08/20/2026
This tiny Anise Swallowtail caterpillar (Papilio zelicaon) is only around 2nd instar, happily hanging out on fennel… but that little cocoon beside it tells a much darker story. 👀
Most likely, a parasitoid wasp or fly laid an egg in or on the caterpillar. The developing parasitoid used the caterpillar as its food source, eventually emerging and spinning that cocoon nearby. 🐛➡️🪰
Yep. Nature invented Alien long before Hollywood did. 😂
And while it’s brutal to watch, parasitoids are an important part of the ecosystem.
They naturally regulate insect populations and become food for other wildlife.
Raising butterflies really teaches you that a host plant isn’t just a nursery—it’s an entire miniature food web.
Generational reactions:
👴 Boomers: “Leave it alone. That’s nature.”
😎 Gen X: “We survived lawn darts. The caterpillar can handle this.”
😂 Millennials: “I was emotionally invested in this caterpillar for 12 seconds and now I need therapy.”
💀 Gen Z: “Bro got parasitized before his first molt. 💀”
Meanwhile, me staring at the fennel: I came here to raise butterflies, not film a National Geographic crime documentary. 😂
🌿 Host plant: Fennel
🦋 Butterfly: Anise Swallowtail
🐛 Stage: ~2nd instar
⚠️ Suspected culprit: parasitoid wasp or fly