Lewis & Short

blattārĭus, a, um, adj. [1. blatta],

  1. I. pertaining to the moth: balnea, for moths, i. e. dark bathing-rooms (so called from the dislike of the moth to the light), Sen. Ep. 86, 7; cf. Plin. 11, 28, 34, § 99.
  2. II. Subst.: blattārĭa, ae, f. (sc. herba), moth-mullein: Verbascum blattaria, Linn.; Plin. 25, 9, 60, § 108.