Dusky Thorn       Early Thorn
September Thorn - Martin Roome
70.236 BF1915  – September Thorn  – Ennomos erosaria  – ([Denis & Schiffermüller], 1775)
Adult Macro:  CAT 2 – Can be confused with other species – Good photographs maybe required – Can be confused with other species      
PDF Icon – click for Adult Macro Verification Guidelines
Green –  Rare / Uncommon / Scarce   
Taxonomy:   Macro  >>.  >>  Geometridae  >> Larrentiinae
ID Difficulty:  amber  – care required in the identification process, as confusion with similar species is likely – quality photographs required.
ID pointers: Although similar to a few other species of “Thorns”, this one is generally plainer in appearance. September Thorn has orange “Leg Socks” – August Thorn has white “Leg Socks”.
Distribution:  (Last record: 29 July 2025 at Mickleover )  –  A resident that is locally distributed and uncommon in Derbyshire. Most records come from the south and east of the county. Easily confused with the rarer August Thorn.
General Comment: None Flight Period: August /  September /  October –  On the wing August – October – one generation Moth Activity: Nocturnal   – and is attracted to light Photographed: Yes –  Photographed By: Stephen Plant, Martin Roome, Christian Heintzen, Brian Hallam, Christine Maughan  © All Rights Reserved
*** Last updated on 7 November 2025 by RP ***
Wingspan: 30-35mm
Forewing: 17-21mm Food Plant: Oak (Quercus), birch (Betula) or lime (Tilia).
Last Recorded Year: 2025
Last Recorded By – Christine Maughan
Last Recorded General Area – Mickleover
Selected Images:  Allestree, Derby August 2021 – image by Stephen Plant ©  /  Chaddesden, Derby – August 2024 – Martin Roome © / Charlesworth – September 2024 – Christian Heintzen©/ Findern 29/6/2025 – Brian Hallam© / Mickleover ( 2025) Christine Maughan©

September Thorn - Geometridae - Ennomos erosaria - Stephen Plant
September Thorn – Ennomos erosaria – Stephen Plant
September Thorn - Martin Roome
September Thorn – Martin Roome
70.236 BF1915 - September Thorn - Christian Heintzen
70.236 BF1915 – September Thorn – Christian Heintzen
70.236 BF1915 - September Thorn - Christian Heintzen
70.236 BF1915 – September Thorn – Christian Heintzen
September Thorn - 29th June 2025 - Findern - Brian Hallam
September Thorn – 29th June 2025 – Findern – Brian Hallam
September Thorn - 29th July 2025 - Mickleover - Christine Maughan
September Thorn – 29th July 2025 – Mickleover – Christine Maughan
September Thorn - Geometridae - Ennomos erosaria - Stephen Plant
September Thorn - Martin Roome
70.236 BF1915 - September Thorn - Christian Heintzen
70.236 BF1915 - September Thorn - Christian Heintzen
September Thorn - 29th June 2025 - Findern - Brian Hallam
September Thorn - 29th July 2025 - Mickleover - Christine Maughan


Image Gallery

September Thorn - 28th June 2024 - Charlesworth - Christian Heintzen September Thorn - 28th June 2024 - Charlesworth - Christian Heintzen

Temporal Distribution Chart
Adults: (between 1959 - 2025)
(click legend below to show/hide datasets)

Distribution Map for Ennomos erosaria

Found 120 records
    ↳ from 2026+
    ↳ 67 from 2020 - 2025
    ↳ 53 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 – Ennomos erosaria

⚠️ 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: Ennomos erosaria
( data includes both Larvae and Adult Stages )

Monthly Counts By Year: Ennomos erosaria
( data is based on 'Adult' stage records only )

First/Last Recorded Dates: Ennomos erosaria
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: Ennomos erosaria
( All data includes both Larvae and Adult Stages )
Annual Growth Rate (AGR): Ennomos erosaria
AGR: 1.44%   |   Total % Change: 31.3%

Hectad (10kmx10km) Coverage: Ennomos erosaria
( data includes both Larvae and Adult Stages )

Flight Periods – Indicative –vs– Recorded Data
Ennomos erosaria

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 2020-2026.

