Which butterflies emerged when?
These are the earliest dates on which each species of adult butterfly was reported to the website. Ordered by date of first sighting.
| Species | 2020 | 2021 |
|---|---|---|
| Red Admiral | 2020-01-02 | 2021-01-20 |
| Brimstone | 2020-01-19 | 2021-01-22 |
| Peacock | 2020-01-05 | 2021-02-05 |
| Painted Lady | 2020-04-03 | 2021-02-22 |
| Comma | 2020-01-19 | 2021-02-26 |
| Large Tortoiseshell | 2020-03-03 | 2021-02-26 |
| Small Tortoiseshell | 2020-01-19 | 2021-02-26 |
| Speckled Wood | 2020-03-21 | 2021-02-27 |
| Small White | 2020-03-01 | 2021-03-09 |
| Clouded Yellow | 2020-04-19 | 2021-03-19 |
| Orange Tip | 2020-03-26 | 2021-03-27 |
| Small Copper | 2020-03-24 | 2021-04-02 |
| Large White | 2020-03-24 | 2021-04-03 |
| Green Hairstreak | 2020-04-08 | 2021-04-04 |
| Green-veined White | 2020-03-16 | 2021-04-04 |
| Holly Blue | 2020-03-25 | 2021-04-04 |
| Grizzled Skipper | 2020-04-08 | 2021-04-17 |
| Dingy Skipper | 2020-04-14 | 2021-04-19 |
| Duke of Burgundy | 2020-05-02 | 2021-04-24 |
| Wall Brown | 2020-04-08 | 2021-04-24 |
| Brown Argus | 2020-04-19 | 2021-04-26 |
| Small Heath | 2020-04-22 | 2021-04-26 |
| Wood White | 2020-04-19 | 2021-04-27 |
| Common Blue | 2020-04-26 | 2021-05-02 |
| Adonis Blue | 2020-04-27 | 2021-05-07 |
| Marsh Fritillary | 2020-04-26 | 2021-05-10 |
| Small Blue | 2020-04-25 | 2021-05-11 |
| Lulworth Skipper | 2020-05-07 | 2021-05-26 |
| Silver-washed Fritillary | 2020-06-07 | 2021-05-27 |
| Large Skipper | 2020-05-19 | 2021-05-29 |
| Glanville Fritillary | - | 2021-05-30 |
| Meadow Brown | 2020-05-17 | 2021-06-06 |
| Dark Green Fritillary | 2020-05-25 | 2021-06-07 |
| Silver-studded Blue | 2020-05-25 | 2021-06-09 |
| Swallowtail | 2020-08-09 | 2021-06-10 |
| Marbled White | 2020-05-19 | 2021-06-11 |
| Small Pearl-bordered Fritillary | 2020-05-27 | 2021-06-13 |
| White Admiral | 2020-06-04 | 2021-06-15 |
| Small Skipper | 2020-05-27 | 2021-06-20 |
| Purple Hairstreak | 2020-06-07 | 2021-06-22 |
| Ringlet | 2020-06-05 | 2021-06-23 |
| Gatekeeper | 2020-06-09 | 2021-06-24 |
| Essex Skipper | 2020-06-14 | 2021-06-25 |
| White-letter Hairstreak | 2020-06-15 | 2021-06-28 |
| Grayling | 2020-06-14 | 2021-06-30 |
| Chalkhill Blue | 2020-07-06 | 2021-07-16 |
| Purple Emperor | 2020-06-23 | 2021-07-16 |
| Brown Hairstreak | 2020-07-12 | 2021-07-20 |
| Silver-spotted Skipper | 2020-08-03 | 2021-08-04 |
| Long-tailed Blue | 2020-08-10 | - |
