Simyra albovenosa, the reed dagger, is a moth of the family Noctuidae.

It is found in most of Europe, then Turkey, Iran, Transcaucasus and into the east Palearctic (Central Asia, Siberia).

Forewings whitish-ochreous, sometimes sprinkled with dark fuscous; indistinct brownish median, submedian, and dorsal streaks; sometimes blackish terminal dots.

Larva blackish or dark brown-grey, pale-marbled; subdorsal and subspiracular lines pale ochreous-yellowish, often reddish-marked; tubercles on these yellow or orange; fascicles of pale reddish-brown and black hairs; head black, streaked with ochreous.

[1] The larvae feed on Typha latifolia, Juncus species, including (Juncus gerardii), Scirpus, Eleocharis palustris, Eriophorum, Elymus arenarius, Phalaris arundinacea, Phragmites communis, Festuca rubra, Festuca arundinacea, Salix, Rumex crispus, Filipendula ulmaria, Potentilla palustris, Angelica archangelica, Sonchus arvensis and Aster tripolium.