The Reed Tussock (Laelia coenosa) is a species of moth in the Lymantriidae family.
This medium sized moth holds it's wings in a tent-like fashion. The forewings are cream-white, often with small black dots near the outer edge. Like other members of the Lymantriidae family, this species has it's front legs forward. The males have large feathery antennae. This species flies from July till August.
Now extinct in Britain, last seen in 1879, but was found in Cambridgeshire and Huntingtonshire before it went extinct. It appears to never have been in large numbers, and went extinct due to habitat loss, which were the fens which were drained.
The larvea feed on Common Reed, and other similar species, can could be seen in any time of the year, except July.