Thyris fenestrella

• Subfamily:
• Wingspan: 14-20 mm
• Flight period: May - Aug
• Spread: Uncommon
• Host plants: Clematis vitalba

Information

The Thyris fenestrella is a moth of the Thyrididae family with a wingspan of 14-20 mm.
It is found in most of Europe but is absent in the northernmost latitudes, in fact it is absent in the British Isles, Denmark, the Scandinavian Peninsula and some Baltic countries.
Its range extends to Asia Minor. *
In Italy it is absent from Sardinia. *

The front wings of Thyris fenestrella are brown / black in color and have orange spots along the front edge and a characteristic whitish spot slightly translucent in the center of each wing. These almost transparent areas are window-like (hence the species name "fenestrella", which means small window).
Two of these spots are also present in the center of the hind wings, wings that have the same color as the front ones.
The abdomen is blackish-brown, with some light white transverse bands. **, ***, ****

This species has two generations per year, and they overwinter at the chrysalis stage. Adults are in flight from May until mid-August. They are particularly active on sunny days.
They frequent riparian environments mainly coastal environments, warm edges of the woods, sunny slopes with calcareous soil, shrubs and hedges where the host plant grows.****

The eggs are ovoid, flattened at the poles, reddish, opaque and strongly knurled. **
The larvae are translucent yellowish in color can reach a length of about 10 millimeters, and have numerous large black warts. The head and prothoracic shield are brown / blackish. **, *****
They live inside a rolled leaf of the host plant. **
The chrysalis is squat brown in color, shiny.

The larvae feed mainly on Clematis vitalba but there are also reports on Sambucus nigra and Arctium lappa.


* Lepidoptera mundi https://lepidoptera.eu/ - Fauna Europea https://fauna-eu.org/
** Bestimmungshilfe für die in Europa nachgewiesenen Schmetterlingsarten - http://lepiforum.de/
*** Nic,funet.fi - https://www.nic.funet.fi/
**** Vlinderstichting - www.vlinderstichting.nl/vlinders/overzicht-vlinders/details-vlinder/bosrankvlinder
***** Łukasz Dawidowicz Confirmation of the occurrence of Thyris fenestrella in Poland and remarks about its biology - https://www.researchgate.net/