The large and striking yellow and black butterflies that are often seen fluttering around parks and gardens in the summer belong to a group known as the swallowtail butterflies. There are several different species of swallowtail butterflies that can be found across North America, Europe, and Asia. They are some of the most familiar and easily recognized butterflies due to their vibrant yellow and black coloration. In this article, we will explore the various swallowtail butterfly species in more detail, looking at their identifying features, life cycles, habitats, and conservation status.
Main Swallowtail Species
There are around 550 species of swallowtail butterflies in the world. Here are some of the most common swallowtail species that have the distinct yellow and black markings:
Eastern Tiger Swallowtail
The eastern tiger swallowtail (Papilio glaucus) is one of the most widespread swallowtail species in North America. It is found across the eastern United States and southeastern Canada. The wingspan ranges from 3-6 inches. The upper wings are black with distinctive yellow stripes, while the lower wings are mainly yellow with black stripes and small blue and orange spots near the tails. The male is yellow with black tiger stripes, while the female is black with more limited yellow markings. The larvae feed on various trees and shrubs, especially wild cherry, ash, tulip tree, and sweetbay magnolia.
Western Tiger Swallowtail
Closely related to the eastern tiger swallowtail, the western tiger swallowtail (Papilio rutulus) occurs along the western half of North America. It also has yellow and black striped upper wings, but the lower wings have a wash of blue instead of orange. The larvae feed on cottonwood, willow, sycamore, hoptree, and ash trees.
Canadian Tiger Swallowtail
The Canadian tiger swallowtail (Papilio canadensis) is found across northern North America in Canada and Alaska. It is very similar to the eastern tiger swallowtail but is darker in coloration. Its primary food plants as larvae are birch, aspen, and willow trees.
European Swallowtail
Widespread across Europe and temperate Asia is the European swallowtail (Papilio machaon). It is the largest butterfly in Europe with a wingspan up to 3.1 inches. The upper wings are yellow with black tiger stripes, while the lower wings are yellow with a wash of blue and several small blue spots around the tails. The larvae feed on plants in the carrot family, including wild parsnip, fennel, and dill.
Old World Swallowtail
Native to Europe, Asia, and North Africa is the Old World swallowtail (Papilio machaon). It is similar in appearance to the European swallowtail but differs in some minor wing markings and larval food plants. The larvae primarily feed on citrus plants such as orange, lemon, and grapefruit trees. A subspecies was introduced to North America and is now found in some southeastern states where citrus is grown.
Black Swallowtail
The eastern black swallowtail (Papilio polyxenes) occurs throughout North America except the far north. The wingspan reaches 3-4 inches. The upper wings are black with yellow bands and spots, while the lower wings have a row of yellow spots and a bright orange spot near the tail. The male has a row of yellow dots, while the female only has the row of yellow spots. Larvae feed on plants in the carrot family, especially Queen Anne’s lace and parsley.
Giant Swallowtail
The largest butterfly in North America is the giant swallowtail (Papilio cresphontes), with a wingspan up to 6 inches. It is mainly confined to the southeastern United States. The upper wings are black with yellow bands and spots, while the lower wings are mostly yellow with black bands and tails marked with orange spots. Larvae feed on citrus trees, prickly ash, and hoptree.
Spicebush Swallowtail
The spicebush swallowtail (Papilio troilus) occurs in the eastern United States. Males are black with broad yellow bands on the upper wings, while females are darker black overall with blue spots on the lower wings. Larvae feed on spicebush, sassafras, and other trees.
Identification Features
Swallowtail butterflies can be identified by the following features:
– Large size, with wingspans between 3-6 inches depending on species
– Distinctive yellow and black coloration, usually with yellow and black stripes on the upper wings
– Tails on the hindwings, often with orange or blue spots
– Lower wings that are either yellow or yellow with black tiger striping
– Blue or orange spots near the tails of the lower wings
– Quick and strong flight on their large wings
The different swallowtail species can be distinguished by examining the specific wing patterns and colors, larval food plants, size, and geographic range. For instance, the presence of blue on the lower wings indicates a western tiger swallowtail instead of an eastern tiger swallowtail. The most reliable way to identify the species is to examine the wings and other markings using a field guide or butterfly reference.
Life Cycle
Swallowtail butterflies go through a complete metamorphosis with four life stages:
Egg – Females lay single eggs on the host plant of the caterpillar. The egg stage lasts around a week.
