Could be as early as next week. Areas with more mature trees & plantings are more likely to be inundated by these periodic pishers.
The upside:
The culprit:

[actual size, for fuck's sake ]
DEAR GOD THE NOISE MAKE IT STOP, THE PHASER SOUND, IT HURTS MY EARS
[click to be deafened]
The upside:
- Don't bite
- Don't carry disease
- Don't seriously harm trees or perennials
- Great supplementary pet food
- Awesome garden mulch
- Halfway decent lawn aerators
- Will eat the snot out of your hostas
- May damage very young trees
- Totally squicktacular: heavily wooded areas can get more than a million per acre
- OH GOD THE NOISE MAKE IT STOP MAKE IT STOP
- They'll be with us until late June
- Their empty shells will remain on your exterior walls until you hose/scrub them off
The culprit:

[actual size, for fuck's sake ]
DEAR GOD THE NOISE MAKE IT STOP, THE PHASER SOUND, IT HURTS MY EARS
[click to be deafened]