Common Yellow Swallowtail (Papilio machaon)

/ / Terrestrial Inverts


The genus Papilio contains over 500 different species and the majority oviposit on a plant on which its caterpillars later parasitize (1). Papilio machaon is a large yellow butterfly with black wing and vein markings.  It has a wingspan of eight to 10 cm and an overall size of 6.5 to 10 cm.  The hind wings of both sexes have a pair of protruding tails which give the butterfly its common name.  Just below each tail is a red eye spot (2).

Life Cycle

Papilio machaon will usually have two to three broods in a year, but in northern areas the species may be single-brooded. In some places, such as the UK, some individuals will pupate and emerge in the same year and others will overwinter as pupae before emerging the following year, a situation known as being partially double brooded (3).


The butterfly has a strong and fast flight but frequently pauses to hover over flowering herbs and sip nectar.  Its flight time is between February and October (4).


It likes hot, dry, sunny places, often found in areas of cultivation, roadsides, disturbed ground etc. but also in wet places: marshes, fens, river banks, in Northern Europe (4).  It is a very diverse species.  In higher elevations it frequents the alpine meadows and hillsides.  At lower elevations it can also be seen visiting gardens (4).


This butterfly is widespread throughout Eurasia and in Europe but in the United Kingdom it is limited to a few areas (2).

Conservation status

It is a UK BAP Species = Species of Conservation Concern (3).


Description written by Lilli Lehtinen (2009)

(1)   Encyclopaedia Britannica (2009) Genus Papilio [online] Available: [date accessed: 13/05/2009]

(2)   Butterfly Conservation (2009) Swallowtail [online] Available: [date accessed: 21/05/2009]

(3)   UK Butterflies (2008) Swallowtail – Papilio machaon [online] Available: [date accessed: 21/05/2009]

(4)   Tolman. T (1997) Collins field guide butterflies of Britain and Europe, Harper Collins Publisher Ltd, Great Britain