Let's not use them! Pesticides kill just as many beneficial insects as pests. If you have severe problems use Safer soap just before dark (so that bees and butterflies are not on the plants). Even dishwashing liquids like Ivory liquid or Palmolive, diluted and sprayed using a spray bottle, will kill citrus leaf miners and aphids. The surfactants in the soap suffocate them. Again, do this in the evening every two weeks.
If you have roses, and there are aphids on the buds, put on a rubber glove and gently squish them off.