Our insect of the week for June 22, 2026 is the Black Swallowtail, Papilio polyxenes. It was described by Fabricius in 1775. He was a Danish zoologist and a student of Carl Linnaeus. Many consider Fabricius one of the most important entomologists of the 18th century. He named roughly 10,000 species of animals. Fun fact, almost all butterflies originally described in the late 1700’s were placed in the genus Papilio. Some swallowtails remain classified in that genus to this day.

This butterfly is found throughout much of North America (east of the Rocky Mountains) and ranges to South America. Caterpillars often feed on plants within the carrot family and will eat a variety of plants. They sequester toxins from these plants to defend themselves against predation. The caterpillar also has an orange forked gland they extrude (called an osmeterium) to deter predators. It resembles the tongue of a snake and releases a foul odor.

Adults display sexual dimorphism (as you can see from these photos). Specimens were collected and photographed by Frank Hitchell in Peoria County, Illinois.

Male

Female