Fit Of The Vapours

I'm confused. This looks like a vapourer moth caterpillar to me but this member of the tussock moth family is usually larger and has four creamy yellow tussocks on its back, not two like this one.

And why vapourer? Maybe it is because the female moth, who has only vestigial wings and can't fly or feed, emits a powerful pheromone that attracts males, with their huge antennae, to come and mate with her?

I got a lovely pink droplet grasshopper and beautiful female speckled bush cricket this afternoon but I have posted both of those before.