Lesley Smitheringale Fine Art

Nature Can be Kind - Garden Guests Diary

After my upsetting post about the evil assassin bug killing the orchard swallowtail caterpillars in my garden I have some really good news.  I actually had not intended for this update to happen and was checking to see if we had any mail in the late afternoon.  Something made me go over and check the citrus tree where the caterpillars had been and I guess I was still upset that the two of them had vanished or been wiped out by the assassin bug.  I examined the lemon tree and saw it, hoping that maybe it was …a pupa..  I was confident that it was and the fragility and preciousness of it is amazing but I wanted to double check and did some research after taking some photographs of what I saw.

The pupa is attached head upwards to a branch by the cremaster on one end and a central silken girdle.  This is an incredible feat and the silken thread in particular is ingenious.  I have been checking on the pupa early every morning and don’t want to miss the butterfly emergence but it’s going to be tricky to be there at exactly the right time!

The pupa stage is where the butterfly makes its incredible change from the larva to the adult. Most butterflies remain in the pupa stage between one and two weeks. During this time inside its pupa, the larva is transforming its body parts into those that the adult will need for it new life as a butterfly. In place of mandibles, the proboscis will begin to form to serve the adult and its liquid diet. Wings will be formed from the thorax, and the parts of the head will undergo drastic changes in appearance.

Visible changes on the outer layer of the pupa can be noticed as the adult butterfly begins to develop within.

As mentioned previously, the larva begins to empty its stomach while in the prepupa stage. You may notice that the pupa is about half the length of the larva. This is due to the fact that about half of the larva is stomach. When the pupa forms, the larva stage is over and the parts it had are no longer necessary. An adult butterfly does not need a large stomach because it only drinks small amounts of liquid. When the pupa later forms, the organism will consume the larval stomach to create energy and carry it through the pupa stage. This is why the pupa is much shorter in appearance.

Pupae cannot fly, bite, sting or run away if discovered by a predator. They are practically helpless. Their principal means of defense is to blend in with their surroundings and remain inconspicuous. Without exception they are brown, gray or green - colors that hide very well in nature. Many of the pupae that one sees, with little or no imagination, can resemble things found in nature such as dried leaves, broken branches, fruit, and even the heads of venomous snakes.

Sourced from <http://www.butterflyfarm.co.cr/ed/guide_mod4.htm>