I agree with zandor....that doesn't look like bugs to me..more likely you are watering with the wrong PH level and it's causing whatever magnesium you have in your nute regimine to be locked out..Check your ph and look At your nutes to be sure they have enough magnesium..a couple spoonfuls of epsom salt in 20 liters of water works well...
The bug spray recipe is a good one..I simply grind plain bar soap up with a cheese grater and mix it 1-40 with water...
Here's a link to deficiencies----> Click here!
And remember..never spray your plants with the lights on...