Protarchanara brevilinea, or Fenn's wainscot, is a moth of the family Noctuidae. The species was first described by Charles Fenn of Lewisham who collected specimens during an entomological excursion to Ranworth in 1864.[1] It is found in western and northern Europe.
A. brevilinea Fenn (49 d). Forewing dull grey brown densely black-dusted; the veins terminally paler; inner and outer lines represented by a series of dark vein dots; a black streak from base below cell: hindwing fuscous, darker towards termen; an outer row of dark dots; the ab. sinelinea Farn (49 d) is more uniform in coloration, without the black streak from base. Larva pale ochreous, with brown freckling; dorsal, subdorsal, and spiracular lines orange edged with yellow; head pale brown.[2] The length of the forewings is 14–17 mm.
The moth flies in one generation from mid-July to August..
The larvae feed on Phragmites living within the stems and when young feeding there; afterwards emerging from the stems by night and feeding on the leaves.