– click for Adult Macro Verification Guidelines
– Generally Common / Widespread
– care required in the identification process, as confusion with similar species is likely – quality photographs required. Confusion Species: Common Rustic
ID pointers: It is almost identical in appearance to Common Rustic, so examination of the genitalia is necessary for reliable separation of the species.
Distribution: A resident whose current status is uncertain in Derbyshire. It is thought to be widely distributed across the county, but not necessarily uncommon. Totally under recorded due to Gen.Det requirements for confirmation of the species. Recorded in very small numbers each year. The photo shown was of a specimen that was identified by Gen Det.
*** Last updated on 2 October 2025 by RP ***
Forewing: 11-16mm
Blue-coded] moths are not stored on the website at this current time. Selected Images: July 3rd 2022 – Hathersage – The late Claire Miles © – Gen.Det confirmed
Image Gallery
No gallery images found for this moth.
Distribution Map for Mesapamea didyma
Found 19 records
↳ 0 from After 2025
↳ 7 from 2020 - 2024
↳ 12 from Before 2020
↳ 0 from After 2025
↳ 7 from 2020 - 2024
↳ 12 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 – Mesapamea didyma
⚠️ 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:
Mesapamea didyma
( data includes both Larvae and Adult Stages )
Monthly Counts By Year: Mesapamea didyma
( data is based on 'Adult' stage records only. )
First/Last Recorded Dates: Mesapamea didyma
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: Mesapamea didyma
( All data includes both Larvae and Adult Stages )
Annual Growth Rate (AGR): Mesapamea didyma
AGR: 4.56% | Total % Change: 133.3%
CUSUM Analysis: Mesapamea didyma
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 15 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 2024, reaching above average levels. The lowest population point occurred near 2020, 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: Mesapamea didyma
( data includes both Larvae and Adult Stages )
Flight Periods – Indicative –vs– Recorded Data
Mesapamea didyma
Mesapamea didyma
( 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 - Mesapamea didyma – 19 records available
Listed by Year - descending - scroll across to see all table columns
| Site Name | Tetrad | Date | Count | Stage | Source |
|---|---|---|---|---|---|
| Birch Vale | SK08I | 26/07/2024 | 2 | adult | vc57_irecords_extract |
| Garden, Walton | SK36U | 18/07/2024 | 3 | adult | vc57_irecords_extract |
| Garden, Walton | SK36U | 31/07/2024 | 2 | adult | vc57_irecords_extract |
| Hathersage, Derbyshire, UK | SK28F | 03/07/2022 | 1 | adult | vc57_irecords_extract |
| Garden, Walton | SK36U | 30/07/2022 | 2 | adult | vc57_irecords_extract |
| Garden, Walton | SK36U | 25/07/2021 | 5 | adult | vc57_irecords_extract |
| Kirk Hallam, Ilkeston | SK44K | 20/07/2020 | 1 | adult | vc57_irecords_extract |
| Station Quarry, Chee Dale | SK17G | 25/07/2016 | 1 | Adult | vc57_danes_bc_data |
| Macclesfield Rd, Whaley Bridge | SK08A | 24/08/2013 | 2 | Adult | vc57_danes_bc_data |
| Macclesfield Rd, Whaley Bridge | SK08A | 09/08/2013 | 3 | Adult | vc57_danes_bc_data |
| Gillfield Wood, Totley, Sheffield | SK27Z | 21/07/2012 | 1 | Adult | vc57_danes_bc_data |
| Oaks Barn Cottage, Monyash Rd, Over Haddon, Bakewell | SK26D | 08/09/2011 | 1 | Adult | vc57_danes_bc_data |
| Oaks Barn Cottage, Monyash Rd, Over Haddon, Bakewell | SK26D | 05/08/2010 | 1 | Adult | vc57_danes_bc_data |
| Glossop (Shire Hill Quarry) | SK09M | 22/07/2008 | 1 | Adult | vc57_danes_bc_data |
| Alport Dale, nr Ladybower Resr | SK18P | 06/09/2005 | 1 | Adult | vc57_danes_bc_data |
| Alport Dale, nr Ladybower Resr | SK18P | 22/08/2005 | 1 | Adult | vc57_danes_bc_data |
| Ivy Cottage, Youlgreave | SK26C | 01/08/1998 | 1 | Adult | vc57_danes_bc_data |
| Beeley Moor, Beeley (site not precies) | SK26Z | 03/08/1984 | 2 | Adult | vc57_danes_bc_data |
| Beeley Moor, Beeley (site not precise) | SK26Z | 03/08/1984 | 2 | Adult | vc57_danes_bc_data |