Swammerdamia caesiella (Hübner, 1796)

birch ermine

on Betula

Betula spec., Belgium, prov. Limbourg, Genk-de Maten, 24.ix.2016 © Carina Van Steenwinkel: free-living larva

Betula pendula, Belgium, prov. Antwerp, Mol, 27.ix.2014 © Carina Van Steenwinkel: much silk on the leaf

Betula pendula, Lattrop, Bergvennen, 23.viii.2004

Betula sp., Belgium, prov. Limburg, Zutendaal de Lieteberg, 29.ix.2012 © Chris Snyers

young larva with three small mines

mine

The young larva makes one of, more probably, several tiny mines, from which much of the frass is ejected. Part of the frass grains are trapped in a slight spinning under the mine.

hostplants

Betulaceae, monophagous

Betula pendula.

phenology

Bivoltine, larvae in June-July and September-October; hibernation as pupa.

BENELUX

BE recorded (Phegea, 2012).

NE recorded (Kuchlein & de Vos, 1999a; Microlepidoptera.nl, 2012).

LUX recorded (Fauna Europaea, 2012).

distribution within Europe

All Europe (Fauna Europaea, 2012).

larva

The free living larva is light or dark greyish green with three darker length lines. The larva lives under a slight spinning at the upper side of the leaf, causing window feeding.

notes

These mines were known already for some years, but only in 2012 Chris Snyers succeeded in finding the link to the responsible species. Similar tiny youth mines seem to be a speciality of the family Yponomeutidae.

references

Agassiz (1996a), Baldizzone (2004a), Bengtsson & Johansson (2011a), Embacher & Kurz (2008b), Friese (1963a), Kuchlein & Donner (1993a), Kuchlein & de Vos (1999a), Leutsch (2011a), Paulavičiūtė (2020a).