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
General Comment: None
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 2 October 2025 by RP ***
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

Selected Images:  Findern, Derbyshire – Image by Brian Hallam © – 9th June 2017 / Glossop, Derbyshire – Image by Christian Heintzen © – 9th July 2024



Distribution Map for Rheumaptera undulata

Found 73 records
    ↳ 8 from After 2025
    ↳ 19 from 2020 - 2024
    ↳ 46 from Before 2020
Flying
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

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 – Rheumaptera undulata

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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 10 (October) 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 2018, 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 – 73 records available

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

Site NameTetradDateCountStageSource
Lowcroft, Hogshaw Nature Reserve, Buxton SK, UKSK07S27/07/20251Adultvc57_irecords_extract
Longdendale, Torside Clough mSK09T22/07/20251adultvc57_irecords_extract
MellorSJ98Z11/07/20251adultvc57_irecords_extract
Darwin ForestSK26X01/07/20251adultvc57_irecords_extract
MellorSJ98Z01/07/20251adultvc57_irecords_extract
Miller's DaleSK17G27/06/20251adultvc57_irecords_extract
BelperSK34N25/06/20251adultvc57_irecords_extract
Midway, Derbys.SK32A12/06/20251adultvc57_irecords_extract
upper cromford gardenSK25Y11/08/20241adultvc57_irecords_extract
MellorSJ98Z06/08/20241adultvc57_irecords_extract
Ladycroft Ave, BuxtonSK07S29/07/20241adultvc57_irecords_extract
Ladycroft Ave, BuxtonSK07S22/07/20241adultvc57_irecords_extract
Birch ValeSK08I19/07/20241adultvc57_irecords_extract
upper cromford gardenSK25Y09/07/20241adultvc57_irecords_extract
Derbyshire Wild Life Trust Long CloughSK09G09/07/20241adultvc57_irecords_extract
Ladycroft Ave, BuxtonSK07S23/06/20231adultvc57_irecords_extract
Birch ValeSK08I05/08/20221adultvc57_irecords_extract
Birch ValeSK08I23/07/20221adultvc57_irecords_extract
Buxton SK, UKSK07S18/07/20221Adultvc57_irecords_extract
Ladycroft Ave, BuxtonSK07S26/07/20211adultvc57_irecords_extract
Clarkes Plantation, Two Dales, MatlockSK26W23/07/20211adultDanes_2019-2021
Clarkes Plantation, Two Dales, MatlockSK26W23/07/20211adultDanes_2019-2021
Birch ValeSK08I16/06/20211Adultvc57_irecords_extract
Longhurst Lane, MellorSJ98Z21/07/20201adultDanes_2019-2021
Longhurst Lane, MellorSJ98Z17/07/20201adultDanes_2019-2021
Longhurst Lane, MellorSJ98Z14/07/20201adultDanes_2019-2021
Longhurst Lane, MellorSJ98Z13/07/20201adultDanes_2019-2021
Station Road, Darley DaleSK26R25/07/20192adultvc57_irecords_extract
Ladycroft Ave, BuxtonSK07S21/07/20191adultvc57_irecords_extract
Birch ValeSK08I18/07/20191adultvc57_irecords_extract
The Mays, Malthouse Lane, FroggattSK27N13/07/20191adultDanes_2019-2021
Birch ValeSK08I04/07/20191adultvc57_irecords_extract
Buxton SK, UKSK07S09/07/20181Adultvc57_irecords_extract
Birch ValeSK08I06/07/20181adultvc57_irecords_extract
Derbyshire, England, United KingdomSK07S25/07/20171Adultvc57_irecords_extract
Millers Dale (quarry - east)SK17G15/07/20171Adultvc57_danes_bc_data
Shirland - Hallfieldgate LaneSK35Z19/06/20171adultvc57_irecords_extract
Gillfield Wood (nr scout hut), TotleySK37E12/07/20141Adultvc57_danes_bc_data
Ladycroft AveSK07S19/07/20131adultvc57_irecords_extract
Macclesfield Rd, Whaley BridgeSK08A12/07/20131Adultvc57_danes_bc_data
Buxton SK, UKSK07S09/08/20121Adultvc57_irecords_extract
Ladycroft Ave,BuxtonSK07S08/08/20121Adultvc57_danes_bc_data
Ladycroft Ave, BuxtonSK07S08/08/20121Adultvc57_danes_bc_data
The Mays,Malthouse Lane,FroggattSK27N26/07/20121Adultvc57_danes_bc_data
The Mays,Malthouse Lane,FroggattSK27N26/07/20121Adultvc57_danes_bc_data
Rosliston (National Forest Centre), SwadlincoteSK21N20/07/20121Adultvc57_danes_bc_data
School Close,Parkway Gardens,Darley DaleSK26R15/07/20111Adultvc57_danes_bc_data
The Hollies,Station Rd,Darley DaleSK26R25/06/20111Adultvc57_danes_bc_data
Whitesprings Plantation, Darley DaleSK26X25/06/20111Adultvc57_danes_bc_data
Whitesprings Plantation, Darley DaleSK26X25/06/20111Adultvc57_danes_bc_data
Rose Av,ClowneSK57D22/07/20101Adultvc57_danes_bc_data
The Hollies,Station Rd,Darley DaleSK26R25/07/20061Adultvc57_danes_bc_data
Millers DaleSK17L14/07/20061Adultvc57_danes_bc_data
Whitesprings Plantation, Flash Lane, Beeley MoorSK26X04/10/20015Larvaevc57_danes_bc_data
Whitesprings Plantation, Flash Lane, Beeley MoorSK26X04/10/20015Larvaevc57_danes_bc_data
Ladycroft Ave,BuxtonSK07S03/08/20001Adultvc57_danes_bc_data
Ladycroft Ave, BuxtonSK07S03/08/20001Adultvc57_danes_bc_data
School Close,Parkway Gardens,Darley DaleSK26R13/07/19991Adultvc57_danes_bc_data
School Close,Parkway Gardens,Darley DaleSK26R06/07/19991Adultvc57_danes_bc_data
Priestcliffe Lees NR, TideswellSK17L25/07/19981Adultvc57_danes_bc_data
Priestcliffe Lees NR, TideswellSK17L25/07/19981Adultvc57_danes_bc_data
Calke Park (Poker's Leys), TicknallSK32L17/07/19981Adultvc57_danes_bc_data
Calke Park (Poker's Leys), TicknallSK32L17/07/19981Adultvc57_danes_bc_data
Matlock Forest, Matlock (site not precise)SK36B01/09/199621Larvaevc57_danes_bc_data
Flash Lane,Beeley MoorSK26X05/08/19965Adultvc57_danes_bc_data
Farley Moor, Farley, MatlockSK34L08/09/19959Larvaevc57_danes_bc_data
Flash Lane,Beeley MoorSK26X10/07/19931Adultvc57_danes_bc_data
Askew Grove, ReptonSK32D22/07/19801Adultvc57_danes_bc_data
Hilton NR, Hilton, Burton on TrentSK23K10/07/19761Adultvc57_danes_bc_data
Elvaston Park (site D), DerbySK43B15/07/19731Adultvc57_danes_bc_data
Elvaston Park (site D), DerbySK43B04/07/19731Adultvc57_danes_bc_data
Chellaston, Derby (site not precise)SK33Q01/07/18951Adultvc57_danes_bc_data
Chellaston, Derby (site not precise)SK33Q01/07/18951Adultvc57_danes_bc_data

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