Hertfordshire & Middlesex Branch
Saving butterflies, moths and our environment
Last updated 31 December 2023
For information at a national level. . . .
Butterfly Conservation First Sightings 2023
35 species of butterfly occur most years in Hertfordshire and 30 in Middlesex, together with the occasional migrant or vagrant. The following table lists the first and last sightings in the two counties. Dates highlighted in green signify the earliest during the period and those highlighted in orange signify the latest
| Species | Date | 2014 | 2015 | 2016 | 2017 | 2018 | 2019 | 2020 | 2021 | 2022 | 2023 |
| Dingy Skipper Erynnis tages |
First | 6-May | 6-May | 5-May | 5-May | 16-May | 21-Apr | 26-Apr | 10-May | 21-Apr | 7-May |
| Last | 8-Jul | 8-Jul | 15-Jun | 17-Jun | 5-Aug | 4-Aug | 20-May | 12-Jun | 29-May | 13-Jun | |
| Grizzled Skipper Pyrgus malvae |
First | 15-Apr | 21-Apr | 12-Apr | 12-Apr | 1-May | 21-Apr | 16-Apr | 23-Apr | 15-Apr | 3-May |
| Last | 14-Jun | 8-Jun | 7-Jun | 1-Jun | 8-Jun | 3-Jun | 31-May | 14-Jun | 22-May | 11-Jun | |
| Essex Skipper Thymelicus lineola |
First | 11-Jun | 28-Jun | 19-Jun | 17-Jun | 11-Jun | 17-Jun | 11-Jun | 4-Jul | 16-Jun | 21-Jun |
| Last | 10-Aug | 27-Aug | 13-Aug | 26-Aug | 4-Aug | 21-Aug | 8-Aug | 14-Aug | 4-Aug | 17-Aug | |
| Small Skipper Thymelicus sylvestris |
First | 8-Jun | 15-Jun | 19-Jun | 10-Jun | 6-Jun | 3-Jun | 8-Jun | 16-Jun | 8-Jun | 13-Jun |
| Last | 7-Aug | 22-Aug | 17-Aug | 30-Jul | 11-Aug | 21-Aug | 1-Aug | 25-Aug | 4-Aug | 21-Aug | |
| Large Skipper Ochiodes sylvanus |
First | 14-May | 26-May | 25-May | 27-May | 27-May | 20-May | 17-May | 31-May | 21-May | 8-Jun |
| Last | 14-Aug | 14-Aug | 13-Aug | 13-Aug | 5-Aug | 28-Aug | 8-Aug | 19-Aug | 17-Jul | 9-Aug | |
| Orange-tip Anthocharis cardamines |
First | 21-Mar | 4-Apr | 5-Apr | 25-Mar | 13-Apr | 23-Mar | 25-Mar | 22-Mar | 24-Mar | 7-Apr |
| Last | 13-Jun | 28-Aug | 22-Jun | 10-Jun | 7-Jul | 20-Jun | 9-Jun | 20-Jul | 10-Jun | 8-Jun | |
| Large White Pieris brassicae |
First | 2-Apr | 6-Apr | 4-Apr | 3-Apr | 17-Apr | 21-Mar | 10-Jan | 17-Apr | 12-Apr | 30-Apr |
| Last | 31-Oct | 11-Oct | 6-Oct | 3-Nov | 13-Oct | 22-Oct | 1-Oct | 27-Oct | 16-Oct | 14-Sep | |
| Small White Pieris rapae |
First | 6-Mar | 23-Mar | 22-Mar | 15-Mar | 26-Mar | 25-Feb | 22-Mar | 21-Mar | 10-Mar | 3-Apr |
