18/06/2026
Good morning Folks, we have another bright and sunny week here in Normandy. While out and about this I spotted this beauty and couldn’t resist a photo and a bit of research. This is the caterpillar for the Old-World Swallowtail butterfly (papillo machaon).
This butterfly is native to France and is particularly prevalent in the north, lucky us.
When it first hatches it resembles a bird dropping in colour, this helps protect it from predators in its early days. It then develops into the magnificent green, orange and black, it also develops a stink gland just behind the head. When threatened it protrudes as an orange fork giving off an unpleasant smell. This works to deter other insects but is not effective on birds.
The adult butterfly lays single eggs on plants in the umbelliferae family, this includes wild carrot, milk parsley, fennel and hogweed. Seen as the eggs are laid singularly, they don’t pose much threat to the plant. It takes between 10 and 30 days for the caterpillar to eat enough to become ready to become a pupa, reaching about 45mm in length.
The butterfly will normally emerge from the cocoon the same year, but if the conditions are unfavourable it can overwinter before hatching.
The adult butterfly has a 7 - 9-centimetre wingspan and will live for several weeks allowing time for the reproduction cycle to continue.
I don’t know about you folks, but I am definitely going to plant some fennel in my wild garden for these beauties.
