Indoor Gardening

Plant Pests & Insecticides

The following is a list of common pests that attack house plants. Hope these descriptions help you identify the pests attacking your houseplants.

Aphids

  • Small, slow moving, oval shaped, soft bodied insects 1/16 to 1/4 inch long. Can be green, black, grey, red, yellow and white.
  • Most adults have no wings but winged forms appear at certain times of the year.
  • Aphids suck on plant sap. They primarily attack new growth and flower buds.
  • Aphids excrete sugary liquid called honeydew. Honeydew causes leaves to become shiny and sticky.
  • Cause discoloration, curling of leaves and wilting of flowers. 

Fungus Gnats

  • Small brown-black flies (look like fruit flies).
  • The larvae (white maggots) can be found in the soil feeding on decomposing organic matter. They are common where soil is kept moist to wet. 
  • Fungus gnats rarely kill plants— infested plants will more likely die from over watering or poor drainage.
  • Considered a nuisance more than anything.

Mealy Bugs

  • Small, flat, oval, segmented grey-white insects. Live in cottony looking clusters. 
  • They can be found in masses in the crotches of the stem or on the leaves. When clustered to feed they look like cotton fluff. 
  • They suck on plant juices. 
  • They secrete honeydew. Plants may become shiny or sticky from the honeydew.
  • Cause wilting, yellowing and stunting of plants.

Scale

  • Brown flattened bumps along stems, leaves and nodes.
  • They find a feeding site and become immobile sucking on plant juices.
  • Scales excrete honeydew leaving the leaves shiny and sticky.
  • Cause leaf spotting.

Spider Mites

  • Tiny, green, red or yellow insects.
  • Spider mites puncture leaf and suck out both water and food producing green chlorophyll. 
  • Leaves become stippled, yellow and dirty. There may be fine webbing on the leaves, in the leaf crotches or on the flower buds. 

Thrips

  • Tiny, black-brown insects.
  • Infest the flowers, flower buds and growing points on the plant.
  • Feeds by filing away the plant tissue then sucking the released sap.
  • Causes distortion and silver streaking or blotching of leaves and flowers.

Whiteflies

  • Small, winged, white insects. 
  • Feed on plant sap, on the undersides of the leaves.
  • Secrete honeydew which can make leaves shiny and sticky.
  • Causes mottling or yellowing of leaves and stunting of growth

Insecticides

Trade Name

Active Ingredient

Mode Of Action

Formulation

Pests Controlled

Botanics - Insecticide Plant Spray Pyrethrins Contact  Aerosol Spray Spider mites, aphids, thrips, white fly

End-All II

Potassium salts of fatty acids; pyrethrin

Contact

Liquid Spray

Aphids, white flies, mealy bugs, scale and spider mites

Green Earth               Insecticidal Soap

Triethanolamine salts and fatty acids

Contact

Liquid Spray

Aphids, white flies, mealy bugs, scale, spider mites

Safer’s Insecticidal Soap

Potassium salts of fatty acids

Contact

Liquid Spray

Aphids, white flies, mealy bugs, scale and spider mites

Trounce

Potassium salts of fatty acids; pyrethrin

Contact

Liquid Spray

Aphids, white flies, mealy bugs, scale and spider mites