Records Behind the Map and Charts - Ennomos erosaria – 120 records available

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

Site NameTetradDateCountStageRecorderSourceRecordKey
Walton ChesterfieldSK36U23/08/20251adultPalethorpe, Amandavc57_irecords_extractiBRC44754000
Findern, DerbyshireSK33A15/08/20251adultHallam, Brianvc57_irecords_extractiBRC44527438
MellorSJ98Z14/08/20251adultKnass, Davidvc57_irecords_extractiBRC44560771
Shaw Farm, New Mills VCSJ98Y12/08/20252adultHind, Stevevc57_irecords_extractiBRC44526588
Mickleover gardenSK33C11/08/20251adultMaughan, Christinevc57_irecords_extractiBRC45153211
Glossop SK, UKSK09C07/08/20251AdultAlex Leesvc57_irecords_extractiBRC44226326
Glossop SK, UKSK09C07/08/20251AdultAlex Leesvc57_irecords_extractiBRC44226332
Dinting Nature ReserveSK09C06/08/20255adultChristian Heintzen, David Walsh, Bill Underwood, Alex Leesvc57_irecords_extractiBRC44291308
Findern, DerbyshireSK33A03/08/20251adultHallam, Brianvc57_irecords_extractiBRC44180559
Mickleover gardenSK33C29/07/20251adultMaughan, Christinevc57_irecords_extractiBRC45112365
MellorSJ98Z17/07/20251adultKnass, Davidvc57_irecords_extractiBRC43588455
MellorSJ98Z16/07/20251adultKnass, Davidvc57_irecords_extractiBRC43588080
LittleoverSK33G12/07/20251adultWatson, Adrianvc57_irecords_extractiBRC43604366
Chaddesden, DerbySK33T11/07/20251adultroome, martinvc57_irecords_extractiBRC44160176
Derby DESK33I05/07/20251adultWatson, Adrianvc57_irecords_extractiBRC43623155
Findern, DerbyshireSK33A30/06/20251adultHallam, Brianvc57_irecords_extractiBRC42918839
MellorSJ98Z14/09/20241adultKnass, Davidvc57_irecords_extractiBRC38491134
Findern, Derbyshire, DEAZSK33A06/09/20241adultHallam, Brianvc57_irecords_extractiBRC39935134
Charlesworth, Cown Edge LandslideSK09A02/09/20242adultHeintzen, Christianvc57_irecords_extractiBRC38657876
Park Haed, CrichSK35M01/09/20242adultBradley, Jonathanvc57_irecords_extractiBRC38295021
Findern, Derbyshire, DEAZSK33A27/08/20241adultHallam, Brianvc57_irecords_extractiBRC39935038
Findern, Derbyshire, DEAZSK33A23/08/20241adultHallam, Brianvc57_irecords_extractiBRC39934974
Ilkeston, DerbyshireSK44K17/08/20241adultHobby, Brianvc57_irecords_extractiBRC38196754
Chaddesden, DerbySK33T12/08/20242adultroome, martinvc57_irecords_extractiBRC38337782
Mickleover gardenSK33C11/08/20241adultMaughan, Christinevc57_irecords_extractiBRC38012440
SandiacreSK43S09/08/20241adultpaul buxtonvc57_irecords_extractiBRC37850691
Findern, Derbyshire, DEAZSK33A05/08/20241adultHallam, Brianvc57_irecords_extractiBRC39934838
Midway, Derbys.SK32A03/08/20241adultWilliams, Michaelvc57_irecords_extractiBRC39954697
Ilkeston, DerbyshireSK44K02/08/20241adultHobby, Brianvc57_irecords_extractiBRC37879092
Chaddesden, DerbySK33T31/07/20241adultroome, martinvc57_irecords_extractiBRC38327901
BelperSK34N29/07/20241adultEvans, Davevc57_irecords_extractiBRC37495000
