Description and biology
The Corsican swallowtail butterfly has an average wingspan of just under 3 inches (7.6 centimeters). Its coloring is primarily black and yellow. Its hind wings are each marked by a small red “eye spot” located near the back of the wings. A row of small blue spots highlights the edges of these wings. The butterfly’s tails are small and tapered.
The caterpillar or larval stage of this butterfly eats various plants of a plant family that includes fennel, giant fennel, and wild carrots.
It is often preyed on by wasps. The caterpillar enters the pupal, or cocoon, stage in late spring to transform into an adult butterfly. It emerges from the pupa between May and June and remains active until early August.
Habitat and current distribution
Corsican swallowtail butterflies are found only on the islands of Corsica and Sardinia in the Mediterranean Sea. Corsica, belonging to France, lies about 100 miles (161 kilometers) southeast of the southern coast of France. Sardinia, belonging to Italy, lies just south of Corsica.
These butterflies inhabit open mountainous country at altitudes between 2,000 and 4,900 feet (610 and 1,494 meters).
History and conservation measures
The chief threats to the Corsican swallowtail butterfly are the loss of its food source and its habitat. The plants eaten by the butterfly when it is in its caterpillar stage are burned by shepherds on the islands.
The shepherds claim these plants are poisonous to their sheep. Human development on these islands, such as the building of ski resorts, has also destroyed much butterfly habitat.
Like many other butterfly species, the Corsican swallowtail butterfly is further threatened by amateur and commercial butterfly collectors. Although protected under international treaty, this butterfly is still illegally captured. It is then sold for large sums of money to collectors around the world.
The French government has passed laws protecting this butterfly on the island of Corsica, but the laws are not well enforced and the butterfly has continued to suffer. The Italian government has yet to pass any laws guarding the Corsican swallowtail butterfly on the island of Sardinia.