| Last | 25-Oct | 26-Oct | 28-Oct | 3-Nov | 29-Oct | 18-Oct | 14-Oct | 27-Oct | 11-Nov | 30-Oct | |
| Green-veined White Pieris napi |
First | 16-Mar | 2-Apr | 2-Apr | 30-Mar | 17-Mar | 23-Mar | 4-Apr | 29-Mar | 10-Apr | 9-Apr |
| Last | 28-Oct | 12-Oct | 2-Oct | 6-Oct | 5-Nov | 4-Oct | 23-Oct | 11-Oct | 8-Oct | 16-Sep | |
| Clouded Yellow Colias croceus |
First | 8-Jun | 9-Jun | 26-Jun | 7-May | 18-Apr | 29-Jul | 12-Jul | 17-Jul | 23-May | 16-May |
| Last | 1-Nov | 22-Sep | 4-Oct | 10-Nov | 2-Nov | 23-Sep | 1-Oct | 6-Sep | 29-Oct | 10-Sep | |
| Brimstone Gonepteryx rhamni |
First | 22-Feb | 15-Jan | 4-Feb | 4-Jan | 10-Jan | 2-Feb | 1-Feb | 20-Feb | 1-Jan | 15-Feb |
| Last | 31-Oct | 29-Dec | 14-Dec | 16-Nov | 14-Nov | 30-Dec | 1-Dec | 9-Nov | 29-Oct | 20-Nov | |
| Speckled Wood Pararge aegeria |
First | 29-Mar | 10-Mar | 4-Jan | 15-Mar | 25-Jan | 24-Mar | 4-Apr | 30-Mar | 22-Mar | 2-Feb |
| Last | 31-Oct | 29-Dec | 31-Oct | 10-Nov | 31-Oct | 27-Oct | 22-Oct | 9-Nov | 28-Oct | 31-Oct | |
| Small Heath Coenonympha pamphilus |
First | 4-May | 10-May | 6-May | 22-Apr | 9-May | 15-Apr | 15-Apr | 11-May | 30-Apr | 7-May |
| Last | 3-Oct | 11-Oct | 23-Sep | 26-Sep | 13-Oct | 28-Sep | 7-Oct | 27-Oct | 25-Oct | 16-Sep | |
| Ringlet Aphantopus hyperantus |
First | 8-Jun | 17-Jun | 16-Jun | 7-Jun | 6-Jun | 14-Jun | 9-Jun | 23-Jun | 10-Jun | 19-Jun |
| Last | 27-Aug | 22-Aug | 18-Aug | 27-Aug | 11-Aug | 31-Aug | 10-Aug | 24-Aug | 31-Jul | 30-Jul | |
| Meadow Brown Maniola jurtina |
First | 1-Jun | 4-Jun | 5-Jun | 27-May | 27-May | 30-May | 25-May | 7-Jun | 27-May | 4-Jun |
| Last | 28-Sep | 2-Oct | 21-Sep | 16-Oct | 29-Sep | 27-Sep | 6-Sep | 6-Oct | 25-Sep | 16-Sep | |
| Gatekeeper Pyronia tithonus |
First | 18-Jun | 25-Jun | 1-Jul | 6-Jun | 21-Jun | 25-Jun | 13-Jun | 5-Jul | 28-Jun | 27-Jun |
| Last | 2-Sep | 8-Sep | 15-Sep | 11-Sep | 14-Sep | 8-Sep | 20-Aug | 15-Sep | 22-Aug | 5-Sep | |
| Marbled White Melanargia galathea |
First | 11-Jun | 15-Jun | 5-Jun | 9-Jun | 1-Jun | 14-Jun | 8-Jun | 15-Jun | 2-Jun | 13-Jun |
| Last | 12-Sep | 15-Aug | 17-Aug | 10-Aug | 4-Aug | 26-Aug | 10-Aug | 20-Aug | 25-Jul | 12-Aug | |
| Silver-washed Fritillary Argynnis paphia |
First | 17-Jun | 29-Jun | 1-Jul | 7-Jun | 10-Jun | 16-Jun | 2-Jun | 23-Jun | 16-Jun | 24-Jun |
| Last | 2-Sep | 19-Sep | 30-Aug | 1-Sep | 22-Aug | 26-Sep | 10-Aug | 13-Sep | 7-Aug | 23-Aug | |
