– click for Adult Macro Verification Guidelines
– Rare / Uncommon / Scarce
– easy to identify, generally distinctive and unlikely to be confused with other species.ID pointers: An unmistakable species. The smooth rather slender moth with a broad unmarked forewing being a light reddish-brown or light greyish-straw. Sometimes darker in colour tones. The colour becomes darker towards the outer edge of the wings.
Distribution: (First record: 1991 ) – (Last record: 26 August 2024 at Markham Vale Complex ) – A rare and localised species in Derbyshire, and a new colonist to the county when first recorded in 1991. Two more records in the 90’s and the first record for the decade in 2008 from Darley Dale. Small numbers are being recorded each year.
*** Last updated on 2 October 2025 by RP ***
Forewing: 14-16mm
First Recorded Year: 1991
Last Recorded By – Sid Morris
Last Recorded General Area – Markham Vale Complex
Selected Images: Darley Dale, Derbyshire – Simon Roddis©
Image Gallery
Distribution Map for Arenostola phragmitidis
Found 15 records
↳ 2 from After 2025
↳ 6 from 2020 - 2024
↳ 7 from Before 2020
↳ 2 from After 2025
↳ 6 from 2020 - 2024
↳ 7 from Before 2020
If the Map Layers function fails, just refresh the page and it should be OK after. Use the +- zoom on the top left, or on a tablet, use two fingers to zoom. Remember, the last layer you ticked is the one which displays the popup information - they sit on top of each other - de-select then re-select, to see the popup values.
Bedrock Geology ** indirectly affects moth distribution by influencing the type of habitat and food plants available in an area. In turn, this may affect the types of moths that can thrive, or where they can most likely be found.
NBN Atlas UK Distribution for – Arenostola phragmitidis
⚠️ Please wait for the map to load fully – do not click the link shown.
Note – the NBN Atlas datasets are listed in the map below and vary in their currency (uptodateness) – however,
the map does give a general indication of the moth's distribution across the UK.
Monthly Records By Year:
Arenostola phragmitidis
( data includes both Larvae and Adult Stages )
Monthly Counts By Year: Arenostola phragmitidis
( data is based on 'Adult' stage records only. )
First/Last Recorded Dates: Arenostola phragmitidis
Adult-only & Anything [Larvae, Pupae, Adult, Mines]
Shading shows moth presence between dates
Click the colour discs below to Select/De-select as Required
Recordings By Year: Arenostola phragmitidis
( All data includes both Larvae and Adult Stages )
Annual Growth Rate (AGR): Arenostola phragmitidis
AGR: 2.41% | Total % Change: 50%
CUSUM Analysis: Arenostola phragmitidis
About this chart: CUSUM (Cumulative Sum) charts track long-term trends in moth populations [ filtered by 'Adult' and 'Mine' life stages ] by showing whether each year’s counts are above or below the historical average. Even small shifts build up over time, making trends of growth, stability, or decline easier to see. CUSUM highlights trend-consistency — asking: “Across the years, have moth counts mostly stayed above or below average?”
The data sample has 19 gap year/s here (zero records) between 2000 and 2025. The moth may have been present in those gap years, but no data was available. Too many year-gaps may exaggerate or skew the chart.
Counts for the current year (2025) are pro-rated based on data available up to month 8 (August) to provide a full-year equivalent.
ⓘ
Purple line rises = years better than average; falls = years worse than average.
Peak (best year)
Trough (worst year)
Growth periods
Decline periods
Population peaked around 2025, reaching above average levels. The lowest population point occurred near 2021, showing a significant decline.
What the Y-axis "Cumulative Deviation" means: Cumulative Deviation shows the running total of how each year’s moth population count differs from the long-term average. i
Hectad (10kmx10km) Coverage: Arenostola phragmitidis
( data includes both Larvae and Adult Stages )
Flight Periods – Indicative –vs– Recorded Data
Arenostola phragmitidis
Arenostola phragmitidis
( data includes Adult Stage only )
Flight Period chart – the grey hatched area above, which can cross one or more months, pictorially represents the best guess we have for this moth's flight periods [month/s]. The coloured lines represent the actual months seen in flight, from site observation records received between 2020-2025.
Records Behind the Map and Charts - Arenostola phragmitidis – 15 records available
Listed by Year - descending - scroll across to see all table columns
| Site Name | Tetrad | Date | Count | Stage | Source |
|---|---|---|---|---|---|
| Markham Vale South Tip Derbyshire | SK47K | 14/07/2025 | 2 | adult | vc57_irecords_extract |
| Markham Vale South Tip | SK47K | 17/07/2025 | 1 | adult | vc57_irecords_extract |
| Markham Vale Derbyshire | SK47L | 26/08/2024 | 1 | adult | vc57_irecords_extract |
| Markham Vale Derbyshire | SK47L | 25/07/2024 | 1 | adult | vc57_irecords_extract |
| Markham Vale Derbyshire | SK47L | 10/08/2023 | 7 | adult | vc57_irecords_extract |
| Markham Vale Derbyshire | SK47L | 05/07/2023 | 1 | adult | vc57_irecords_extract |
| Woodland Ave | SK43R | 28/07/2023 | 1 | adult | vc57_irecords_extract |
| Woodland Ave | SK43R | 20/07/2021 | 1 | adult | vc57_irecords_extract |
| Pleasley Pit CP, Pleasley | SK46X | 25/07/2018 | 1 | Adult | vc57_danes_bc_data |
| Pleasley NR (Pit Head) | SK46X | 13/08/2012 | 1 | Adult | vc57_danes_bc_data |
| The Hollies,Station Rd,Darley Dale | SK26R | 30/07/2008 | 1 | Adult | vc57_danes_bc_data |
| Stevens Rd, Sandiacre | SK43T | 27/07/1995 | 1 | Adult | vc57_danes_bc_data |
| Holbrook Heath, Killamarsh | SK48K | 30/07/1994 | 2 | Adult | vc57_danes_bc_data |
| Deerlands Rd, Ashgate, Chesterfield | SK37K | 17/07/1991 | 1 | Adult | vc57_danes_bc_data |
| Deerlands Rd, Ashgate, Chesterfield | SK37K | 17/07/1991 | 1 | Adult | vc57_danes_bc_data |