How to Identify and Get Rid of Bugs from Indoor Plants (12 Houseplants Pests)

Mealybugs are white, soft-bodied, cottony-looking, sap-sucking insects. Large clusters occur on stems and under the leaves of many plants. A serious attack can lead to stunted growth, wilting, yellowing and leaf fall on the plants.

Mealybugs also excrete large amounts of honeydew which attracts ants and is a fertile ground for black sooty mold and disease infestations. The sooty mold causes stunted growth and reduced vigour by blocking pores and shading the leaf surface area for light absorption.

Aphids also called Plant Lice are tiny, soft-bodied insects, which are prevalent in poorly ventilated, dry conditions. They are sap-sucking insects which are usually green but may be black, grey or orange.

All plants with soft tissues can be attacked by aphids; the shoot tips and flower buds are the most often attacked. This weakens the plant, causes yellowing, stunted growth, distorted growth and leaf curl.

They also deposit a sticky honeydew residue on plants, called sooty mold, which attracts ants and may be fertile ground for disease infestation. It also reduces plant growth and vigour by blocking pores and shading the leaf surface area for light absorption.

Aphids also transmit viral diseases from one plant to another. They multiply very fast and can spread very fast from plant to plant.

Spider Mites are minute sap-sucking insects which infest the underside of leaves of almost all houseplants growing in hot, dry conditions coupled with stagnant air. They may be red, green or yellow in color.

The Spider Mites cause yellow blotches on the upper surface of the leaves and premature leaf fall. A severe infestation by Spider Mites may cause the plant to die.

Look out for white webbing between the leaves and stems. If you hold a white piece of paper under a leaf and tap it, you will see tiny particles crawling around, these are spider mites.

Scale Insects or simply scales are small, brown discs attached to the underside of leaves and on the stem from where they suck the plant sap. They are covered with an outer waxy shell which protect them from chemical penetration. Scales are more common in dry, poorly-aerated growing conditions.

A heavy infestation by Scale Insects can cause stunted growth, wilting, yellowing of the leaves and leaf loss. Scales produce a sticky honeydew which attracts ants and is a fertile ground for sooty mold. The sooty mold reduces plant growth and vigour by blocking the pores and shading the leaf surface area for light absorption.

Fungus gnats are a major problem in houseplants care. The small, black, flying adults are harmless. The problem is that they lay eggs in the soil which hatch into tiny, black-headed maggots which are harmful.

These black-headed Fungus Gnat maggots normally feed on organic matter in the soil but they can devour young roots. Fungus Gnats are troublesome in over-damp conditions. They multiply very fast and easily spread from one plant to another.

Whiteflies are tiny, white, moth-like insects which occur in clusters on the underside of leaves of most houseplants. They are sap-sucking insects, which secrete a honeydew sticky substance which attracts ants and a sooty black mold.

Infestation by Whiteflies results in leaves turning yellow and dropping, stunted growth and a sticky, sugary substance on the leaves. They thrive in warm, poorly-ventilated environments where they reproduce rapidly, often resulting in all the life stages (eggs, nymphs, adults) being present on the plant at the same time. The nymphs and eggs are primarily found on the underside of leaves, often looking like tiny, flat, oval, pale yellow or transparent discs.

Thrips are tiny, black insects which fly or jump from leaf to leaf, causing tell-tale silvery streaks. They feed on the plant sap and a severe infestation can cause dehydration, resulting in wilting and drooping of the leaves. These pests are more prevalent in dry, poorly-ventilated conditions.

Thrips attack the soft growing tissue and cause the worst damage on flowers which become spotted and distorted. They also cause stunted growth, yellowing and leaf loss.

They are difficult to eliminate because they reproduce rapidly and can complete their life cycle in just 2-3 weeks, with the eggs being embedded deep inside the plant tissue where chemical sprays cannot reach.

Cyclamen Mites are minute mites, which look like a film of dust on the underside of leaves. These pests will flourish in cool, humid conditions coupled with poor air circulation.

Infested houseplants are stunted, have curled leaf edges, twisted stems and withered flower buds. Cyclamen Mites are especially common in Cyclamens, Pelargoniums and African Violets (Saintpaulia).

Root-knot Nematodes (Meloidogyne spp) also called eelworms are microscopic soil-living worms which interfere with the plants' ability to absorb water, resulting in wilting, drooping, yellowing and eventual plant collapse for no apparent reason.

Root-knot Nematodes invade the plant roots from where they reproduce rapidly. A single female can produce up to 1000 eggs. The life cycle can be completed in as little as 21 to 28 days during warm conditions, allowing populations to build up very fast.

The Root-knot Nematodes release chemicals that cause root cells to grow and form galls (swellings), which cannot be easily rubbed off, differentiating them from the beneficial nitrogen-fixing nodules on legumes roots.

When you remove the plant from its pot and inspect the roots, you will find large, corky swellings on the roots. Since they live inside the roots and the soil, Root-knot Nematodes infestation is difficult to control once established.

The adult bettles of the Vine Weevils chew the leaves at night causing characteristic, U-shaped notches along the edges of the leaves. The creamy-white, C-shaped, legless grubs (larvae) with light brown heads which live in the soil, cause the real damage; they rapidly devour plant roots, bulbs and tubers. Their presence is indicated by wilting, drooping and sudden collapse of the plant.

All adults are female and reproduce asexually, therefore, a single beetle can establish an infestation within a short time. Vine Weevil infestations are common on Begonias, Fuchsias, Sedums, Cyclamens, Heuchera, Primula and many succulents.

Earwigs are dark-brown pests with a pincer-like tail. They hide during the day and feed at night on the leaves and the flower buds. They thrive in damp, dark conditions.

The presence of Earwig Pests on houseplants is marked by ragged holes on the leaves and flowers and / or tunnels in the soil.

Many types of caterpillars can infest houseplants but rarely do they attack plants that are grown indoors. The caterpillars vary in color from green, red, brown or black.

The main sign of the caterpillars on the plants is the presence of holes in the leaves; they are rarely seen as they eat up the plant and go into hiding.