- Author: Kathy Keatley Garvey
It's a bird! It's a plane! Is it Superman?
No, it's a bird dropping.
If you're growing sweet fennel (anise), you may have noticed what appear to be two species of swallowtail butterflies populating your plant.
You'll see larvae (caterpillars) that are pale green with black bands containing orange spots. But look more closely and you'll see the smaller larvae or early instars. They look like bird droppings. A gift from above?
Those are both the immature stages of the anise swallowtail, Papillo zelicaon, (Check out the beautiful images of the butterfly and its immature stages on the Natural History of Orange County website.)
Butterfly guru Art Shapiro, UC Davis distinguished professor of evolution and ecology, says the anise swallowtails have several generations (late February or March-October) "and breed very largely on sweet fennel (anise), Foeniculum vulgare and in the first half of the season, poison Hemlock (Conium maculatum)."
These are naturalized European weeds, he says on his website. "We believe this ecotype originally lived in the tule marshes and bred on water hemlock (Cicuta) and another Apiaceous plant named Oenanthe. These are still used but only rarely in comparison ot he weeds; they are the only native hosts available in the Mediterranean summer that could have sustained repeated breeding."
Colors of the iconic anise swallowtail caterpillars also differ. "In hot, dry sites there is more green and less black, while under cool, humid conditions, the green may even disappear!" Shapiro says. And the pupae (chrysalids) may be brown or green.
Meanwhile, our caterpillars are feasting on the fennel and shedding their protective, camouflaged "bird dropping" skin. The California scrubjays that dine on the Gulf Fritillary caterpillars on the nearby passionflower vine (Passilfora) don't seem to notice.
Here's hoping they won't touch the anise swallowtails. Why would they want to eat something that looks like bird poo?
- Author: Kathy Keatley Garvey
Something was wrong.
The Anise Swallowtail (Papillo zelicaon) that fluttered into our bee garden last weekend and began nectaring on zinnia wasn't quite herself.
Her yellow and black coloring and the striking blue spot on the rear left wing looked fine. But the blue spot was MIA on the rear right wing. In fact, a huge chunk of that wing was MIA.
Its missing parts told part of the story: It had managed to escape a predator, probably a bird, praying mantis or spider.
"Good thing she survived," said butterfly expert Art Shapiro, distinguished professor of evolution and ecology at the University of California, Davis who monitors the butterflies of Central California. "It's a gravid female." (Distended with or full of eggs.)
"They have several generations (late February or March-October)," he writes on his website, Art's Butterfly World. The Anise Swallowtails breed largely on fennel or anise (Foeniculum vulgare) and poison hemlock (Conium maculatum). Both, he says, are naturalized European weeds.
The butterfly's usual range, according Wikipedia, "extends from British Columbia and North Dakota at its northern extreme, south to the Baja California peninsula and other parts of Mexico. It is occasionally reported from the southeastern United States, but its normal range does not extend east of New Mexico. In all the more northerly parts of the range, the chrysalis hibernates."
The Anise Swallowtail is commonly found in fairly open country, Wikipedia says, and "is most likely to be seen" on bare hills or mountains, in fields or along roadsides. "It is often seen in towns, in gardens or vacant lots."
We've seen P. zelicaon on plants from A to Z: anise along roadsides and zinnias in our garden.
Zelicaon on a zinnia...