Stenamma westwoodii is a small dark reddish brown myrmicine ant very similar to the more common S. debile (Förster). Up until the 1990s it was thought to be the only species of its genus in the British Isles. It is now clear that S. debile is much more common and older records for S. westwoodii are now treated as S. westwoodii agg and most early records are likely to be S. debile.
The map shows S. westwoodii iso Dubois.
There are a few confirmed records for southern England. Only a minority of the S. westwoodii agg records are likely to be S. westwoodii iso Dubois and it is hoped that where vouchers exist these can be examined and more confirmed records can be added to the map.
Elswhere in Europe there are a few isolated records from Belgium (Dubois, 1998; Seifert, 2007) and the Netherlands (Seifert, 2007).