Lewis Short
hēmĕrŏbĭon (noun 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.
Charlton T. Lewis, Charles Short, A Latin Dictionary