Sorry I can't be more helpful than that, but at least that's one species ruled out. I've been captive-rearing H. axyridis this summer, and they look different at egg hatch, solid black without the hint of orange pattern than yours have. They're also a more compact shape with shorter abdomens and legs - that's probably not scientific, but I've looked at so many that I have a feel for them.

Congratulations on *not* having that particular introduced species, anyway...