The Canadian Tiger Swallowtail Butterfly (Papilio canadensis) is a stunning species of butterfly that can be found in the K-Country. Being large and bright yellow and black, with distinctive extensions on the wings near the tail, they’re hard to miss!
Eggs to caterpillars
Female Swallowtails lay their eggs on the leaves of host plants. This includes species such as cottonwood, willow, and aspen trees. Swallowtails typically lay eggs in the late spring or early summer, from May to June, depending on the region and weather conditions. The eggs take about a week to hatch. The caterpillars begin feeding on the leaves of their host plants soon after.
It is worth noting that the Canadian Tiger Swallowtail Butterfly may have two broods per year in some regions. This means that there can be two generations of butterflies produced each year. In these regions, the first brood typically emerges in the late spring or early summer. The second brood emerges in the late summer or early fall. The timing of the broods can vary depending on the weather, the availability of host plants, and other factors.
The caterpillars of Swallowtails are most active during the summer months, from June to August. During this time, they go through several “instars”, or stages of growth, as they feed on the leaves of host plants and prepare to form their chrysalis.
The Swallowtail caterpillar is quite distinctive in appearance. It has a green body with black and white bands or stripes. It also has several rows of yellow or orange spots along its sides. The head of the caterpillar is yellow-green with two black eye-spots. This helps to deter predators. It also has several spines along its body, which provide additional protection against birds and wasps. The caterpillar is well adapted to its environment. Its green coloration helps it to blend in with the leaves of its host plants.
The pupal stage
Once the caterpillar has reached maturity, it will form a chrysalis or pupa. This is a protective casing that allows it to undergo metamorphosis and transform into an adult butterfly. The chrysalis hangs from a branch or other structure. The butterfly emerges after about two weeks, but possibly much, much longer.
Unlike Mourning Cloaks or other common K-Country butterflies that overwinter as adults, the Canadian Tiger Swallowtail Butterfly overwinters in the pupal stage, inside its chrysalis. The chrysalis is typically attached to a branch or other structure. The adult butterfly will emerge in the spring or early summer, depending on the weather and other environmental factors.
Swallowtails are commonly found in forested areas and along riverbanks, where its host plants are found. As an adult butterfly, it feeds on the nectar of wildflowers such as asters and clover. The one pictured at the top is on a non-native Lilac. To the right is one on a Hawkweed flower. The one at the bottom is on a Western Wood Lily.
Swallowtails have several predators, including birds such as jays, robins, and chickadees. In addition, the caterpillars are sometimes parasitized by wasps and flies. They lay their eggs on the caterpillar’s body and feed on its tissues as they develop.
See some of the other butterflies of K-Country here!