Battus philenor

Battus philenor, the pipevine swallowtail or blue swallowtail, is a swallowtail butterfly found in North America and Central America. This butterfly is black with iridescent-blue hindwings. They are found in many different habitats, but are most commonly found in forests. Caterpillars are often black or red, and feed on compatible plants of the genus Aristolochia. They are known for sequestering acids from the plants they feed on in order to defend themselves from predators by being poisonous when consumed. The adults feed on the nectar of a variety of flowers. Some species of Aristolochia are toxic to the larvae, typically tropical varieties. While enthusiasts have led citizen efforts to conserve pipevine swallowtails in their neighborhoods on the West coast, the butterfly has not been the subject of a formal program in conservation or protected in legislation. The butterfly is however of 'Special Concern' in Michigan, which is on the Northern limit of its range. The pipevine swallowtail was first identified in 1771 by Linnaues and originally was placed in the genus Papilo, as was typical for swallowtail butterflies. In 1777, it was moved to the genus Battus by Scopoli. The name Battus comes from the founder of the Greek colony of Cyrenaica, Battus I, and the species name philenor comes from the Greek word meaning ‘fond of husband’. The pipevine swallowtail also belongs to the tribe Troidini, a group of butterflies whose larvae all feed on plants of the genus Aristolochia. They are referred to as the Aristolochia butterflies. The pipevine swallowtail has a wide distribution across the Northern Americas. In the United States, the butterfly is found in New England down to Florida west to Nebraska, Texas, New Mexico, Arizona, California, and Oregon. There is also an isolated population in midland California. They have been observed as far south as Mexico and as far north as Ontario, although these sightings are inconsistent. The butterfly frequents warmer, more temperate environments, and can be found mostly in open grasslands, woodlands, meadows, and backyard gardens. They favor anywhere pipevine (Aristolochia) can grow in abundance. Pipevine swallowtail larvae feed on plants within the genus Aristolochia. These are commonly known as pipevine plants, which is where the butterfly gets its common name. This plant genus is known to have active aristolochic acids, which pipevine swallowtail larvae sequester and use for defensive properties. A common host plant is the Virginia snakeroot, (Aristolochia serpentaria), which can be found in the Eastern United States and in Florida. It has broad-leaved and narrow-leaved forms, and both act as hosts for swallowtail larvae. Other host plants include Pipevine (Aristolochia macrophylla), Woolly Dutchman’s pipe (Aristolochia tomentosa), Texas Dutchman’s pipe (Aristolochia reticulate), Watson's Dutchman’s pipe (Aristolochia watsonii), and California Dutchman’s pipe (Aristolochia californica). Some Aristolochia species are actually toxic or extremely distasteful to larvae and thus may act as death traps for the butterflies. This is especially true of exotic variants. Pipevine swallowtail adults use nectar producing plants as hosts, and thus there are many plants that fit this criterion. These butterflies frequent thistle (Cirsium) flowers, the pink and purple flowers of the Phlox species, and ironweed of Vernonia species. The eggs of the pipevine swallowtail vary in color from red to orange. They are small and are laid on host plant stems. A distinctive feature of these eggs which is shared by all Aristolochia butterflies is that the outer layer of the egg is covered by a firm and nourishing excretion laid in vertical stripes along the outside. The egg appears bumpy due to the excretion forming large beads along the bands. The female pipevine swallowtail deposits this excretion from a gland above the ovipositor during the egg laying process.