That is natural coloring being expressed by K and night time temp drops of over 10deg......15deg swings and it will do it faster!
NOT a mold or fungus...
Your outdoors. That bug action is normal......Hard to control without major (not recommended!) chemical warfare.....As you can see it's not a major problem - ignore or spray lightly with neem once a week if it "bugs" you..Stop neem at week 6.
Doc