Allestree, DerbySK33P21/07/20241adultPlant, Stephenvc57_irecords_extractiBRC37229622
Allestree, DerbySK33P21/07/20241adultPlant, Stephenvc57_irecords_extractiBRC40176486
Ilkeston, DerbyshireSK44K19/07/20241adultHobby, Brianvc57_irecords_extractiBRC37608052
Allestree, Derby, Elm GroveSK34K15/09/20231adultGrange, Williamvc57_irecords_extractiBRC36502332
MellorSJ98Z09/09/20231adultKnass, Davidvc57_irecords_extractiBRC32940255
Garden, WaltonSK36U09/09/20231adultPalethorpe, Amandavc57_irecords_extractiBRC46020504
MellorSJ98Z08/09/20231adultKnass, Davidvc57_irecords_extractiBRC32940039
Park Head, CrichSK35M20/08/20231AdultBradley, Jonathanvc57_irecords_extractiBRC35418986
MellorSJ98Z19/08/20231adultKnass, Davidvc57_irecords_extractiBRC32552110
Findern GardenSK33A18/08/20231AdultHallam, Brianvc57_irecords_extractiBRC34638144
Findern GardenSK33A16/08/20234AdultHallam, Brianvc57_irecords_extractiBRC34638094
Findern GardenSK33A11/08/20232AdultHallam, Brianvc57_irecords_extractiBRC34638032
BelperSK34U10/08/20231adultEvans, Davevc57_irecords_extractiBRC35297163
Findern GardenSK33A31/07/20231AdultHallam, Brianvc57_irecords_extractiBRC34637896
Findern GardenSK33A28/07/20231AdultHallam, Brianvc57_irecords_extractiBRC34637858
Findern, Derbyshire, DEAZSK33A14/08/20221adultBrian and Jean Hallamvc57_irecords_extractiBRC35167622
Kirk Hallam, IlkestonSK44K22/07/20221adultHobby, Brianvc57_irecords_extractiBRC41046036
EA depotSK43G19/07/20221adultCollins, Stuartvc57_irecords_extractiBRC28766650
Findern, Derbyshire, DEAZSK33A18/07/20221adultBrian and Jean Hallamvc57_irecords_extractiBRC35167244
Findern, Derbyshire, DEAZSK33A17/07/20221adultBrian and Jean Hallamvc57_irecords_extractiBRC35167152
Ninelands RoadSK28F16/09/20211adultBlues, Clarevc57_irecords_extractiBRC27389868
Birch ValeSK08I05/09/20211AdultHewitt, Janevc57_irecords_extractiBRC34472498
Findern, Derbyshire, DEAZSK33A26/08/20211adultBrian and Jean Hallamvc57_irecords_extractiBRC35165837
Findern, Derbyshire, DEAZSK33A20/08/20211adultBrian and Jean Hallamvc57_irecords_extractiBRC35165754
Findern, Derbyshire, DEAZSK33A06/08/20211adultBrian and Jean Hallamvc57_irecords_extractiBRC35165611
Findern, Derbyshire, DEAZSK33A02/08/20211adultBrian and Jean Hallamvc57_irecords_extractiBRC35165575
Allestree, DerbySK33P20/07/20211adultPlant, Stephenvc57_irecords_extractiBRC46669895
Longhurst Lane, MellorSJ98Z23/08/20201adultKNASS, Mr D.Danes_2019-2021367
Findern, Derbyshire, DEAZSK33A17/08/20201adultBrian and Jean Hallamvc57_irecords_extractiBRC35163852
Longhurst Lane, MellorSJ98Z14/08/20201adultKNASS, Mr D.Danes_2019-2021383
Findern, Derbyshire, DEAZSK33A11/08/20201adultBrian and Jean Hallamvc57_irecords_extractiBRC35163721
Findern, Derbyshire, DEAZSK33A10/08/20201adultBrian and Jean Hallamvc57_irecords_extractiBRC35163664
Brook Road, ThulstonSK43B09/08/20201adultBryce, Marionvc57_irecords_extractiBRC17299577
