This is a difficult species to survey as it spends most of its time up in the canopy of elms. Therefore, it is often thought to be under recorded. However, Jenyns’ notes show that it was found from at least a couple locations across the county. The larvae of the white-letter hairstreak feed on elms and with the loss of millions of elms due to Dutch elm disease this butterfly has suffered a corresponding decline. Despite this, it is quite widely distributed and can be found where resistant elms have managed to persist. This includes hedgerows and narrow woodland strips comprising good-sized trees and the white-letter hairstreak probably exists in the wider landscape of southern Cambridgeshire but is not regularly observed. 2018 was a bumper year for the species and it was recorded from many hedgerows in the landscape in significant numbers, as well as in many woods.