Larvae feeding on Fennel. Note that they feed exlusively on the flowers and stems of the seed heads, and were never
observed feeding on any other part of the plant during this project.
The host plant is easily kept fresh by keeping the cut stalks in a bucket of water as shown. It should last at least 7
days this way. There is about 4 inches of water at the bottom, and it was not changed. More water was added as it evaporated.
The cut seed heads are placed in a plastic vitamin jar filled with water. The jar was placed in a larger plastic
container (to catch frass and plant debris) which was then placed in a rearing cage (hamper) and hung from a hook
indoors. The larvae never ventured from the stalk clippings, except when finished feeding and ready to pupate.
In spite of the bold colorful pattern, the larvae blend very well with the host plant and can be very difficult to spot.
In the second picture, there are three larvae and one pupae. See them?
When finished feeding, the larvae begin to wander around, even leaving the host plant entirely, looking for a suitable
place to pupate. At that point, the larvae were placed in a brown paper bag, folded shut at the top. They found a
suitable spot on a crease and happily spun-up. The pupa shown below was found already attached to a host plant stalk, so the bag was not necessary.
The pupae can vary from green and yellow (as shown) to a light brown/tan with darker markings. The mechanism for
determining coloration was not obvious. Lighting, surrounding vegatation, and temperature may all play a role. The pupae
may also change color gradually as the season progresses and the host plant dries-out and turns brown, although this has not yet been observed in this project.