Only a small percentage of them are harmful to mankind. Integrated pest management, or IPM, uses a variety of low-toxicity methods to control unwanted insects. One of them is the use of beneficial insects to thwart harmful ones. Predatory mites are safe to use, and once their job is done, they'll die.
Scale insects look like tiny beige bumps or turtles without legs.
Use parasitic wasps to effectively control scale insects. Lady beetles, or ladybugs, are the aphid's natural enemy. If lady beetles don't find enough aphids on a plant, they won't lay eggs there. Ladybug larvae are even more voracious consumers of aphids than the adult beetles. Because more insects are helpful than harmful, it's wise to make sure you can identify an insect as a pest before you destroy it.