Pests of Indoor Plants

Pest

Typical Damage

Control Measures

Aphids

Green (red/orange, black/grey) insects sucking plant juices. Cause small, distorted, weak growth and leave sticky, clear residue. Plant shoot tips and flower buds most susceptible.

Wash whole plant several times. Apply insecticidal soap as recommended. Spray with insecticide containing Pyrethrum or Malathion.* Systemic powder, granules or spray at recommended rates maintain control.

Fungus Gnat

Harmless tiny black flying insects. Distructive white larvae come to soil surface, feed on nutrients in soil and (occasionally) young roots Avoid over damp conditions.

Water soil with dilute (not spray strength) solution of Pyrethrum or Malathion.*

Leaf Miners

Irregular yellow, cream or brown channels across leaves.

Spray with insecticide containing Malathion.* Systemic powder, granules or spray at recommended rates maintain control.

Mealy Bugs

Cottony white secretions along stems and under leaves. Small flat insects move, though slowly.

Wash off insects and secretions with clean warm water. Kill by wiping with rubbing alcohol - first check plant's tolerance. Apply insecticidal soap as recommended. Spray insecticidal soap containing Pyrethrum, Malathion or Diazinon.*  Systemic powder, granules or spray at recommended rates maintain control.

Scale Insects

Clustered or single green to brown disc-like scales under leaves and on stems, plus mottling of foliage when seen against the light. Timely attention is essential as bad infestations are difficult to eradicate.

Rub off scales w/ moist cotton swab, soft toothbrush (for stout leaves like bromeliads) or wipe w/ cotton balls soaked in rubbing alcohol (check plant for sensitivity by treating one leaf - waiting 24 hours) Apply insecticidal soap as recommended. Spray Malathion or Cygon 2E;* rinse w/ water after 24 hours; repeat 1 week later. Systemic powder, granules or spray at rec. rates maintain control.

Red Spider Mites

Tiny white/yellow spots on leaves, later becoming a mottled and dusty residue or webbing. Fine webs under leaves and in growing tips. Leaves may curl up. Thrive in hot, dry climates.

Wash and spray with clean warm water several times in 2-3 weks. Apply insecticidal soap as recommended. Spray Kelthane, Dimite, or other miticide. * Systemic powder, granules or spray at recommended rates maintain control.

Thrips

Thin, papery disfiguring scars on leaves remain after insects have sucked plant juices.

Apply insecticidal soap as recommended. Control thrips with insecticidal containing Pyrethrum or Malathion.* Systemic powder, granules or spray at recommended rates maintain control.

Whiteflies

Tiny white moth-like insects. Larvae suck plant juices, causing general weakening. Thrive in dry climates, generally on flwr. plants. Can spread rapidly - timely attention is key.

Wash off tiny wingless larvae. Apply insecticidal soap as recommended. Spray with insecticide containing Pyrethrum or Malathion.* Systemic powder, granules or spray at recommended rates maintain control.