Powdery Mildew or Insect?

[ferice]

I live in zone 10a, and it had been pretty hot lately. I transferred my butternut squash a couple weeks ago. I noticed the lower leves have some spots on them (see pics). Is this the beginning of powdery mildew, or is it the resut of some kind of insect?

 

[Tjohn]

Looks more like water damage...wet leaves being hit by strong sun.

 

[ferice]

We did get some rain here, and it has been extremely hot too. It's a possibility.