Anise Swallowtail (Papilio zelicaon) is a large butterfly, with a wingspan of 2.75 to 3.5 inches. It can be seen from March to September. Numbers peak in July. It can be widely found all over East Bay, since one of its host plants is Fennel (Foeniculum vulgare), which grows here, there and everywhere.
Eggs are laid singly, on stems, leaves, or flowers. Caterpillars molt four times; it is the fifth instar that pupates. The early caterpillar instars tend to resemble bird droppings. That is a defense mechanism. The appearance changes considerably as they grow. The chrysalis can be brown or green.
It is found only in the western half of North America, from British Columbia to Alberta in the north and down to Baja California to New Mexico.
