December mosquitoes depend on how much rain we've had and what direction the wind is blowing. Little rain and a decent breeze from the East keeps them away, lots of rain and Northwest breezes or no breeze brings them in. A little repellent on the ankles is usually good enough to keep them at bay (they love to hang out under tables.)
Pica Pica usually starts in April and goes through May into June but it did arrive a bit early this year, sometime around the 1st week of March. I haven't seen any major outbreaks yet.