While Monarchs have been rare this summer, there have been lots of Black Swallowtails around laying eggs in St. Louis. I have personally raised or given away about thirty caterpillars to schools.
Luckily Black Swallowtails have a wide palette of host plants. These include, bronze fennel (their favorite this year), rue (also good for Giant Swallowtails), Golden Alexander – Zizia aptera, dill. fennel, Parsley, and Queen Anne’s lace. If you see a caterpillar on any of these plants, there’s a good chance it’s a Black Swallowtail.
Butterfly Gardening 
Hi Tom,
This is the first time i have ever responded to a blog! I saw only my second Monarch of the year last Thursday at the prairie. In my experience, and I do not quite know why, Black Swallowtails are pretty scarce. I had 2 this year and think it has been years since I have seen one. Not sure why they are so scarce. Interesting site below about them that I have yet to read.
thttp://www.butterfliesofmassachusetts.net/black-swallowtail.htm
Thanks again for helping me out the other evening with the laptop!
Mark
Good 4 you. Haven’t had any probs attracting Nonarchs here in Mandeville, La (just north of New Orelans). I did plant about 8 parsley plants and a few fennel via seeds with hope of attracting the Swallows, but none materialized. ALso planted a spice bush I ordered but it died. Will keep trying.
Tony
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