Houseplants add beauty and interest to the home, but they can be infested by pests. Spider mites are one of the most serious pests. They cause damage, defoliation and plant death. Spider mites are not true insects but related to spiders and ticks. Spider mites and eggs are extremely tiny so they are hard to detect with the naked eye. They are oval shaped and yellowish or greenish in color. Their eggs are amber-colored and they reproduce rapidly.
Place a white sheet of paper under discolored leaves of your houseplant. Tap the leaves and watch for moving dots on the paper. This is a common way to check for spider mites.
Isolate the infected plant away from your other houseplants. This minimizes the risk of infecting your other houseplants.
Mix together 1/2 tsp. of liquid dish detergent with 1 qt. of lukewarm water. Dip a soft cotton cloth in this liquid. Wipe the spider mites and eggs off the leaves. If your houseplant is heavily infested, then spray it with a hard stream of water.
Thin mineral oil with a little water and place it in a spray bottle. Spray oil on the plants including under the leaves. Apply this oil once every 7 to 10 days until all traces of spider mites are gone. Neem oil and plant oil extracts can also be used.
Leave your houseplant in the shade until the oil had dried off of the leaves. Spider mites have short life cycles, so more then one generation may be on your houseplant. It will take a couple of repeated applications to kill all the spider mites on your houseplant.