Argent & Sable       Scarce Tissue
70.121 BF1789  –  Geometridae –  Larentiinae – Rheumaptera undulata – Scallop Shell – (Linnaeus, 1758) Adult Macro:  CAT 1 – Distinctive species unlikely to be confused with others –       PDF Icon – click for Adult Macro Verification Guidelines
Green –  Rare / Uncommon / Scarce   
Taxonomy:   Macro   >>  Geometridae  >> Larentiinae
Other Name/s: Hydria undulata
ID Difficulty:  green  – easy to identify, generally distinctive and unlikely to be confused with other species.
ID pointers: A beautiful and diagnostic looking geometrid moth that cannot be confused with anything else.
Distribution:  (First record: 1895 )  –  (Last record: 2024 )  –  A resident but locally distributed and scarce in the county. First recorded in 1895, then no more records until the 1970’s. A scattering of records since then. Only one record from the south of the county in June 2017, otherwise the rest have come from NW Derbyshire
Flight Period: June /  July /  –  On the wing between June – July. Moth Activity: Nocturnal   – and is attracted to light Photographed: Yes –  Photographed By: Brian Hallam, Christian Heintzen  © All Rights Reserved
*** Last updated on 21 July 2025 by WS ***
Wingspan: 25-30mm
Forewing: 16-19mm Food Plant: Sallows, Aspen, Bilberry.
Last Recorded Year: 2024
First Recorded Year: 1895
Last Recorded By – Not Recorded
Last Recorded General Area – Not Recorded
IMAGES BELOW:  Findern, Derbyshire – Image by Brian Hallam © – 9th June 2017 / Glossop, Derbyshire – Image by Christian Heintzen © – 9th July 2024

Scallop Shell - 9th June 2017 - Findern - Brian Hallam
Scallop Shell – 9th June 2017 – Findern – Brian Hallam
Scallop Shell - Rheumaptera undulata - 9th July 2024 -Christian Heintzen
Scallop Shell – Rheumaptera undulata – 9th July 2024 -Christian Heintzen
Scallop Shell - 9th June 2017 - Findern - Brian Hallam
Scallop Shell - Rheumaptera undulata - 9th July 2024 -Christian Heintzen

no images were found

Distribution Map for Rheumaptera undulata

Found 72 records
    ↳ 7 from After 2025
    ↳ 19 from 2020 - 2024
    ↳ 46 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.

******* Choose ONLY one at a time, of either Monad, Tetrad or Hectad Distribution - each has it's own set of data. Also, the distribution maps cover ALL recorded data. *******

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 – Rheumaptera undulata

⚠️ 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.

Visit NBN Site


Monthly Records By Year: Rheumaptera undulata
( data includes both Larvae and Adult Stages )

Monthly Counts By Year: Rheumaptera undulata
( data is based on 'Adult' stage records only. )


First/Last Recorded Dates: Rheumaptera undulata
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: Rheumaptera undulata
( All data includes both Larvae and Adult Stages )
Annual Growth Rate (AGR): Rheumaptera undulata
AGR: 0%   |   Total % Change: 0%


CUSUM Analysis: Rheumaptera undulata
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 10 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 7 (July) 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 2024, 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: Rheumaptera undulata
( data includes both Larvae and Adult Stages )

Flight Periods – Indicative –vs– Recorded Data
Rheumaptera undulata
( 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 - Rheumaptera undulata – 72 records available

