Integrated Pest Management · Agriculture and Natural Resources
University of California
Aphids, scales, thrips
These are all small, soft-bodied insects that feed by sucking plant sap. Damage may include leaf stippling, leaf bleaching, leaf curling and distortion, whitish waxy growth, or sticky honeydew (condensed sap) which may support the growth of sooty mold. Although most of these insects are related, thrips are classified in a different group.
Adults of these tiny pests often lack wings. Aphids can produce copious amounts of sticky honeydew, which can lead to the growth of black sooty mold.
These insects feed by sucking plant juices and may leave drops of sticky excrement. Damage includes stippled, bleached or brownish leaves.
Mealybugs often have waxy filaments radiating from their bodies. They are wingless, move slowly, and congregate in groups covered with whitish mealy or cottony wax.
Psyllids and whiteflies suck plant sap and excrete sticky honeydew. As adults, psyllids resemble miniature cicadas; whiteflies look like tiny flies with whitish wings.
Scales are immobile, wingless, and lack a separate head or other recognizable body parts, so many people don’t recognize them as insects.
Thrips are tiny, slender insects, with fringed wings and piercing mouth parts. They often leave tiny black dots of waste on leaves.