A Spicebush swallowtail butterfly, or Green-clouded swallowtail, is a butterfly that lives in North America, and is unique for a survival tactic known as the Batesian mimicry. It makes itself look like a species that doesn’t taste good, which discourages the predators from eating them.
Spicebush swallowtail species summary
| Scientific Name | Papilio troilus |
| Family Name | Papilionidae |
| Kingdom | Animalia |
| Genus | Papilio |
| Habitat | Edge of the fields or moist woodlands |
| Range | Eastern and mid-western US |
| Host Plants | Spicebush, sweet pepperbush, sassafras tree, thistles, silk bay, sweetbay |
| Butterfly Description | Dark, almost black, with bluish markings on hindwings |
| Caterpillar Description | Green or brown, with prominent fake eyes |
Spicebush swallowtail Butterfly Description
This butterfly species is generally black, with the hindwings showing hints of pale green spots. Some butterflies show a predominant brown shade instead of the usual black. Its wingspan measures about 3.5 to 4.5 inches.
You can tell the Spicebush swallowtail’s gender by checking the rest of the markings on the hindwings. If it’s showing hints of blue-green bands along the middle of the hindwings, it’s most likely a male butterfly.
There might be variations, such as pale green spots along the underside of the hindwings. Some male variations show bright orange spots separated by blue and back patches on the same region.
On the other hand, a bright blue half-moon marking or splotch along this part of the hindwings means a great chance you’re dealing with its female counterpart. In addition, the forewing may also have oval spots that are usually cream.
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The difference between a spicebush and a black swallowtail
The main difference between these butterflies is the presence (or lack) of a bluish “swosh” pattern without the orange dot. The Spicebush swallowtail has this area on its hindwing undersides. On the other hand, the Black swallowtail is darker, with a line of yellow spots across its wings.
Caterpillar Physical Description
The Spicebush swallowtail caterpillar is bright green with hints of white spiral stripes spanning the dorsal and a significant part of the ventral side of the thorax. This is especially present in its first and eighth abdominal segments.
Once an instar reaches peak maturity, it can measure from 2 to 3 inches. Newly molten matured instars can appear pale green but eventually turn pinkish brown or burgundy as it approaches the pupal stage.
Another variation is the presence of large black spots on both sides of the head and along the sides of the body. The spots may appear brown or tan along the dorsal segments in other variations.
Why are these butterflies referred to as Swallowtails?
The tails at the end of their wings somewhat look like the forked ends of the Swallows’ tails. This is especially evident when the butterflies reach full maturity.
Distribution
You can find the Spicebush swallowtail butterflies in the eastern US and southern Ontario (Canada). It’s also somewhat present in Alabama and Texas. During the last 5 years, it’s been around the Upper Plains and the Coastal regions.
Preferred Habitat
Spicebush swallowtails usually live on the edge of the fields or in moist woodlands. Their other habitats may include:
- Meadows
- Roadsides
- Gardens
- Parks
- Forest margins
- Pastures
Where do spicebush swallowtails lay their eggs?
The following plant species can be considered host plants of the Spicebush swallowtail:
- Camphor tree (Cinnamomum camphora)
- Milkweed
- Tulip tree
- Lantana
- Spicebush (Lindera benzoin)
- Sweet pepperbush
- Sassafras tree (Sassafras albidum)
- Thistles
- Silk bay
- Sweetbay
- Red bay
- Swamp bay
An experiment proved that when the larva doesn’t have access to the host plant, it will rather starve to death than feed on other plants.
What do spicebush swallowtails eat?
Adult butterflies usually get nectar from the plants in the Lauraceae family. To ensure that they will get the most out of this diet, aspiring butterfly gardening cultivators in Florida should only include native plants in their butterfly gardens.
Usual Behavior
The adult Spicebush swallowtail butterflies use the host plants as their ideal mating areas. Female butterflies also lay eggs there right after mating. Finally, matured larvae also prefer these plants as ideal sites to establish their chrysalis or pupae.
Female butterflies have also been found to build leaf nests around their eggs to ensure that predators don’t see their eggs and caterpillars.
Predators
Just like other butterfly species, Spicebush swallowtails should avoid the common predators that may feed on them, mostly birds and spiders.
Some scientists have documented that tachinid flies feed on these butterfly species. Wasps are also the most probable predators of both larvae and adult butterflies.
Batesian mimicry is a defense tactic that this species uses to avoid getting eaten. For example, the eyespots on their bodies look like lizards or bird droppings.
Are Spicebush Swallowtails cultural symbols?
Some countries liken this butterfly to the human soul. Other cultures believe this butterfly is an embodiment of the soul’s freedom and grace. People believe it can explore the intricacies of human life.
Are spicebush swallowtails rare?
This butterfly is somewhat common in natural habitats. It is prevalent in the eastern and mid-western US.
Joan is a nocturnal person who loves traveling and coffee. She’s also an animal lover (and rescuer) who makes it a point to befriend every animal she meets. Her passion for learning led her to writing about various topics. As someone who is a nature lover, she aims to continue learning about the wonderful creation—especially butterflies, and at the same time, share her knowledge here at Butterfly Hobbyist.