Ninelands RoadSK28F07/08/20205adultBlues, Clarevc57_irecords_extractiBRC27431253
Findern, Derbyshire, DEAZSK33A30/07/20202adultBrian and Jean Hallamvc57_irecords_extractiBRC35163425
Longhurst Lane, MellorSJ98Z28/07/20201adultKNASS, Mr D.Danes_2019-2021482
Findern, Derbyshire, DEAZSK33A02/08/20192adultBrian and Jean Hallamvc57_irecords_extractiBRC35161724
Findern, Derbyshire, DEAZSK33A26/07/20191adultBrian and Jean Hallamvc57_irecords_extractiBRC35161666
Oaks Barn Cottage, Monyash Rd, Over Haddon, BakewellSK26D30/07/20111AdultD.A. Clarkevc57_danes_bc_dataLC000334001OK7B7
Kedleston Park,DerbySK34F11/08/20071AdultI. Travers-Ayre;I.M. Vilesvc57_danes_bc_dataLC000334001OKICV
Church St,Holloway,MatlockSK35I18/09/20061AdultF. Harrisonvc57_danes_bc_dataLC000334001OI91W
Stocksmoor Farm, Ashover Rd, Old TuptonSK36S19/08/19981AdultVC57 Derbyshire Recordervc57_danes_bc_dataLC000334001OI3EY
Calke Park (Betty's Pool),TicknallSK32R10/08/19981AdultVC57 Derbyshire Recordervc57_danes_bc_dataLC000334001OHNYK
South Wood, Calke, TicknallSK32R25/07/19971AdultI. Travers-Ayre;I.M. Vilesvc57_danes_bc_dataLC000334001OJ0M5
The Field,Shipley,IlkestonSK44M26/09/19961AdultT. Durovc57_danes_bc_dataLC000334001OJ0D8
The Field,Shipley,IlkestonSK44M26/09/19961AdultT. Durovc57_danes_bc_dataLC000334001WPESP
Stevens Rd, SandiacreSK43T27/08/19961AdultVC57 Derbyshire Recordervc57_danes_bc_dataLC000334001OI2TV
Stevens Rd, SandiacreSK43T19/08/19962AdultVC57 Derbyshire Recordervc57_danes_bc_dataLC000334001OJ08L
Pond House, Mapperley Res, IlkestonSK44G10/09/19921AdultT. Durovc57_danes_bc_dataLC000334001OIWOD
Pond House, Mapperley Res, IlkestonSK44G10/09/19921AdultT. Durovc57_danes_bc_dataLC000334001WQAGH
Pond House, Mapperley Res, IlkestonSK44G13/08/19921AdultT. Durovc57_danes_bc_dataLC000334001OHLS1
Pond House, Mapperley Res, IlkestonSK44G13/08/19921AdultT. Durovc57_danes_bc_dataLC000334001WOMVS
Pond House, Mapperley Res, IlkestonSK44G11/09/19902AdultT. Durovc57_danes_bc_dataLC000334001OHL33
Pond House, Mapperley Res, IlkestonSK44G11/09/19902AdultT. Durovc57_danes_bc_dataLC000334001WOPTC
Pond House, Mapperley Res, IlkestonSK44G22/07/19891AdultT. Durovc57_danes_bc_dataLC000334001OITUG
Pond House, Mapperley Res, IlkestonSK44G22/07/19891AdultT. Durovc57_danes_bc_dataLC000334001WON7Q
Pond House, Mapperley Res, IlkestonSK44G19/08/19883AdultT. Durovc57_danes_bc_dataLC000334001OI09A
Pond House, Mapperley Res, IlkestonSK44G19/08/19883AdultT. Durovc57_danes_bc_dataLC000334001WOQCV
Pond House, Mapperley Res, IlkestonSK44G15/08/19862AdultT. Durovc57_danes_bc_dataLC000334001OISD6
Shardlow Hall, Shardlow, Long EatonSK43F11/09/19841AdultVC57 Derbyshire Recordervc57_danes_bc_dataLC000334001OIR80
Shardlow Hall, Shardlow, Long EatonSK43F11/09/19841AdultR.H. Dumelowvc57_danes_bc_dataLC000334001WOZQN
Shipley Wood, Shipley ParkSK44L17/08/19843AdultVC57 Derbyshire Recordervc57_danes_bc_dataLC000334001OIR3E
