Pests

Aphid (Greenfly) Small, sap-sucking insects, usually green but may be black, gray, or orange. All plants with soft tissues can be attacked; shoot tips and flower buds are the preferred site. Flowering pot plants are especially susceptible. The plant is weakened and sticky honeydew is deposited. Spray with permethrin -- alternatively use malathion or derris. Repeat as necessary.		Caterpillar Caterpillars of many types can infest the plants in a conservatory, but these pests are rarely found on specimens in the living room. The tell-tale sign is the presence of holes in the leaves; some species of caterpillar spin leaves together with silken threads. Pick off and destroy individual caterpillars -- spraying with fenitrothion or derris is usually not necessary.
Cyclamen Mite Minute mites, looking like a film of dust on the underside of leaves. Cyclamen, impatiens, Petargonium and Saintpaulia are susceptible. The infested plant is stunted; leaf edges are curled, stems are twisted, flower buds wither. Unlike red spider mite, this pest will flourish in humid conditions. Spraying with standard insecticides is not effective -- destroy infested leaves.		Earwig A familiar garden and household pest with a dark brown body and pincer-like tail, it is rarely if ever seen on house plants as it hides during the day, feeding at night on leaves and flower petals. Ragged holes are produced and leaves may be skeletonized. Pick off the insects -- look under the leaves and shake the flowers. Spraying with malathion is rarely necessary.
Eelworm Fortunately these microscopic, soil-living worms are not common house plant pests. If a plant collapses for no apparent reason, remove it from its pot -- large, corky swellings on the roots are a sure sign of root knot eelworm attack. Destroy the plant immediately -- do not put it on the compost heap. In future use sterilized compost and buy plants from a reputable supplier.		Fungus Gnat The small, black, adult insects which fly around the plant are harmless, but they lay eggs on the compost and the tiny, black-headed maggots they produce can be harmful. The maggots normally feed on organic matter in the compost but they will occasionally devour young roots. Fungus gnats can be troublesome in over-damp conditions. Water with malathion solution.
Mealy Bug These are small pests covered with white, cottony fluff. Large clusters can occur on the stems and under the leaves of a wide variety of plants. A serious attack leads to wilting, yellowing, and leaf fall. A light infestation is easily dealt with -- wipe off with a damp cloth or a babycare cotton bud. A severe infestation is difficult to control -- spray weekly with malathion or systemic insecticide.		Red Spider Mite Minute, sap-sucking pests which can infest the underside of leaves of nearly all house plants growing in hot and dry conditions. The upper surface becomes speckled with yellow blotches and the leaves fall prematurely; white webbing is sometimes produced between the leaves and stems. Daily misting will help to prevent attacks; spray with derris, malathion or systemic insecticide as soon as the first signs are seen. Repeat as necessary.
Scale Small, brown discs attached to the underside of leaves, especially along the veins. These immobile adults are protected from sprays by the outer waxy shells, but they can be wiped off with a damp cloth or a babycare cotton bud. After removal spray the whole plant with malathion. If a plant is allowed to become badly infested the leaves turn yellow and sticky with honeydew, eradication is difficult or impossible at this stage.		Thrips These tiny, black insects are a minor pest of house plants, but Begonia, Dodiaeum and Fuchsia are sometimes disfigured. They fly or jump from leaf to leaf, causing tell-tale silvery streaks, but the worst damage is to flowers which are spotted and distorted. Growth is stunted. Control is not difficult -- spray with permethrin, malathion, or derris at the first sign of attack and repeat as necessary.
Vine Weevil The adult beetles attack leaves, but it is the 1 inch creamy grubs which do the real damage. They live in the compost and rapidly devour roots, bulbs, and tubers. Control is difficult or impossible -- the root system will have been seriously damaged by the time the plant has started to wilt. Water immediately with lindane. Use it as a precautionary measure if beetles are noticed on Cyclamen or Primula leaves.		Whitefly Tiny, white moth-like insects which can be troublesome, especially to Begonia, Fuchsia, Impatiens, and Pelargonium. The adult flies are unsightly; the greenish larvae on the underside of the leaves suck sap and deposit sticky honeydew. Badly infested leaves turn yellow and drop. Whitefly can occur in great numbers and rapidly spread from plant to plant. Eradication is difficult -- spray with permethrin and repeat at 3-day intervals.