Psychidae

The Psychidae (bagworm moths, also simply bagworms or bagmoths) are a family of the Lepidoptera (butterflies and moths). The bagworm family is fairly small, with about 1,350 species described. Bagworm species are found globally, with some, such as the snailcase bagworm (Apterona helicoidella), in modern times settling continents where they are not native. Another common name for the Psychidae is "case moths", but this is just as well used for the case-bearers (Coleophoridae). The names refer to the habits of caterpillars of these two families, which build small protective cases in which they can hide. The Psychidae belong to the superfamily Tineoidea, which appears to be sister to the other lineages of the Ditrysia. They are not closely related to moths of the superfamily Gelechioidea, which includes case-bearers. Most bagworms are inoffensive to humans and inconspicuous; some are occasional nuisance pests. However, a few species can become more serious pests, and have caused significant damage e.g. to wattle (Acacia mearnsii) in South Africa and orange (Citrus sinensis) in Florida. If detected early, picking the cases from the trees while in their pupa stage is an effective way to check an infestation; otherwise, insecticides are used. One bagworm species, the fangalabola (Deborrea malgassa) of Madagascar, is in some places encouraged to breed on wattle trees, because its pupae are collected as a protein-rich food.

from Wikipedia