| Dark Green Fritillary Argynnis aglaja |
First | 11-Jun | 15-Jun | 19-Jun | 13-Jun | 16-Jun | 16-Jun | 30-May | 15-Jun | 7-Jun | 14-Jun |
| Last | 4-Aug | 22-Aug | 29-Aug | 13-Aug | 1-Aug | 12-Aug | 3-Aug | 13-Aug | 5-Aug | 26-Jul | |
| White Admiral Limentitis camilla |
First | 13-Jun | 27-Jun | 29-Jun | 14-Jun | 13-Jun | 23-Jun | 9-Jun | 27-Jun | 10-Jun | 21-Jun |
| Last | 9-Aug | 3-Aug | 6-Aug | 25-Jul | 21-Jul | 1-Aug | 20-Jul | 17-Aug | 17-Jul | 23-Jul | |
| Purple Emperor Apatura iris |
First | 21-Jun | 30-Jun | 4-Jul | 18-Jun | 19-Jun | 22-Jun | 20-Jun | 4-Jul | 22-Jun | 24-Jun |
| Last | 27-Jul | 9-Aug | 12-Aug | 17-Jul | 28-Jul | 11-Aug | 28-Jul | 19-Aug | 17-Jul | 22-Jul | |
| Red Admiral Vanessa atalanta |
First | 2-Jan | 9-Jan | 7-Feb | 2-Jan | 2-Jan | 18-Jan | 9-Jan | 26-Feb | 1-Jan | 5-Feb |
| Last | 20-Dec | 28-Dec | 22-Dec | 31-Dec | 3-Dec | 7-Dec | 22-Oct | 12-Dec | 25-Nov | 23-Dec | |
| Painted Lady Vanessa cardui |
First | 1-May | 10-Apr | 20-Apr | 3-Apr | 3-Apr | 23-Feb | 14-Apr | 27-Apr | 14-Apr | 7-Apr |
| Last | 10-Nov | 23-Sep | 14-Oct | 22-Sep | 22-Sep | 22-Oct | 14-Sep | 28-Oct | 7-Oct | 14-Sep | |
| Peacock Aglais io |
First | 3-Jan | 14-Jan | 21-Mar | 17-Feb | 27-Jan | 8-Jan | 3-Jan | 21-Jan | 30-Jan | 13-Jan |
| Last | 23-Dec | 12-Nov | 12-Nov | 22-Nov | 4-Nov | 13-Nov | 17-Dec | 18-Nov | 23-Nov | 6-Nov | |
| Small Tortoiseshell Aglais urticae |
First | 13-Feb | 8-Feb | 30-Jan | 5-Jan | 12-Jan | 14-Feb | 9-Jan | 24-Feb | 1-Jan | 13-Feb |
| Last | 31-Oct | 28-Dec | 30-Sep | 6-Nov | 13-Nov | 23-Dec | 7-Nov | 9-Nov | 15-Aug | 3-Sep | |
| Camberwell Beauty Nymphalis antiopa |
First | 9-Mar | 30-May | 30-May | 7-Sep | ||||||
| Last | 24-Mar | 30-May | 30-May | 16-Oct | |||||||
| Comma Polygonia c-album |
5-Mar | 24-Feb | 7-Mar | 2-Jan | 4-Jan | 11-Mar | 28-Jan | 7-Jan | 21-Feb | 1-Feb | 19-Feb |
| Last | 16-Oct | 12-Nov | 29-Nov | 9-Dec | 2-Dec | 27-Oct | 17-Sep | 22-Nov | 3-Oct | 16-Sep | |
| Small Copper Lycaena phlaeas |
First | 13-Apr | 27-Apr | 29-Apr | 6-Apr | 26-Apr | 20-Apr | 22-Apr | 20-Apr | 6-May | 30-Apr |
| Last | 31-Oct | 26-Oct | 18-Oct | 13-Nov | 17-Nov | 28-Oct | 22-Oct | 17-Oct | 29-Oct | 16-Sep | |
| Brown Hairstreak Thecula betulae |
First | 19-Jul | 28-Jul | 18-Jul | 26-Jul | 14-Jul | 30-Jul | ||||
