Solitary wasp species

[A McLee]

Help please. In Kirklevington is a large dead elm stump with rotten areas in which many wasps excavate horizontal tunnels each year. The wasps are 1/2 the size of the usual wasp with black and yellow body stripes as standard and the thorax is black. I D please

[DaveOB]

These sound like Sphecid wasps, probably of the genus Ectemnius. There are a number of similar species - I've found 3 in our region. They all nest in dead timber, and stock the nests with paralysed flies which provide food for the developing larvae.
Your find highlights the importance of dead wood as a habitat, which sometimes isn't recognised by people who should know better. Many years ago I found a colony of these wasps in a fallen tree limb at Brewsdale nature reserve near Hilton. When I went back a few days later, a Wildlife Trust work party had "tidied" it up, and the wasp colony ended up on the bonfire! This also demonstrates why it is better to share wildlife records!

Dave

[A McLee]

Thanks, Dave.