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:
Antennae small, nub-like, and inconspicuous, positioned approximately equidistant between anterior margin of head and eyes. Pro- and mesonota sclerotized, but metanotum mostly membranous, with some small sclerites. Pronotum broadest at middle when viewed dorsally. Prosternal horn usually present, sometimes short. Mesonotum with double notch medially along anterior margin. Metanotal anteromesal setal areas (sa1) each usually with tiny sclerite and 1 or 2 setae. First abdominal segment always with lateral humps and median dorsal hump. At least some abdominal segments with chloride epithelia (each evident as oval area surrounded by very fine dark line). Larvae building stout cases from pieces of rock, usually with small ballast stones arranged along sides.