We have been alerted to the presence of 4 of these caterpillars on Bronze Fennel in a garden in a Wiltshire village very close to the Dorset border.

These are Swallowtail caterpillars and the owner of the garden where they were seen has no idea how they got there. The Fennel has been growing in the garden for many years rather than having been brought in as a new plant with eggs already in situ.

In the UK the resident subspecies, britannicus is restricted to an area in the Norfolk Broads but migrants from continental Europe have occasionally been recorded in other areas of the country.

Swallowtail Caterpillar

The foodplant of the UK subspecies, britannicus is Milk Parsley whereas the continental Swallowtails feed on umbellifers other than milk parsley.

The caterpillars have now been re-located to another more suitable site in Dorset where there is also Bronze Fennel where they can be well looked after and then hopefully turn into pupae and next spring emerge as adults.