Listed by Year - descending - scroll across to see all table columns

TaxonSite NameTetradYearDateCountStageSource
Rheumaptera undulataDarwin ForestSK26X202501/07/20251adultvc57_irecords_extract
Rheumaptera undulataMellorSJ98Z202501/07/20251adultvc57_irecords_extract
Rheumaptera undulataMellorSJ98Z202511/07/20251adultvc57_irecords_extract
Rheumaptera undulataLowcroft, Hogshaw Nature Reserve, Buxton SK, UKSK07S202527/07/20251Adultvc57_irecords_extract
Rheumaptera undulataMidway, Derbys.SK32A202512/06/20251adultvc57_irecords_extract
Rheumaptera undulataBelperSK34N202525/06/20251adultvc57_irecords_extract
Rheumaptera undulataMiller's DaleSK17G202527/06/20251adultvc57_irecords_extract
Rheumaptera undulataMellorSJ98Z202406/08/20241adultvc57_irecords_extract
Rheumaptera undulataupper cromford gardenSK25Y202411/08/20241adultvc57_irecords_extract
Rheumaptera undulataupper cromford gardenSK25Y202409/07/20241adultvc57_irecords_extract
Rheumaptera undulataDerbyshire Wild Life Trust Long CloughSK09G202409/07/20241adultvc57_irecords_extract
Rheumaptera undulataLadycroft Ave, BuxtonSK07S202422/07/20241adultvc57_irecords_extract
Rheumaptera undulataLadycroft Ave, BuxtonSK07S202429/07/20241adultvc57_irecords_extract
Rheumaptera undulataBirch ValeSK08I202419/07/20241adultvc57_irecords_extract
Rheumaptera undulataLadycroft Ave, BuxtonSK07S202323/06/20231adultvc57_irecords_extract
Rheumaptera undulataBirch ValeSK08I202205/08/20221adultvc57_irecords_extract
Rheumaptera undulataBuxton SK, UKSK07S202218/07/20221Adultvc57_irecords_extract
Rheumaptera undulataBirch ValeSK08I202223/07/20221adultvc57_irecords_extract
Rheumaptera undulataLadycroft Ave, BuxtonSK07S202126/07/20211adultvc57_irecords_extract
Rheumaptera undulataClarkes Plantation, Two Dales, MatlockSK26W202123/07/20211adultDanes_2019-2021
Rheumaptera undulataClarkes Plantation, Two Dales, MatlockSK26W202123/07/20211adultDanes_2019-2021
Rheumaptera undulataBirch ValeSK08I202116/06/20211Adultvc57_irecords_extract
Rheumaptera undulataLonghurst Lane, MellorSJ98Z202021/07/20201adultDanes_2019-2021
Rheumaptera undulataLonghurst Lane, MellorSJ98Z202017/07/20201adultDanes_2019-2021
Rheumaptera undulataLonghurst Lane, MellorSJ98Z202014/07/20201adultDanes_2019-2021
Rheumaptera undulataLonghurst Lane, MellorSJ98Z202013/07/20201adultDanes_2019-2021
Rheumaptera undulataBirch ValeSK08I201918/07/20191adultvc57_irecords_extract
Rheumaptera undulataBirch ValeSK08I201904/07/20191adultvc57_irecords_extract
Rheumaptera undulataLadycroft Ave, BuxtonSK07S201921/07/20191adultvc57_irecords_extract
Rheumaptera undulataStation Road, Darley DaleSK26R201925/07/20192adultvc57_irecords_extract
Rheumaptera undulataThe Mays, Malthouse Lane, FroggattSK27N201913/07/20191adultDanes_2019-2021
Rheumaptera undulataBuxton SK, UKSK07S201809/07/20181Adultvc57_irecords_extract
Rheumaptera undulataBirch ValeSK08I201806/07/20181adultvc57_irecords_extract
Rheumaptera undulataDerbyshire, England, United KingdomSK07S201725/07/20171Adultvc57_irecords_extract
Rheumaptera undulataMillers Dale (quarry - east)SK17G201715/07/20171Adultvc57_danes_bc_data
Rheumaptera undulataShirland - Hallfieldgate LaneSK35Z201719/06/20171adultvc57_irecords_extract
Rheumaptera undulataGillfield Wood (nr scout hut), TotleySK37E201412/07/20141Adultvc57_danes_bc_data
Rheumaptera undulataLadycroft AveSK07S201319/07/20131adultvc57_irecords_extract
