Many of us know the dreadful feeling of finding pests on our houseplants. Here is your quick guide to dealing with an infestation in your home.
- With spring coming up rather quickly, prevention is the best way to control insects on houseplants.
- Proper water, light, heat, and fertilizer is the first step to prevention. Healthy plants are far less susceptible to pests. Pests often target stressed, unhealthy plants.
- Before buying or bringing a plant inside, always inspect the plant and container for signs of pests. Try to isolate new plants for several weeks and watch for any new signs of pests during that time. Infestations are much easier to control when caught early.
- Always use commercially prepared potting soil rather than soil from outdoors.
- Wiping smooth-leaved plants every couple of weeks can boost the overall health of the plant while discouraging pest infestations.
Identifying and Treating the Major Pests
- Spider Mites: Mites are very common in early spring and late fall. Spider mite damage includes the telltale sign of spider web type webbing on the plant. They are very difficult to see with the naked eye because they are so small. If you suspect you have spider mites, hold a white sheet of paper under the leaves of the plant and shake gently. If it is spider mites, they will appear like specks of pepper. When combatting mites, know they are not insects, therefore common pesticides will not kill them. They are more closely related to spiders and require special treatment. Using a miticide, or an insecticidal oil, like neem oil, will kill them.
- Fungus Gnats: Adult fungus gnats can be seen running across or flying around the soil surface of the plant. While the adults do not feed on houseplants, they are a nuisance to people. Young plants are especially damaged by fungus gnats. The larvae are whitish with black shiny heads and can grow as large as ¼-inch. They feed on decaying organic material in the soil and some will also feed on the roots. Fungus gnats are especially a problem when overwatering occurs and when potting soil is rich in organic matter. When controlling fungus gnats, allow the soil to dry between watering for plants that can tolerate it. Dry conditions kill the larvae. Sticky traps can be used to capture adult gnats. Bon-Neem can be used to control the gnats as well.
- Aphids: Aphids are small, soft-bodied insects that are usually green, but maybe pink, brown, black, or yellow. They are usually found on the undersides of leaves and on new growth. Leaves may become yellow and misshapen from the aphids sucking on the plant sap. The leaves may appear shiny and sticky from the material they excrete, called honeydew. With minor infestations, picking off the insects by hand, or wiping them off may be practical. An insecticidal soap may be used to kill them. Treatments will most likely need to be repeated.
- Scales: Their unusual appearance makes them somewhat easy to identify. Adults are small and immobile with no visible legs. They are generally found on stems and undersides of leaves. Some will appear flat against the plant, while others will appear a colored mass. Early infestations can be scraped off. Adult scales have a wavy coating that makes them relatively protected from insecticides. They can be smothered by neem oil.
- Mealybugs: Mealybugs are small and pale. They move sluggishly and are related to scales. Adult females cover themselves and their eggs in a waxy material making themselves look like cotton. The wax covering them makes them difficult to control as it helps repel pesticides. Check under the leaves and on lower surfaces. Like aphids, minor infestations can be controlled by picking or wiping off insects, or by using an insecticidal soap. With heavy infestations, discarding the plant may be necessary.
- Whiteflies: Contrary to the name, whiteflies are not true flies, but more closely related to mealybugs, aphids, and scales. They have a white powdery appearance like tiny moths. They suck on the sap and cause damage similar to aphids. Infested plants may be stunted, and leaves can turn yellow and die. They excrete honeydew, leaving the leaves shiny and sticky while encouraging mold fungi. When disturbed, the whiteflies flutter around a while before landing again. Wash the plant thoroughly with an insecticidal soap, paying close attention to the lower leaf surfaces.
Other less common pests may occur such as thrips, leafminers, beetles, and caterpillars. If you suspect you may have an infestation of any kind call us at 248-553-7141, or email firstname.lastname@example.org, so we can further assist you in identification and treatment.