• Mealybugs should be the most significant problem on Aglaonema indoors.
• Calcium and Magnesium, added in the form of dolomite, will help plants look their best for long term use.  One application every six month is sufficient.
• In the nursery, caterpillars, thrips and disease are common issues, but these should not be a problem indoors.

Mealybugs can be removed with a systemic insecticide drench (Safari), and hand cleaning.  If pesticides are not an option, try horticultural oil directly sprayed onto the insects.  A second and third treatment, if using oils, will be necessary.  Space out the sprays at 3 week intervals to break up the mealybug life cycle.  This interval should be shortened if temperatures are above 80 degrees Fahrenheit.   

When Aglaonemas are big and are not receiving enough fertilizer, Magnesium deficiency may occur.  Watch for yellow leaf margins to appear on the oldest foliage to indicate magnesium deficiency.  The easiest way to prevent this is with infrequent applications of dolomite along with a regular balanced fertilizer program.  Dolomite supplies calcium and magnesium.  Dolomite will also stabilize the pH of the soil allowing for optimal use of fertilizer.

Other Links:

Horticultural Oils

Safari Pesticide Label