Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
† hēmĕrŏbĭon, ĭi, n., = ἡμερόβιον, an insect that lives but a day, an ephemeron: erumpit volucre quadrupes, nec ultra unum diem vivit, unde hemerobion vocatur, Plin. 11, 36, 43, § 120.