Black Swallowtail butterfly is common in Wisconsin.
The butterfly commonly feeds on many different members of the parsley family, including parsley, carrots, dill, and parsnip. It may also feed on Common Meadow Rue.
Feeding on members of the parsley family could make this butterfly a pest for avid herb raisers if you would see heavy butterfly travel. Although, they are not normally an issue.
The best time to look for them is from June 1 – August 1. Higher numbers are always seen during July.