Houseplants can harbor a variety of insects. Pests to look for are aphids, mealybugs, spider mites, white flies and scale.
Aphids are small, black or green crawling insects that live in thick colonies along the soft parts of stems, sometimes covering them entirely. They excrete a sweet liquid called honeydew, which often attracts ants. Aphids cause distorted and curled leaves, malformed flowers and hardened buds.
Mealybugs are about the same size as aphids but are white and fuzzy. Masses of them, resembling pieces of cotton, nestle and lay eggs where leaves and branches attach to stalks. Mealybugs can stunt and kill plants by depleting their fluids.
White flies also are small and white, but unlike mealybugs, will take flight if you shake the plant.
Spider mites are miniscule but very destructive. An infested plant will have yellow-speckled leaves and may be covered with tent-like webs.
Scale
appears as blister-like areas on stems and the undersides of leaves. These areas can be circular, oyster-shell-shaped or rectangular and are colored white, brown, gray or black. Scale also produces honeydew, which may drip from the leaves.
With
a small infestation, you may be able to wipe the pests off with a Q-Tip dipped
in alcohol. Rinsing the plant under a gentle stream of water for a few minutes
can wash away insects and eggs. Keep checking the plant for a recurring
infestation during the next couple of weeks.
Serious, persistent infestations can be treated with an insecticidal soap spray or a multipurpose insecticide containing a miticide. Both are available from gardening centers. Be careful to follow the directions on the label exactly. Excess spray can be toxic to the plant. And if you spray too closely to the leaves, the aerosol propellant can freeze them.
After spraying, keep the plant in a large plastic bag for a few hours to contain and
concentrate the spray, then isolate it for about two weeks or until you're sure it's pest-free.If you are unsure what is wrong with your houseplant, you can either bring the whole plant or a few of the affected leaves into the Piscataquis County Extension Office to identify the pest. If I can't identify the problem, I can send it to our state office in Orono for identification.
Source: Nuss, R., Penn State Pointers Penn State Agricultural Information Services, http://www.aginfo.psu.edu/psp/01psp/pr/01145_pr.html