At this time of year, the whole area of our garden under concrete (a
terrace and paved areas) are swarming with what I believe are
Phytoseiulus persimilis, best known as the predator for red spider
mite.

The only references for this species I can find through Google are to
its use to control red spider mite. As far as I know we have no red
spider mite. The infestations have happened every summer since the
house was built in 1998.

While they seem to be harmless, nobody wants to sit out on our terrace
because of this 'red carpet'.

What do you recommend to control/eliminate this pest. And where can I
find out something about their habitat, breeding, etc?

Ian