The Black Swallowtail (Papilio polyxenes) or the eastern black swallowtail is a North American butterfly that typically feeds on several host plants. They claim territories in order to mate and male butterflies actively defend it. They are also found and Canada. It is the national butterfly of the Oklahoma state.
Black Swallowtail Butterfly Facts
- Young butterfly are nearly all black while the older larvae are mainly recognized by green and black bands. They have got some yellow spots on these bands.
- The prominent two rows of the yellow spots are set on the upper surface of the wings. The background is all black.
- The caterpillars feed on host plants from where they take toxins which is quite dangerous to the predating birds. There is a ‘forked gland’ in the black swallowtail butterfly that produces a foul smell in order to drive off predators. The gland seems more like a snake’s tongue.
- The color of the pupae is brown and green.
- The wingspan of a black swallowtail is about 6.9–8.4 cm. Adult males are slightly smaller than females.
- They are also known as the American swallowtail butterfly.
Distribution & Habitat
- The eastern black swallowtail is thought to occur in North America as well as on the Rocky Mountains and southern Canada. Their range also includes eastern United States, northern Mexico, and Arizona.
- They are known to make homes in many habitats such as wet prairies, weedy areas, gardens, pine savannas, fields, flat-woods, and open areas.
- The black swallowtail butterfly maintains its temperature at 24o They regulate their temperature by altering body position toward sun, or perching at a height.
- Males mark territories which they later actively defend it. The territories are less likely to be abundant in host plants and nectar sources. They often chase down the intruders and the chase continues until the intruder flies outside the territory.
- During courtship, males gather in particular sites for display. It’s up to the female to choose males.
- The courtship display continues for up to 45 minutes.
Feeding Ecology & Diet
- Eastern black swallowtails are thought to rely on herbs and most commonly on carrot family. Prominent among the host plants are roughfruit scaleseed, water cowbane, canby’s dropwort, spotted water hemlock, and mock bishopweed.
- A female butterfly mostly lays eggs on host plants but egg-laying also occurs on flowers.
- The stage of the egg lasts about 4 – 9 days while the duration of larval stage is about 10 – 30 days.
- The pupal stage goes up to 18 days. The duration mainly depends on the quality of host plants and temperature.
- Young butterfly begins their first flight in mid-May to late June.
- The average lifespan of the eastern black swallowtail is quite long.
- They don’t seem to have many predators for black swallowtails are extremely quick