I am sorry for the kind swallows and martins, but I find this flea particularly sympathetic, for unknown reasons…
It is very common on the house martin (Delichon urbica), but can also be found on barn swallow (Hirundo rustica), on sand martin (Riparia riparia), Columba livia, Passer domesticus, Gallus domesticus, Ptyonoprogne rupestris and even… Homo sapiens !
It can be found in very different types of habitats, except strangely, in Great Britain, where the flea seems nearly only found in nests under eaves, according to Professor Beaucournu. If you find counter examples, please let us know !
The types of the species are probably lost, taking into account that it was first described by Curtis in 1826.
Big thank again to Paul Leroy for the great mount and photos !