Cimbex connatus
A very large (3 cm body length) sawfly, vaguely resembling a hornet but fatter bodied.

Around alder species, sometimes Italian Alder planted in city centres and supermarket car parks.
Mid to late summer.
The larvae feed on various alder species. When fully grown, they are about 50 mm long and have a dark dorsal stripe all the way along the body. They generally feed between July and September, but may still be found as late as October.
Once thought extinct in Britain it was re-discovered in Wiltshire in the 1990's and has since spread through southern England and up the east coast as far as Yorkshire.
We think this record from central Leicester may be only the third record for Leicestershire and Rutland (VC55).
Leicestershire & Rutland Map
Enter a town or village to see local records
MAP KEY:
Yellow squares = NBN records (all known data)
Coloured circles = NatureSpot records: 2020+ | 2015-2019 | pre-2015