Hornet Moth Sesia apiformis
Wingspan 33-48 mm.
Rather similar to the Lunar Hornet Moth, this species can easily be distinguished by the yellow head and tegulae.
It has a more southerly distribution than that species, rarely being encountered north of the Midlands.
The larvae burrow into the wood of black poplar (Populus nigra), and other species of poplar. The moths emerge in June and July, and can be found low down on the trunks in early to mid morning.