Black swallowtails are laying eggs!

Those black swallowtails have been laying eggs on my fennel. I've collected about 60 eggs lately and am raising them in covered containers. The fennel is about 3 feet high and I will cut about half of it to the ground soon. There is so much of it, it's about taken over a good part of the flower garden. As a perennial, it should come with a warning label ~ "Beware! Fennel spreads rapidly!" I don't mind since it does attract so many black swallowtails. Once emerged as adults, they are very striking when released from a container all at once. I'll try to dry some of the leaves when I cut it. I will collect the seeds in the fall, also. I use the seeds to season sauces, especially tomato sauces.