Black Swallowtail Caterpillar

Natural Habitat

Gardens, meadows, fields, and open woodlands where host plants (Apiaceae family) are present. They are commonly found in North and South America.

Diet & Feeding

The caterpillars are herbivorous, feeding on plants in the Apiaceae (umbellifer) family, including dill, parsley, fennel, carrots, and Queen Anne's Lace. Adult butterflies feed on nectar from various flowers.

Behavior Patterns

The caterpillars are typically solitary feeders. When disturbed, they can evert an orange, Y-shaped organ called an osmeterium from behind their head, which releases a foul-smelling substance to deter predators. They undergo complete metamorphosis, forming a chrysalis before emerging as a Black Swallowtail butterfly. The adult butterflies are active during the day.

Risks & Benefits

Potential risks to gardeners include defoliation of host plants, especially dill and parsley in vegetable gardens. However, they are beneficial as pollinators in their adult stage. The caterpillars themselves are harmless to humans, and their presence indicates a healthy ecosystem. The adult butterflies are aesthetically pleasing and contribute to the beauty of natural environments.

Identified on: 9/24/2025