Why this cellular envelope?
Because the nest of the _Ameles_, like that of the Praying Mantis, has to endure through the winter, fixed to a stone or a twig, and is thus exposed to the full severity of the dangerous season.
The _Empusa pauperata_, on the other hand (one of the strangest of European insects), builds a nest as small as that of the _Ameles_, although the insect itself is as large as the Praying Mantis.

This nest is quite a small structure, composed of a small number of cells, arranged side by side in three or four series, sloping together at the neck.

Here there is a complete absence of the porous envelope, although the nest is exposed to the weather, like the previous examples, affixed to some twig or fragment of rock.

The lack of the insulating rind is a sign of different climatic conditions.

The eggs of the _Empusa_ hatch shortly after they are laid, in warm and sunny weather.