Like other related species C. coniuncta has mottled brown fore-wings and crimson-red hind-wings with a black central line. The species differs from its European congeners in the shape of the post-median line on the fore-wing and the straighter black line on the hind-wings. The larvae feed on holm oak (Quercus ilex).
Extra-limitally, C. coniuncta has occurred just once in Britain, being found at light by Robin Harvey at the RSPB Minsmere reserve on the Suffolk coast on 14 September 2004.[1] Following this record the English name Minsmere crimson underwing has been adopted.
References
^Higgott, J. B. and Harvey, R. M., 2005. Catocala conjuncta (Esper, 1787) (Lepidoptera: Noctuidae) new to the British Isles. Entomologist’s Gazette. 56: 217-222