Caterpillar – The caterpillar hatches and eats leaves of the host plant, shedding its skin several times as it grows. The caterpillar stage lasts 2-4 weeks.
Pupa – The caterpillar forms a chrysalis and undergoes metamorphosis into the adult butterfly. This pupal stage lasts 1-2 weeks.
Adult – The adult butterfly emerges, expands and dries its wings, and flies off to feed on flower nectar. Adults live 2-6 weeks during one flight season.
The generation time from egg to adult ranges from 30-60 days depending on the swallowtail species and temperature. There may be several generations per year in warmer climates. Overwintering occurs in the chrysalis stage to emerge in spring.
Habitats
Swallowtail butterflies are found in a variety of habitat types, usually where their host plants are present:
– Deciduous forest areas with trees such as oak, ash, cherry, tulip, magnolia
– Citrus groves
– Hoptree scrublands
– Riverside vegetation with willows and cottonwoods
– Gardens, parks, and urban areas with suitable nectar and host plants
They prefer areas with a mix of sun and shade, and are especially abundant along forest edges and streams. Tiger swallowtails in particular adapt readily to parks and gardens in urban and suburban settings. Swallowtails roost at night high up on trees and other sheltered sites.
Behavior
Swallowtail behaviors include:
– Powerful flight – They are strong fliers capable of gliding over long distances.
– Nectar feeding – Adults drink nectar from flowers with their long proboscis. Favorite nectar sources are lilac, milkweed, thistle, and daisy flowers.
– Hilltopping – Some species congregate on hilltops to find mates.
– Puddling – They gather at wet ground to suck up mineral nutrients and moisture.
– Wing basking – They perch with wings open to regulate temperature.
– Ovipositing – Females search out suitable host plants to lay single eggs on the leaves.
– Pupal defense – Some swallowtail larvae have osmeteria organs that release stinky scents to deter predators.
– Overwintering – Most species overwinter as a pupa attached to a plant stem or branch.
Threats and Conservation
Some swallowtail butterflies are threatened by:
– Habitat loss from development and agriculture
– Pesticide use
– Vehicle strikes during migration and dispersal
– Invasive species that displace native host plants
– Climate change affecting seasonal patterns
However, many species adapt readily to human environments and thrive in gardens. Providing suitable nectar flowers and host plants for larvae can help attract and support these butterflies. Some tips:
– Plant native trees and shrubs used by local swallowtail species
– Include nectar plants like lilac, butterfly bush, and zinnia
– Avoid pesticide use where possible
– Create large open sunny areas protected from wind
– Join citizen science monitoring programs to help conserve populations
With appropriate habitats, swallowtail butterflies can flourish and provide enjoyment with their large, colorful wings and energetic flight. Protecting their forest and wetland ecosystems will be key to ensuring their survival.
Conclusion
The big yellow and black butterflies commonly seen flying powerfully through parks and gardens are swallowtail butterflies. Around 550 swallowtail species exist worldwide with diverse wing patterns and coloration. In North America, some of the most recognizable species include the eastern tiger swallowtail, Canadian tiger swallowtail, giant swallowtail, and black swallowtail. Swallowtails go through a complete metamorphosis and thrive in areas where their host plants are found. Providing suitable flowers, trees, and open habitat can help attract these beautiful butterflies to gardens. Though some species are threatened by habitat loss and pesticides, swallowtails can flourish in human-altered environments. Their vibrant wings and graceful flight make swallowtails some of the most familiar and enjoyable butterflies to observe.
References
Butterflies and Moths of North America. 2022. Swallowtail Butterflies of North America. https://www.butterfliesandmoths.org/swallowtails
US Forest Service. 2022. Swallowtail Butterflies of North America. https://www.fs.fed.us/wildflowers/pollinators/pollinator-of-the-month/swallowtail_butterflies.shtml
Wikipedia contributors. “Papilionidae.” Wikipedia, The Free Encyclopedia. https://en.wikipedia.org/w/index.php?title=Papilionidae&oldid=211698368
Scheider, Jessica. 2014. The Swallowtail Butterflies: Their Ecology and Evolutionary Biology. Princeton University Press.
Tyler H, Brown KS, Wilson K. 1994. Swallowtail Butterflies of the Americas. Scientific Publishers.
