Tiger Swallowtail Butterfly

Description:

Spotted at Roxborough Primary School, Littleton, CO. Large, colorful butterflies in the family Papilionidae, which includes over 550 species.Though the majority are tropical, members of the family occur on every continent except Antarctica. The family includes the largest butterflies in the world, the birdwing butterflies of the (genus Ornithoptera). Swallowtails have a number of characteristic features; for example, on the prothorax a Papilionid caterpillar bears a repugnatorial organ called the osmeterium. The osmeterium normally is hidden, but when threatened, the larva everts it through a transverse dorsal groove by inflating it with blood. It is a fleshy, forked structure and emits smelly secretions containing terpenes, which the larva typically tries to smear onto any attacker touching it. The adults of some species have conspicuous posteriad prolongations of the hind wings in the region of the M3 vein. The forked appearance of these features as seen in the butterfly when resting with its wings spread, gave rise to the common name swallowtail. As for the formal name, Linnaeus chose Papilio for the type genus, Papilio being the Latin for a butterfly. For the specific epithets of the genus, Linnaeus applied the names of Greek heroes to the swallowtails. The type species: Papilio machaon honoured Machaon, one of the sons of Asclepius, mentioned in the Iliad.

Habitat:

As of 2005, 552 extant species have been identified which are distributed across the tropical and temperate regions of all continents except Antarctica. Various species occur from sea level to high mountains, as in the case of most species of Parnassius. The majority of swallowtail species and greatest diversity in form and lifestyle are found in the tropics and subtropical regions between 20°N and 20°S,: particularly Southeast Asia, and between 20°N and 40°N in East Asia. Only 12 species are found in Europe and only one species, Papilio machaon is found in the British Isles. North America records 40 species which include tropical species and Parnassius. The northernmost swallowtail is the Arctic Apollo (Parnassius arcticus) which is found in the Arctic Circle in northeastern Yakutia, at an altitude of 1500 meters above sea level. In the Himalayas, various Apollo species such as Parnassius epaphus, besides others, have been recorded to occur up to an altitude of 6,000 meters above sea level.

Notes:

The key characteristics that differentiate the Papilionidae from the other butterfly families are: The presence of the osmeterium, a forked, fleshy eversible organ found in the prothoracic segment of papilionid caterpillars. Venation in the adult forewing of papilionids is characteristic. In swallowtails, the second anal vein, extends up to the wing margin and does not link with the first anal vein, These veins are fused in other butterfly families and does not reach the wing margin. The sclerites of the cervix (membranous neck between the head and thorax) are fused beneath the neck where the muscles for head movement are anchored.