Black Swallowtail (Papilio polyxenes)

      For several years we have raised butterflies indoors, generally of three species, Black Swallowtail (Papilio polyxenes), Giant Swallowtail (P. cresphontes) and Monarch (Danaus plexippus).

     We have done this for several reasons, first among them to educate ourselves and have the experience of watching this amazing metamorphosis from tiny egg to giant butterfly, with all its intermediate stages. A second, equally important reason (arguably even more important) has been to expose children to this wonder of nature and increase their knowledge of the other beautiful and interesting creatures with whom they share their lives. Thirdly, knowing that very few caterpillars survive to become a butterfly (some estimates are as low as one percent), it didn't seem unreasonable to give a few of them a helping hand, despite going against a fundamental commitment not to interfere with the process of nature. When we see caterpillars being paralyzed by wasps to be stashed as food for their larvae we find it hard not to rescue at least a couple of them. We are not unfeeling automatons and if we are guilty of a momentary anthropomorphic reaction we can live with the stain on our record!

16 July, 2002

     A total of six caterpillars were feeding on Common Rue (Ruta graveolens) from our garden, permitting us to watch their transition from one instar to the next.

     Miriam is remarkably conscientious about taking photographs, with the result that we have a far better record than we would have if it were left to me.

     Pupation has already occurred for this individual and you can see very clearly how the chrysalis is anchored by the silk "harness" produced by the caterpillar.

     Camouflage is an important consideration since the risk of predation is still present, and when attached to a green substrate the chrysalis is cryptically coloured.

     A second caterpillar had assumed the "lazy J" position and was just beginning to exude the silk necessary for it to complete the transition to a chrysalis.

     I am sure you will agree that these caterpillars are very handsome creatures.

     A couple of chrysalises were attached to a twig we had put into the cage, and you will note that they are accordingly camouflaged brown.

     The picture below is a very pleasing closeup enabling you to see the way the caterpillars navigate the stalks, gripping the stem with their feet to gain access to the leaves on which they feed.

     Radical chemical changes are occurring within the chrysalis; who could even guess that a butterfly with a wingspan up to 8.4 cm will emerge within mere days?

     But it will!

24 July, 2022

     It is astounding how quickly the butterflies wiggle free of the chrysalis (a process called eclosion, driven by hormones). You can check and find nothing is happening, only to look twenty minutes later to find a butterfly hanging there, drying out and inflating its wings.

     The now empty chrysalis is at the left of the butterfly.

     It does not take long for the butterfly to start to flex its wings and take exploratory walks around the cage.

     Many species of butterfly are sexually dimorphic and we know that this individual is a female by the frosty blue wash on the hindwings and the reduced amount of yellow on the forewings.

     One down and five to go. What a privilege it is to observe this wonder of nature. It's a thrill every time.