Battling bugs on your houseplants from time to time is inevitable. They often find their way into your home with the introduction of new plants or by piggybacking on clothes and garden tools. The indoor environment offers conditions for pests to thrive with little resistance. Before treating your houseplants, identify the insect pest to decide on the proper course to take. Environmental conditions can play a major part in the ability of plant pests to become a problem. Identification will allow you recognize and alter conditions for your plants to remain healthy.
Identify the pest before treating your plants. The most common insect pests on house plants include whiteflies, mealybugs, spider mites, aphids, scales and fungus gnats. Whiteflies can easily be identified since they take flight when the plant is disturbed. Mealybugs look like small balls of cotton and congregate on buds and tender young growth. Aphids have tear-drop shaped bodies and exude a sticky secretion called honeydew. Spidermites are more difficult to spot. Look for their fine webs in the axles of stems. On closer examination (you may need a magnifying glass), you will be able to see them moving around in the webs. Scales are brown, waxy oval-shaped insects that can usually be found on the undersides of leaves and along stems. Fungus gnats are easier to spot. They have dark bodies and can be seen flying around the plant.
Treat your plants by beginning with the least toxic method available. Wash the plants with a forceful stream of water. In many cases, this will take care of the problem. Other treatments, in order of toxicity, include insecticidal soaps, pyrethrins and pyrethroids, and systemic insecticides.
Insecticidal soaps are safe and gentle to use. They work well against soft bodied pests such as whitefly, aphids and mealybugs. They have no residual effects, so spraying the actual insect is important. Thoroughly wet all plant surfaces.
Pyrethrins are natural pesticides derived from the pyrethrin daisy and have no residual effect and may require several treatments to get rid of the problem.
Synthetic pyrethroids are chemically manufactured to resemble pyrethrin. They have some residual affect lasting from several hours to several days. Although they are based on natural sources, they are toxic and should be handled with care.
Systemic insecticides are absorbed by the plant and work by making the entire plant poisonous to insects. They are applied as plant stakes or granules sprinkled on the soil. Never use them on herbs or edible plants, and keep them and treated plants away from children and pets. Water draining out of plant containers will be contaminated.
Prevent infestations by practicing good sanitation and by providing the proper environment for your plants. Air circulation and abundant light are important. Clean up fallen leaves and keep saucers clean. Lack of humidity creates an environment for spider mites, while over-watering is promotes fungus gnats. Keep newly purchased plants isolated, and clean all garden tools after use.