The story
From nettle + tap, because of the distinctive way at least one species flies along the tops of nettle plants.
Etymology from Wiktionary, CC BY-SA 4.0.
nettle-tap
Today it means: Certain moths of the family Choreutidae such as Anthophila fabriciana (syn. Simaethis fabriciana), Prochoreutis myllerana (syn. Simaethis myllerana), and Choreutis pariana (syn.Simaethis pariana) Full definition →