Charles Aubrey Ealand, Insect Life, Londres, A. & C. Black, 1921, p. 135.

In less than a month the larvae emerge, and being soft-bodies and a likely prey for voracious creatures, they lose no time in constructing their dwellings of leaves, sticks, shells, sand, or similar material, and they are always characteristic of the species. The case, whatever its design, is so made that the larva need never expose more of its person than its horny head and thorax.