This report presents an analysis of butterfly sightings data for the month and identifies reports that are notable due to unusual timing, abundance, rare forms, behaviour or other aspect of interest.
The analysis presented on this page was produced by Claude, an AI assistant developed by Anthropic, as part of an exploratory exercise to surface interesting patterns and insights from our butterfly sighting records. The results are intended to demonstrate the potential of AI-assisted analysis in citizen science contexts.
AI-generated outputs can contain errors or misinterpretations and while the analysis has been sample checked by human reviewers, the Editor may not agree with all of the comments. The findings should not be treated as definitive scientific conclusions and are best understood as indicative insights. If you spot any errors please let us know at webmaster at sussex-butterflies.org.uk.
Species: Queen of Spain Fritillary
What's Unusual: The observer photographed a Queen of Spain Fritillary in excellent condition at Stoke Bottom, during a 27-species day that also took in Fairmile Bottom and Marlpost Wood. This scarce migrant is rarely seen in Sussex, and June is an unusually early month for this species, with August and September the more typical arrival window.
Context: The editor's reaction was unambiguous, calling it "a fantastic record" and noting that a confirmed sighting in such good condition, this early, suggests more individuals were likely present locally. The same visit also produced Chalk Hill Blue, itself around a week ahead of its 10-year average first-sighting date.
Location: Stoke Bottom | Grid Ref: TQ0411
Species: Brown Hairstreak (male)
What's Unusual: A male Brown Hairstreak was seen on the Amberley Downs during a long and eventful day of recording, described by the observer as "by far my earliest ever sighting of this species." Brown Hairstreak is normally one of the last species to appear each season, and a sighting before the end of June breaks new ground for the county.
Context: The editor believes this to be the first-ever June record of Brown Hairstreak in Sussex, and set out how quickly the species' emergence has been shifting: the average first sighting date moved from 26 July across 2006 to 2015, to 15 July across 2015 to 2025, with matching early records on 2 July in both 2022 and 2025. This sighting arrives weeks ahead of even those recent early dates. The same visit also produced two sightings of Queen of Spain Fritillary and took the season's tally to 47 butterfly species recorded in Sussex before the end of June.
Location: Amberley Downs
Species: Wood White (female, egg-laying)
What's Unusual: A single Wood White was found nectaring and egg-laying on a local patch in Crawley, many miles from the nearest known colonies around Chiddingfold in Surrey and the discrete Wood White strongholds elsewhere in Sussex. The observer located and photographed the egg that was laid.
Context: The editor called it "an astonishing record," and suggested there may be other undiscovered individuals in the woodland between Horsham and Crawley. Wood White is known to disperse over long distances, and the sighting adds weight to a wider pattern this month: a garden record from Plaistow (Report #7854) and earlier accounts from Ifold, Billingshurst and Wisborough Green all point to the species turning up well beyond its known colonies.
Location: Crawley (exact site withheld to protect the record)
Species: Long-tailed Blue (worn individual)
What's Unusual: A worn Long-tailed Blue, a rare immigrant species, arrived in a Felpham garden and was seen nectaring and resting with wings open for ten to fifteen minutes before it could not be relocated. Its condition and behaviour suggested a recent Channel crossing.
Context: The editor confirmed this as "a very early date," roughly three weeks ahead of a 2023 Newhaven sighting and well outside the typical arrival window: the average first sighting date for 2015 to 2025 was 17 July, with a range of 28 June to 5 August. The early arrival was linked to the run of heat events affecting North Africa, Spain and France over the preceding months.
Location: Felpham
Species: Large Tortoiseshell
What's Unusual: The editor revealed a very early emergence of an adult Large Tortoiseshell at an undisclosed Sussex location, a species that has historically emerged in July or August. Large Tortoiseshells typically enter hibernation within one to two weeks of emerging, which means that each individual offers only a brief window in which it can be observed.
Context: This record, dated 7 June, beats the previous earliest emergence of 13 June 2025 by nearly a week, continuing a run of unusually early phenology across the month. The editor noted that further adults could still appear in the coming weeks and encouraged recorders to keep the species in mind while out in the field.
Location: Undisclosed, Sussex
1 June 2026
A moth hovering over valerian was initially taken for a Humming-bird Hawk-moth but was confirmed by Sussex Wildlife Trust as a Striped Hawkmoth, a scarce immigrant normally seen between May and October and usually only active at dusk and dawn.
5 June 2026
A single Dingy Skipper among a small count of Painted Ladies, Meadow Browns, Common Blues, Red Admirals and Speckled Wood. First-brood Dingy Skippers are rarely recorded this late; in 2025 there were only two June records across the whole county.
13 June 2026
A single Purple Hairstreak, alongside a lone Ringlet, took the season's Sussex tally to 41 species. The editor described it as probably a county record for the earliest date on which the 40th species of the year has been reached.
13 June 2026
Four Purple Emperors were reported on the wing at Knepp on 12 June, the earliest date ever recorded on the website since 2006. The 10-year average first sighting date is 21 June, with a previous range of 15 to 30 June.
14 June 2026
At least three male Gatekeepers were seen at a wildflower border managed by local volunteers. The editor noted that Berwick has produced the county's earliest Gatekeeper record for three years running: 16 June 2024, 12 June 2025 and now 14 June 2026.
16 June 2026
A single Essex Skipper on the Rottingdean coast path was the second-earliest record for the species on the website since 2006, beaten only by a sighting on 14 June 2011. The 10-year average first sighting date is 24 June.
21 June 2026
A Father's Day circuit through Abbot's Wood, Cradle Bottom and Berwick Station produced 22 butterfly species in a single day, including Silver-washed Fritillary, White Admiral, Small Blue and a first-of-year Gatekeeper. The editor called it "very special" for June.
27 June 2026
A pristine female Wall in a North Lancing garden this species not seen in N. lancing since 22 May, pointing to a very early second brood. The editor confirmed it as such, noting it beats the observer's own previous record, a 30 June 2025 sighting thought at the time to be the earliest modern-era second-brood record.
30 June 2026
75 Dark Green Fritillaries, around 90% of them males, were counted in the West Combe alone, suggesting a site total in the region of 150 or more. The observer expects the peak count in about a week's time to reach around 200.
29 June 2026
Four blue species were seen, which is unusual for June: Chalk Hill Blue, Common Blue, Brown Argus and Adonis Blue. The same visit produced an immaculate female Clouded Yellow, presumed to have emerged locally, following up the Queen of Spain Fritillary sighting from the day before.
June 2026 was a remarkable month for butterflies in Sussex, characterised by:
Taken together, these records suggest 2026 is shaping up to be another landmark year for butterfly recording in Sussex, with the timing of first sightings continuing to shift earlier across a wide range of species.
