The large infestation of white bugs on cycads indicates a pest called Cycad Scale. These white scale insects are found on the underside of the leaves, sucking the tree sap and causing the leaves to turn yellow, then brown and eventually die. Chemical control is difficult for two reasons: the females’ hard, waxy covering and the difficulty to thoroughly spray the undersides of leaves. With heavy infestations, it is best to prune all leaves. A tiny black lady beetle, present on the Island of Hawaii (the Big Island), is highly effective in controlling the cycad scale; there is good biological control. If these beetles are found on a cycad in your area, trim off some of its leaves (with the predatory beetle on them) and place these leaves on your scale infested plants to help the predator migrate.
