Researchers will attempt to rear swallowtail butterflies from eggs that have been cryopreserved in nitrogen at -196°C, in a test to see if freezing techniques could aid the preservation of Britain’s largest native species.
As part of an innovative initiative, experts will preserve embryos of captive-bred Papilio machaon gorganus in nitrogen at ultra-low temperatures and then strive to rear adults from the thawed eggs, comparing their success with individuals reared from eggs that have remained unfrozen.
Should this approach work, it could result in genetic material of the British swallowtail being stored to support long-term conservation strategies, such as captive breeding and reintroduction projects.
Conservation Challenges for the British Swallowtail
Papilio machaon britannicus is a distinct variant but its range is declining and it is vulnerable to extinction, confined to low-lying parts of the East Anglian wetlands expected to be overwhelmed by rising seas over the coming decades. In 2024, it experienced its most challenging season since record-keeping started.
Collaborative Efforts in Cryopreservation Research
Cryopreservation for butterflies is being tested by researchers from a university in partnership with a conservation center and a charity focused on biobanking for wildlife.
“Our project will combine outdoor studies and laboratory work to see if we can develop a effective technique for preserving the native butterfly's DNA by using its closely related, but more common, European cousin. Cryopreservation is a valuable method for supporting preservation work, but we believe this is the first time it has been tried with butterflies.”
A wildlife park founder stated: “Dedication to the science of entomology, and especially protecting butterflies, means this project is a natural fit for us. Working together with research institutions and non-profits allows us to utilize our expertise to projects that could make a real difference in protecting the British swallowtail for future generations.”
“This project holds significant importance for the advancement of cryopreservation techniques – not only for the British swallowtail, but across bees and butterflies and invertebrates as a whole.”
Looking Ahead
Should it work, this technique could pave the way for broader use in preserving other endangered species and strengthening global biodiversity.