Rheumaptera undulataMacclesfield Rd, Whaley BridgeSK08A201312/07/20131Adultvc57_danes_bc_data
Rheumaptera undulataBuxton SK, UKSK07S201209/08/20121Adultvc57_irecords_extract
Rheumaptera undulataLadycroft Ave,BuxtonSK07S201208/08/20121Adultvc57_danes_bc_data
Rheumaptera undulataLadycroft Ave, BuxtonSK07S201208/08/20121Adultvc57_danes_bc_data
Rheumaptera undulataThe Mays,Malthouse Lane,FroggattSK27N201226/07/20121Adultvc57_danes_bc_data
Rheumaptera undulataRosliston (National Forest Centre), SwadlincoteSK21N201220/07/20121Adultvc57_danes_bc_data
Rheumaptera undulataThe Mays,Malthouse Lane,FroggattSK27N201226/07/20121Adultvc57_danes_bc_data
Rheumaptera undulataSchool Close,Parkway Gardens,Darley DaleSK26R201115/07/20111Adultvc57_danes_bc_data
Rheumaptera undulataThe Hollies,Station Rd,Darley DaleSK26R201125/06/20111Adultvc57_danes_bc_data
Rheumaptera undulataWhitesprings Plantation, Darley DaleSK26X201125/06/20111Adultvc57_danes_bc_data
Rheumaptera undulataWhitesprings Plantation, Darley DaleSK26X201125/06/20111Adultvc57_danes_bc_data
Rheumaptera undulataRose Av,ClowneSK57D201022/07/20101Adultvc57_danes_bc_data
Rheumaptera undulataThe Hollies,Station Rd,Darley DaleSK26R200625/07/20061Adultvc57_danes_bc_data
Rheumaptera undulataMillers DaleSK17L200614/07/20061Adultvc57_danes_bc_data
Rheumaptera undulataWhitesprings Plantation, Flash Lane, Beeley MoorSK26X200104/10/20015Larvaevc57_danes_bc_data
Rheumaptera undulataWhitesprings Plantation, Flash Lane, Beeley MoorSK26X200104/10/20015Larvaevc57_danes_bc_data
Rheumaptera undulataLadycroft Ave,BuxtonSK07S200003/08/20001Adultvc57_danes_bc_data
Rheumaptera undulataLadycroft Ave, BuxtonSK07S200003/08/20001Adultvc57_danes_bc_data
Rheumaptera undulataSchool Close,Parkway Gardens,Darley DaleSK26R199906/07/19991Adultvc57_danes_bc_data
Rheumaptera undulataSchool Close,Parkway Gardens,Darley DaleSK26R199913/07/19991Adultvc57_danes_bc_data
Rheumaptera undulataPriestcliffe Lees NR, TideswellSK17L199825/07/19981Adultvc57_danes_bc_data
Rheumaptera undulataCalke Park (Poker's Leys), TicknallSK32L199817/07/19981Adultvc57_danes_bc_data
Rheumaptera undulataCalke Park (Poker's Leys), TicknallSK32L199817/07/19981Adultvc57_danes_bc_data
Rheumaptera undulataPriestcliffe Lees NR, TideswellSK17L199825/07/19981Adultvc57_danes_bc_data
Rheumaptera undulataMatlock Forest, Matlock (site not precise)SK36B199601/09/199621Larvaevc57_danes_bc_data
Rheumaptera undulataFlash Lane,Beeley MoorSK26X199605/08/19965Adultvc57_danes_bc_data
Rheumaptera undulataFarley Moor, Farley, MatlockSK34L199508/09/19959Larvaevc57_danes_bc_data
Rheumaptera undulataFlash Lane,Beeley MoorSK26X199310/07/19931Adultvc57_danes_bc_data
Rheumaptera undulataAskew Grove, ReptonSK32D198022/07/19801Adultvc57_danes_bc_data
Rheumaptera undulataHilton NR, Hilton, Burton on TrentSK23K197610/07/19761Adultvc57_danes_bc_data
Rheumaptera undulataElvaston Park (site D), DerbySK43B197304/07/19731Adultvc57_danes_bc_data
Rheumaptera undulataElvaston Park (site D), DerbySK43B197315/07/19731Adultvc57_danes_bc_data
Rheumaptera undulataChellaston, Derby (site not precise)SK33Q189501/07/18951Adultvc57_danes_bc_data
Rheumaptera undulataChellaston, Derby (site not precise)SK33Q189501/07/18951Adultvc57_danes_bc_data

Argent & Sable       Scarce Tissue

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