The Swallowtail Butterfly

They are large, colorful butterflies that form the family Papilionidae. There are at least 550 species, and though the majorities are tropical, members of the family are found on all continents except Antarctica. The family includes the largest butterflies in the world, the birdwing butterflies of Australia (genus Ornithoptera).


The Swallowtail butterflies in the tribe Papilionini number about 225 species and studied have been made on their host-plant coevolution and phylogeny. A study found that the Papilios are monophyletic and old morphological classifications where also found to be valid in that they formed clusters. Species belonging to the groups that use Rutaceae as host plants formed two groups corresponding to Old World and American taxa. Those that fed on Lauraceae and Magnoliaceae were found to form another cluster which includes both Asian and American taxa.

Swallowtails differ from all other butterflies in a number of anatomical traits. Most notably, their caterpillars possess a unique organ behind their heads, called the osmeterium. Normally hidden, this forked structure can be everted when the caterpillar is threatened, and emits smelly secretions containing terpenes. The adults are often tailed like the forked tail of some swallows, giving the insect its name.

Swallowtail butterflies, being large, colorful, and attractive, have been the target of butterfly collectors in earlier times. The largest of these, the Birdwing butterflies are particularly sought after and are cultured in butterfly farms for the purpose of collectors.
Many members of the family feed as larvae on plants of the citrus family, Rutaceae. Some of these attractive butterflies are therefore considered pests in citrus orchards.

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