Brown Soft Scale Coccus hesperidum
This species apparently occurs on a variety of plants but these were found on Ivy following a tip-off from Rob Yaxley and Keith Kerr who found several on Ivy at Litcham and Brisley the previous day.
Reference material for identification of scale insects seems to be pretty hard to find (especially to species level) so I am assuming this is the correct identification. It's a very common species, they look like other individuals reported to be this species and Ivy is listed as one of its hosts (and photos of other species I've seen reported as being on Ivy don't look similar).
Update: oK, I'm not sure I've got these right. It seems that Viburnum Cushion Scale Lichtensia viburni is also very common on Ivy (as well as Viburnum) and looks very much like these - especially the greener ones. I'm now thinking that this may be the correct ID for some, if not all, of the insects shown on this page. If anyone can clarify I would love to hear from you!
3x Coccus hesperidum (?), St Mary's churchyard, North Elmham (Norfolk, UK), 28th February 2022
Coccus hesperidum (?) (including views under microscope from above and below), North Elmham Cathedral Meadows (Norfolk, UK), 28th February 2022
2 different Coccus hesperidum (?), North Elmham Cathedral Meadows (Norfolk, UK), 28th February 2022
Coccus hesperidum (?) (including views under microscope from above and below), County School Station, North Elmham (Norfolk, UK), 28th February 2022