Scale Insects: Pest Control | Identify & Treat

Whiteflies (family Aleyrodidae) are tiny, sap-sucking insects that thrive in warm, still air. They are common on houseplants, greenhouse crops, and garden plants such as tomatoes, peppers, cucumbers, fuchsias, hibiscus, poinsettias, citrus, and many herbs. You’ll often see small white adults flutter up when you touch the plant, sticky honeydew on leaves or nearby surfaces, black sooty mould growing on that honeydew, and leaves that yellow, curl, or drop. Check the undersides of leaves for pale, scale-like nymphs and tiny eggs laid in small arcs. Heavy infestations weaken plants and slow growth.

Phyllaphis is a genus of woolly aphids that primarily attack beech (Fagus), typically common beech and copper beech in hedges and as trees. They suck plant sap from young shoots and the undersides of leaves in spring and early summer. Signs of infestation include curled or rolled leaves, sticky honeydew, black sooty mold, and a white, cottony coating around the colonies. The plants usually survive, but heavy infestations can weaken new growth and make the hedge sticky and unsightly. The aphids often overwinter as eggs on thin twigs near buds.

Flea beetles are small, jumping insects that feed on the leaves of many vegetable crops. They chew numerous small, circular holes, creating a characteristic 'shothole' appearance. While established plants can often tolerate the damage, young seedlings are highly susceptible and can be stunted or killed if the infestation is severe.

Prociphilus is a genus of woolly aphids that feed by sucking sap from plants. They produce a fluffy, white, cotton-like coating on leaves, shoots, or sometimes roots. Signs include sticky honeydew, black sooty mold growing on the honeydew, leaf curling or distortion, and clusters of tiny, soft-bodied insects hidden in the "wool." Ants are often active around them because they feed on the honeydew. These aphids commonly affect alder and maple (woolly alder aphid) and ash (woolly ash aphid). They rarely kill established trees, but they can stress young plants and create a messy, sticky problem.