| Last | 6-Sep | 19-Sep | 11-Sep | 3-Sep | 10-Sep | 15-Sep | |||||
| Purple Hairstreak Favonius quercus |
First | 21-Jun | 30-Jun | 25-Jun | 17-Jun | 11-Jun | 1-Jun | 9-Jun | 22-Jun | 16-Jun | 22-Jun |
| Last | 7-Sep | 26-Sep | 8-Sep | 27-Aug | 11-Aug | 6-Sep | 11-Aug | 8-Sep | 13-Aug | 6-Sep | |
| Green Hairstreak Callophrys rubi |
First | 1-May | 18-Apr | 4-May | 8-Apr | 20-Apr | 19-Apr | 21-Apr | 9-Apr | 16-Apr | 28-Apr |
| Last | 6-Jun | 8-Jun | 7-Jun | 13-Jun | 6-Jun | 15-Jun | 13-Jun | 14-Jun | 29-May | 15-Jun | |
| White-letter Hairstreak Satyrium w-album |
First | 17-Jun | 24-Jun | 25-Jun | 10-Jun | 5-Jun | 5-Jun | 30-May | 23-Jun | 10-Jun | 22-Jun |
| Last | 9-Aug | 7-Sep | 10-Aug | 27-Jul | 7-Aug | 31-Jul | 2-Aug | 11-Aug | 30-Jul | 20-Jul | |
| Small Blue Cupido minimus |
First | 18-May | 13-May | 6-May | 5-May | 15-May | 30-Apr | 24-Apr | 19-May | 10-May | 18-May |
| Last | 13-Aug | 2-Aug | 13-Aug | 11-Aug | 7-Aug | 4-Aug | 8-Aug | 20-Aug | 27-Aug | 19-Aug | |
| Holly Blue Celastrina argiolus |
First | 16-Mar | 4-Apr | 22-Mar | 25-Mar | 17-Mar | 27-Feb | 8-Jan | 30-Mar | 22-Mar | 7-Apr |
| Last | 9-Nov | 8-Nov | 31-Oct | 6-Dec | 23-Dec | 27-Nov | 7-Nov | 18-Nov | 9-Nov | 15-Nov | |
| Brown Argus Aricia agestis |
First | 6-May | 27-Apr | 6-May | 3-May | 14-May | 30-Apr | 24-Apr | 17-May | 30-Apr | 11-May |
| Last | 5-Oct | 1-Oct | 2-Oct | 27-Oct | 25-Oct | 23-Sep | 28-Sep | 22-Sep | 25-Oct | 16-Sep | |
| Common Blue Polyommatus icarus |
First | 1-May | 4-May | 1-May | 5-May | 23-Apr | 20-Apr | 6-May | 18-May | 6-May | 16-May |
| Last | 1-Nov | 29-Sep | 18-Oct | 27-Oct | 29-Oct | 10-Oct | 16-Oct | 24-Sep | 13-Nov | 16-Sep | |
| Adonis Blue Polyommatus bellargus |
First | 20-Aug | 8-May | 27-May | 8-May | 22-May | |||||
| Last | 8-Sep | 10-Sep | 22-Sep | 3-Oct | 9-Sep | ||||||
| Chalkhill Blue Polyommatus coridon |
First | 26-Jun | 29-Jun | 2-Jul | 28-Jun | 28-Jun | 2-Jul | 22-Jun | 4-Jul | 22-Jun | 6-Jul |
| Last | 15-Sep | 19-Sep | 24-Aug | 1-Sep | 1-Sep | 12-Sep | 10-Sep | 18-Sep | 22-Aug | 9-Sep |
The first and last sightings are gathered as the current butterfly season progresses so as to provide up-to-date information about species emergence. For previous years the first and last dates will be the actual dates as recorded on our branch database when they become available; empty entries indicate absence.