Termites come from the ground.....
....but that doesn't mean that the damage is manifested at the bottom,
The little beasties usually keep tunnelling as far up as they can go. They often go straight up wall cavities to those yummie pine trusses and then build a bit of a hang-out for themselves to use as a base while they get into the rest of the place, starting with the tastiest timbers.....in really bad infestations it is possible to hear them munching away at night......quite fascinating if the house doesn't belong to you....
My pergola posts (100x100 oregon) went decidedly spiral about 600 above the ground, when the paint decided it wasn't strong enough to hold up the structure above, but by the time the damage was evident, they had well and truly got stuck into the beams as well. The bottoms were completely intact, the only sign of entry was a small mud tunnel built into the corner of the steel stirrups.
Be afraid.....
P
Vergolas are termite proof
...but there is a (quite large) cost!
Probably about exactly more dollars per square metre of any form of roofing, but they are a lot easier than draping a tarp over the pergola on the rainy days.
P