Swallowtail (Papilio Machaon, Swedish subspieces)
When you start with butterfly breeding it can be good to start when the butterfly is in stage pupae. The pupae can safely be sent in a package the full winter and main part of the spring without risk to damage the butterfly in the pupa. You will also be able to start the full range of breeding activities since you immediately after the butterfly has emerged from the pupa have to arrange for feeding (nectar flowers and supporting hand feeding), pairing (by hand is safest) and egg laying. In addition, you get the opportunity to see the fully developed butterfly in full beauty already the first summer you start your breeding.
Also eggs can be sent by post during a limited period during end May to June (and possibly also a second brood during July to August). If you buy eggs, you get the pleasure to see the larvae hatch, grow and finally go into pupa stage for hibernation for the winter.
I the Butterfly breeding gude your learn the basics to butterfly breeding directly on this homepage. Normally it takes one to two years before one is successful with all steps. The part that take most time to learn is the hand pairing. Egg laying and rearing of the larvae is relatively easy if you only allow sufficient time hand make sure you have enough of host plant for the number of larvae you plan to breed. Consider here that a female can lay up to 200 eggs. To this, a big amount of host plants are required. One can however chose to use 10-20 eggs for breeding and place the rest in the nature in places with plenty of food plants. One can also put the surplus larvae in the garden providing one has robust fennel, dill or parsley plants or any of the wild food plants grown there (Garden Angelica thrives very well in flower beds). Maybe the best way after all is to release the butterfly when it has laid the eggs one wants to breed.