The rubber tree, or Ficus elastica, is a species of tree native to parts of southern Asia and Australia. It is known for its thick, dark green leaves. It is often called a rubber plant or Indian rubber tree. Rubber trees are popular decorative houseplants, but they are susceptible to a number of different pests and diseases.
Mealy bugs are small insects that produce white cottony or waxy secretions. They are only about 1 to 4 millimetres long. Adult male mealy bugs have wings and appear much like white flies, while the females do not have wings. Mealy bugs damage rubber plants by sucking the plant's sap and leaving behind saliva, which contains toxins. The leaves of the rubber plant develop yellow spots and can prematurely wither and die.
Armoured and Soft Scale Bugs
Armoured scale bugs and soft scale bugs are small, oval-shaped insects that appear flat. They have a protective outer covering on their bodies which is brown or tan in colour. Scale bugs can infest rubber plants and suck away their sap, causing damage to the tree by robbing it of important nutrients. Armoured scale bugs are the most destructive of the two types of scale bugs. Soft scale bugs secrete a yellow honeydew-like secretion that can cause mould growth on the rubber plant. Scale bugs frequently attack the leaf joints and the underside of leaves. Scale bugs are most common in warm, dry environments.
Bortrytis cinerea is a grey mould that can be found on rubber trees. It causes brown spots of the leaves of the tree and dark greenish grey patches on the edges of the leaves. This mould can also cause necrosis between leaf sheathes and newly developing leaves. Bortrytis cinerea is often caused by misting the rubber tree too often, making it moist and susceptible to mould growth.
Phomopsis is a slow growing fungus that can be found growing on rubber trees. It can cause loosened bark and dry, greenish grey leaves. It also causes the roots to become fragile and hollow. The disease usually begins on one area of the tree and, if left untreated, spreads throughout the entire plant. Phomopsis can be spread from tree to tree through reusing contaminated pruning sheers or clippers.