Numbers
About 560 spp. worldwide
(1)
Nearctica lists 33 species in 5 genera for North America, including eight tropical strays.
Identification
Large, striking butterflies with hind wings usually displaying characteristic elongated tails. These are believed to mimic antennae, distracting predators from more crucial body parts. It is not uncommon to see swallowtail butterflies with one or both tails missing, probably for this reason. However, there are a few species, for instance in genus Parides, that have no significant tails, and some that have more than one per wing.
Eggs are globular. Larvae have antennae-like structures called osmeteria behind the head that they can extrude, at the same time emitting pungent chemicals, to deter predators. Pupae (chrysalides) are usually green or brown and are attached by a knob of silk at one end and a thin silken girdle around the middle. All North American species overwinter as pupae.
(1)Food
Adults feed on flower nectar. Caterpillars feed on a variety of woody and herbaceous plants, depending on the species.
