Papilio machaon

Old World Swallowtail
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Lepidoptera
Superfamily:	Papilionoidea
Family:	Papilionidae
Subfamily:	Papilioninae
Tribe:	Papilionini
Genus:	Papilio
Species:	P. machaon
Binomial name
	Papilio machaon; Linnaeus, 1758

The Old World Swallowtail (Papilio machaon), is a butterfly of the family Papilionidae. The butterfly is also known as the Common Yellow Swallowtail or, simply, The Swallowtail (a common name applied to all members of the family). It is the type species of the genus Papilio and occurs throughout the Palearctic region in Europe and Asia; it also occurs across North America, and thus is not restricted to the Old World, despite the common name.

Description

This striking butterfly is yellow with black wing and vein markings and a wingspan of 8 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.

Distribution

This butterfly is present throughout the entire Palearctic region through Russia to China and Japan (including the Himalayas and Taiwan) and across into Alaska, Canada, and the United States. In Asia it is reported as far south as Saudi Arabia, Oman and the high mountains of Yemen.

In Southern Asia it occurs in Pakistan and Kashmir, Northern India (Sikkim, to Assam and Arunachal Pradesh) Nepal, Bhutan and northern Myanmar.

This butterfly is widespread in Europe but in the United Kingdom it is limited to a few areas in the Norfolk Broads of East Anglia. It is the UK's largest resident butterfly. The Monarch Danaus plexippus is slightly larger but is only a rare vagrant.

Taxonomy

There are 37 subspecies.

Papilio machaon gorganus is strongly migratory in Europe and can be found in almost all habitats.
In the UK, P. m. brittanicus is an endemic subspecies, but occasionally individuals of the continental subspecies gorganus breed temporarily on the south coast. Subspecies brittanicus differs from the continental subspecies in being more heavily marked in black.
The Maltese Islands are home to another endemic subspecies, P. m. melitensis.

Status

Widespread throughout Eurasia, often common and not threatened as a species.
It is listed as "Vulnerable" in South Korea and the Austrian Red Data Book, and, also in the Red Data Book of the former Soviet Union.
The Swallowtail is protected by law in the following countries:

Papilio machaon machaon is protected by law in six provinces of Austria, Czech Republic, Slovakia and Hungary.
UK (subsp. brittanicus occurs in the UK, but the law covers all subspecies).
India (subsp. verityi).

Habitat

In occupied Kashmir, the Common Yellow Swallowtail, as Papilio machaon is called there, inhabits alpine meadows in the Himalayas occurring from 2000 feet in held Kashmir valley to 16,000 feet in the Garhwal Himalayas. In India Himachal Pradesh, it is found over 4000 feet only and in Sikkim over 8000 feet only.

At lower elevations these butterflies fly from March to September. At higher elevations the butterflies are limited by the short summer seasons.

British subspecies brittanicus is less mobile than its European continental counterpart and stays within or close by its fenland habitat.

Habits

The butterfly has a strong and fast flight but frequently pauses to hover over flowering herbs and sip nectar. It frequents the alpine meadows and hillsides and is fond of 'hilltopping'. At lower elevations it can also be seen visiting gardens.

Life cycle and foodplants

There are usually two to three broods in a year, but in northern areas the species may be single-brooded. In some places like the UK some 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.

Caterpillar

The caterpillar spends the first part of its life with the appearance of a bird dropping, an effective defence against predators. As the caterpillar grows larger it becomes green with black and orange markings. The caterpillar still has a defence against predators in the form of an organ called an osmeterium which consists of retractable, fleshy projections behind its head that can release a foul smell.

Stages of life cycle

Foodplants

Unlike other swallowtails, this species specialises in using plants of family Umbelliferae, females laying eggs singly.
In the UK Milk Parsley Peucedanum palustre (also known as Marsh Hog's Fennel) is normally the only foodplant used by the caterpillars of the British sub-species and is essential for the survival of populations but plants such as wild angelica Angelica sylvestris are sometimes listed in the scientific literature.
The foodplants of the Swallowtail in Europe, Asia and North America are more varied than in the UK. It uses a wide variety of Umbellifers including wild carrot Daucus carota, wild angelica Angelica sylvestris, fennel Foeniculum vulgare and hogweeds Heracleum spp.
In the Maltese Islands, the caterpillar feeds on plants such as rue Ruta chalepensis and fennel Foeniculum vulgare.