Brimstone Gonepteryx rhamni
Both larvae and pupae are masters of camouflage. Quick growing, the larvae feed on Buckthorns Rhamnus catharticus or Frangula alnus. There are no substitutes, so locate some bushes in advance. We recommend sleeving the larvae on growing bushes.
Resulting pupae produce butterflies this summer. They hibernate amongst ivy (when closed, the wings resemble ivy leaf undersides). They are difficult to hibernate in captivity so, by releasing the butterflies in summer sunshine, you may help to perpetuate the species each spring in your area.