Stems and fronds are covered with white, cottony, cushionlike masses or brown, crusty bumps. The cottony masses do not move when touched. The bumps can be scraped or picked off easily. Fronds turn yellow and may drop. The bumps are sometimes mistaken for reproductive spores produced by the fern.
Isolate infested plants as soon as scales are discovered. Remove as many scales as possible with a cloth or toothbrush dipped in soapy water. Apply an insecticidal soap or horticultural oil, following label directions. Avoid bringing scale crawlers into the house.