In 2020, the Woodland Trust commissioned a review of the flower-visiting insects associated with old trees and dead wood, and here Steven Falk and Emma Gilmartin provide an overview of the key insect groups that fall into this category, highlighting some of the rarest and most spectacular species found in Britain.
Pollinating insects and saproxylic insects, two large ecological assemblages, are the subject of considerable conservation concern on account of demonstrable species decline and loss within each category. There could be as many as 6,000 species of flower-visiting insect in Britain (Falk, unpublished data) and the number of saproxylic insect species is at least 2,000 (based on Alexander 2002, adjusted for additional species).