Make sure that any product you use is labeled for use indoors and lists the target pest as well as the plant you plan to treat. Even when using such low-toxicity products as insecticidal soap or horticultural oil, it's important to always read and follow all label instructions and precautions. The foliage of some houseplants may be sensitive to injury from certain products - many ferns, palms orchids, African violets, and begonias, for example, can be damaged by pesticides, even insecticidal soap - so check the label for information on plants to avoid treating with a particular product.