Easton's Bible Dictionary

Moth - Heb. 'ash, from a root meaning "to fall away," as moth-eaten garments fall to pieces (Job 4:19; 13:28; Isa. 50:9; 51:8; Hos. 5:12).

Gr. ses, thus rendered in Matt. 6:19, 20; Luke 12:33. Allusion is thus made to the destruction of clothing by the larvae of the clothes-moth. This is the only lepidopterous insect referred to in Scripture.