UKMoths Swammerdamia passerella - Distribution map
Please note that the NBN Gateway map service has been terminated as of 1 April 2017.
As soon as a replacement map service is available, distribution maps will hopefully appear here again.
In the meantime, you can get some idea of distribution from the NBN Atlas website.
16.016 BF437a
Swammerdamia passerella
(Zetterstedt, 1839)
Wingspan c.10 mm.
A rare species, restricted in the British Isles to high altitude in the Scottish Highlands. Abroad it also occurs in the Scandinavian mountains.
The larva spins a light web on the surface of leaves of dwarf birch (Betula nana), feeding on the leaf surface within.
Adults emerge in late May, coinciding with the leaf-flush of Betula nana. They can be seen flying low over the plant in the early evening.
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