70.297 BF1665  –  Geometridae –  Geometrinae – Pseudoterpna pruinata – Grass Emerald – (Walker, 1863) Adult Macro:  CAT 1 – Distinctive species unlikely to be confused with others –       PDF Icon – click for Adult Macro Verification Guidelines

Brown –  Significant Record / Very Rare / Vagrant    
Taxonomy:   Macro   >>  Geometridae  >> Geometrinae
ID Difficulty:  green  – easy to identify, generally distinctive and unlikely to be confused with other species.
ID pointers: The pale bluish tinged green forewings are characteristic. The darker post-median lines also help to identify thi species
Distribution:  (Last record: 15 August 2023 at Markham Colliery Site )  –  A resident that is generally uncommon and locally distributed in Derbyshire. General loss of suitable habitat seems to be the cause of losses in population of what has never been a common species in the county. The central Coal Measures of Derbyshire were once the main stronghold and relict populations may still exist.
Flight Period: June /  July /  August /  –  June – August Moth Activity: Cathemeral   – and is attracted to light Photographed: Yes –  Photographed By: Sid Morris  © All Rights Reserved
*** Last updated on 2 October 2025 by RP ***
Wingspan: 30-35mm
Forewing: 14-19mm
Food Plant: Petty whin (Genista anglica, gorse (Ulex) and broom (Cytisus scoparius).
Last Recorded Year: 2023
Last Recorded By – Sid Morris
Last Recorded General Area – Markham Colliery Site

Selected Images:  

Markham Vale – 15th August 2023 – Sid Morris©



Distribution Map for Pseudoterpna pruinata

Found 19 records
    ↳ 1 from After 2025
    ↳ 1 from 2020 - 2024
    ↳ 17 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 – Pseudoterpna pruinata

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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: Pseudoterpna pruinata
( data includes both Larvae and Adult Stages )

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


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


CUSUM Analysis: Pseudoterpna pruinata
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 24 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 2023, 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: Pseudoterpna pruinata
( data includes both Larvae and Adult Stages )

Flight Periods – Indicative –vs– Recorded Data
Pseudoterpna pruinata
( 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 - Pseudoterpna pruinata – 19 records available

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

Site NameTetradDateCountStageSource
Shallcross Avenue, High Peak, England, GBSK07E19/06/20251Adultvc57_irecords_extract
Markham Vale DerbyshireSK47K15/08/20231adultvc57_irecords_extract
Lang Rd, Alvaston, DerbySK33R21/07/19921Adultvc57_danes_bc_data
Whitwell Wood,WhitwellSK57E20/07/19901Adultvc57_danes_bc_data
Whitwell Wood,WhitwellSK57E20/07/19901Adultvc57_danes_bc_data
Shardlow Hall, Shardlow, Long EatonSK43F09/07/19841Adultvc57_danes_bc_data
Askew Grove, ReptonSK32D29/07/19771Adultvc57_danes_bc_data
Field Studies Building, Drakelow Nature TrailSK21J05/07/19771Adultvc57_danes_bc_data
Askew Grove, ReptonSK32D29/07/19771Adultvc57_danes_bc_data
Field Studies Building, Drakelow Nature TrailSK21J03/07/19763Adultvc57_danes_bc_data
Askew Grove, ReptonSK32D09/07/19761Adultvc57_danes_bc_data
Askew Grove, ReptonSK32D10/07/19761Adultvc57_danes_bc_data
Askew Grove, ReptonSK32D09/07/19761Adultvc57_danes_bc_data
Askew Grove, ReptonSK32D10/07/19761Adultvc57_danes_bc_data
Newbold Ave, ChesterfieldSK37R07/07/19701Adultvc57_danes_bc_data
Gleadless area (site not precise)SK38W07/07/19701Adultvc57_danes_bc_data
Welbeck Rd, BolsoverSK47V03/08/19691Adultvc57_danes_bc_data
Berry St, Hepthorne Lane, North WingfieldSK46C23/07/19671Adultvc57_danes_bc_data
Berry St, Hepthorne Lane, North WingfieldSK46C31/07/19671Adultvc57_danes_bc_data

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