Have you ever seen a tiger swallowtail? Perhaps you thought it looked like a big, yellow paper airplane flitting from flower to flower. Perhaps now you want to know more about these magnificent butterflies. What are they, exactly? Where do tiger swallowtails lay their eggs? Keep reading! In this article, we’ll answer these questions and more.
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What Are Tiger Swallowtails?
The eastern tiger swallowtail is a type of butterfly found widespread throughout the Midwest and eastern parts of the United States, as well as parts of Mexico. It looks almost exactly like the closely-related western swallowtail butterfly, which belongs to the same family but is found in the western parts of the U.S.
Tiger swallowtails have large, yellow wings with black stripes, similar to the pattern and coloring of tigers. A few members of this species have a genetic mutation that makes them all black with darker black stripes.
These butterflies also have blue patterns on their lower wings, with females having more blue markings than males. Both males and females have a couple of orange spots on their lower wings as well.
As caterpillars, tiger swallowtails look somewhat like bird droppings when they are young. As they grow, they shed their skin multiple times, turning green and developing false eye patterns on their back; these markings make them look somewhat like small snakes, which is a deterrent to birds that would otherwise eat them.
When they are ready to go into the pupa stage, they spin a silk saddle to attach themselves to a stick or some other object. They then shed their skin a final time, producing a green or brown chrysalis where their immature cells transform to produce the adult butterflies.
Tiger swallowtails produce two broods a year and can be found throughout the late spring, summer, and fall months. The last brood overwinters in its chrysalis before hatching out as a butterfly the following spring.
What is the Life Cycle of a Tiger Swallowtail?
There are four distinct stages of a tiger swallowtail’s life cycle:
At this stage, small shiny green eggs are deposited on the tops of leaves. Tiger swallowtails are less picky than some butterflies about the plants they choose to lay eggs on; there are a variety of different plants they choose, which we’ll talk about in the next section of this article.
The eggs turn black when the baby caterpillars are ready to hatch; they chew through the thin shells, then eat them after hatching. The baby caterpillars are black and white, their patterns similar to that of bird droppings.
The caterpillars feed heavily and grow rapidly, shedding their skin multiple times and eventually turning green with blue and yellow eye-shaped spots. They create silk beds for themselves on the topsides of leaves, where they sit and rest when they aren’t eating.
After a week or two, the caterpillar begins searching for a place to morph into a chrysalis, or pupa. When it finds what it deems is a safe, sheltered spot, it will attach itself to its chosen stick or other surface by spinning a silk saddle to hold itself in place.
The caterpillar sheds its skin a last time, leaving a green or tan chrysalis behind. The chrysalis will remain for another week or two while the immature cells of the caterpillar transition and reshuffle into the adult cells of the butterfly.
The chrysalis will turn dark brown to black when the butterfly is ready to emerge, and some of the yellow and black markings of the butterfly may show through. The outer shell of the chrysalis will split open, and the butterfly will emerge.
At first, the butterfly will have a swollen, fluid-filled body and small, shriveled wings. It will hang upside-down from a stick, leaf, or its own chrysalis, allowing the fluid from its body to flow into the wings and expand them.
After a few hours, when the wings are dry and the body has slimmed down, the butterfly flies away.
Tiger swallowtails live in the butterfly stage for a few weeks, eating nectar from flowers, mating, and laying eggs.
What Plants Do Tiger Swallowtails Lay Eggs On?
Tiger swallowtails lay small, pearlescent green eggs individually on the topside of leaves. They choose the leaves of various trees and plants, including:
- Tulip trees: Also known as tulip poplars, these trees don’t actually belong to the poplar family. They have uniquely-shaped and highly recognizable leaves and are grown throughout the eastern United States, often as ornamentals.
- Rose bushes: In some areas, tiger swallowtails lay eggs on various members of the rose family. These can include both wild and domestic rose bushes.
- Magnolia trees: Sweet bay magnolias appear to be the tree of choice for many tiger swallowtails. These trees grow throughout extreme southern and eastern areas of the United States.
- Wild black cherry trees: These trees grow throughout the tiger swallowtail’s range, from Florida to Main and westward as far as Oklahoma. They produce small purple berries, but the dark, serrated leaves are the food of choice for many tiger swallowtail caterpillars.
- Chokeberry: Chokeberry plants are related to wild cherries, but the plants are usually shorter; they may be only shrub-size, whereas wild cherries often grow to large trees. Tiger swallowtails will lay eggs on these plants if there are no other options from among their preferred plants.
Check out this video of a tiger swallowtail caterpillar feeding on a tulip tree leaf.
Tiger swallowtails live throughout the eastern half of the United States, and they lay their eggs on a variety of different trees and plants in the magnolia and rose families. Some of these plants include tulip trees, sweet bay magnolias, and chokeberry shrubs.