Members of the family Yponomeutidae are nocturnal moths, and their larvae lives under a communal tent-like webbed structure, like here. At this stage of development, they are about 3 to 4 cm long, white-cream in color, with two rows of black spots and black head. As they grow, the tent expands - we first noticed this one few weeks before, and it was much smaller, barely a one-fifth of the one on photo N° 6.
In between the wheat fields and deciduous forest, straight on France-Switzerland border.
I thought it could be Yponomeuta padella or Y. cagnagella...
Lat: 46.25, Long: 6.10
Spotted on May 7, 2018
Submitted on Aug 24, 2018