Season (Adult / Immature):
National Status: RDB2
Local Status: Rare and restricted resident.
Local Record: Grade 4 See here for explanation
Flight time: Jun-Jul.
|Year first recorded||1932||1932|
|Year last recorded||2010||2010|
|Number of records||17||34|
|Number of individuals||64||128|
For the region, we have a total of 34 records from 8 sites. Earliest record on file is in 1932.
For further information refer UK Moths.
Davey, P., 2009: A rare species that is well established at Wicken Fen and Chippenham Fen and local in the Norfolk Broads. One or two eggs are inserted in the leaf sheath of common reed (Phragmites australis) and the resulting larvae then feed for nearly two years on the pith within reed stems. The insect spends a further month as a pupa remaining within the stem before emerging in June. Male adults are freely attracted to light, and females may occasionally be seen flying over the reed canopy at dusk, and thereafter rest on the host plant.
The species is resident at a single extensive freshwater reedbed at Morden Bog, a SSSI near Wareham. Searches for the species in the larger but more brackish reedbeds around the Poole Basin have so far proved negative, although sampling has been restricted to reedbed edges due to the wet terrain; detecting colonies and quantifying colony size remains a challenge. The reedbed at Morden differs from these other sites in that the individual plants are scattered and not densely packed together. Core samples have been taken from Morden Bog and it appears that the reedbed has been in existence for at least one thousand years (Haskins, 1978).
The threats to the host plant at Morden Bog include a lowering of the water table, drainage, fire, pollution and over-grazing. The first two threats are unlikely given the current high level of protection afforded to the Bog. A major fire in the severe drought of 1934 burnt much of the reed temporarily, but two years on, the moth was again seen in good numbers within the regenerated reedbed (A Russell). Effluent seeping into the mire from a nearby caravan site has created nitrate-rich conditions where stinging nettle (Urtica dioica) flourishes in a small area on the western side of the reed habitat. Stock has been introduced by Natural England on to Morden Bog and adjacent heathland to graze grass species, particularly purple moor-grass (Molinia caerulea). The cattle do not tend to enter the heart of the reedbed as those used for grazing at Morden do not like getting their feet wet (Natural England, pers comm). However, sika deer do frequent the bog where new reed shoots form part of their diet. Continued monitoring of this Dorset rarity is recommended at Morden Bog.
Hill, L., 2014: Briantspuddle on 9 June 2014 (J McMillan), presumed import from local thatching in nearby Tolpuddle.