The Swallowtail Papilio machaon britannicus is the UK's largest butterfly and one of our rarest, confined to the fenlands of the Norfolk Broads.

These pages are in homage of this very attractive butterfly and serve as a pictorial article on this species' life-cycle along with some observations made at Hickling in 2011.

Eggs (1) Eggs (2) Swallowtail butterfly (12) Larvae (2) Swallowtail butterfly (4) Larvae 2-3 instar (3) Larvae 2-3 instar (4) Larvae 2-3 instar (5) Larvae 2-3 instar (2) Larvae 2-3 instar (1) Swallowtail butterfly (11) Larvae 2-3 instars (4) Larvae 2-3 instars (3) 2

Egg-laying on Milk Parsley

Newly-laid egg

Egg darkens with age

1st instar larvae to final instar (4 instars (shedding of skin) in total).....

Larvae (3) Larvae (1) Larvae (4) Larvae (5) Larvae (6) Larvae assuming position

Shedding skin

Assuming the position

to pupate on reed stem

Final instar


Left and centre:  Diseased final instar showing osmeterium (orange projections)-produced when alarmed or in distress.  Larvae eventually died.

Papilio machaon britannicus

Swallowtail Butterfly