Apterona helicoidella (snailcase bagworm) is a moth of the Psychidae family. It is widely distributed in Europe, from Portugal through most of central Europe and the Alps, up to the Ural. It is also found on the Balkan and in Turkey. It was introduced in the United States by accident during the 1940s. It is now found in many mid-Atlantic states, including Pennsylvania, and has also been reported in the Pacific coastal states, as well as Colorado, Michigan, Nevada, Utah and Idaho. It has been collected in Ontario as well (Royal Ontario Museum Collection).