White powder on zucchini and yellow squash leaves?
I seem to have some sort of fungus or pest leaving white powder on my zucchini leaves. The powder started on one large leaf, and within a week had appeared on most of the leaves. After browsing the forum I initially thought it was mealy bugs, but the powder is more widespread and I haven't seen any insects that resemble mealies.
The fruit seems unaffected - I've had a great yield so far.
Now the powder seems to be spreading to my other (yellow crookneck) squash plant, but isn't affecting the tomatoes or herbs that are growing in close proximity.
These are growing in a hydroponic garden, if that makes a difference.
Bonus points if you can identify and help me treat the little worm trails visible on some of the leaves, as seen in the photo.