[1] In the spring, female Neochlamisus lay eggs singly on the leaves or stems of their host plant and then form a case of fecal material around each.

The larvae remain on the natal host plant and add to and enlarge their fecal cases as they grow.

After about twenty days the newly hardened adult cuts a clean circle around the apex of the case, lifts this cap, and flies off to feed and mate.

A rather well-known exception is N. bebbianae which feeds on particular species from six tree genera representing five different plant families.

N. bebbianae populations associated with each of these plants are referred to as separate "host forms" and are the subject of ongoing studies of host-associated speciation.