Order:
Larvae: Wings/wing pads absent. Eye spots present, but compound eyes absent. Antennae usually small, inconspicuous. Three pairs of segmented legs present on thorax. Pair of anal prolegs, each with single hook, located on last abdominal segment. Larvae can be free-living, in silken retreats attached to substrate, or in usually-portable tubes or cases made of sand, rocks, or plant material.
Family:
Pro-, meso-, and metanota entirely covered by sclerites. Ventral side of abdomen with rows of branched gills. Conspicuous tuft or fan of long hairs on each anal proleg. Anal claw with stout apical hook. Larvae building stationary retreats of silk, detritus, and rock fragments and add a silken net for filter feeding.