Shipley Wood, Shipley ParkSK44L27/08/19821AdultT. Durovc57_danes_bc_dataLC000334001OHI81
Shardlow Hall, Shardlow, Long EatonSK43F22/08/19821AdultVC57 Derbyshire Recordervc57_danes_bc_dataLC000334001OIAHQ
Shardlow Hall, Shardlow, Long EatonSK43F22/08/19821AdultR.H. Dumelowvc57_danes_bc_dataLC000334001WPUVE
Drummond Rd, IlkestonSK44R08/08/19822AdultT. Durovc57_danes_bc_dataLC000334001OIAGQ
Shipley Wood, Shipley ParkSK44L06/08/19824AdultT. Durovc57_danes_bc_dataLC000334001OHI6B
Shipley Wood, Shipley ParkSK44L30/07/19821AdultVC57 Derbyshire Recordervc57_danes_bc_dataLC000334001OIP6X
Shipley Wood, Shipley ParkSK44L23/07/19822AdultVC57 Derbyshire Recordervc57_danes_bc_dataLC000334001OHI33
Shardlow Hall, Shardlow, Long EatonSK43F19/09/19811AdultVC57 Derbyshire Recordervc57_danes_bc_dataLC000334001OHYE8
Shardlow Hall, Shardlow, Long EatonSK43F19/09/19811AdultR.H. Dumelowvc57_danes_bc_dataLC000334001WOZL8
Shardlow Hall, Shardlow, Long EatonSK43F16/09/19811AdultVC57 Derbyshire Recordervc57_danes_bc_dataLC000334001OHYDZ
Shardlow Hall, Shardlow, Long EatonSK43F16/09/19811AdultR.H. Dumelowvc57_danes_bc_dataLC000334001WOZL2
Askew Grove, ReptonSK32D26/08/19811AdultVC57 Derbyshire Recordervc57_danes_bc_dataLC000334001OIA9O
Shardlow Hall, Shardlow, Long EatonSK43F18/09/19801AdultVC57 Derbyshire Recordervc57_danes_bc_dataLC000334001OHH84
Shardlow Hall, Shardlow, Long EatonSK43F18/09/19801AdultR.H. Dumelowvc57_danes_bc_dataLC000334001WP93J
Shardlow Hall, Shardlow, Long EatonSK43F18/09/19791AdultVC57 Derbyshire Recordervc57_danes_bc_dataLC000334001OHGNR
Shardlow Hall, Shardlow, Long EatonSK43F18/09/19791AdultA. Dickvc57_danes_bc_dataLC000334001WPUO8
Shardlow Hall, Shardlow, Long EatonSK43F14/09/19791AdultVC57 Derbyshire Recordervc57_danes_bc_dataLC000334001OILZ8
Shardlow Hall, Shardlow, Long EatonSK43F14/09/19791AdultA. Dickvc57_danes_bc_dataLC000334001WPUNS
Shardlow Hall, Shardlow, Long EatonSK43F31/08/19791AdultVC57 Derbyshire Recordervc57_danes_bc_dataLC000334001OILXK
Shardlow Hall, Shardlow, Long EatonSK43F31/08/19791AdultA. Dickvc57_danes_bc_dataLC000334001WOPIX
Field Close, Hilton, Burton on TrentSK23K24/08/19761AdultVC57 Derbyshire Recordervc57_danes_bc_dataLC000334001OIK0U
Field Close, Hilton, Burton on TrentSK23K20/08/19761AdultVC57 Derbyshire Recordervc57_danes_bc_dataLC000334001OIK0K
Field Close, Hilton, Burton on TrentSK23K18/08/19761AdultVC57 Derbyshire Recordervc57_danes_bc_dataLC000334001OIJZN
Field Close, Hilton, Burton on TrentSK23K12/08/19751AdultVC57 Derbyshire Recordervc57_danes_bc_dataLC000334001OIJD4
The Old Manse, Ault Hucknall, GlapwellSK46S04/09/19681AdultJ.H. Johnsonvc57_danes_bc_dataLC000334001WPGE8
Moorend, Beeley, MatlockSK26T10/09/19591AdultVC57 Derbyshire Recordervc57_danes_bc_dataLC000334001OHVNC
Moorend, BeeleySK26T10/09/19591AdultB.S. Fletchervc57_danes_bc_dataLC000334001WP9HC

Dusky Thorn       Early Thorn

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