Note to self: just because it has been cold and miserable outside does not mean it has been cold and miserable enough to get rid of the bugs. Try to plant bulbs or otherwise dig in the dirt, apparently, and they will come out in force.
My miscalculation on this front, however, does tell me that the patio is excellently performing the function I originally had in mind for it, i.e. creating a space to sit and look around without stirring up the ravening swarm.
Anyway. Time to deploy the mosquito hat, even if it looks dorky.