Swallowtail Butterfly - Papilio machaon

Alternative names
Old World Swallowtail
Description

This is the Britain's largest and most spectacular butterfly, with a wingspan that may reach 9 cm. It has creamy-yellow wings with heavy black veins and blue margins. The hindwings have distinctively long 'tails' and a red spot.

Note that any sightings in Leicestershire and Rutland are almost certainly the result of reared adults being released.

Identification difficulty
Recording advice

Please provide a photograph to support your record.

Habitat

Wetlands and reedbeds - favouring areas where the sole larval foodplant, Milk Parsley (Peucedanum palustre), grows

When to see it

Adults usually fly between May and July, peaking in mid June. Sometimes, a second brood may emerge from the end of August to mid September.

Life History

The sole larval foodplant Milk Parsley (Peucedanum palustre).

UK Status

The resident British population (subspecies britannicus) is only found in the open fens and marshes of east Norfolk where its foodplant Milk-parsley (Peucedanum palustre) grows.  The species was once more widely distributed in the fens of Norfolk, Suffolk and Cambridgeshire. Any records from elsewhere in Britain almost certainly result from the release of adults in the local area rather than natural migration.

VC55 Status

Unknown as a naturally ocurring species in Leicestershire and Rutland (the food plant is absent). Any records in our area are almost certainly the result of released adults.

Reference
1539 - ABH 56.003
Further Information

The British Swallowtail, Papilio machaon britannicus, is a rare subspecies now confined to the Norfolk Broads. Very occasionally migrants may arrive in Britain from the Continent, these are subspecies gorganus and will use a variety of foodplants such as Wild Carrot.

Leicestershire & Rutland Map

MAP KEY:

Yellow squares = NBN records (all known data)
Coloured circles = NatureSpot records: 2025+ | 2020-2024 | pre-2020

UK Map

Species profile

Common names
Swallowtail
Species group:
Butterflies
Kingdom:
Order:
Family:
Records on NatureSpot:
2
First record:
27/07/2025 (Kate Heath)
Last record:
02/08/2025 (Porter, Rob)

Total records by month

% of records within its species group

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