Ticks & Flies

I have only recently discovered Ventana (or more correctly, Silver Peak) having completed a couple backpacking trips so far this year - third is planned for this weekend. I have become an avid follower of this forum and really enjoy the input from those who obviously have a great deal of experience in these woods.
I am sure that weather plays a large role, but at what time of year do the ticks and flies go from mearly annoying to downright unbearable? Unbearable to me is having to wear a head net all day.
The trips in January and February were insect-free, save for a single tick bite.
Feedback as always is much appreciated.
Pablo