A Review of the Status of Microlepidoptera in Britain.
Butterfly Conservation, Wareham. (Butterfly Conservation Report No.
1 – Occurs in 5 or less 10km squares
pRDB 2 – Occurs in 6 – 10 10km squares
pRDB 3 – Occurs in 11 – 15 10km squares
pRDB K – Suspected, but not definitely known,
to be in one of the above categories but not enough information
available to say which.
Nationally Scarce A – Occurs in 16 – 30
Nationally Scarce B – Occurs in 31 to 100
Local – Occurs in 101 – 300 10km squares
Common – Occurs in more than 300 10km squares
Adventive – Only found in Britain as a result
of deliberate or accidental importation by humans
Migrant – Occurs naturally in Britain but
only as a result of immigration