The caterpillar/s was an early stage in the formation of the Eastern Black Swallowtail butterfly, an important pollinator. Plants in the carrot family—including parsley, dill, fennel, and Queen Anne's Lace (in the wild) as well as carrots—are its desirable host, and it eats only these, which contain furanocoumarins (chemicals in the seed coat). Some sources say that "infestations" of the larva are uncommon.
You could plant one or more of the hosts as an alternate lure. Or plant more parsley so as to have enough later. Or try row/plant cover, to keep the plants from becoming hosts.
We hope this helps.
The caterpillar/s was an early stage in the formation of the Eastern Black Swallowtail butterfly, an important pollinator. Plants in the carrot family—including parsley, dill, fennel, and Queen Anne's Lace (in the wild) as well as carrots—are its desirable host, and it eats only these, which contain furanocoumarins (chemicals in the seed coat). Some sources say that "infestations" of the larva are uncommon.
You could plant one or more of the hosts as an alternate lure. Or plant more parsley so as to have enough later. Or try row/plant cover, to keep the plants from becoming hosts.
We hope this helps.