I'm in the High Desert, Ridgecrest, CA.

Suddenly my zuchinni plants have some sort of brownish microscopic powdery insect on the underside and the fruit is not developing. I'm wondering if I should just pull out the plants, (I have two) and get rid of them. I tried spraying the leaves, but was afraid of it spreading to my tomatoe plants that are adjacent in neighboring raised beds.

I've never seen this before. It looks kind of like what attacks roses only it's brownish, almost like a fine sawdust.

Any help would be appreciated.

Thank you.

Nevessa