The leaves and the branches of my schefflera are coated with a shiny sticky substance and small oval brown spots all over. What is it and should I be worried?
Your schefflera is infested with scale. These insects suck the plant juices and secrete the excess as a clear sticky substance called honeydew. Once the adult forms the hard shell it is difficult to control. Start by carefully scrapping off the hard brown spots. Then spray the plant with Neem or another eco-friendly insecticide labeled for use on houseplants. Test insecticidal soap on a leaf or two before using as it has caused damage on schefflera plants. Insecticides will kill the immature scales that have not yet formed their protective covering. Repeat applications will be needed since this insecticide only controls the immature scale not the hard shelled adults or eggs. Be persistent since it usually takes months to control this difficult pest.
USDA Forest Service - Ogden Archive