Status and Distribution
Rare, known with regularity from only one site in Kent where it was reported from 1984, with larvae found there in 2022. One-off reports of single adults have been received from Devon (2002), Hampshire (2009), Dorset (2017) and East Sussex (2019), suggesting it may be under-recorded as a breeding species (Beavan and Heckford, 2022).
Foodplant and Larval Feeding Signs
Persicaria amphibia (Amphibious Bistort), see plant distribution map.
Feeds in upper parts of the stem, usually between nodes. Small holes in the stem near the leaf nodes with a small build up of frass indicate the presence of a larva.
In England found regularly in a single extensive freshwater reed-bed. The other records are associated with a rough coastal meadow and mixed reed-bed, grassland and close to a large disused clay quarry with pools. In Denmark it is associated with damp meadows.
Finding the Moth
Larva: look for small holes in the stem of the foodplant in September, sometimes extruded frass being visible which may indicate the presence of a larva. Distinctively red-striped larva needs to be seen to exclude the possibility of a weevil species, the larva of which feeds in the stem of this plant.
Adult: sweeping areas of the foodplant may be worthwhile. It comes readily to light.
Similar to, but larger than, Monochroa suffusella.
Single brooded from mid-June to July.
Earliest: 20th June 1995 (VC15)
Latest: 8th July 1984 (VC15)
There is only very limited date information available.